Ecological site VX163X01X003

4. Shrub Invaded Grassland State

3. Native Forest State

States 1, 5 and 2 (additional transitions)

1.1. White Leadtree (Koa Haole)/Guineagrass

R1A	-	It is possible to restore the Reference State (1) to a plant community resembling the Native Forest State (3). Weed control must be applied to forage species and the many opportunistic plant species that would invade the site. Weed control would be a perpetual process to maintain the site. Fire must be excluded. Domestic and feral ungulates must be excluded by a suitably designed and maintained fence. Extensive planting of native species would follow.
T1A	-	The Reference State (1) transitions to the Shrub Invaded Grassland State (4) through further overgrazing or abandonment. Fire will temporarily prevent this transition. White leadtree (koa haole) will be greatly reduced by over browsing. If the site contained abundant koa haole and was then abandoned, these small trees overtop guineagrass and greatly increase in abundance. Otherwise, there is gradual invasion by weedy shrubs and small trees.
T2A	-	The Invaded Understory State (2) transitions to the Reference State (1) by land clearing with heavy machinery followed by weed control. Land clearing can promote germination of the weed seed bank in the soil, requiring intensive weed control. After clearing and weed control, the site would be planted to forage species.
R2A	-	The Invaded Understory State (2) may be restored to the Native Forest State (3), or to a facsimile of the Reference State, by removal of the introduced understory through weed control. Reintroduction of native understory species is required. The site must be fenced securely to exclude ungulates.
T2B	-	The Invaded Understory State (2) transitions the Exotic Tree Invaded State (5) by growth of introduced tree species through and above the native canopy. Lack of reproduction leads to gradual loss of most native plants.
T3B	-	The Native Forest State (3) transitions to the Reference State (1) by clearing the forest and planting desirable forage species.
T3A	-	The Native Forest State (3) transitions to the Invaded Understory State (2) through grazing, browsing, rooting, and trampling by domestic or feral ungulates (cows, sheep, deer, goats, and pigs). These activities destroy small native plant species and seedlings and saplings of large species. Regeneration of the native forest is prevented, leading to tree populations consisting almost entirely of mature plants. Lack of competition from native plants, introduction of weed seeds, and disturbance of the soil lead to an understory dominated by introduced plant species. Weeds can invade intact native forest even in the absence of ungulates and gradually bring about the transition. Invasive vines, shrubs, and small trees will grow under intact native canopies and begin to degrade the forest. Eventually, introduced grasses provide fine fuels that can carry intense fires that destroy the native tree canopy.
R4A	-	The Shrub-Invaded Grassland State (4) can be restored to the Reference State (1) by brush management with follow-up control of resprouting shrubs and emerging weedy forbs. Forage species may then be replanted and maintained by prescribed grazing.
T4A	-	The Shrub-Invaded Grassland State (4) transitions to the Exotic Tree Invaded State (5) with lack of fire. Fast-growing introduced tree species invade Shrub Invaded Grassland and overtop shrubs, or Brazilian peppertree (christmasberry) increases in stature and density to become dominant.
R5B	-	The Exotic Tree-Invaded State (5) may be restored to the Reference State (1). Total clearing of the site would be necessary. If clearing is done by heavy machinery, soil disturbance would occur. This would probably induce germination of the weed seed bank and increase the potential for soil erosion. Weed control and brush management must then be applied multiple times to control new weed germination and resprouting. After clearing and weed control, the site would be planted to forage species. Ungulates must be excluded until forages are well established; prescribed grazing must then be applied.
R5A	-	It may be possible to restore the Exotic Tree-Invaded State (5) to a community resembling the Native Fores State (3). Total clearing of the site would be necessary. Alternatively, it may be worthwhile to kill taller weed species in place by herbicide applications in order to provide some shelter for the ground. If clearing is done by heavy machinery, soil disturbance would occur. This could induce germination of the weed seed bank and also increase the potential for soil erosion. Weed control would be ongoing. Protection from fire is needed, and ungulates must be excluded by a suitable fence.

State 1 submodel, plant communities

1.2. Guineagrass – Windmill Grass (Annual Fingergrass) Species

1.1A	-	Community phase 1.1 converts to phase 1.2 by continuous grazing without adequate rest for preferred forages. This conversion can be avoided by timely application of deferred or prescribed grazing to control guineagrass stature and allow recovery of desirable species after grazing or browsing.
1.2A	-	Community phase 1.2 can be converted to phase 1.1 by removing undesirable species and favoring and establishing desirable pasture species. Because guineagrass is still fairly abundant, prescribed grazing may eventually affect the conversion. Pitted beardgrass (Bothriochloa pertusa) and rose Natal grass (Melinis repens) have some value as forage. However, annual fingergrasses, barbwire grass, Colombian bluestem, broomsedge bluestem are unpalatable to livestock and difficult to control by grazing. If pasture condition is very poor, active weed control measures followed by reestablishment of guineagrass will be necessary.

State 1
Reference State

The Reference State (1) consists of two community phases. It is naturalized grassland with introduced grasses, forbs, and trees. Scattered large trees are sometimes present.

Community 1.1
White Leadtree (Koa Haole)/Guineagrass

Figure 2. Reference State (1). Phase 1.1. White leadtree (koa haole)/guineagrass. Iao clay, 3 to 7 percent. Elevation ~ 50 feet. Precipitation Zone ~ 30 inches. Taken in Waihee, Hawaii on the island of Maui. John Proctor. 11/14/23.

This community phase consists of introduced grasslands dominated by guineagrass (Urochloa maxima). Preferred forage species are guineagrass, the leguminous vine perennial soybean or glycine (Neonotonia wightii), and white leadtree or koa haole, a small leguminous tree. Brazilian peppertree or christmasberry (Schinus terebinthifolius) is present but not abundant. With continuous heavy grazing, particularly by cattle, preferred forage grasses decrease, as will preferred small trees, vines, and shrubs. Less preferred grass, forb, and shrub species increase under such circumstances. With severe deterioration, shrubby species can increase to eventually dominate.

Dominant plant species

white leadtree (Leucaena leucocephala), tree
guineagrass (Urochloa maxima), grass

Community 1.2
Guineagrass – Windmill Grass (Annual Fingergrass) Species

Shrub-sized Brazilian peppertree or christmasberry (Schinus terebinthifolius) has become more abundant. Guineagrass is still the most abundant grass species but is less dominant. Primary increaser grass species that increase under heavy grazing include rose Natal grass or Natal redtop (Melinis repens), barbwire grass (Cymbopogon refractus), feather fingergrass (Chloris virgata), Indian goosegrass or wiregrass (Eleusine indica), rat-tail grass (Sporobolus indicus var. capensis), crabgrass (Digitaria spp.), Bermudagrass (Cynodon dactylon), Colombian bluestem (Schizachyrium condensatum), and broomsedge bluestem (Andropogon virginicus). Unpalatable increaser forbs include sensitive partridge pea (Chamaecrista nictitans), shameplant or sensitive plant (Mimosa pudica), smooth rattlebox or rattlepod (Crotalaria pallida), lilac tasselflower or red pualele (Emilia sonchifolia), and spiny amaranth (Amaranthus spinosus). Shrubby species include lantana (Lantana camara), American black nightshade or apple of Sodom (Solanum americanum), threelobe false mallow (Malvastrum coromandelianum), Sacramento burbark (Triumfetta semitriloba), balloon plant (Asclepias physocarpa), hairy Indian mallow (Abutilon grandifolium), and castorbean (Ricinus communis).

Dominant plant species

guineagrass (Urochloa maxima), grass
windmill grass (Chloris), grass

Pathway 1.1A
Community 1.1 to 1.2

Community phase 1.1 converts to phase 1.2 by continuous grazing without adequate rest for preferred forages. This conversion can be avoided by timely application of deferred or prescribed grazing to control guineagrass stature and allow recovery of desirable species after grazing or browsing.

Pathway 1.2A
Community 1.2 to 1.1

Community phase 1.2 can be converted to phase 1.1 by removing undesirable species and favoring and establishing desirable pasture species. Because guineagrass is still fairly abundant, prescribed grazing may eventually affect the conversion. Pitted beardgrass (Bothriochloa pertusa) and rose Natal grass (Melinis repens) have some value as forage. However, annual fingergrasses, barbwire grass, Colombian bluestem, broomsedge bluestem are unpalatable to livestock and difficult to control by grazing. If pasture condition is very poor, active weed control measures followed by reestablishment of guineagrass will be necessary.

State 2
Invaded Understory State

The Invaded Understory State (2) consists of one community phase having an open or closed canopy of common native trees with an understory of introduced grasses, ferns, vines, small trees, and shrubs. Foraging by feral or domestic ungulates removes native understory plants and prevents regeneration of overstory species, resulting in a mature and diminishing canopy of native trees. This may occur more gradually by weed invasion into intact native forest. The understory of this plant community contains fine fuels, particularly guineagrass, that are susceptible to intense fires.

Community 2.1
Lama – ‘Ohi’a Lehua/Pukiawe/Guineagrass

Native tree species dominate the overstory. The understory consists of a variable array of introduced plant species along with remnant native species. The overstory is dominated by lama, 'ohi'a lehua, and other typical native dry forest species such as wili wili (Erythrina sandwicensis) and 'ohe makai (Reynoldsia sandwicensis) at lower elevations and cheesewood or hoawa (Pittosporum spp.) and Hawai’i olive or olopua (Nestegis sandwicensis) at higher elevations (Rock, 1913; Wagner et al., 1999). Among native shrubs, Florida hopbush or aalii (Dodonaea viscosa) and pukiawe (Styphelia tameiameiae) may still be present. The introduced shrub lantana (Lantana camara) can be very abundant. The introduced vine corkystem passionflower or huehue haole (Passiflora suberosa) can become very abundant, covering the canopies of remnant, low-stature native understory plants. Guineagrass is abundant beneath the overstory canopy, which generally is not adequately dense to reduce its growth. Brazilian peppertree or christmasberry (Schinus terebinthifolius), an introduced small tree that produces a dense, shady canopy, may be abundant.

Dominant plant species

lama (Diospyros sandwicensis), tree
'ohi'a lehua (Metrosideros polymorpha), tree
guineagrass (Urochloa maxima), grass

State 3
Native Forest State

The Native Forest State (3) consists of one community phase. This description is historical, because very little native vegetation remains in this ecological site. The following description is based on literature and historical accounts of the islands before human influences disturbed these native plant communities as well as similar ecological sites. The general appearance of this ecological site is an open to nearly closed canopy up to 40 feet (12 meters) tall when dominated by lama (Diospyros sandwicensis) or to 70 feet (22 meters) when dominated by ohia lehua, an understory of shrubs and small trees, and a ground layer of vines, forbs, and grasses. The canopy becomes shorter and sparser where the forest grades into drier areas near the coast.

Community 3.1
Lama – ‘Ohi’a Lehua/Alahe’e

The tree canopy is dominated by lama (Diospyros sandwicensis) and ‘ohi’a lehua (Metrosideros polymorpha). Alahe’e (Psydrax odorata), a small tree or shrub, is the most abundant species in the understory. Common shrubs are Florida hopbush or aalii (Dodonaea viscosa), yellow ‘ilima (Sida fallax), Hawai’i hawthorn or ulei (Osteomeles anthyllidifolia), and false ohelo or akia (Wikstroemia spp.). Queen coralbead or huehue (Cocculus orbiculatus) is the most common vine. Native forbs, grasses, and ferns are present but not abundant (Rock, 1913; Wagner et al., 1999).

Dominant plant species

lama (Diospyros sandwicensis), tree
'ohi'a lehua (Metrosideros polymorpha), tree
alahe'e (Psydrax odorata), shrub

State 4
Shrub Invaded Grassland State

The Shrub Invaded Grassland State (4) consists of one community phase. It may have developed from abandoned grazing land, land cleared by wildfire, or abandoned farmland. Shrubs are dominant in canopy cover and stature. Typically, an array of introduced grass species is present. There is a moderate but increasing cover of small trees, some which potentially can grow to large stature. This tree cover creates the potential for a transition to the Exotic Tree Invaded State (5).

Community 4.1
Brazilian Peppertree (Christmasberry)/Lantana/Guineagrass – Windmill Grass (Annual Fingergrass) Species

This community is dominated by small trees, shrubs, and grasses. The most common introduced trees present are Brazilian peppertree or christmasberry (Schinus terebinthifolius) and, if it has not been eliminated by excessive browsing, white leadtree or koa haole (Leucaena leucocephala). Lantana (Lantana camara) is the most common shrub. If still heavily grazed, windmill grass or annual fingergrasses are most common; otherwise, guineagrass is dominant between shrubs and beneath koa haole.

Dominant plant species

Brazilian peppertree (Schinus terebinthifolius), tree
lantana (Lantana camara), shrub
guineagrass (Urochloa maxima), grass
windmill grass (Chloris), grass

State 5
Exotic Tree Invaded State

The Exotic Tree Invaded State (5) is comprised of one community phase dominated by introduced trees. Density and composition of understory shrubs, forbs, and grasses varies greatly with overstory closure and height, which affects the susceptibility of this plant community to fire. The density, vigor, and biomass of introduced vegetation can be very high, making restoration to other states expensive and difficult.

Community 5.1
Brazilian Peppertree (Christmasberry)/Lantana

In many cases, the overstory consists of very dense Brazilian peppertree or christmasberry that is 15 to 25 feet (4.5 to 7.6 meters) tall with very little understory. Introduced tree species such as silkoak (Grevillea robusta), Scotch attorney or autograph tree (Clusia rosea), Indian walnut or kukui (Aleurites moluccanus), and octopus tree (Schefflera actinophylla) that have greater height potentials than christmasberry may overtop the christmasberry canopy and eventually dominate the site. Remnant, mature ‘ohi’a lehua (Metrosideros polymorpha) trees may be present but are not able to regenerate. Native alahe’e (Psydrax odorata) trees sometimes can reproduce and maintain a sparse population in the understory. The overstory composition can be highly variable from site to site, but christmasberry is often the most abundant species. Christmasberry often dominates the understory (less than 13 feet or 4 meters tall) and can be so dense as to exclude most other species. Where more light is available, the small, introduced trees common guava (Psidium guajava) and white leadtree or koa haole (Leucaena leucocephala) are common. Lantana (Lantana camara) is the most common shrub.

Dominant plant species

Brazilian peppertree (Schinus terebinthifolius), tree
lantana (Lantana camara), shrub

Restoration pathway R1A
State 1 to 3

It is possible to restore the Reference State (1) to a plant community resembling the Native Forest State (3). Weed control must be applied to forage species and the many opportunistic plant species that would invade the site. Weed control would be a perpetual process to maintain the site. Fire must be excluded. Domestic and feral ungulates must be excluded by a suitably designed and maintained fence. Extensive planting of native species would follow.

Transition T1A
State 1 to 4

The Reference State (1) transitions to the Shrub Invaded Grassland State (4) through further overgrazing or abandonment. Fire will temporarily prevent this transition. White leadtree (koa haole) will be greatly reduced by over browsing. If the site contained abundant koa haole and was then abandoned, these small trees overtop guineagrass and greatly increase in abundance. Otherwise, there is gradual invasion by weedy shrubs and small trees.

Transition T2A
State 2 to 1

The Invaded Understory State (2) transitions to the Reference State (1) by land clearing with heavy machinery followed by weed control. Land clearing can promote germination of the weed seed bank in the soil, requiring intensive weed control. After clearing and weed control, the site would be planted to forage species.

Restoration pathway R2A
State 2 to 3

The Invaded Understory State (2) may be restored to the Native Forest State (3), or to a facsimile of the Reference State, by removal of the introduced understory through weed control. Reintroduction of native understory species is required. The site must be fenced securely to exclude ungulates.

Transition T2B
State 2 to 5

The Invaded Understory State (2) transitions the Exotic Tree Invaded State (5) by growth of introduced tree species through and above the native canopy. Lack of reproduction leads to gradual loss of most native plants.

Transition T3B
State 3 to 1

The Native Forest State (3) transitions to the Reference State (1) by clearing the forest and planting desirable forage species.

Transition T3A
State 3 to 2

The Native Forest State (3) transitions to the Invaded Understory State (2) through grazing, browsing, rooting, and trampling by domestic or feral ungulates (cows, sheep, deer, goats, and pigs). These activities destroy small native plant species and seedlings and saplings of large species. Regeneration of the native forest is prevented, leading to tree populations consisting almost entirely of mature plants. Lack of competition from native plants, introduction of weed seeds, and disturbance of the soil lead to an understory dominated by introduced plant species. Weeds can invade intact native forest even in the absence of ungulates and gradually bring about the transition. Invasive vines, shrubs, and small trees will grow under intact native canopies and begin to degrade the forest. Eventually, introduced grasses provide fine fuels that can carry intense fires that destroy the native tree canopy.

Restoration pathway R4A
State 4 to 1

The Shrub-Invaded Grassland State (4) can be restored to the Reference State (1) by brush management with follow-up control of resprouting shrubs and emerging weedy forbs. Forage species may then be replanted and maintained by prescribed grazing.

Transition T4A
State 4 to 5

The Shrub-Invaded Grassland State (4) transitions to the Exotic Tree Invaded State (5) with lack of fire. Fast-growing introduced tree species invade Shrub Invaded Grassland and overtop shrubs, or Brazilian peppertree (christmasberry) increases in stature and density to become dominant.

Restoration pathway R5B
State 5 to 1

The Exotic Tree-Invaded State (5) may be restored to the Reference State (1). Total clearing of the site would be necessary. If clearing is done by heavy machinery, soil disturbance would occur. This would probably induce germination of the weed seed bank and increase the potential for soil erosion. Weed control and brush management must then be applied multiple times to control new weed germination and resprouting. After clearing and weed control, the site would be planted to forage species. Ungulates must be excluded until forages are well established; prescribed grazing must then be applied.

Restoration pathway R5A
State 5 to 3

It may be possible to restore the Exotic Tree-Invaded State (5) to a community resembling the Native Fores State (3). Total clearing of the site would be necessary. Alternatively, it may be worthwhile to kill taller weed species in place by herbicide applications in order to provide some shelter for the ground. If clearing is done by heavy machinery, soil disturbance would occur. This could induce germination of the weed seed bank and also increase the potential for soil erosion. Weed control would be ongoing. Protection from fire is needed, and ungulates must be excluded by a suitable fence.

Additional community tables

Supporting information

Other references

REFERENCES for R163XY003HI East Aspect Isohyperthermic Naturalized Grassland

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BH Greenwell Ethnobotanical Garden, Kealakekua, Hawai‘i. Honolulu, HI: Bishop
Museum Press.

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Cuddihy, L.W. and C.P. Stone. (1990). Alteration of Native Hawaiian Vegetation: Effects of Humans, Their Activities and Introductions. University of Hawaii Cooperative National Park Resources Study Unit.

Department of Land and Natural Resources (2024). Hawaii State Aha Moku. [Hawaii State Aha Moku | Island Councils].

Giambelluca, T.W., Q. Chen, A.G. Frazier, J.P. Price, Y.-L. Chen, P.-S. Chu, J.K. Eischeid, and D.M. Delparte. (2013): Online Rainfall Atlas of Hawaii. Bull. Amer. Meteor. Soc. 94, 313-316, doi: [10.1175/BAMS-D-11-00228.1].

Giambelluca, T.W., X. Shuai, M.L. Barnes, R.J. Alliss, R.J. Longman, T. Miura, Q. Chen, A.G. Frazier, R.G. Mudd, L. Cuo, and A.D. Businger. (2014). Evapotranspiration of Hawaii. Final report submitted to the U.S. Army Corps of Engineers - Honolulu District, and the Commission on Water Resource Management, State of Hawaii.

Handy, E.S.C., E.G. Handy, and Pukui, M.K. (1972). Native Planters in Old Hawaii Their Life, Lore, and Environment. (Revised Edition, 1991). Bernice P. Bishop Museum Bulletin 233. Honolulu.

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

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

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

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

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[https://doi.org/10.3389/fsufs.2023.1116929].

Lincoln, N. K., and Vitousek, P. (2017). Indigenous Polynesian agriculture in Hawai‘i. In: Oxford Research Encyclopedia of Environmental Science.

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

Rock J.F. (1st edition 1913, reprinted 1974). The Indigenous Trees of the Hawaiian Islands. C. E. Tuttle Company, Rutland, V.T. and Tokyo, Japan.

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

Schroeder T.A. (1981). Characteristics of local winds in northwest Hawaii. Journal of Applied Meteorology 20: 874-881. Study of naulu winds in Kohala, Island of Hawaii.

U.S. Department of Agriculture, Natural Resources Conservation Service. (2006). Major Land Resource Regions. USDA Agriculture Handbook 296. [http://soils.usda.gov/MLRAExplorer].

U.S. Department of Agriculture, Soil Survey Conservation Service. (1972). Soil Survey of Islands of Kauai, Oahu, Maui, Molokai, and Lanai, State of Hawaii. Foote D.E., Hill E.L., Nakamura S., and F. Stephens, in cooperation with The University of Hawaii Agricultural Experiment Station.

U. S. Department of Interior, Fish and Wildlife Service. (2023). Download Seamless Wetlands Data by State. National Wetlands Inventory website. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C. Accessed April 24, 2024. [https://www.fws.gov/program/national-wetlands-inventory/download-state-wetlands-data].

U.S. Department of Interior, Geological Survey. (2006). A Gap analysis of Hawaii: February 2006 final report. National Gap Analysis Program. [https://catalog.lib.uchicago.edu/vufind/Record/6329681/Details].

U.S. Department of Interior, Geological Survey. (2019). National Hydrography Dataset (NHD) – USGS National Map Downloadable Data Collection: USGS – National Geospatial Technical Operations Center (NGTOC). [https://www.usgs.gov/national-hydrography/access-national-hydrography-products].

Wagner W.L., D.R. Herbst, and S.H. Sohmer. (1999). Manual of the Flowering Plants of Hawaii, Revised Edition. Bishop Museum Press, Honolulu.

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

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.

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.

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.

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.

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.

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

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.

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.

Residuum: Unconsolidated mineral material that has chemically and physically weathered from rock and has not moved from its place of origin.

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 1,500 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.

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.

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.

Contributors

David Clausnitzer PhD
John Proctor
Carolyn Wong
Amy Koch
Kendra Moseley
Ann Tan
Daniel Bowman
Jennifer Fedenko
Sarah Quitsberg

Approval

Kendra Moseley, 5/08/2025

Acknowledgments

Assistance, advice, review, and/or insights:

Randy Bartlett, Puu Kukui Watershed Preserve
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
Bob Hobdy, consultant, Maui
Wallace Jennings, NRCS
Mike Kolman, NRCS
Mathew Cocking, NRCS
Jennifer Higashino
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	05/09/2025
Approved by	Kendra Moseley
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

Click on box and path labels to scroll to the respective text.

Ecosystem states

4. Shrub Invaded Grassland State

3. Native Forest State

States 1, 5 and 2 (additional transitions)