Print Report
G410 Waltheria indica / Heteropogon contortus Lowland Dry Shrubland & Grassland Group
Type Concept Sentence: This Hawaiian lowland dry grassland and shrubland group is characterized by either a grass layer typically dominated by Heteropogon contortus, or an open to closed short (<2-m tall) shrub layer. The shrub layer is dominated by Artemisia australis, Psydrax odorata, Dodonaea viscosa, Bidens spp., Sesbania tomentosa, Waltheria indica, or Wikstroemia spp.
Common (Translated Scientific) Name: Uhaloa / Pili Lowland Dry Shrubland & Grassland Group
Colloquial Name: Hawaiian Lowland Dry Shrubland & Grassland
Hierarchy Level: Group
Type Concept: This lowland dry grassland and shrubland group is characterized by either a grass layer typically dominated by Heteropogon contortus, or an open to closed short (<2-m tall) shrub layer. The shrub layer is dominated by Artemisia australis, Psydrax odorata, Dodonaea viscosa, Bidens spp., Sesbania tomentosa, Waltheria indica, or Wikstroemia spp. The grasslands may include other native grasses such as Eragrostis variabilis, Fimbristylis spp., Lepturus repens, or Sporobolus virginicus which are more common near coasts where these stands grade into coastal strand. Scattered shrubs such as Dodonaea viscosa, Sida fallax, and Waltheria indica are often present and become more abundant with absence of fire. The grasslands were once fairly widespread and were maintained and expanded by regular burning by ancient Hawaiians. The shrublands often have other native shrubs present such as Argemone glauca, Canavalia spp., Chamaesyce spp., Cassytha filiformis, Ipomoea spp., Lipochaeta spp., Nototrichium spp., Osteomeles anthyllidifolia, Peperomia tetraphylla, Peperomia blanda var. floribunda, Santalum ellipticum, Senna gaudichaudii, Sicyos spp., Myoporum sandwicense, Sida fallax, and Styphelia tameiameiae. Indicators species of this group include Abutilon spp., Achyranthes spp., Capparis sandwichiana, Gossypium spp., Heteropogon contortus, Hibiscus brackenridgei, Plectranthus parviflorus, Portulaca spp., and Waltheria spp. Dry species may include ferns Doryopteris and Pellaea and grasses Panicum spp. Exotic species such as Pennisetum setaceum are often present in disturbed stands, but do not dominate. The density and height of shrubs may be reduced by recent fire or increased with increased moisture, for example when near riparian areas. Lowland dry shrublands are relatively intolerant to grazing pressure and fire and are replaced by alien-dominated communities when subjected to these disturbances. Many dry grasslands have been replaced by exotic grass species or converted to exotic shrublands. This group was widespread historically and occurred on leeward sides of all the main islands and on many of the smaller dry islands, although the shrublands are not reported from Ni`ihau and Kaho`olawe. It is less common now and remaining stands are mostly disturbed by invasive species or altered fire regime. Elevation ranges up to 1000 m and grades into dry strand along the coasts. High-elevation stands transition to montane shrublands near 1000 m elevation. These shrublands occur on open gentle slopes to steep ridges of dissected slopes. Climate is tropical with summers hot and dry. Annual precipitation is mostly restricted to the winter months, and ranges from 500 to 1750 mm for shrublands and most grasslands, but grasslands also occur in drier areas (down to 100 mm annual precipitation). Substrates are variable. Soils range from silty loams to relatively unweathered pâhoehoe lava. This group also includes coastal dry grasslands that occur beyond the immediate coastal effects of the sea with wind, salt spray and salinity.
Diagnostic Characteristics: This dry grassland and shrubland group is characterized by either a grass layer typically dominated by Heteropogon contortus, or an open to closed short (<2-m tall) shrub layer dominated by Artemisia australis, Psydrax odorata, Dodonaea viscosa, Bidens spp., Sesbania tomentosa, Waltheria indica, or Wikstroemia spp.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This lowland dry shrubland and grassland group grades into dry coastal strand near the leeward coasts. Coastal dry shrublands and grasslands that are affected by immediate sea coast processes (salt spray and salinity) are classified in ~Hawaiian Scrub & Herb Coastal Strand Group (G421)$$. Over 90% of this group has been lost to development or displacement by non-native vegetation. There are few stands in good condition remaining to base this classification (S. Gon pers. comm.).
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This grassland and shrubland group is characterized by either a perennial grass layer <2 m tall or an open to closed short (<2-m tall) shrub layer.
Floristics: This lowland dry grassland and shrubland group is characterized by either a grass layer typically dominated by Heteropogon contortus, or an open to closed short (<2-m tall) shrub layer. The shrub layer is dominated by Artemisia australis, Psydrax odorata (= Canthium odoratum), Dodonaea viscosa, Bidens spp., Sesbania tomentosa, Waltheria indica, or Wikstroemia spp. The grasslands were once fairly widespread and were maintained and expanded by regular burning by ancient Hawaiians. Other native dry lowland grasses include Eragrostis variabilis, Fimbristylis spp., Lepturus repens, or Sporobolus virginicus which are more common near coasts where these stands grade into coastal strand. Scattered shrubs such as Dodonaea viscosa, Sida fallax, and Waltheria indica are often present and become more abundant with absence of fire. The shrublands often have other native shrubs present such as Argemone glauca, Canavalia spp., Chamaesyce spp., Cassytha filiformis, Ipomoea spp., Lipochaeta spp., Nototrichium spp., Osteomeles anthyllidifolia, Peperomia tetraphylla, Peperomia blanda var. floribunda (= Peperomia leptostachya), Santalum ellipticum, Senna gaudichaudii, Sicyos spp., Myoporum sandwicense, Sida fallax, and Styphelia tameiameiae. Indicators species of this group include Abutilon spp., Achyranthes spp., Capparis sandwichiana, Gossypium spp., Heteropogon contortus, Hibiscus brackenridgei, Plectranthus parviflorus (= Plectranthus australis), Portulaca spp., and Waltheria spp. Dry species may include ferns Doryopteris and Pellaea; and grasses Panicum spp. Exotic species such as Pennisetum setaceum are often present in disturbed stands, but do not dominate.
Dynamics: Heteropogon contortus is a fire-adapted grass. Ecologically stable Heteropogon contortus-dominated stands may occur on dry lowland cliffs where woody plants cannot form dense canopies (Gagne and Cuddihy 1990). The density and height of shrubs may be reduced by recent fire or increased with increased moisture, for example when near riparian areas. Lowland dry shrublands are relatively intolerant to grazing pressure and fire and are replaced by alien-dominated communities when subject to these disturbances. Severe drought can favor grasses. Burning by early Hawaiians to encourage Heteropogon contortus may have suppressed shrubs in favor of grasses.
Environmental Description: This group historically occurred on the leeward side of all the main islands and some of the smaller dry islands, although the shrublands are not reported from Ni`ihau and Kaho`olawe. Elevation ranges up to 1000 m and grades into dry strand along the coasts. High-elevation stands transition to montane shrublands near 1000 m elevation. These shrublands occur on open gentle slopes to steep ridges of dissected slopes.
Climate: Climate is tropical with summers hot and dry. Annual precipitation is mostly restricted to the winter months, and ranges from 500 to 1750 mm for shrublands and most grasslands, but grasslands also occur in drier areas (down to 100 mm annual precipitation).
Soil/substrate/hydrology: Substrates are variable. Soils range from silty loams to relatively unweathered pâhoehoe lava. This group also includes coastal dry grasslands that occur beyond the immediate coastal effects of the sea with wind, salt spray and salinity.
Climate: Climate is tropical with summers hot and dry. Annual precipitation is mostly restricted to the winter months, and ranges from 500 to 1750 mm for shrublands and most grasslands, but grasslands also occur in drier areas (down to 100 mm annual precipitation).
Soil/substrate/hydrology: Substrates are variable. Soils range from silty loams to relatively unweathered pâhoehoe lava. This group also includes coastal dry grasslands that occur beyond the immediate coastal effects of the sea with wind, salt spray and salinity.
Geographic Range: This lowland dry grassland and shrubland group is less common now but was widespread and occurred on leeward sides of all the main Hawaiin Islands and on many of the smaller dry islands, although the shrublands are not reported from Ni`ihau and Kaho`olawe.
Nations: US
States/Provinces: HI
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.860875
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.A Tropical Grassland, Savanna & Shrubland Subclass | S01 | 2.A |
| Formation | 2.A.1 Tropical Lowland Grassland, Savanna & Shrubland Formation | F019 | 2.A.1 |
| Division | 2.A.1.Ol Polynesian Lowland Shrubland, Grassland & Savanna Division | D074 | 2.A.1.Ol |
| Macrogroup | 2.A.1.Ol.1 Hawaiian Lowland Shrubland, Grassland & Savanna Macrogroup | M217 | 2.A.1.Ol.1 |
| Group | 2.A.1.Ol.1.a Uhaloa / Pili Lowland Dry Shrubland & Grassland Group | G410 | 2.A.1.Ol.1.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: >< Lowland Dry Grassland (Gagne and Cuddihy 1990)
> Lowland Dry Shrubland (Gagne and Cuddihy 1990)
> Pili (Heteropogon) Grassland (Gagne and Cuddihy 1990)
> Lowland Dry Shrubland (Gagne and Cuddihy 1990)
> Pili (Heteropogon) Grassland (Gagne and Cuddihy 1990)
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Gagne, W. C., and L. W. Cuddihy. 1990. Vegetation. Pages 45-114 in: W. L. Wagner, D. R. Herbst, and S. H. Sohmer, editors. Manual of the Flowering Plants of Hawaii. 2 volumes. University of Hawaii Press, Honolulu.
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