User:Paleorthid/Sandbox/Article Nursery/steppe ecoregions articles



Snake-Columbia shrub steppe

https://www.worldwildlife.org/publications/terrestrial-ecoregions-of-the-world Olson, D. M., Dinerstein, E., Wikramanayake, E. D., Burgess, N. D., Powell, G. V. N., Underwood, E. C., D'Amico, J. A., Itoua, I., Strand, H. E., Morrison, J. C., Loucks, C. J., Allnutt, T. F., Ricketts, T. H., Kura, Y., Lamoreux, J. F., Wettengel, W. W., Hedao, P., Kassem, K. R. 2001. Terrestrial ecoregions of the world: a new map of life on Earth. Bioscience 51(11):933-938.

The Snake-Columbia shrub steppe is an arid ecoregion covering 84,200 square miles. This ecoregion takes in the Snake River Plain from the continental divide down to Hell's Canyon and then southwest to cover Deschutes River basin. From there it extends north into the western portion of the Columbia Basin in Washington.It also includes parts of northern Nevada and the extreme northeast of California. Due to the rain shadow of the Cascade Mountains this ecoregion receives little precipitation.

https://www.worldwildlife.org/ecoregions/na1309 S. Primm

Colorado Plateau shrublands: Listed as among the Shrub-steppe ecoregions of North America in shrub-steppe

https://www.worldwildlife.org/ecoregions/na1304 Colorado Plateau shrublands

Colorado Plateau

Great Basin shrub steppe https://www.worldwildlife.org/ecoregions/na1305

Fire was a major force in shaping the Palouse. For thousands of years, Native Americans set periodic, cool-burning fires that did not damage perennial grasses. Without frequent burning to reduce fuel levels, conditions were ideal for rare but intense fires that destroyed the native perennial species and allowed exotic grasses and annual forbs to invade. Excessive grazing also resulted in the demise of many of the perennial grasses

Fire was a major force in shaping the Palouse ecoregion. For thousands of years, Indigenous peoples set periodic, cool-burning fires that did not damage perennial grasses. Without frequent burning to reduce fuel levels, conditions were ideal for rare but intense fires that destroyed the native perennial species and allowed exotic grasses and annual forbs to invade. Excessive grazing also resulted in the demise of many of the perennial grasses

SIMS, P. L., 1988. Grasslands. In: North American terrestrial vegetation: 266–286 (M. G. Barbour & W. D. Billings, Eds.). Cambridge University Press, New York.

Section 331A--Palouse Prairie

Geomorphology. This Section comprises moderately to strongly dissected loess-covered basalt plains, hills with large steptoes, undulating plateaus, and some river breaklands. Mountains occur in the southeast part of the Section. This Section is within the Columbia Plateau physiographic province. Elevation ranges from 1,200 to 6,000 ft (366 to 1,830 m).

Lithology and Stratigraphy. There is Tertiary basalt with some Paleozoic granitic and metasedimentary outcrops in breaklands. Granitoid rocks of the Blue Mountain uplift are evident, as well as sedimentary rocks which occur at the boundaries of the flood basalt deposits.

Soil Taxa. Soils include mesic Xerolls with some Xeralfs, Albolls, and Aquolls. These soils are generally deep, loamy to silty, and have formed in loess, alluvium, or glacial outwash. Soils in mountainous areas are shallower and contain rock fragments.

Potential Natural Vegetation. Grasslands and meadow-steppe vegetation dominated by grasses are the prototypical vegetation of the Palouse. Woodlands and forests occur in the eastern portion of the Section on hills and low mountains. The relatively arid western portion of the Section is dominated by grassland, where bluebunch wheatgrass and Idaho fescue are the most prominent. Meadow-steppe vegetation characterized by Idaho fescue and common snowberry dominates areas with more precipitation, but still too dry to support forest vegetation on deep loamy soils. Most of this meadow-steppe as well as the grassland to the west, has been converted to crop lands. Ponderosa pine woodlands and forests form the lower timberline in the eastern portion of the Section on hills and low mountains. The transition zone between forest and meadow-steppe consists of a complex interfingering between these two vegetation types. Douglas-fir series forests dominate at higher elevations in the mountains. Isolated fragments of the Western Red Cedar series and Grand Fir series occur on sheltered north slopes in the mountains.

Fauna. Birds are typical of grasslands with intermittent riparian systems and pine hills. Grassland species include American kestrel, ring-necked pheasant, upland sandpiper, western kingbird, horned lark, black-billed magpie, western meadowlark, and savanna sparrow. Riparian system species include Lewis' woodpecker, gray catbird, western bluebird, orange-crowned warbler, northern oriole, black-headed grosbeak, and lazuli bunting. Birds which reach or nearly reach the extent of their range include mountain quail, barn owl, white-headed woodpecker, eastern kingbird, and American redstart. The bald eagle, an endangered species, also occurs around larger water bodies. Typical herbivores and carnivores include white-tail deer, mule deer, and bobcat. Smaller common herbivores include the blacktail jackrabbit and Washington ground squirrel. Rare species include the whitetail jackrabbit, and possibly the pygmy rabbit. Herpetofauna typical of this Section are the bullfrog, painted turtle, western fence lizard, and the northern Pacific rattlesnake.

Climate. Precipitation ranges from 10 to 30 in (250 to 760 mm), evenly distributed throughout fall, winter, and spring. Winter precipitation is mostly snow; summers are relatively dry. Climate is warm temperate with a maritime influence. Temperature averages 45 to 54 oF (7 to 12 oC). The growing season lasts 100 to 170 days.

Surface Water Characteristics. There are scattered coulees and deeply-incised major drainages. Loess plains have low to medium density dendritic drainage patterns. Rapid changes in runoff volumes are possible on basalt due to gain or loss of water to gravel interbeds. The Snake River flows through this Section.

Disturbance Regimes. Wind is the principal source of natural disturbance.

Land Use. Dry farming and livestock grazing occurs on about 90 percent of the area.

in Great Plains-Palouse Dry Steppe https://www.fs.fed.us/land/pubs/ecoregions/ch41.html

Research has established a positive effect of fire on CO2 flux in tallgrass prairie. Burning increases leaf area during the active growth period and stimulates photosynthesis, resulting in higher carbon uptake of burned relative to unburned plants.

Svejcar, T.J., Browning, J.A., 1988. Growth and gas exchange of Andropogon gerardii as influenced by burning. J. Range Manage. 41, 239–244 "In general, mass of tallgrass prairie vegetation increases with burning (Hadley and Kiekhefer 1963, Peet et. al. 1975, Knapp 1984, Town and Owensby 1984) although the magnitude of the increase is affected by timing of burn, climatic conditions, prior site history, community composition, etc. Our results [an Oklahoma tallgrass prairie] shows peak mass of big bluestem is increased almost 3-fold by burning."

Temperate grasslands can be further subdivided. Prairies are grasslands with tall grasses while steppes are grasslands with short grasses. Prairie and steppes are somewhat similar but the information given above pertains specifically to prairies — the following is a specific description of steppes.

Steppes are dry areas of grassland with hot summers and cold winters. They receive 25.4-50.8 cm (10-20 inches) of rainfall a year. Extensive steppes occur in the interiors of North America and Eurasia. Plants growing in steppes are usually greater than 1 foot tall. They include blue grama and buffalo grass, cacti, sagebrush, speargrass, and small relatives of the sunflower. Steppe fauna includes badgers, hawks, owls, and snakes. Today, people use steppes to graze livestock and to grow wheat and other crops. Overgrazing, plowing, and excess salts left behind by irrigation waters have harmed some steppes. Strong winds blow loose soil from the ground after plowing, especially during droughts. This causes the dust storms of the Great Plains of the U.S.

Grasslands. University of California Museum of Paleontology

http://www.ucmp.berkeley.edu/exhibits/biomes/grasslands.php

Rangeland burning Fire is another useful tool in managing Great Plains grassland (Wright, 1974, 1978; Wright and Bailey, 1982). Vallentine (1989) lists 18 separate objectives in rangeland burning but suggests that there are three main reasons to burn: 1. To kill or suppress undesirable brush plants (Plate 6.19). 2. To prevent invasion of inferior species in the understorey. 3. To increase forage production and thus grazing capacity. Especially in tall-grass prairie, prescribed burning is often used to reduce old growth and stimulate new, more palatable growth (Anderson, Smith and Owensby, 1970; McMurphy and Anderson, 1965; Smith and Owensby, 1972).

Wright (1978) suggested that burning in tall-grass vegetation increased palatability, suppressed encroachment of trees and shrubs and reduced competition from cool-season plants. However, timing of the burning is very important. Cool-season grasses are detrimentally affected by spring burning (Hensel, 1923; Wright, 1978). Spring burning tends to increase summer gains of cattle, but gains may not hold up into the autumn (Anderson, Smith and Owensby, 1970; Vallentine, 1989).

Late winter burning may initiate spring growth two to three weeks earlier than in the absence of burning (Ehrenreich and Aikman, 1963).

Chapter 6 Grasslands of central North America in Grasslands of the world

Rex D. Pieper Grasslands of North America http://www.fao.org/tempref/docrep/fao/008/y8344e/y8344e06.pdf file:///Users/philipsmall/Pictures/Grasslands-y8344e06.pdf

northern plains steppe
Northern short grasslands In pre-settlement times, drought, fire, and grazing were probably the major disturbance factors, with fire playing less of a role than in other grassland ecoregions. https://www.worldwildlife.org/ecoregions/na0811

332 Great Plains Steppe Province equivalent to mixed grass prairie https://www.fs.fed.us/land/ecosysmgmt/colorimagemap/images/332.html