Date of Award:
5-1-1980
Document Type:
Dissertation
Degree Name:
Doctor of Philosophy (PhD)
Department:
Biology
Department name when degree awarded
Life Sciences:Biology
Committee Chair(s)
James A. MacMahon
Committee
James A. MacMahon
Committee
D. Balph
Committee
I. Palmblad
Committee
K. Dixon
Committee
G. Bohart
Abstract
The spider fauna of a shrub steppe (Artemisia-Agropyron) community at the mouth of Green Canyon, Cache Co., Utah, was described. Herb, shrub and ground stratum spiders were sampled by sweep-netting, beating and pitfall trapping, respectively. Spiders of the ground were generally different from those of the vegetation. The two most abundant spider species and families in each stratum were distinctive. Horizontal distributions of spiders differed in four study plots with vegetation ranging from mostly herbaceous to very shrubby. Seasonal and diurnal spider abundance patterns were noted. Spiders were grouped into guilds based on their predatory strategies. This allowed comparisons between spiders presumably functioning in different ways in the community. Guild abundance patterns usually paralleled those of the dominant spider family within each guild, and family abundance patterns paralleled those of dominant species. Many environmental variables, acting simultaneously, affect spider community structure. In this study weather and some structural characteristics of the vegetation (density of grass, shrub size) correlated with spider abundance patterns. From evidence presented it was suggested that coexistence of spiders in the sage steppe was due to separation along niche axes of 1) horizontal habitat space, 2) vertical strata, 3) season of reproduction and 4) daily activity period. Causal mechanisms for the above probably included differing responses to microclimate, vegetation structure and prey.
Recommended Citation
Abraham, Barbara J., "Spatial and Temporal Changes in Spider Communities" (1980). Biology. 452.
https://digitalcommons.usu.edu/etd_biology/452
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