Ecological Siteson Rangeland

Ecological Siteson Rangeland

http://www.youtube.com/watch?v=76pfB5eA0po&list=PL7CD3CD7A9350A858

Ecological Site definition: Ecological site = kind of land with:

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.

Ecological sites vary in kind and amount of vegetation

(Example 1)

(Example 2)

(Example 3)

(Example 4)

Ecological Sites – Based on Soil 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 Ecological Site Descriptions (ESD)

are reports that describe the: Biophysical properties of ecological sites

Physical, Climatic, Soil and Vegetation Vegetation and surface soil properties of reference

conditions 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 ConceptsIn Dividing the Landscape

Spatial scale – what is a site?

Temporal scale- how does change occur?

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

Regions with similar climate, land use

LAND RESOURCE REGIONS

Loamy soil (active piedmont)Susceptible to water erosion andgrass loss: vulnerable/restorable

Clayey soil (basin floor)Receives water and sediment: low risk

Limestone Grass protected byrocks, higher rainfall,good water capture: low risk

Soil mapping units of the Jornada Basin (15 km)

Gravelly soil (shallow, relict piedmont)Surface soil water limited, high risk for grass loss and erosion: vulnerable/restorable

Sandy soil (relict basin floor)Erodible surface soils once grasses removed: vulnerable/hard to restore

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

An ecological site groups severalsimilar soil map unit components

Map unit/components Ecological siteST: Stellar association 40% Stellar clay loam, 0-3% slopes = Clayey40% Stellar clay loam, 0-3% slopes, flooded = Bottomland20% other inclusions

BK: Berino-Dona Ana association50% Berino fine sandy loam, 1-5 % slopes = Sandy30% Dona Ana fine sandy loam, 1-5% slopes = Sandy20% other inclusions

OP: Onite-Pajarito association40% Onite loamy sand, 1-4% slopes = Sandy30% Pajarito fine sandy loam, 0-5% slopes = Sandy15% Pintura fine sand, 0-5% slopes = Deep sandy15% other inclusions

A soil map unit can contain more than one ecological site because map units may contain components

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

Applications of Ecological Sites and Ecological Site Descriptions

ECOLOGICAL STATE

ECOLOGICAL SITE

CLIMATE

SOIL PROPERTIES

LANDSCAPE POSITION

GEOMORPHOLOGY

ECOSYSTEM SERVICES

PROVISIONINGfood, fibre

SUPPORTINGwater cycling, nutrient cycling, primary production

CULTURALeducational, recreation, heritage

REGULATINGclimate, waste control, pollinationH

ISTO

RICA

L AN

D C

URR

ENT

MAN

AGEM

ENT

PRIO

R EC

OSY

STEM

SER

VICE

S

FUTU

RE E

COSY

STEM

SER

VICE

S

From Brown and MacLeod 2011

Land Use and Land Management Changes Can Alter Ecosystem Services Regardless of Land Use

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: Map Units Lime Alluvium Loess

Web Soil Survey http://www.youtube.com/watch?v=E

h96zARD-Io