Ecological Sites on Rangeland Ecological Sites on Rangeland

Ecological Sites on Rangeland

Ecological Sites on Rangeland http: //www. youtube. com/watch? v=76 pf. B 5 e A 0 po&list=PL 7 CD 3 CD 7 A 9350 A 858

Ecological Site definition: o Ecological site = kind of land with: n n n o o specific physical characteristics (soil, topography, climate) which differs from other kinds of land in its ability to produce distinctive kinds and amounts of vegetation In other words, a kind of land with similar natural potential. Other stratification systems can be an have been used to described rangelands.

(Example 1) Ecological sites vary in kind amount of vegetation

(Example 2)

(Example 3)

(Example 4)

Ecological Sites – Based on Soil o o o Soil affects the type of plants that grow on the land. Therefore, soil maps usually form the basis for maps of ecological sites. Ecological Site Descriptions – can be found by starting with soil maps in the Web Soil Survey

Ecological Site Descriptions o Ecological Site Descriptions (ESD) are reports that describe the: n Biophysical properties of ecological sites n Physical, Climatic, Soil and Vegetation and surface soil properties of reference conditions o o n a) Pre-European vegetation and historical range of variation (in the United States) b) Proper functioning condition or potential natural vegetation Ecosystem services provided by the ecological site and other interpretations

Important Concepts In Dividing the Landscape Spatial scale – what is a site? Temporal scale- how does change occur?

Regions with similar climate, land use Geographic areas with similar soils Similar landscape patterns Groups of Ecological Sites that share landscapes Intermingled ecological sites or single site Individual representative of the site An observation of plant-soil relationships

LAND RESOURCE REGIONS

Gravelly soil (shallow, relict piedmont) Limestone Surface soil water limited, high risk for grass loss and erosion: vulnerable/restorable Sandy soil (relict basin floor) Grass protected by rocks, higher rainfall, good water capture: low risk m) Erodible surface soils once grasses removed: vulnerable/hard to restore asi B a nad 5 k n (1 r l Soi ts o ni gu in pp ma e Jo h t f Loamy soil (active piedmont) Susceptible to water erosion and grass loss: vulnerable/restorable Clayey soil (basin floor) Receives water and sediment: low risk From Bestelmeyer et al 2010

Within LRUs are clusters of sites with similar parent material, but differing in landscape position Each site has a typical soil profile

A soil map unit can contain more than one ecological site because map units may contain components Map unit/components Ecological site ST: Stellar association 40% Stellar clay loam, 0 -3% slopes = Clayey 40% Stellar clay loam, 0 -3% slopes, flooded = Bottomland 20% other inclusions BK: Berino-Dona Ana association 50% Berino fine sandy loam, 1 -5 % slopes = Sandy 30% Dona Ana fine sandy loam, 1 -5% slopes = Sandy 20% other inclusions OP: Onite-Pajarito association 40% Onite loamy sand, 1 -4% slopes 30% Pajarito fine sandy loam, 0 -5% slopes 15% Pintura fine sand, 0 -5% slopes 15% other inclusions = Sandy = Deep sandy An ecological site groups several similar soil map unit components

Applications of Ecological Sites and Ecological Site Descriptions The utility of Ecological Sites is based on the ability to systematically stratify the landscape according to varying ecological potential

Land Use and Land Management Changes Can Alter Ecosystem Services Regardless of Land Use GEOMORPHOLOGY LANDSCAPE POSITION SOIL PROPERTIES HISTORICAL AND CURRENT MANAGEMENT PRIOR ECOSYSTEM SERVICES CLIMATE PROVISIONING food, fibre ECOLOGICAL STATE SUPPORTING water cycling, nutrient cycling, primary production CULTURAL educational, recreation, heritage REGULATING climate, waste control, pollination FUTURE ECOSYSTEM SERVICES ECOLOGICAL SITE From Brown and Mac. Leod 2011

Land cover/use classifications are increasingly useless in making policy decisions • people change land use frequently • ecological processes are much more complex and variable than a land use category • resistance and resilience are vital to predicting ecosystem behavior • landscape scale models require ecological process information to allow sites to interact

Some terminology: o o Map Units Lime Alluvium Loess

Web Soil Survey o http: //www. youtube. com/watch? v=Eh 96 z ARD-Io