Variation in the diversity of ducks along a gradient of environmental variability

摘要: Tramer (1969) proposed that communities regulated by competition in benign, predictable environments were characterized (i) damped variation evenness relative to richness over time, and (ii) high the abundance diversity of resources rigorous, unpredictable environments. To test whether patterns could reflect mechanisms regulate community structure, temporal spatial changes diversity, breeding duck examined along a gradient variability wetland conditions using thirty-three years census climate data from Canadian prairie boreal forest regions. Temporal was independent habitat variability. Changes more parsimoniously explained appearance ducks displaced (by drought) variable, habitats into relatively benign ones, than areas. Evenness not significantly higher for guilds constant habitats, as predicted. Variation richness, predicted Tramer, do provide basis distinguishing factors structure.