Rangeland Ecology & Management

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THE GRADIENT CONCEPT OF LANDSCAPE STRUCTURE FOR WILDLIFE HABITAT IN RANGELANDS
Author
Perotto, Humberto L.
Mata, Jose M.
Ortiz, Janel L.
Edwards, John T.
Torres Conkey, April A.
Hernandez, Fidel
Brennan, Leonard A.
Rideot-Hanzak, Sandra
Wester, David B.
Publisher
Society for Range Management
Publication Year
2018
Body

The gradient concept of landscape structure is a relatively new conceptual paradigm in landscape ecology that provides an additional framework to pattern-process relationships occurring in the landscape. This model, takes into consideration the inherent environmental variability that exists in a landscape. This variability results in a gradient influencing organisms and ecological processes and their corresponding responses to changes along this gradient. This inherent continuous nature of ecological attributes was not previously well represented with the patch mosaic model, which has been used by landscape ecologists to describe landscape spatial heterogeneity. The goal of our research was to assess the value of the gradient concept of landscape structure based on remote sensing data to quantify suitable areas of northern bobwhite habitat (example 1) and hotspots of guild richness (example 2) in ground foraging avian species in South Texas. The first example uses existing data from northern bobwhite to assess suitability in habitats affected by tanglehead. The second example uses surface metrics to quantify potential hotspots for ground foraging birds. We applied the gradient concept of landscape structure by quantifying landscape metrics to develop surface metrics. We used moving window analyses to develop surface layers that describe landscape structure for northern bobwhites and ground foraging birds in South Texas. The selected metrics for these analyses included percent woody cover, mean patch area, edge density, aggregation index, interspersion and juxtaposition index, and cohesion index for woody cover and herbaceous cover (including tanglehead for northern bobwhites). These surface metrics were then used to develop spatial models that can quantify habitat suitability for avian populations in rangelands. Our results show that these models can be very useful to identify suitable areas for northern bobwhite habitat as well as predicting guild richness for ground foraging avian species.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Reno, NV