Ecological Site Descriptions Ecological Site Descriptions and State-and-Transition and State-and-Transition models of the Caldenalmodels of the Caldenal

Sampling PointsSampling Points

• Random: Random: statistically valid designstatistically valid design

• Selected: Selected: knowledge of historical managementknowledge of historical management

Random PointsRandom Points•One hundred points were randomly distributed using ArcGIS throughout the various soil types documented by the INTA Provincia de La Pampa 1976 soil survey for the caldenal ecoregion

•The points were converted into a .kmz file and transferred to Google Earth

Random PointsRandom Points

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Random PointsRandom Points

•Is the point in an area with calden?

•Is it near an area with calden?

•Is it near an accessible road?

•Is it near a house or farming facility?

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Random PointsRandom Points

PA 3 PA 3a

Selected PointsSelected Points

•Sites with known management regimes where data can be obtained from the producer/land owner

•Sites with spatial interest based on imagery analysis

•Sites in the vicinity of randomly selected points that demonstrate potentially valuable information

Selected PointsSelected PointsExample Parque Luro

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•Area has not been burned since the 1980s, nor grazed since the 1970’s

•Trees show signs of mortality due to competition

The SamplesThe Samples

• Soil pitSoil pit

• Vegetation transectVegetation transect

• Belt transect (tree and shrub)Belt transect (tree and shrub)

• Soil surface classificationsSoil surface classifications

SamplingSamplingDesignDesign

Line-point intercept every 20cm

Soil pit

Photo Photo

30m

1-3m

Downslope (if flat, transect placed

North/South)

20x20m soil surface quadrant

2-10mBelt transect

Soil pitSoil pit•50x50cm profile pit was dug to 40cm

•Samples were augered and laid in order by depth from 40cm to 100cm

•The soil was then characterized using the USDA-NRCS Soil Survey Field Manual including: horizon descriptions, effervescence (reaction to NHcl), color, % clay, hand texture, grade, structure, size, and landscape descriptions

Vegetation transectVegetation transect

•The transect was placed 1-3m above the soil pit if there was a slope (3% or more) or 1-3m to the East if it was a flat area (1-2% slope), and was centered on the soil pit

•The transect was read every 20cm with a pin flag. The plants and surface that the pin touched were noted.

Belt transectBelt transect•The belt was placed on the side of the transect opposite the soil pit

•The trees and shrubs were inventoried and put into categories based on size per species.

•The trees and shrubs were recorded based on what category they fall under, along with the % dead canopy and % cover within the belt.

Soil SurfaceSoil SurfaceCharacterization of the soil surface (those which dominated the 20x20m quadrat) based on plant patch composition (resource retention class), erosional status (soil retention class) and physical state of the soil surface (pedoderm class) was accomplished utilizing the classifications set by Brandon Bestelmeyer with his manual on surface classifications (to be published).

Overall descriptionOverall description•Photos were taken with a Nikon D5000 camera 2m back from each end of the transect. Photos were also taken along the transect of the surrounding landscape and points of interest.

•A description of the site was written including general description of the state, notes on the dominant plant species and compositions, landscape characteristics, an overview of the soil, evidence of disturbance, and a preliminary interpretation of the site dynamics.

Defining Ecological SitesDefining Ecological Sites

A preliminary map of ecological sites was developed from the soil samples taken by field collections, use of the INTA Provincia de La Pampa 1976 soil survey, and references to the 2005 landsat dem of La Pampa for landscape features for the region of calden forests.

Defining StatesDefining StatesPreliminary models of state-and-transitions according to the dominant soil types of the caldenal ecoregion are being developed. Discussions regarding the formation of these models and essential questions that need to be addressed in the development process are currently

PreguntasPreguntas