Relationships of human disturbance, bird communities, and plant communities along the land-water interface of a large reservoir.

Abstract

We examined the relationships of human activity, bird communities, and plant communities along the land-water interface of Lake Texoma, a large human-made reservoir on the Texas-Oklahoma border. Measurements of human activity, plant surveys, and bird surveys were performed at 40 paired transects, one with human disturbance, the other undisturbed. Both principal components and correspondence analyses of bird-survey data separated disturbed sites from paired undisturbed sites, and typical disturbance-tolerant species from those less tolerant of human activity. Compared to undisturbed sites, disturbed sites tended to have more individual birds per survey, pavement, and mowed lawns, and less canopy, vegetation volume, and vegetation vertical diversity. A principal components analysis of quantitative disturbance measurements revealed that most bird and plant measures were highly correlated with the first disturbance component. However, the correlation between birds and human activity was much stronger than that between birds and plants, or between plants and disturbance. Our data suggest that bird-species composition is regulated more by human activity than by plant-community composition. Also, in this system, bird communities are a better choice than plant communities to index the effect of human disturbance. To maintain regional diversity of both birds and plants, undisturbed areas should be maintained around reservoirs.