GIS Assessment of the decline of gray partride (Perdix perdix) nesting habitat in the Elbe River Lowlands, the Czech Republic, 1949-1996
2001
Figala, J. (VSB Technical University, Ostrava-Poruba (Czech Republic). Institute of Environmental Engineering) | Prchalova, J. | Tester, J.R.
The change in nesting habitat for the gray partridge between 1949 and 1996 in an agricultural landscape of the Elbe River Lowlands in Czech Republic was analysed using area maps, aerial photos, and landscape surveys. A vector - based geographic information system (GIS) was employed to digitise and categorise landscape elements into agriculture, residential, shrub/grass, forest, stream, railroad, and road. Using the GIS, we calculated the changes in area of the land use categories, field numbers, and size of fields. We studied the associated changes in linear habitat which represents preferred nesting habitat for the gray partridge. The number of agricultural units (fields, meadows, pastures) decreased from 542 to 38 and the average unit size increased from 1.0 ha to 13.7 ha. We analysed the linear habitat along the borders of field units and found that in terms of percent of total length to edge, the importance shifted from field - field borders in 1949 to field - roadside borders in 1996. In 1949 the private strip farming management of fields allowed for the potential of 16.7 km edge/km2 or 66.9% of the total field edge length. Road - field borders in 1949 supplied 4.9 km edge/km2 and represented 19.5% of the total field edge length. Coversely, in 1996 the increase in field size and decrease in number of units due to collectivisation policies of the former communist government caused the decrease in field - field border length (1.4 km edge/km2; 18.0% of total field edge length) and road - field border increased in importance (39.7%) even with the decrease in road field length (3.03 km edge/km2). We also present gray partridge abundance for 1949 and 1996 which shows the drastic decrease from 40-50 birds/km2. In light of the nesting habitat analyses performed in this work we discuss implications for the gray partridge
显示更多 [+] 显示较少 [-]