Natural Resources
Conservation Service

Ecological site VX158X01X005

Naturalized Grassland 50 to 90 inch PZ
Ohia lehua/kikuyugrass
(Metrosideros polymorpha/Pennisetum clandestinum)

Last updated: 4/17/2025
Accessed: 09/15/2026

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General information

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

MLRA notes

Major Land Resource Area (MLRA): 158X–Semiarid and Subhumid Low Mountain Slopes

MLRA 158 – Semiarid and Subhumid Low Mountain Slopes

This MLRA occurs in the State of Hawaii on the islands of Hawaii, Maui, Lanai, Molokai, Oahu, and Kauai. It consists primarily of nearly level to moderately steep slopes that are dissected in places by gulches. It occurs on leeward, drier sides of the older volcanoes within the Hawaiian Islands. Elevation ranges from sea level to 1600 feet (0 to 490 meters). Geology is largely highly weathered volcanic ash overlying basic igneous rocks. Alluvium derived from basic igneous rocks occurs in some areas. Average annual precipitation typically ranges from 10 to 30 inches (255 to 760 millimeters), rising to over 60 inches (1525 millimeters) in some areas, and mostly occurs from November through March. Much of the rainfall occurs in kona storms during winter. Average annual temperatures range from 69 to 76 degrees F (21 to 24 degrees C), with very little seasonal variation. Soils are mostly Oxisols, Mollisols, and Aridisols with isohyperthermic soil temperature regime and ustic or aridic (torric) soil moisture regimes. Native vegetation is rare and consists mostly of species characteristic of dry forests or savannas, such as lama, koaia, wiliwili, ohe makai, and ulei. Naturalized grasses, such as buffelgrass and guineagrass, and trees, such as koa haole and kiawe, are common.

Classification relationships

This ecological site occurs within Major Land Resource Area (MLRA) 158 - Arid and Semiarid Low Mountain Slopes.

Ecological site concept

This ecological site is located on the leeward sides of West Maui, Molokai, Oahu, Kauai, and, to a very small extent, Lanai. An outlier is located on the north coast of East Maui on some delineations of Honolua silty clay, 7 to 15 percent slopes (HwC) in an area that receives 120 to 240 inches (3000 to 6000 millimeters) annual rainfall, which is far wetter than the rest of the ecological site. Further field work is needed to determine if these delineations belong in this ecological site. Most of the area lies within MLRA 158, although large parts are in MLRAs 165 and 167. Field work is needed to determine if the MLRA 165 and 167 parts should constitute separate ecological sites or if the MLRA lines need revision.

Most of the ecological site is in government ownership. A few examples of this ecological site are accessible near Rte. 340 on the windward coast of West Maui, but most of it is well mauka of the highway. Some areas are accessible along the northern end of Rte. 470 on Molokai, on the outskirts of Wahiawa in central Oahu, and from numerous public highways and roads along the eastern side of Kauai between Kalaheo and Kilauea.

The central concept of the Naturalized Grassland 50 to 90 Inch Precipitation Zone is of well drained, moderately deep to very deep soils formed in residuum or alluvium from basic igneous rock or in volcanic ash. Surface soil reaction ranges from extremely acid to strongly acid (pH 4.0 to 5.4); extreme pH of subsurface soils within 30 inches (75 centimeters) of the surface ranges from very strongly acid to moderately acid (pH 4.6 to 5.8). This pH range indicates that aluminum toxicity can be a problem for growth of susceptible plant species. The annual rainfall amounts fall into a range referred to in botanical literature as “mesic,” which is not to be confused with the soil temperature regime of mesic used in Soil Taxonomy. In this case it means moisture conditions that are transitional between dry and moist. Native forests in this ecological site are referred to as “Lowland Mesic Forests” (Wagner et al. 1999; Lowe et al. 2019) or “Evergreen Seasonal Forest” (Hatheway 1952); these forests have high plant diversity, especially for trees. However, this ecological site is not synonymous with Diverse Mesic Forest (Wagner et al. 1999), which occurs on western Kauai and the Waianae Mountains of Oahu and is associated with a separate ecological site.

The most common introduced grass is kikuyugrass (Cenchrus clandestinus). Forested areas contain many introduced species, with strawberry guava (Psidium cattleianum), Java plum (Syzygium javanicum), and silk oak (Grevillea robusta) among the more common species. Common trees in native forest include olopua (Nestegis sandwicensis), hame (Antidesma pulvinatum), koa (Acacia koa), ohia lehua (Metrosideros polymorpha), lama (Diospyros sandwicensis), and papala kapau or Australasian catchbirdtree (Pisonia brunoniana), among others.

Associated sites

VX158X01X401	Isohyperthermic Ustic Naturalized Grassland Koa haole/guineagrass/glycine (Leucaena leucocephala/Urochloa maxima/Neonotonia wightii) The Isohyperthermic Ustic Naturalized Grassland occurs on the islands of Hawaii, Maui, Molokai, Lanai, Oahu, and Kauai. It forms much of the high elevation boundary of the Naturalized Grassland, 50 to 90 Inch Precipitation Zone. It has warmer soil temperatures, lesser average annual rainfall (30 to 60 versus 50 to 90 inches), supports typical dry forest rather than native forest that is transitional to rainforest, and has different dominant forage grass species (guineagrass versus kikuyugrass and californiagrass) compared to the Naturalized Grassland, 50 to 90 Inch Precipitation Zone.
VX165X01X001	Isothermic Ustic Naturalized Grassland The Naturalized Grassland 30 to 60 Inch Precipitation Zone occurs on West Maui, Molokai, Lanai, Oahu, and Kauai. It has similar soil temperatures, lesser average annual rainfall (30 to 60 versus 50 to 90 inches), similar elevation range, typical native dry forest versus transitional dry-to-moist forest, and a different dominant forage grass species (guineagrass versus kikuyugrass and californiagrass) compared to the Naturalized Grassland, 50 to 90 Inch Precipitation Zone.
VX167X01X001	Oxidic Dissected Lowland The Oxidic Dissected Lowland occurs on the islands of Maui, Oahu, and Kauai and forms most of the higher elevation boundary of the Naturalized Grassland, 50 to 90 Inch Precipitation Zone on Kauai. It has similar soil temperatures, higher average annual rainfall (50 to 150 versus 50 to 90 inches), and similar vegetation compared to the Naturalized Grassland, 50 to 90 Inch Precipitation Zone.

VX158X01X401

Isohyperthermic Ustic Naturalized Grassland Koa haole/guineagrass/glycine (Leucaena leucocephala/Urochloa maxima/Neonotonia wightii)

The Isohyperthermic Ustic Naturalized Grassland occurs on the islands of Hawaii, Maui, Molokai, Lanai, Oahu, and Kauai. It forms much of the high elevation boundary of the Naturalized Grassland, 50 to 90 Inch Precipitation Zone. It has warmer soil temperatures, lesser average annual rainfall (30 to 60 versus 50 to 90 inches), supports typical dry forest rather than native forest that is transitional to rainforest, and has different dominant forage grass species (guineagrass versus kikuyugrass and californiagrass) compared to the Naturalized Grassland, 50 to 90 Inch Precipitation Zone.

VX165X01X001

Isothermic Ustic Naturalized Grassland

The Naturalized Grassland 30 to 60 Inch Precipitation Zone occurs on West Maui, Molokai, Lanai, Oahu, and Kauai. It has similar soil temperatures, lesser average annual rainfall (30 to 60 versus 50 to 90 inches), similar elevation range, typical native dry forest versus transitional dry-to-moist forest, and a different dominant forage grass species (guineagrass versus kikuyugrass and californiagrass) compared to the Naturalized Grassland, 50 to 90 Inch Precipitation Zone.

VX167X01X001

Oxidic Dissected Lowland

The Oxidic Dissected Lowland occurs on the islands of Maui, Oahu, and Kauai and forms most of the higher elevation boundary of the Naturalized Grassland, 50 to 90 Inch Precipitation Zone on Kauai. It has similar soil temperatures, higher average annual rainfall (50 to 150 versus 50 to 90 inches), and similar vegetation compared to the Naturalized Grassland, 50 to 90 Inch Precipitation Zone.

Similar sites

VX159A01X403	Isohyperthermic Udic Naturalized Grassland (Guineagrass / Desmodium) The Isohyperthermic Naturalized Grassland, 60 to 95 Inch Precipitation Zone occurs on the island of Hawaii. It is similar to the Naturalized Grassland, 50 to 90 Inch Precipitation Zone in soil temperature, soil moisture, annual average rainfall, soils, and vegetation, but has a lower elevation range (0 to 1800 feet versus 250 to 3500 feet). The two ecological sites occur in different Major Land Resource Areas.

VX159A01X403

Isohyperthermic Udic Naturalized Grassland (Guineagrass / Desmodium)

The Isohyperthermic Naturalized Grassland, 60 to 95 Inch Precipitation Zone occurs on the island of Hawaii. It is similar to the Naturalized Grassland, 50 to 90 Inch Precipitation Zone in soil temperature, soil moisture, annual average rainfall, soils, and vegetation, but has a lower elevation range (0 to 1800 feet versus 250 to 3500 feet). The two ecological sites occur in different Major Land Resource Areas.

Table 1. Dominant plant species

Tree	(1) Metrosideros polymorpha
Shrub	Not specified
Herbaceous	(1) Pennisetum clandestinum

Legacy ID

R158XY005HI

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Physiographic features

This ecological site occurs on lava flows on sloping mountainsides of shield volcanoes. Lava flows are aa (loose, cobbly) or pahoehoe (smooth, relatively unbroken).

Table 2. Representative physiographic features

Landforms	(1) Shield volcano > Aa lava flow (2) Shield volcano > Pahoehoe lava flow
Runoff class	Very low to medium
Flooding frequency	None
Ponding frequency	None
Elevation	250 – 3500 ft
Water table depth	60 in
Aspect	W, NW, N, NE, E, SE, S, SW

Climatic features

(Unless otherwise cited, the information in this section is derived from Western Regional Climate Center, cited 2020).

Summary for this ecological site

Average annual precipitation in this ecological site ranges from 50 to 100 inches (1250 to 2500 mm). Extremes of average annual precipitation range as low as 25 inches (625 mm); some of these low precipitation outliers are at relatively high, cool elevations, which can reduce evapotranspiration. In other places, these low-rainfall outliers grade into other ecological sites. Most of the precipitation occurs from October through April. Average annual temperatures range from 65 to 73 degrees F (18 to 23 degrees C). Rainfall occurs as trade wind showers that drift over or around the mountains from the windward side of the islands and as heavier rainfall during major winter storms. Major storms are important for soil moisture recharge, and the number of major storms is highly variable; drought can result from a winter with few or no storms. Due to the latitude, daylength varies little during the year, resulting in only about a 50 percent variation in solar energy input between June maximum to December minimum; this variation is somewhat less than that found in the continental United States. Conditions are generally clear to moderately cloudy. Sites near the ocean along the northern coast of west Maui are frequently windy, which can stunt vegetation or promote shrubland over forest.

General principles

Air temperature in the Hawaiian Islands is buffered by the surrounding ocean so that the range in temperature through the year is narrow. This creates “iso-“ soil temperature regimes in which mean summer and winter temperatures differ by less than 6 degrees C (11 degrees F).

Hawaiian indigenous understanding recognized two seasons during the year: Kau or Kauwela (dry season) when the sun was directly overhead, days are long and warm and tradewinds are stronger and more consistent; Kau started on the first new moon in May when the Pleiades set at sunrise (Handy, 1991). During Ho’oilo (wet season) the sun is declined toward the south, days are shorter, temperatures cooler and winds more variable and generally started with the first new moon in November. Ho’oilo is also the season when extensive low-pressure systems often approach the islands from the west, producing heavy rainstorms that primarily affect the leeward sides, but can envelope the entire island. (Malo, 1903, Handy 1991, Sanderson, 1993). These seasons are mostly consistent with modern observations today. These phenomena of pressure systems and seasonal differences interact with the islands’ topography which together creates the various climate zones and patterns observed in the islands. One such general pattern can be seen in the differences in rainfall amounts between winter and summer; in low elevation dry areas the differences are greater whereas wetter areas exhibit less seasonal variation in rainfall.

The islands lie within the trade wind zone. Moisture is picked up from the ocean y trade winds to an altitude of about 6,000 feet (1850 meters). As the trade winds from the northeast are forced up the islands’ mountains their moisture condenses, creating rain on the windward slopes; the leeward sides of the island receive little of this moisture. The zones of highest rainfall on the windward flanks of the highest mountains (more than 10,000 feet or 3075 meters), which include Mauna Kea, Mauna Loa, and Haleakala, occur at elevations of 2,000 to 4,000 feet (615 to 1230 meters). A temperature inversion that fluctuates between about 5,000 and 7,000 feet (1540 to 2150 meters) on these three highest mountains creates a boundary between lower moist air and higher dry air. Above the inversion, rainfall is scant, skies are usually clear, humidity is low, and temperatures can drop below freezing. On West Maui, Kauai, Molokai, Oahu, and Lanai, where the mountains are all lower than 6,000 feet (1850 meters), the highest rainfall amounts occur along or near the summits. The moist trade winds usually flow across these lower mountains and around the higher mountains. Lanai is sheltered from the trade winds by the much larger island of Maui, putting it in a rain shadow during trade wind weather; rainfall on Lanai is uncharacteristically low for Hawaii.

Besides the trade winds discussed above, other rainfall sources on the Hawaiian Islands include: a) Widespread winter storms that usually approach the islands from the west, producing heavy rainstorms that primarily affect the leeward sides but can envelope much larger areas; b) "Naulu storms" (Leopold 1948) caused by local convergence of sea breezes and trade winds to produce summertime cumulus clouds, resulting in infrequent, short-duration, high-intensity rainfall and afternoon shade over leeward dry areas; and c) Fog drip, particularly important to areas with relatively low rainfall, that adds a significant amount of water to areas where clouds intersect mountains (Juvik and Nullet 1993; Western Regional Climate Center).

The heaviest rains are brought by winter storms. The greatest amounts of storm rainfall do not always occur in areas with the highest average rainfall, and a storm may bring half of the mean annual rainfall to a dry area in one day.

Table 3 Representative climatic features

Frost-free period (characteristic range)	370 days
Freeze-free period (characteristic range)	370 days
Precipitation total (characteristic range)	50-100 in
Frost-free period (actual range)
Freeze-free period (actual range)
Precipitation total (actual range)	30-100 in
Frost-free period (average)
Freeze-free period (average)
Precipitation total (average)	80 in

Soil features

This ecological site is correlated with soil series and their phases that occur on multiple islands and are classified in a variety of soil orders. However, they share certain characteristics. They are all well drained. They are in the moderately deep (20 to 40 inches or 50 to 100 centimeters), deep (40 to 60 inches or 100 to 150 centimeters), or very deep (deeper than 60 inches or 150 centimeters) classes. Most of the soils formed in place in residuum of basic igneous rock or alluvium derived from basic igneous rock and are relatively old and weathered; they are classified in the soil orders Oxisols and Ultisols. Two soils formed in volcanic ash deposits; one is classified in the order Andisols and one has some andic properties. Both are highly weathered relative to Andisols in general. One soil is a Mollisol; it is discussed below.

Surface soil reaction ranges from extremely acid to strongly acid (pH 4.0 to 5.4). Extreme pH of subsurface soils within 30 inches (75 centimeters) of the surface ranges from very strongly acid to moderately acid (pH 4.6 to 5.8); one soil has subsoil that is slightly acid (pH 6.1). Soil temperature regimes are isohyperthermic (very warm) to isothermic (warm), and a soil moisture regimes range from ustic (in normal years, dry for more than 90 cumulative days but less than 180 days) to udic ((in most years, not dry for as long as 90 cumulative days). These ranges of soil temperature and moisture fall in the middle range between hot-dry and cool-wet that produces the distinctive vegetation environment referred to botanically as “mesic.”

HONOLUA, LEILEHUA, and OLELO soils are classified as Humults, in the Ultisols soil order. The unique properties common to Ultisols are an argillic horizon (containing clay translocated from overlying horizons) and a low supply of bases, particularly in the lower horizons. The cation-exchange capacity in Ultisols is moderate or low. The decrease in base saturation with increasing depth reflects cycling of bases to the surface by plants or additions from fertilizers. In Ultisols that have not been cultivated, the highest base saturation is normally in the few centimeters directly beneath the surface. The clayey horizons can retain substantial amounts of water, much of it available to plants. Ultisols in the suborder Humults have at least 1.5 percent organic matter in the upper part of the argillic horizon, as defined in the 1972 Soil Survey. Ultisols tend to form in moist climates that promote weathering of soil materials and leaching of base cations, resulting in strongly to extremely acid soils. Many Ultisols in Hawaii are presently in seasonally dry climates; their ultic characteristics formed under wetter ancient climates.

Honolua soils have an umbric surface horizon, indicating high organic matter content that has good water-holding and root penetration characteristics. Concentrations of base nutrient cations are low. Honolua has pH ranging from 5.0 to 5.1, which is just low enough to induce some aluminum toxicity to non-adapted plant species. The organic matter in the umbric horizon will ameliorate this toxicity by binding up soluble aluminum. Plant-available phosphorus is likely to be low because of formation of solid aluminum-phosphorus compounds.

Leilehua soils have an umbric surface horizon, indicating high organic matter content that has good water-holding and root penetration characteristics. Concentrations of base nutrient cations are very low. Honolua has pH ranging from 4.6 to 4.8, which is low enough to induce aluminum toxicity to non-adapted plant species. The organic matter in the umbric horizon will ameliorate this toxicity by binding up soluble aluminum to an extent. Plant-available phosphorus is low because of formation of solid aluminum-phosphorus compounds. The subsurface has a kandic horizon, which has very low cation exchange capacity. The mineralogy of this soil is ferruginous, which means much of the mineral portion of the soil consists of iron oxides; these soils are low in nutrient content and fix phosphorus in forms unavailable to plants.

Olelo soils are similar to Leilehua soils except the mineralogy is parasesquic rather than ferruginous, so plant nutrient conditions are not as bad. Also, Olelo soils occur at higher, cooler elevations than Leilehua soils. Plant roots in this soil are concentrated in the upper 4 inches (10 centimeters) due to high bulk density and poor soil structure just below the surface horizon.

PAALOA and PUHI soils are classified as Oxisols. Oxisols are more highly weathered than other soils; they have a deep, subsurface oxic horizon dominated by clay-size particles of iron and aluminum hydrous oxides. Plant nutrients have been largely leached out of the soil. At low pH, phosphorus is adsorbed onto the oxides, making it largely unavailable to plants, and the ability to retain cation nutrients such as calcium, magnesium, and potassium against leaching is low. Both soils have surface pH of 5 or higher, so aluminum toxicity is unlikely to be a problem, and the high organic matter contents in the surface soils ameliorate aluminum toxicity. Paaloa soils develop a root mat at depth of about 17 inches (42 centimeters). There is no apparent physical root obstructing layer in the soil description. Lack of good root growth below this depth may be due to aluminum toxicity associated with the low subsurface pH that goes as low as 4.7.

NIULII soils are Andisols; NAIWA soils are Inceptisols with Andic properties. They formed in volcanic ash and are old and weathered enough to have low soil pH. Naiwa soils have surface pH of 5.3 and subsurface pH as low as 4.8, so aluminum toxicity risk is borderline. Niulii soils have surface pH of 4.0 and subsurface pH as high as 5.8, so aluminum toxicity risk is high in the surface, although probably offset by high organic matter contents. Niulii soils at the highest elevation range often have fog and cloud cover.

The volcanic ash soils of Hawaii are derived mostly from basaltic ash that varies relatively little in chemical composition (Hazlett and Hyndman 1996; Vitousek 2004)). Most of these volcanic ash soils are classified today as Andisols, which have these “andic” characteristics: ion exchange capacity that varies with pH, but at low pH mostly retaining anions such as nitrate; high phosphorus adsorption, which restricts phosphorus availability to plants; excellent physical properties (low bulk density, good friability, weak stickiness, stable soil aggregates) for cultivation, seedling emergence, and plant root growth; resistance to compaction and an ability to recover from compaction following repeated cycles of wetting and drying; and high capacity to hold water that is available to plants. These characteristics are due to the properties of the parent material, the clay-size noncrystalline materials formed by weathering, and the soil organic matter accumulated during soil formation (Shoji et al. 1993).

KAWAIHAPAI soils are classified as Mollisols. Only one phase of this soil, Kawaihapai silty clay loam, 2 to 7 percent slopes (KlcB), is correlated with this ecological site; all other phases are in R158XY003HI Isohyperthermic Ustic Naturalized Grassland. This phase is noted in the Soil Survey as unique among the series, occurring at higher, cooler elevations, having much lower pH (5.3 to 5.8), and having higher amounts of soil moisture because it occurs in alluvium in narrow drainageways where it receives runoff from surrounding areas. The important properties of Mollisols are a combination of a relatively thick, dark surface horizon (mollic epipedon) that does not become hard when dry, a dominance of calcium among the extractable cations, and a dominance of crystalline clay minerals of moderate or high cation-exchange capacity. These properties are conducive to plant growth. Although Mollisols usually form under grass in seasonally dry climates, they can form under a forest ecosystem. Although today this phase is largely in kikuyugrass and kaimi clover, the original native vegetation would have been forest.

Adjoining the soils described above are areas mapped as MISCELLANEOUS AREAS. By definition, they have little or no soil and support little or no vegetation. In the Five Islands Soil Survey upon which this ecological site is based, Miscellaneous Areas are extensive, and most and were mapped by low-intensity reconnaissance methods that provide less-detailed information than that presented for soil series and their phases. In many cases, however, Miscellaneous Areas in Maui, Molokai, Lanai, Oahu, and Kauai are moderately- to well-vegetated and/or contain plant and animal species of interest to conservationists. They are either extremely difficult to access or were not considered important enough at the time of this survey to warrant full expenditure of resources. They are described in the following paragraphs.

ROCK LAND (rRK) ROCK LAND (rRK) occurs on parent materials of basalt or andesite. Rock cover on the surface ranges from 25 to 90 percent; soils are very shallow (less than 10 inches or 25 centimeters). Near this ecological site it occurs mostly in gulches created by ephemeral streams. Vegetation is generally sparse, but in some spots, vegetation is dense due to localized accumulations of soil and extra moisture from seasonal stream flows. Common plant species are Java plum (Syzygium cumini), christmasberry (Schinus terebinthifolius), lantana (Lantana camara), molassesgrass (Melinis minutiflora), and kukui (Aleurites moluccana).

ROCK OUTCROP (rRO) ROCK OUTCROP (rRO) has exposed bedrock covering more than ninety percent of the surface. Small areas of lithified coral sand occur on Kauai, Oahu, Lanai, and Molokai. Gulches on Kauai support sparse vegetation on steep sides and denser vegetation in gulch bottoms. Gulch sides on Maui, Molokai, and Lanai are sparsely vegetated; bottoms can be sparse or moderately vegetated.

ROUGH BROKEN LAND ( rRR) ROUGH BROKEN LAND (rRR) occurs on very steep sides of gulches and mountainsides. Soil amounts and characteristics are variable; beneath the soil is soft weathered rock. Most occurrences in the vicinity of this ecological site appear to support substantial vegetation cover. Common plant species are common guava (Psidium guajava), Natal redtop (Melinis repens), bermudagrass (Cynodon dactylon), koa haole (Leucaena leucocephala), and molassesgrass (Melinis minutiflora). Active soil erosion is common.

ROUGH BROKEN AND STONY LAND (rRS) ROUGH BROKEN AND STONY LAND (rRS) occurs only on Maui in very steep, stony gulches. Some soil is present in variable amounts. It generally supports shrubs, small trees, and grass with a significant amount of bare ground.

ROUGH MOUNTAINOUS LAND (rRT) occurs on very steep gulches and narrow ridges; slopes are often greater than 60 percent. Soils often occur over highly-weathered rock (saprolite); this saprolite is usually permeable to roots. Soils are shallow (<20 inches or 50 centimeters) and sometimes very shallow (<10 inches or 25 centimeters). In wetter areas and on ridgetops the soils are similar to Amalu and Olokui series, which have gleyed subsurface horizons caused by anaerobic conditions. Vegetation is generally dense and often consists of native species such as ohia lehua (Metrosideros polymorpha), uluhe fern (Dicranopteris linearis), tree ferns (Cibotium spp.), and pukiawe (Leptecophylla tameiameiae). Because this land type is rather inaccessible, it often harbors rare plant species. Some common introduced species occurring here are kukui (Aleurites moluccana), lantana (Lantana camara), and hilograss (Paspalum conjugatum).

STONY BLOWN-OUT LAND (rSN) occurs only on Lanai. It occurs on knolls and in gulches. The soil has eroded down to stones, boulders, and rock outcrop over soft, highly weathered rock. It is sparsely vegetated by introduced species such as molassesgrass (Melinis minutiflora), dallisgrass (Paspalum dilitatum), lantana (Lantana camara), and Natal redtop (Melinis repens).

Table 4. Representative soil features

Parent material	(1) Residuum – igneous rock (2) Alluvium – igneous rock
Surface texture	(1) Silty clay (2) Clay (3) Silty clay loam
Drainage class	Well drained
Permeability class	Moderate to moderately rapid
Soil depth	30 – 75 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	4.2 – 4.7 in
Soil reaction (1:1 water) (0-20in)	4 – 5.4
Subsurface fragment volume <=3" (Depth not specified)	Not specified
Subsurface fragment volume >3" (Depth not specified)	Not specified

Ecological dynamics

The information in this ecological site description (ESD), including the state-and-transition model (STM), was developed using archaeological and historical data, professional experience, and scientific studies. The information is representative of a complex set of plant communities. Not all scenarios or plants are included. Key indicator plants, animals, and ecological processes are described to inform land management decisions.

States and community phases within this ecological site were differentiated by inspection of data; ordination programs were not available. They were verified by professional consensus and observation of examples in the field.

Natural Disturbances

The natural (not human-caused) disturbances most important for discussion in this ecological site are natural fires, and wind throw. Natural fires caused by lightning might occasionally occur in the drier portions of this ecological site. Wind throw of vegetation can occur during hurricanes or other high wind events.

Human Disturbances

Human-related disturbances have been much more important than natural disturbances in this ecological site since the arrival of Polynesians and, later, Europeans. These reflected in the State and Transition Model Diagram.

The first humans are believed to have migrated to Hawaii between 1000 and 1260 AD (Allen, 2014, Wilmhurst, 2011). Subsequent migrations and population growth increased so that by 1600 AD at least 80% of all the lands in Hawaii below about 1500 feet (roughly 500meters) in elevation had been extensively altered by humans (Kirch 1982); some pollen core data suggest that up to 100% of lowlands may have been altered (Athens 1997). By the time of European contact late in the 18th century, the Polynesians had developed high population densities and placed large areas under intensive agriculture (Cuddihy and Stone 1990).

Prehistoric native lowland forest disturbance can be attributed to clearing for agriculture by hand or by fire, introduction of new plants and animals, and wood harvesting. Less accessible areas may have been affected by factors such as inadvertently introduced plant diseases and seed predation the introduced Pacific rat (Athens 1997).

After the arrival of Europeans, documentary evidence attests to accelerated and extensive deforestation, erosion, siltation, and changes in local weather patterns (Kirch 1983) due to more intensive land use, modern tools, and introduction of more plant, animal, and microbe species.

The Polynesians introduced dogs, Pacific rats, and small pigs to the islands. Cattle, sheep, horses, goats, and larger European pigs were introduced in the final decade the 18th century. These animals ranged free on the islands, becoming very numerous and destructive by the early decades of the 19th century.

Through the 20th and into the 21st centuries, increases in human populations with attendant land development, as well as accelerated introduction of non-native mammals, birds, reptiles, amphibians, invertebrates, plants, and microorganisms, have brought about dramatic changes to wild ecosystems in Hawaii. This ecological site evolved without the presence of large mammals or human-caused fires.

The most important human disturbances in the ecological site are clearing for agriculture, domestic and feral ungulate foraging, and invasion by introduced plant and animal species. Much of the area is currently used for agriculture and pasture. Some areas had been cleared in the past and then abandoned; these areas are now dominated by forests of introduced species.

The most common introduced grass is kikuyugrass (Cenchrus clandestinus). Forested areas contain many introduced species, with strawberry guava (Psidium cattleianum), Java plum (Syzygium javanicum), and silk oak (Grevillea robusta) among the more common species. Common trees in native forest include olopua (Nestegis sandwicensis), hame (Antidesma pulvinatum), koa (Acacia koa), ohia lehua (Metrosideros polymorpha), lama (Diospyros sandwicensis), and papala kapau or Australasian catchbirdtree (Pisonia brunoniana), among others.

State and transition model

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Standard diagram

Figure 1. STM for R158XY005 Naturalized Grassland 50 to 90 Inch Precipitation Zone

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Ecosystem states

1. Reference

2. Invaded Understory

3. Invaded Over and Understory

4. Native Forest

5. Weed Invaded Grassland

States 1 and 5 (additional transitions)

1. Reference

5. Weed Invaded Grassland

T1A	-	State 1 Reference transitions to State 5 Weed Invaded Grassland by long-term continuous grazing and lack of weed control measures. Remnant desirable forages have been grazed out and replaced entirely by weedy grasses, forbs, shrubs, and small trees.
R2B	-	State 2 Invaded Understory can be restored to State 1 Reference by clearing the native forest overstory with heavy machinery and planting desirable forage species. Implement brush management and invasive plant species control measures as needed.
T2A	-	State 2 Invaded Understory transitions to State 3 Invaded Over and Understory through the process of fast-growing weeds inhibiting reproduction of native plants and gradually replacing them. This process is accelerated by feral pigs and cattle directly damaging native plants and promoting the spread of weeds by disturbing the soil and spreading weed seeds.
R2A	-	State 2 Invaded Understory may be restored to a facsimile of State 4 Native Forest. Construction of a suitable fence and removal of all ungulates are necessary. Intensive weed control must then be initiated and maintained in the long term. In some cases, large amounts of dead weed biomass must be dealt with by removal or decomposition. Reintroduction of missing native species will be necessary.
R3A	-	State 3 Invaded Overstory and Understory can be converted to State 1 Reference by clearing vegetation using heavy machinery, appropriately dealing with slash piles, applying aggressive weed control measures, and planting desirable forage species.
T4B	-	State 4 Native Forest can transition to State 1 Reference by clearing the forest with heavy machinery and planting desirable pasture species. Native forest may be cleared gradually by allowing cattle access to the forest. Cattle eventually eat or destroy native understory ferns, forbs, shrubs, and saplings, opening the forest so that introduced grasses will thrive.
T4A	-	State 4 Native Forest transitions to State 2 Invaded Understory by the very aggressive, introduced weed species present in this ecological site invading intact native forest and gradually replacing native species in the understory. This invasion is greatly facilitated by feral pigs and cattle that damage and consume native plants, disturb the soil, and spread weed seeds.
R5A	-	State 5 Weed-Invaded Grassland can be restored to State 1 Reference by brush management, re-establishment of desirable forage species, persistent weed control, and prescribed grazing.
T5A	-	State 5 Weed-Invaded Grassland transitions to State 3 Invaded Over and Understory due to the presence of fast-growing, introduced tree species; wildfire may delay this process.

State 1 submodel, plant communities

1.1. Kikuyugrass (Pennisetum clandestinum)

1.2. Molassesgrass – kikuyugrass/Hamakua pamakani (spreading snakeroot) (Melinis minutiflora – Pennisetum clandestinum/Ageratina riparia)

P1.1A	-	Phase 1.1 changes to phase 1.2 by long-term continuous grazing. Remnant high-quality forages have been greatly reduced in abundance and largely replaced by lower-value species. Weedy forbs and shrubs are increasing.
P1.2A	-	A planned grazing system is needed that provides for intensive but temporary grazing of pastures to ensure that cattle consume some low-value forage species along with preferred forages and to allow preferred forages time to recover from defoliation. Kikuyugrass is highly competitive and able to recover with proper management. The grazing plan may require splitting the herd, creating additional water sources, and creating multiple pastures by cross-fencing. Invasive plant species and brush management control may be necessary to eliminate some species such as inedible shrubs.

State 1
Reference

Figure 2. State 1. Reference. Kikuyugrass, Saint Augustine, and Bahaia grasses in pasture. Barbwire grass on slopes with guava and christmasberry. Niuli silty clay loam, medium texture variant, 7 to 30 % slopes. John Proctor. Feb 2021.

This state consists of two community phases dominated by introduced grass species. This state is considered to be the Reference State because few intact examples of native forest remain, and the species compositions of the forests consisting of introduced species are variable.

Continuous grazing results in increased abundance of less desirable forage species, as represented by the phase change from 1.1 Kikuyugrass to 1.2 Molassesgrass – kikuyugrass/Hamakua pamakani. Longer-term overgrazing and lack of weed control measures results in a transition to State 5 Weed-Invaded Grassland.

Resilience management. A transition from State 1 Reference to State 5 Weed Invaded Grassland may be avoided through application of planned grazing system/prescribed grazing, brush management and invasive plant species control measures.

Community 1.1
Kikuyugrass (Pennisetum clandestinum)

Dominance of desired forage species is maintained by prescribed grazing techniques that allow desired species time to recover from grazing and trampling but includes periods of grazing of sufficient intensity to suppress invasion of weedy shrubs and trees. Failure to properly maintain the selected forage species results in this community phase shifting to community phase 1.2.

There typically is little or no overstory in this community. The common forage species is kikuyugrass (Cenchrus clandestinus), sometimes in mixture with leguminous desmodium species (Desmodium spp.).

Dominant plant species

kikuyugrass (Pennisetum clandestinum), grass

Community 1.2
Molassesgrass – kikuyugrass/Hamakua pamakani (spreading snakeroot) (Melinis minutiflora – Pennisetum clandestinum/Ageratina riparia)

This community phase is dominated by grasses of lower forage value. Desirable forage legumes largely have been grazed out, and weedy forbs and shrubs have increased. It can be shifted back to phase 1.1 by using a prescribed grazing plan.

There typically is little or no overstory in this community. Molassesgrass (Melinis minutiflora) and remnant kikuyugrass (Pennisetum clandestinum) are typically dominant. Forbs such as Hamakua pamakani (spreading snakeroot), Jamaica vervain (Light-blue snakeweed), and Asian swordfern (Nephrolepis multiflora) are common. Desmodium species have disappeared or decreased in abundance.

Dominant plant species

molassesgrass (Melinis minutiflora), grass
kikuyugrass (Pennisetum clandestinum), grass
spreading snakeroot (Ageratina riparia), other herbaceous

Pathway P1.1A
Community 1.1 to 1.2

Phase 1.1 changes to phase 1.2 by long-term continuous grazing. Remnant high-quality forages have been greatly reduced in abundance and largely replaced by lower-value species. Weedy forbs and shrubs are increasing.

Key drivers

Livestock grazing or browsing

Key ecosystem services affected

Food and fiber: livestock forage

Pathway P1.2A
Community 1.2 to 1.1

A planned grazing system is needed that provides for intensive but temporary grazing of pastures to ensure that cattle consume some low-value forage species along with preferred forages and to allow preferred forages time to recover from defoliation. Kikuyugrass is highly competitive and able to recover with proper management. The grazing plan may require splitting the herd, creating additional water sources, and creating multiple pastures by cross-fencing. Invasive plant species and brush management control may be necessary to eliminate some species such as inedible shrubs.

Conservation practices

Brush Management
Prescribed Grazing
Planned Grazing System
Invasive Plant Species Control

Key drivers

Livestock grazing or browsing

Key ecosystem services affected

Food and fiber: livestock forage

State 2
Invaded Understory

Figure 3. State 2. Invaded Understory. Mature Ohia lehua trees in the overstory. Understory invaded by Christmasberry and guava. Niuli silty clay loam, medium textured variant, 7 to 30 % slopes. John Proctor. Feb 2021.

This state consists of one community phase. Native trees are dominant or very common in the overstory. However, introduced trees, shrubs, vines, and ferns produce a dense layer of low, competitive vegetation that severely inhibits reproduction of native species. Activity of feral pigs and cattle further reduces native plant abundance and produces bare, disturbed soil patches that promote weed invasion. Eventually, this state transitions to State 3 Invaded Overstory and Understory through growth of introduced tree species.

Resilience management. A transition from State 2 Invaded Understory to State 3 Invaded Overstory and Understory may be avoided by implementing measures which effectively exclude cattle and feral pigs (fencing, animal control, invasive pest species management) from the site and through application of invasive plant species control measures to eradicate or reduce abundance of introduced trees, shrubs, vines and ferns before they can invade and degrade the native overstory.

Community 2.1
Olopua – hame/lantana/Asian swordfern/kikuyugrass - basketgrass (Nestegis sandwicensis – Antidesma pulvinatum/Lantana camara/Nephrolepis minutiflora (syn. N. brownii)/Pennisetum clandestinum – Oplismenus hirtellus)

Native overstory tree species can occur in various combinations from very diverse to dominance by a few species to dominance by just one or two species. While native trees are abundant in the overstory, shade-tolerant introduced trees and shrubs gradually produce extremely dense canopies and root systems that exclude other species. Dense stands of introduced ferns, vines, and grasses form a layer that inhibits reproduction of native species.

Some typical native tree species in the overstory are olopua (Nestegis sandwicensis), hame (Antidesma pulvinatum), ohia lehua (Metrosideros polymorpha), tall-statured lama (Diospyros sandwicensis), koa (Acacia koa), mahe (Alectryon macrococcus), broadleaf papala (Charpentiera obovata), kolea lau nui (Myrsine lessertiana), papala kepau (Pisonia brunoniana), and hoawa (Pittosporum spp.). The occurrence of species varies from site to site and changes over environmental gradients, especially moisture availability and temperature. At the lower elevation, drier, and warmer extremes of this ecological site, the most common species are those associated with dry forest ecological sites, such as small-statured lama (Diospyros sandwicensis), hao (Rauvolfia sandwicensis), and maua (Xylosma hawaiiense). Higher, cooler, moister extremes are likely to include ahakea lau nui (Bobea elatior), kalia (Elaeocarpus bifidus), manono (Kadua axillaris syn. Hedyotis hillebrandii), variable starviolet or manono (Kadua affinis syn. Hedyotis terminalis), ohe (Polyscias hawaiensis syn. Tetraplasandra hawaiensis), and paihiihi or ohia ha (Syzygium sandwicense).

The understory consists almost entirely of introduced species. Strawberry guava (Psidium cattleianum), common guava (Psidium guajava), and/or Java plum (Syzygium javanicum) are abundant, gradually forming dense stands in the understory. The introduced ferns Asian swordfern (Nephrolepis minutiflora syn. N. brownii), maile-scented or musk fern (Phymatosorus grossus), and downy maiden fern (Cyclosorus dentatus, or Christella dentata or Thelypteris dentatus in some references) and parasitic maiden fern (Christella parasitica) form dense stands under 3 feet (about 1 meter) tall. Native uluhe fern or Old World forkedfern (Dicranopteris linearis) occurs in some locations. Lantana (Lantana camara), West Indian raspberry (Rubus rosifolius) and shampoo ginger or bitter ginger (Zingiber zerumbet) are present and increasing in abundance. The introduced vines paederia or stinkvine (Paederia foetida) and Huehue haole or corkystem passionflower (Passiflora suberosa) can be common. Kikuyugrass (Pennisetum clandestinum) can cover the ground except in the densest shade. Basketgrass (Oplismenus hirtellus) thrives in shadier areas. Introduced grasses that are common in moister parts of the ecological site are common carpetgrass (Axonopus fissifolius), hilograss (Paspalum conjugatum), glenwoodgrass (Sacciolepis indica), and, in wetter spots, californiagrass or para grass (Urochloa mutica).

Native species that may survive in small numbers in the understory are Hawaii birdnest fern (Asplenium nidus), hapuu tree ferns (Cibotium spp.), and alahee (Psydrax odoratum).

Dominant plant species

Hawai'i olive (Nestegis sandwicensis), tree
hame (Antidesma pulvinatum), tree
lantana (Lantana camara), shrub
kikuyugrass (Pennisetum clandestinum), grass
basketgrass (Oplismenus hirtellus), grass
Asian swordfern (Nephrolepis multiflora), other herbaceous

State 3
Invaded Over and Understory

Figure 4. State 3. Invaded Overstory and Understory. Guava, christmasberry and Asian sword fern encroachment and attacks from the sugar cane beetle borer have killed native Muroe's Loulu palms. John Proctor. Feb 2021.

This state consists of one community phase dominated by introduced species in both the overstory and understory. Some individual native trees may persist for their lifetime. The diversity of weedy trees, shrubs, vines, ferns, and herbs is high, and the species mix is variable. Conversion to State 1 Reference is possible by using heavy machinery and applying aggressive weed control and ungulate-exclusion measures until desirable forages are established.

Community 3.1
Java plum – strawberry guava/shampoo (bitter) ginger/Asian swordfern/basketgrass (Syzygium javanicum – Psidium cattleianum/Zingiber zerumbet/Nephrolepis minutiflora (syn. N. brownii)/Oplismenus hirtellus)

Large native trees persist in the overstory until they die, but do not successfully reproduce. Scattered individuals of kopiko or wild coffee (Psychotria kaduana and P. mariniana) seem to persist in some sites. Hawaii birdnest fern (Asplenium nidus) may persist on the ground or as an epiphyte on introduced tree species.

The introduced species present on different sites varies considerably. Monotypic or mixed stands of strawberry guava (Psidium cattleianum), common guava (Psidium guajava), kukui or Indian walnut (Aleurites moluccana), silkoak (Grevillea robusta), and Java plum (Syzygium javanicum) may develop. Fast-growing albizia or peacocks plume (Falcataria moluccana) may eventually overtop all other species.

The understory varies among locations. Dense overstories of strawberry guava, silkoak, or ironwood may allow only a sparse understory to grow. Otherwise, lantana (Lantana camara), common guava (Psidium guajava), strawberry guava (Psidium cattleianum), and shampoo ginger or bitter ginger (Zingiber zerumbet) may be abundant. Introduced ferns (see Community 2.1) are typically present, and grass species such as basketgrass (Oplismenus hirtellus), common carpetgrass (Axonopus fissifolius), molassesgrass (Melinis minutiflora), hilograss (Paspalum conjugatum), glenwoodgrass (Sacciolepis indica), and californiagrass or para grass (Urochloa mutica) grow where enough light penetrates the overstory. The introduced vines paederia or stinkvine (Paederia foetida), huehue haole or corkystem passionflower (Passiflora suberosa), and West Indian raspberry (Rubus rosifolius) can be abundant where the overstory is not too dense.

Dominant plant species

Java plum (Syzygium javanicum), tree
strawberry guava (Psidium cattleianum), tree
Asian swordfern (Nephrolepis multiflora), grass
basketgrass (Oplismenus hirtellus), grass
bitter ginger (Zingiber zerumbet), other herbaceous

State 4
Native Forest

Figure 5. State 4. Native Forest. This image of Ohia lehua serves as a representation of the Native Forest State. John Proctor. Feb 2021.

This state consists of one community phase. Because few examples of this state remain, the following description is partly hypothetical, based on observations of similar ecological sites and on the known ranges and environmental preferences of likely native plant species.

When cleared of understory and much of the overstory by machinery or long-term, heavy ungulate browsing and replanted with desirable forage species, this state transitions to State 1 Reference. Abandonment and gradual invasion by weedy, introduced plant species brings a transition to State 2 Invaded Understory.

Resilience management. The transition from State 4 Native Forest to State 2 Invaded Understory may be avoided by implementing measures which effectively exclude cattle and feral pigs (fencing, animal control, invasive pest species management) from the site and through application of invasive plant species control measures to eradicate or reduce introduced trees, shrubs, vines and ferns.

Dominant plant species

Hawai'i olive (Nestegis sandwicensis), tree
hame (Antidesma pulvinatum), tree
Hawai'i jadevine (Strongylodon ruber), shrub

Community 4.1
Olopua – hame/nukuiiwi (Hawaii jadevine) (Nestegis sandwicensis – Antidesma pulvinatum/Strongylodon ruber)

The partly hypothetical community is a forest of medium canopy stature (30 to 40 feet or 9 to 12 meters), usually with a closed overstory. Some tree species can grow to about 70 feet tall (22 meters) to project through the rest of the canopy. Ground cover typically is sparse; vines are not uncommon.

Overstory tree species can be very diverse, although stands dominated by one or two species occur locally. Dominant species are usually ohia lehua (Metrosideros polymorpha), koa (Acacia koa), lama (Diospyros sandwicensis), hame (Antidesma pulvinatum), ohia ha (Syzygium sandwicense), papala kepau (Pisonia brunoniana), olopua (Nestegis sandwicensis), and ohe (Polyscias hawaiensis). Mehamehame (Flueggea neowawraea) was formerly a major species in this ecological site but has been greatly diminished by black twig borer infestation.

Some of the smaller statured trees here include hala pepe (Pleomele spp.), nenelau (Rhus sandwicensis), papala (Charpentiera obovata), mamaki (Pipturus albidus), and alahee (Psydrax odoratum). Common vines include maile (Alyxia stellata), ieie (Freycinetia arborea), and nukuiiwi or Hawaii jadevine (Strongylodon ruber). A scattering of shrubs, small ferns, grasses, sedges, and forbs (Peperomia spp.) occur in the low understory. Patches of uluhe fern (Dicranopteris linearis) cover the ground in places.

Occurrence of individual species varies across the gradient from the lower, drier extremes to the higher, moister extremes of this ecological site. Lama and ohia lehua can occur throughout the gradient but their stature increases toward the higher, moister end. Tree ferns (Cibotium spp.), clermontia (Clermontia spp.), cyanea (Cyanea spp.) can occur in moister areas. Typical dry forest species such as maua (Xylosma hawaiiense) lonomea (Sapindus oahuensis), and hao (Rauvolfia sandwicensis occur only in the lower, drier part of the ecological site. See the accompanying species list for a fuller accounting of likely species.

Dominant plant species

Hawai'i olive (Nestegis sandwicensis), tree
hame (Antidesma pulvinatum), tree
Hawai'i jadevine (Strongylodon ruber), shrub

State 5
Weed Invaded Grassland

Figure 6. State 5. Weed Invaded Grassland. This grassland has been invaded by formosa koa, christmasberry, sourgrass and weedy forbs. John Proctor. Feb 2021.

This state consists of one community phase consisting primarily of weedy shrubs and small trees. Weedy grasses and forbs dominate between shrub patches. Introduced tree species are present and will eventually attain dominance.

Community 5.1
Common guava – christmasberry/Asian swordfern/molassesgrass (Psidium guajava – Schinus terebinthifolius/Nephrolepis minutiflora (syn. N. brownii)/Melinis minutiflora)

This community phase has a wide diversity of mostly introduced species. Tree overstory is typically sparse to absent.

Strawberry guava (Psidium cattleianum), common guava (Psidium guajava), christmasberry (Schinus terebinthifolius), Java plum (Syzygium javanicum), and sourbush (Pluchea carolinensis) are common and poised to expand rapidly. Asian swordfern (Nephrolepis multiflora or N. brownii in updated references) is abundant. Forage legumes such as desmodium (Desmodium spp.) and koa haole (Leucaena leucocephala) are no longer present. Kikuyugrass is still present but greatly reduced in abundance, while species of lower forage quality such as rat-tail grass (Sporobolus africanus), molassesgrass (Melinis minutiflora), hilograss (Paspalum conjugatum), and narrow leaved carpetgrass (Axonopus fissifolius) are abundant.

Dominant plant species

guava (Psidium guajava), tree
Brazilian peppertree (Schinus terebinthifolius), tree
molassesgrass (Melinis minutiflora), grass
Asian swordfern (Nephrolepis multiflora), other herbaceous

Transition T1A
State 1 to 5

Reference

Weed Invaded Grassland

State 1 Reference transitions to State 5 Weed Invaded Grassland by long-term continuous grazing and lack of weed control measures. Remnant desirable forages have been grazed out and replaced entirely by weedy grasses, forbs, shrubs, and small trees.

Key drivers

Livestock grazing or browsing

Key ecosystem services affected

Food and fiber: livestock forage

Restoration pathway R2B
State 2 to 1

Invaded Understory

Reference

State 2 Invaded Understory can be restored to State 1 Reference by clearing the native forest overstory with heavy machinery and planting desirable forage species. Implement brush management and invasive plant species control measures as needed.

Conservation practices

Brush Management
Land Clearing
Range Planting
Invasive Plant Species Control

Transition T2A
State 2 to 3

Invaded Understory

Invaded Over and Understory

State 2 Invaded Understory transitions to State 3 Invaded Over and Understory through the process of fast-growing weeds inhibiting reproduction of native plants and gradually replacing them. This process is accelerated by feral pigs and cattle directly damaging native plants and promoting the spread of weeds by disturbing the soil and spreading weed seeds.

Key drivers

Livestock grazing or browsing
Seed dispersal by livestock
Nonnative pest presence and/or establishment
Nonnative plant species presence and/or establishment

Key ecosystem services affected

Pollination
Genetic resources
Sense of place
Wildlife habitat
Animal biodiversity
Plant biodiversity

Restoration pathway R2A
State 2 to 4

Invaded Understory

Native Forest

State 2 Invaded Understory may be restored to a facsimile of State 4 Native Forest. Construction of a suitable fence and removal of all ungulates are necessary. Intensive weed control must then be initiated and maintained in the long term. In some cases, large amounts of dead weed biomass must be dealt with by removal or decomposition. Reintroduction of missing native species will be necessary.

Conservation practices

Brush Management
Fence
Native Plant Community Restoration and Management
Invasive Plant Species Control
Invasive Species Pest Management

Restoration pathway R3A
State 3 to 1

Invaded Over and Understory

Reference

State 3 Invaded Overstory and Understory can be converted to State 1 Reference by clearing vegetation using heavy machinery, appropriately dealing with slash piles, applying aggressive weed control measures, and planting desirable forage species.

Conservation practices

Brush Management
Land Clearing
Range Planting
Invasive Plant Species Control

Transition T4B
State 4 to 1

Native Forest

Reference

State 4 Native Forest can transition to State 1 Reference by clearing the forest with heavy machinery and planting desirable pasture species. Native forest may be cleared gradually by allowing cattle access to the forest. Cattle eventually eat or destroy native understory ferns, forbs, shrubs, and saplings, opening the forest so that introduced grasses will thrive.

Conservation practices

Brush Management
Land Clearing
Range Planting

Key drivers

Livestock grazing or browsing
Seed dispersal by livestock
Timber management
Nonnative plant species presence and/or establishment
Seeding

Key ecosystem services affected

Educational values
Pollination
Aesthetic values
Genetic resources
Sense of place
Nutrient cycling
Knowledge systems
Spiritual and religious values
Inspiration
Water regulation
Climate regulation: carbon cycling and storage
Wildlife habitat
Animal biodiversity
Plant biodiversity
Biochemicals and pharmaceuticals
Climate regulation

Transition T4A
State 4 to 2

Native Forest

Invaded Understory

State 4 Native Forest transitions to State 2 Invaded Understory by the very aggressive, introduced weed species present in this ecological site invading intact native forest and gradually replacing native species in the understory. This invasion is greatly facilitated by feral pigs and cattle that damage and consume native plants, disturb the soil, and spread weed seeds.

Key drivers

Livestock grazing or browsing
Seed dispersal by livestock
Nonnative plant species presence and/or establishment

Key ecosystem services affected

Educational values
Pollination
Aesthetic values
Genetic resources
Sense of place
Nutrient cycling
Spiritual and religious values
Climate regulation: carbon cycling and storage
Wildlife habitat
Animal biodiversity
Plant biodiversity

Restoration pathway R5A
State 5 to 1

Weed Invaded Grassland

Reference

State 5 Weed-Invaded Grassland can be restored to State 1 Reference by brush management, re-establishment of desirable forage species, persistent weed control, and prescribed grazing.

Conservation practices

Brush Management
Prescribed Grazing
Range Planting
Planned Grazing System
Invasive Plant Species Control

Transition T5A
State 5 to 3

Weed Invaded Grassland

Invaded Over and Understory

State 5 Weed-Invaded Grassland transitions to State 3 Invaded Over and Understory due to the presence of fast-growing, introduced tree species; wildfire may delay this process.

Key drivers

Nonnative plant species presence and/or establishment
Fire frequency

Key ecosystem services affected

Food and fiber: livestock forage

Additional community tables

Table 5. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 6. Community 1.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 7. Community 2.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 8. Community 3.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 9. Community 4.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 10. Community 5.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Supporting information

Other references

Definitions

These definitions have been greatly simplified for brevity and do not cover every aspect of each topic.

Aa lava: A type of basaltic lava having a rough, jagged, clinkery surface and a vesicular interior.

Alluvial: Materials or processes associated with transportation and/or deposition by running water.

Aquic soil moisture regime: A regime in which the soil is free of dissolved oxygen because it is saturated by water. This regime typically exists in bogs or swamps.

Aquisalids: These are salty soils in wet areas. Although wet, the dissolved salts make the soils physiologically dry (the chemical activity, or effective concentration, of water is low). Aquisalids typically support plant species that are adapted to these conditions.

Aridic soil moisture regime: A regime in which defined parts of the soil are, in normal years, dry for more than half of the growing season and moist for less than 90 consecutive days during the growing season. In Hawaii it is associated with hot, dry areas with plants such as kiawe, wiliwili, and buffelgrass. The terms aridic and torric are basically the same.

Ash field: a land area covered by a thick or distinctive deposit of volcanic ash that can be traced to a specific source and has well defined boundaries. The term “ash flow” is erroneously used in the Physiographic section of this ESD due to a flaw in the national database.

Ashy: A “soil texture modifier” for volcanic ash soils having a water content at the crop wilting point of less than 30 percent; a soil that holds relatively less water than “medial” and “hydrous” soils.

Available water capacity: The amount of soil water available to plants to the depth of the first root-restricting layer.

Basal area or basal cover: The cross-sectional area of the stem or stems of a plant or of all plants in a stand.

Blue rock: The dense, hard, massive lava that forms the inner core of an aa lava flow.

Bulk density: the weight of dry soil per unit of volume. Lower bulk density indicates a greater amount of pore space that can hold water and air in a soil.

CaCO3 equivalent: The amount of free lime in a soil. Free lime exists as solid material and typically occurs in regions with a dry climate.

Canopy cover: The percentage of ground covered by the vertical projection downward of the outermost perimeter of the spread of plant foliage. Small openings within the canopy are included.

Community pathway: A description of the causes of shifts between community phases. A community pathway is reversible and is attributable to succession, natural disturbances, short-term climatic variation, and facilitating practices, such as grazing management.

Community phase: A unique assemblage of plants and associated dynamic soil properties within a state.

Dominant species: Plant species or species groups that exert considerable influence upon a community due to size, abundance, or cover.

Drainage class: The frequency, duration, and depth of a water table in a soil. There are seven drainage classes, ranging from “excessively drained” (soils with very rare or very deep water tables) to “well drained” (soils that provide ample water for plant growth but are not so wet as to inhibit root growth) to “very poorly drained” (soils with a water table at or near the surface during much of the growing season that inhibits growth of most plants).

Electrical conductivity (EC): A measure of the salinity of a soil. The standard unit is deciSiemens per meter (dS/m), which is numerically equivalent to millimhos per centimeter (mmhos/cm). An EC greater than about 4 dS/m indicates a salinity level that is unfavorable to growth of most plants.

Friability: A soil consistency term pertaining to the ease of crumbling of soils.

Gleyed: A condition of soil from which iron has been reduced (in the redox chemistry sense) and removed during soil formation or that saturation with stagnant water has preserved a reduced state. If iron has been removed, the soil is the color of uncoated sand and silt particles. If iron is present in a reduced state, the soil is the color of reduced iron (typically bluish-gray). Redox concentrations (spots of oxidized iron, formerly called mottles are often present.

Hydrous: A “soil texture modifier” for volcanic ash soils having a water content at the crop wilting point of 100 percent or more; a soil that holds more water than “medial” or “ashy” soils.

Ion exchange capacity: The ability of soil materials such as clay or organic matter to retain ions (which may be plant nutrients) and to release those ions for uptake by roots.

Isohyperthermic soil temperature regime: A regime in which mean annual soil temperature is 72 degrees F (22 degrees C) or higher and mean summer and mean winter soil temperatures differ by less than 11 degrees F (6 degrees C) at a specified depth.

Isomesic soil temperature regime: A regime in which mean annual soil temperature is 47 degrees F (8 degrees C) or higher but lower than 59 degrees F (15 degrees C) and mean summer and mean winter soil temperatures differ by less than 11 degrees F (6 degrees C) at a specified depth.

Isothermic soil temperature regime: A regime in which mean annual soil temperature is 59 degrees F (15 degrees C) or higher but lower than 72 degrees F (22 degrees C) and mean summer and mean winter soil temperatures differ by less than 11 degrees F (6 degrees C) at a specified depth.

Kipuka: An area of land surrounded by younger (more recent) lava. Soils and plant communities within a kipuka are older than, and often quite different from, those on the surrounding surfaces.

Major Land Resource Area (MLRA): A geographic area defined by NRCS that is characterized by a particular pattern of soils, climate, water resources, and land uses. The island of Hawaii contains nine MLRAs, some of which also occur on other islands in the state.

Makai: a Hawaiian word meaning “toward the sea.”

Mauka: a Hawaiian word meaning “toward the mountain” or “inland.”

Medial: A “soil texture modifier” for volcanic ash soils having a water content at the crop wilting point of 30 to 100 percent; a soil that holds an amount of water intermediate to “hydrous” or “ashy” soils.

Mollisols: Soils with relatively thick, dark surface horizons, high cation-exchange capacity, high calcium content, that do not become hard or very hard when dry. Mollisols are conducive to plant growth. They characteristically form under grass in climates that are seasonally dry, but can form under forests.

Naturalized plant community: A community dominated by adapted, introduced species. It is a relatively stable community resulting from secondary succession after disturbance. Most grasslands in Hawaii are in this category.

Oxisols: Soils characteristic of humid, tropical or subtropical regions that formed on land surfaces that have been stable for a long time. In Hawaii, they typically occur on islands or parts of islands that have been volcanically inactive for a long time. Oxisols are highly weathered, consist largely of quartz, kaolin clays, and aluminum oxides, and have low ion exchange capacity and loamy or clayey texture.

Pahoehoe lava: A type of basaltic lava with a smooth, billowy, or rope-like surface and vesicular interior.

Parent material: Unconsolidated and chemically weathered material from which a soil is developed.

Perudic soil moisture regime: A very wet regime found where precipitation exceeds evapotranspiration in all months of normal years. On the island of Hawaii, this regime is found on top of Kohala and on parts of the windward side of Mauna Kea.

pH: The numerical expression of the relative acidity or alkalinity of a soil sample. A pH of 7 is neutral; a pH below 7 is acidic and a pH above 7 is basic.

Phosphorus adsorption: The ability of soil materials to tightly retain phosphorous ions, which are a plant nutrient. Some volcanic ash soils retain phosphorus so strongly that it is partly unavailable to plants.

Psamments: Sandy soils that have low water-holding capacity, are susceptible to wind erosion, and typically have ground water deeper than 20 inches (50 centimeters).

Reference community phase: The phase exhibiting the characteristics of the reference state and containing the full complement of plant species that historically occupied the site. It is the community phase used to classify an ecological site.

Reference state: A state that describes the ecological potential and natural or historical range of variability of an ecological site.

Restoration pathway: A term describing the environmental conditions and practices that are required to recover a state that has undergone a transition.

Sodium adsorption ratio (SAR): A measure of the amount of dissolved sodium relative to calcium and magnesium in the soil water. SAR values higher than 13 create soil conditions unfavorable to most plants.

Soil moisture regime: A term referring to the presence or absence either of ground water or of water held at a tension of less than 1500 kPa (the crop wilting point) in the soil or in specific horizons during periods of the year.

Soil temperature regime: A defined class based on mean annual soil temperature and on differences between summer and winter temperatures at a specified depth.

Soil reaction: Numerical expression in pH units of the relative acidity or alkalinity or a soil.

Spodosols: Soils with a spodic B horizon that has an accumulation of black or reddish amorphous materials that have a high pH-dependent ion exchange capacity, coarse texture, and few base cations. Above the spodic horizon there often is a light-colored albic horizon that was the source of the amorphous materials in the spodic horizon.

State: One or more community phases and their soil properties that interact with the abiotic and biotic environment to produce persistent functional and structural attributes associated with a characteristic range of variability.

State-and-transition model: A method used to display information about relationships between vegetation, soil, animals, hydrology, disturbances, and management actions on an ecological site.

Torric soil moisture regime: See Aridic soil moisture regime.

Transition: A term describing the biotic or abiotic variables or events that contribute to loss of state resilience and result in shifts between states.

Udic soil moisture regime: A regime in which the soil is not dry in any part for as long as 90 cumulative days in normal years, and so provides ample moisture for plants. In Hawaii it is associated with forests in which hapuu (tree ferns) are usually moderately to highly abundant.

Ultisols: Soils that have been intensively leached and weathered. They have a B horizon that has accumulated clay that has translocated there from higher horizons. They have moderate to low cation exchange capacity and low base saturation. The highest base saturation normally is in the few centimeters directly beneath the surface due to cycling of bases by plants.

Ustic soil moisture regime: A regime in which moisture is limited but present at a time when conditions are suitable for plant growth. In Hawaii it usually is associated with dry forests and subalpine shrublands.

Other References

Abrahamson I. 2013. Fire regimes in Hawaiian plant communities. In: Fire Effects Information System, US Dept. of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. Available" www.fs.fed.us/database/feis/fire_regimes/Hawaii/all.html

Allen, M.S., 2014. Marquesan colonization chronologies and post colonization interaction: implications for Hawaiian origins and the ‘Marquesan Homeland’ hypothesis. Journal of Pacific Archaeology, 5(2), pp.1-17. Discussions of earliest Polynesian migrations to Hawaii.

Armstrong RW. 1973. Atlas of Hawaii. University of Hawaii Press, Honolulu.

Athens JS. Ch. 12 Hawaiian Native Lowland Vegetation in Prehistory in Historical Ecology in the Pacific Islands – Prehistoric Environmental and Landscape Change. Kirch, PV and TL Hunt, eds. 1997. Yale U. Press, New Haven.

Burney DA, HF James, LP Burney, SL Olson, W Kikuchi, WL Wagner, M Burney, D McCloskey, D Kikuchi, FV Grady, R Gage II, and R Nishek. 2001. Fossil evidence for a diverse biota from Kauai and tis transformation since human arrival. Ecological Monographs 71:615-641.

Christensen CC. 1983. Report 17: Analysis of land snails. In: Archaeological investigations of the Mudlane-Waimea-Kawaihae Road Corridor, Island of Hawaii: An Interdisciplinary Study of an Environmental Transect. Clark JT. and Kirch PV, eds. Dept. of Anthropology, Bernice Pauahi Bishop Museum, Report 83-1, Honolulu, HI.

Clark JT. 1983. Report 3: The Waimea-Kawaihae Region: Historical Background. In: Archaeological investigations of the Mudlane-Waimea-Kawaihae Road Corridor, Island of Hawaii: An Interdisciplinary Study of an Environmental Transect. Clark JT and Kirch PV, eds. Dept. of Anthropology, Bernice Pauahi Bishop Museum, Report 83-1, Honolulu, HI.

Clark JT. 1983. Report 7: Archaeological investigations in Section 4. In: Archaeological investigations of the Mudlane-Waimea-Kawaihae Road Corridor, Island of Hawaii: An Interdisciplinary Study of an Environmental Transect. Clark JT and Kirch PV, eds. Dept. of Anthropology, Bernice Pauahi Bishop Museum, Report 83-1, Honolulu, HI.

Clark JT. 1983. Report 8: Archaeological investigations of agricultural sites in the Waimea area. In: Archaeological investigations of the Mudlane-Waimea-Kawaihae Road Corridor, Island of Hawaii: An Interdisciplinary Study of an Environmental Transect. Clark JT and Kirch PV, eds. Dept. of Anthropology, Bernice Pauahi Bishop Museum, Report 83-1, Honolulu, HI.

Craighill ES and EG Handy. 1991. Native Planters in Old Hawaii – Their Life, Lore, and Environment. Bernice P. Bishop Museum Bulletin 233, Bishop Museum Press, Honolulu, HI

Cuddihy LW and CP Stone. 1990. Alteration of Native Hawaiian Vegetation: Effects of Humans, Their Activities and Introductions. Honolulu: University of Hawaii Cooperative National Park Resources Study Unit.

Deenik J and AT McClellan. 2007. Soils of Hawaii. Soil and Crop Management, Sept. 2007, SCM-20. Cooperative Extension Service, College of Tropical Agriculture and Human Resources. University of Hawaii at Manoa. Available online at: https://www.ctahr.hawaii.edu/oc/freepubs/pdf/SCM-20.pdf

Dixon JB and Schulze DG, eds. 2002. Soil Mineralogy with Environmental Applications. Volume 7. Soil Science Society of America. Available online at: https://acsess.onlinelibrary.wiley.com/doi/book/10.2136/sssabookser7

Giambelluca TW and TA Schroeder. 1998. Climate. In: Atlas of Hawaii, 3rd edition. SP Juvik, JO Juvik, and RR Paradise, eds. pp. 49-59. Honolulu: University of Hawaii Press.

Gil CR. 2016-2017. Ananas comosus. Colegio Bolivar Agricultural Science. Available online at: https://www.colegiobolivar.edu.co/garden/wp-content/uploads/2017/06/Crosas-Ananas-comosus-2017.pdf

Handy ESC Handy EG and Pukui MK. 1972. Native Planters in Old Hawaii Their Life, Lore, and Environment. (Revised Edition, 1991). Bernice P. Bishop Museum Bulletin 233. Honolulu.

Hazlett RW and DW Hyndman. 1996. Roadside Geology of Hawaii. Mountain Press Publishing Company, Missoula MT.

Henke LA. 1929. A Survey of Livestock in Hawaii. Research Publication No. 5. University of Hawaii, Honolulu.

Horrocks M. 2009. Sweet potato (Ipomoea batatas) and banana (Musa sp.) microfossils in deposits from the Kona Field System, Island of Hawaii. Journal of Archaeological Science, May 2009.

Imada, C. 2012. Hawaiian Native and Naturalized Vascular Plants Checklist (December 2012 update). Bishop Museum Technical Report 60. Bishop Museum Press, Honolulu.

Jacobi JD. 1989. Vegetation Maps of the Upland Plant Communities on the Islands of Hawaii, Maui, Molokai, and Lanai. Technical Report 68. Cooperative National Park Resources Studies Unit, University of Hawaii at Manoa and National Park Service.

Juvik JO and D Nullet. 1993. Relationships between rainfall, cloud-water interception, and canopy throughfall in a Hawaiian montane forest. IN: Tropical Montane Cloud Forests. Proc. Int. Sym., San Juan, PR. Hamilton LS, JO Juvik, and FN Scatena, eds. East-West Center.

Kirch PV. 1982. The impact of the prehistoric Polynesians in the Hawaiian ecosystem. Pacific Science 36(1):1-14.

Kirch PV. 1983. Introduction. In: Archaeological investigations of the Mudlane-Waimea-Kawaihae Road Corridor, Island of Hawaii: An Interdisciplinary Study of an Environmental Transect. Clark JT and Kirch PV, eds. Dept. of Anthropology, Bernice Pauahi Bishop Museum, Report 83-1, Honolulu, HI.

Kirch PV. 1985. Feathered Gods and Fishhooks: An Introduction to Hawaiian Archaeology and Prehistory. Honolulu: University of Hawaii Press.

Kirch PV. 2000. On the Road of the Winds: An Archaeological History of the Pacific Islands Before European Contact. Berkeley: University of California Press.

Kirch, P.V., 2011. When did the Polynesians settle Hawaii? A review of 150 years of scholarly inquiry and a tentative answer. Hawaiian Archaeology, 12(2011), pp.3-26.

Leopold LB. 1949. The interaction of trade wind and sea breeze, Hawaii. Journal of Meteorology 6: 312-320.

Little EL Jr. and RG Skolmen. 1989. Common Forest Trees of Hawaii (Native and Introduced). US Department of Agriculture-US Forest Service Agriculture Handbook No. 679. (out of print). Available at www.fs.fed.us/psw/publications/documents/misc/ah679.pdf

Malo, David. 1903. Hawaiian Antiquities. N.B. Emerson (trans.). Bishop Museum Special Publication 2. Honolulu.

Maly K and O Maly. 2004. He Moolelo Aina: A Cultural Study of the Puu O Umi Natural Area Reserve and Kohala-Hamakua Mountain Lands, Districts of Kohala and Hamakua, Island of Hawaii. Kumu Pono Associates, Hilo HI.

McEldowney H. 1983. Report 16: A description of major vegetation patterns in the Waimea-Kawaihae region during the early historic period. In: Archaeological investigations of the Mudlane-Waimea-Kawaihae Road Corridor, Island of Hawaii: An Interdisciplinary Study of an Environmental Transect. Clark JT and Kirch PV, eds. Dept. of Anthropology, Bernice Pauahi Bishop Museum, Report 83-1, Honolulu, HI.

Mubyana T. 1997/98. Effects of continuous sugarcane and pineapple cropping on organic matter and soil microbial biomass. Journal of African Research and Development 27&28:258-269.

Mueller-Dombois D and FR Fosberg. 1998. Vegetation of the Tropical Pacific Islands. Springer-Verlag New York, Inc.

Palmer DD. 2003. Hawaii’s Ferns and Fern Allies. University of Hawaii Press, Honolulu.

Pratt HD. 1998. A Pocket Guide to Hawaii’s Trees and Shrubs. Mutual Publishing, Honolulu.

Reppun F, Silva JHS, Wong K, and Deenik JL. 2017. A Soil Phosphorus Primer for Hawaiian Soils. Soil and Crop Management, August 2017, SCM-33. College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. Available online at: https://www.ctahr.hawaii.edu/oc/freepubs/pdf/SCM-33.pdf

Ripperton JC and EY Hosaka. 1942. Vegetation zones of Hawaii. Hawaii Agricultural Experiment Station Bulletin 89:1-60.

Rock JF. The Indigenous Trees of the Hawaiian Islands. 1st edition 1913, reprinted 1974, Charles E. Tuttle Company, Rutland, VT and Tokyo, Japan.

Sanderson, M (ed.). 1993. Prevailing Trade Winds, Weather and Climate in Hawaii. University of Hawaii Press. Honolulu.

Schroeder TA. 1981. Characteristics of local winds in northwest Hawaii. Journal of Applied Meteorology 20: 874-881.

Shoji SD, M Nanzyo, and R Dahlgren. 1993. Volcanic Ash Soils: Genesis, Properties and Utilization. Elsevier, New York.

Silva JA and R Uchida, eds. 2000. Plant Nutrient Management in Hawaii’s Soils, Approaches for Tropical and Subtropical Agriculture. College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. Available online at: https://www.ctahr.hawaii.edu/oc/freepubs/pdf/pnm0.pdf

Sohmer SH and R Gustafson. 2000. Plants and Flowers of Hawaii. University of Hawaii Press, Honolulu.

Soil Survey Staff. 2014. Soil Taxonomy, Twelfth Edition. USDA – NRCS.

Steadman DW. 1995. Prehistoric extinctions of Pacific island birds: biodiversity meets zooarchaeology. Science 267:1123-1131.

USDA-NRCS-PIA T&E Species GIS files. Not publicly available.

USDA-NRCS. 2011. Soil Survey Laboratory Information Manual. Soil Survey Investigations Report No. 45, Version 2.0. National Soil Survey Center, Lincoln, Nebraska.

USDA-NRCS. 2006. Major Land Resource Regions. USDA Agriculture Handbook 296. http://soils.usda.gov/MLRAExplorer

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USDA-SCS. 1972. Soil Survey of Islands of Kauai, Oahu, Maui, Molokai, and Lanai, State of Hawaii. Foote DE, Hill EL, Nakamura S, and F Stephens, in cooperation with The University of Hawaii Agricultural Experiment Station.

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Welch DJ 1983. Report 5: Archaeological investigations in Section 2. In: Archaeological investigations of the Mudlane-Waimea-Kawaihae Road Corridor, Island of Hawaii: An Interdisciplinary Study of an Environmental Transect. Clark JT and Kirch PV, eds. Dept. of Anthropology, Bernice Pauahi Bishop Museum, Report 83-1, Honolulu, HI.

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Contributors

David Clausnitzer
John Proctor
Carolyn Wong
Mike Kolman
Mathew Cocking
Amy Koch
Kendra Moseley
Jennifer Higashino

Approval

Kendra Moseley, 4/17/2025

Acknowledgments

Assistance, advice, review, and/or insights: Kip Dunbar, Dunbar Ranch John Colon (Koa), NRCS David Duvauchelle (Kawika), NRCS Richard Ogoshi, NRCS Elena Dosamantes, NRCS Robin Leimomi Proctor, Earth Team Volunteer Randy Bartlett, Puu Kukui Watershed Preserve Hanohano Naehu, Fishpond Guardian of Keawanui Alison Cohan, The Nature Conservancy Michael Constantinides, NRCS-PIA Gordon Cran, Kapapala Ranch Diana Crow, Ulupalakua Ranch Lance DeSilva, Hawaii DLNR Kerri Fay, Waikamoi Preserve, The Nature Conservancy Alex Franco, Kaupo Ranch Ranae Ganske-Cerizo, NRCS Carl Hashimoto, NRCS Jennifer Higashino, USFWS and NRCS Bob Hobdy, consultant, Maui Wallace Jennings, NRCS Mel Johansen, The Nature Conservancy Jordan Jokiel, Haleakala Ranch David Leonard, volunteer Penny Levin Reese Libby, GIS - NRCS Hannah Lutgen, Maui SWCD Joseph May, NRCS Scott Meidel, Haleakala Ranch Anna Palomino, Hoolawa Farms Inc. Jon Price, USGS Tamara Sherrill, USFWS, Maui Nui Botanical Garden Amber Starr, Hana Ranch Kahana Stone, NRCS Mark Vaught, Water Resources, Alexander & Baldwin Jacqueline Vega, NRCS Rich von Wellsheim, Whispering Bamboos, Kipahulu

Rangeland health reference sheet

Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.

Author(s)/participant(s)
Contact for lead author
Date	09/15/2026
Approved by
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
Presence of water flow patterns:
Number and height of erosional pedestals or terracettes:
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Number of gullies and erosion associated with gullies:
Extent of wind scoured, blowouts and/or depositional areas:
Amount of litter movement (describe size and distance expected to travel):
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):

Dominant:

Sub-dominant:

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Perennial plant reproductive capability:

Download reference sheet

Natural ResourcesConservation Service

Ecological site VX158X01X005

Naturalized Grassland 50 to 90 inch PZ Ohia lehua/kikuyugrass (Metrosideros polymorpha/Pennisetum clandestinum)

Last updated: 4/17/2025 Accessed: 09/15/2026

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General information

MLRA notes

Classification relationships

Ecological site concept

Associated sites

Similar sites

Table 1. Dominant plant species

Legacy ID

Natural Resources
Conservation Service

Naturalized Grassland 50 to 90 inch PZ
Ohia lehua/kikuyugrass
(Metrosideros polymorpha/Pennisetum clandestinum)

Last updated: 4/17/2025
Accessed: 09/15/2026