Patterns of mammalian species richness in relation to temperature, productivity, and variance in elevation

摘要: In Texas, the relationship between environmental factors and species richness of all mammals, bats, rodents, carnivores was investigated by multiple-regression methods. Variance in elevation a strong, positive predictor for bats (Chiroptera), rodents (Rodentia). It significant but weak (Carnivora). Productivity had significant, negative regression coefficients rodents. positive, relatively stronger carnivores. Species may follow hump-shaped curve along gradient increasing productivity. Mean-annual temperature range with sign Mean intermonthly variability precipitation to carnivores, Variation mammals carnivore richness, bat signs, maximum minimum temperatures, record, respectively. All bat, rodent varied significantly, coefficient variation mean January temperature. Overall, climatic-variability indices exhibited only control over density mammalian species. With exception productivity their influence on current ecological hypotheses complex. Statistical support, contradiction, statistical lack significance depended upon particular combination taxa under consideration. Results suggest that often function directions not concordant predictions are satisfactory as general explanations biotic these vertebrate groups.