Grantee Research Project Results

2000 Progress Report: Methodologies for Extrapolating from Local to Regional Ecosystem Scales: Scaling Functions and Thresholds in Animal Responses to Landscape Pattern and Land Use

EPA Grant Number: R826764
Title: Methodologies for Extrapolating from Local to Regional Ecosystem Scales: Scaling Functions and Thresholds in Animal Responses to Landscape Pattern and Land Use
Investigators: Wiens, John A. , Horne, Beatrice Van
Institution: Colorado State University
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1998 through September 30, 2001 (Extended to December 31, 2002)
Project Period Covered by this Report: October 1, 1999 through September 30, 2000
Project Amount: $581,519
RFA: Regional Scale Analysis and Assessment (1998) RFA Text |  Recipients Lists
Research Category: Aquatic Ecosystems , Ecological Indicators/Assessment/Restoration

Objective:

In simple terms, the objectives of this research are to: (1) develop ways of assessing scaling of landscape patterns and of organism responses to landscape variation, and (2) develop predictive models that can be used to extrapolate landscape-organism linkages among scales. In this context, "scaling" refers to the ways in which ecological patterns or processes change with changes in the spatial scale on which they are viewed. The results of this research will help to establish a methodology for extrapolating among scales of analysis or management, and for evaluating the scales at which environmental disturbances or anthropogenic stresses may have the greatest impacts on ecological systems.

In practice, these objectives translate into three questions that guide this research:

1. How do we develop ways to extrapolate among scales, particularly in the face of scaling nonlinearities?
2. Can landscape measures taken over multiple scales be used to predict the scaling properties of communities or ecosystems, and thus serve as a basis for deriving extrapolation algorithms?
3. Do different taxonomic or functional groups respond differently to broad-scale gradients in environmental or landscape features?

Progress Summary:

The research program has been divided into three phases:

Phase 1: Preliminary Analyses and Methodology Development. To explore how landscape patterns and the distributional patterns of organisms relate to each other, and how these relationships change with changes in scale, we have evaluated three existing data sets, using somewhat different methodologies. One analysis has considered the distribution of grasshopper species and communities in relation to land-cover, land-use, soil, topography, temperature, and precipitation patterns in eastern Wyoming. One thrust of this approach has been to contrast the effects of viewing landscape features categorically versus continuously (i.e., as gradients, analyzed by ordination procedures). The relationships that emerge using the two approaches differ with respect to geography, and it appears that ordination may provide a more informative framework for evaluating broad-scale environmental responses of organisms to landscape patterns. Multiscale analyses of these data are in progress.

A second analysis has used information on vegetation coverage and bird distributions from surveys conducted in the Snake River Birds of Prey Conservation Area in Idaho. Here the focus has been on developing causal models of bird community-environment relationships and examining the sensitivity of such models to changes in scale. Vegetation composition was associated with bird species composition at the local scale, and its effect decreased somewhat as scale increased. Fire history had very little influence at a local scale, but its effect increased with increasing scale.

A third analysis has focused on a detailed, spatially explicit data set on plant distributions available from the Oosting Experimental Forest in North Carolina. Here the objective has been to use statistical approaches based on spatial covariance to integrate variogram modeling and multiscale ordination to evaluate assembly rules in plant communities. The variogram matrix provides a framework for partitioning spatial covariance and for factoring out specific components. This mathematical approach greatly increases the interpretability of variograms of biotic communities, extends multi-scale ordination to non-systematic spatial samples, and provides a spatial extension and an empirical null model for the variance test of species richness.

Phase 2: Gradient-based Field Studies. We are using the insights gained in the first phase of this research to structure a series of field studies that incorporate multiscale analyses of landscape patterns and features with surveys of several biological taxa (vascular plants, beetles, butterflies, and birds), which also may be analyzed at multiple scales. The basic research design involves studies at five sites located on a broad-scale precipitation/land-use gradient from the shortgrass steppe of northeastern Colorado to the tallgrass prairie of eastern Kansas. At each site, surveys are conducted on two to four 2-km-long transects that span gradients in local topography and vegetation cover, centered on grassland and riparian cover types. During the summer of 2000, information was gathered along each transect for environmental variables (soil hardness, soil pH, soil texture, near-surface temperature, and shrub coverage) and biotic variables (bird and butterfly surveys, pitfall trapping for ground-dwelling beetles, and quadrat sampling of vegetation). The minimum scale of resolution of these data (i.e., sampling grain) is 50 m.

The information obtained from this direct sampling will be combined with indirect assays of landscape pattern and composition obtained from satellite imagery and aerial photography. The data obtained from this remote sensing will be used to assess how the different taxa respond to the surrounding landscape over a range of scales. They also can be used to determine whether such remote sensing, coupled with basic inventory and life-history information, may yield models that can be used to predict species and community responses to landscapes with changing scales and how these relationships vary across broad, geographic gradients. Preliminary analyses of the direct field data indicate that the five sites do exhibit a reasonably even spacing on the broad-scale environmental gradient. Analysis of the transect-level data is in progress.

Phase 3: Modeling and Development of Scaling Protocols. Upon completion of the initial analyses of data gathered in Phase 1 and Phase 2 of this research, we will begin to develop models that integrate landscape structure with biotic responses over multiple scales. This modeling will be empirically rather than theoretically driven, and therefore cannot be initiated until substantial progress has been made in Phases 1 and 2.

Future Activities:

In addition to continuing the analyses of the data gathered in Phase 1 and Phase 2, new field studies will be conducted during the spring-fall 2001 field season to resolve some issues, expand the coverage of environmental gradients, and/or test the field and analytical methodology in a different ecosystem type. The initial development of modeling also will be undertaken during this reporting period. Presentations will be given at several meetings (i.e., US-IALE in Arizona, Ecological Society of America in Wisconsin), and papers resulting from the Phase 1 studies will be submitted for publication.

Journal Articles:

No journal articles submitted with this report: View all 38 publications for this project

Supplemental Keywords:

terrestrial ecosystems, animals, indicators, scaling, habitat assessment, grazing, conservation, EMAP, Great Plains, land management. ecological effects, sensitive populations, ecosystem, terrestrial, habitat, biology, ecology, modeling, monitoring, surveys, measurement methods, landsat, remote sensing, western, central, Colorado, CO, Kansas, KS, Wyoming, WY, Idaho, ID, birds, insects., RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Geographic Area, Ecological Indicators, Ecological Risk Assessment, State, Ecosystem Protection, Agricultural Engineering, Ecosystem/Assessment/Indicators, Regional/Scaling, Monitoring/Modeling, Ecological Effects - Environmental Exposure & Risk, climate change, Environmental Monitoring, animal responses, EMAP, terrestrial ecosystems, ecosystem assessment, Environmental Monitoring & Assessment Program, biodiversity, Idaho (ID), risk assessment, New Mexico (NM), landscape patterns, ecological exposure, scaling, conservation , land use, GIS, extrapolation methods, grazing, Colorado (CO), indicators, land management, landscape context, regional scale impacts, spatial scale, conservation, land use change

Progress and Final Reports:

Original Abstract

1999 Progress Report

2001 Progress Report

2002

Final Report