Spatial pattern and temporal dynamics of northern bobwhite abundance and agricultural landuse, and potential casual factors
| Title: | Spatial pattern and temporal dynamics of northern bobwhite abundance and agricultural landuse, and potential casual factors |
| Author: | Okay, Atiye Zeynep, 1970- |
| Abstract: | There was a long -term decline in northern bobwhite (Colinus virginianus , NBW ) abundance since the 1920s , based on the Christmas Bird Count (CBC ) data , but with substantial spatial and temporal variations across its range . There were four recognizable periods in the spatial and temporal dynamics of NBW abundance between 1920 and 1990 . Severe weather conditions and habitat loss due to land use change appeared to be the most important factors influencing the long -term trends and spatial patterns in NBW abundance . A spatial database of agricultural land use was developed based on the Census of Agriculture to evaluate the spatial patterns of land use variables over NBW range from 1920 to 1997 . The results showed dramatic changes in land use over the period and the influence of socio -economic events , natural disasters and federal agricultural policies on the dynamics of land use pattern , and potential implications to NBW abundance were identified . Replacement of less intensive agriculture with intensive monoculture production and mechanization coincided with World War I , and the post -war collapse in agriculture and the economy , partly associated with the Dust Bowl , enhanced this trend . Monoculture production and clean farming practices were further intensified during World War II and the years following the war . These land use changes had overall negative effects on NBW habitat . Analysis of the changes in spatial pattern of NBW abundance in the Great Plains region during the severe drought of the 1950s showed a significant decline in NBW abundance during the drought and a contraction of the NBW range at its western edge . The post -drought recovery exhibited spatial patterns significantly different from the predrought ones . These findings suggested that severe drought caused short -term changes in regional distribution of NBW and range contraction , as well as long -lasting , largescale changes in spatial distribution of NBW abundance . This study provides scientific basis for landscape planning and management . Evaluating the spatial pattern and temporal dynamics of certain wildlife species at large scales over long -term periods , and identifying potential causal factors are key strategies for implementing innovative and sustainable approaches to planning and policy . Such strategies will have a significant impact on future landscape and wildlife species . |
| URI: |
http : / /handle .tamu .edu /1969 .1 /3355
http : / /hdl .handle .net /1969 .1 /3355 |
| Date: | 2006-04-12 |
Citation
(December 2004).
Spatial pattern and temporal dynamics of northern bobwhite abundance and agricultural landuse, and potential casual factors.
Doctoral dissertation,
Texas A&M University. Available electronically from
http : / /handle .tamu .edu /1969 .1 /3355
.
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|---|---|---|---|
| etd-tamu-2004C-URSC-Okay.pdf | 8.341Mb | application/pdf |
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