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UNDERSTANDING ECOLOGICAL SYSTEM: AN EXAMPLE OF TEMPORAL AND SPATIAL VARIABILITY OF CONOMYMA INSANA IN A STRESSED SYSTEM
Citation:
Nash, M S. AND W. G. Whitford. UNDERSTANDING ECOLOGICAL SYSTEM: AN EXAMPLE OF TEMPORAL AND SPATIAL VARIABILITY OF CONOMYMA INSANA IN A STRESSED SYSTEM. JOURNAL OF ANIMAL AND VETERINARY ADVANCES 3(9):631-637, (2004).
Impact/Purpose:
The primary objectives of this research are to:
Develop methodologies so that landscape indicator values generated from different sensors on different dates (but in the same areas) are comparable; differences in metric values result from landscape changes and not differences in the sensors;
Quantify relationships between landscape metrics generated from wall-to-wall spatial data and (1) specific parameters related to water resource conditions in different environmental settings across the US, including but not limited to nutrients, sediment, and benthic communities, and (2) multi-species habitat suitability;
Develop and validate multivariate models based on quantification studies;
Develop GIS/model assessment protocols and tools to characterize risk of nutrient and sediment TMDL exceedence;
Complete an initial draft (potentially web based) of a national landscape condition assessment.
This research directly supports long-term goals established in ORDs multiyear plans related to GPRA Goal 2 (Water) and GPRA Goal 4 (Healthy Communities and Ecosystems), although funding for this task comes from Goal 4. Relative to the GRPA Goal 2 multiyear plan, this research is intended to "provide tools to assess and diagnose impairment in aquatic systems and the sources of associated stressors." Relative to the Goal 4 Multiyear Plan this research is intended to (1) provide states and tribes with an ability to assess the condition of waterbodies in a scientifically defensible and representative way, while allowing for aggregation and assessment of trends at multiple scales, (2) assist Federal, State and Local managers in diagnosing the probable cause and forecasting future conditions in a scientifically defensible manner to protect and restore ecosystems, and (3) provide Federal, State and Local managers with a scientifically defensible way to assess current and future ecological conditions, and probable causes of impairments, and a way to evaluate alternative future management scenarios.
Description:
The responses of pyramid ants Dorymyrmex (Conomyrma) insana (Buckley) to structural change (removal of an invasive shrub species) and to an environmental stress (short-term intense 12 grazing by cattle) are presented from an experiment study in Chihuahuan Desert grassland. Spatial and temporal responses of D. insana were examined by analysis of variances, kriging maps and regression analyses. There were no significant responses of D. insana to grazing. The numerical and spatial responses of ants recorded from pit- fall trap data were the same as those 16 recorded from mapping ant nests. The spatial distribution of D. insana nests was a function of the canopy cover of the invasive, woody shrub, honey mesquite (Fabaceae: Prosopis glandulosa Torrey) (r = 0.82) and explained 68% of the variability in nests distribution. The dominant liquid feeding ant species (D. insana) responded numerically and spatially to structural change and environmental stress. Spatially referenced data are as important or more important for monitoring ecosystem change than are numerical data.