Environmental Stability and Community Persistence: A Multivariate Perspective

摘要: Six physical and hydrological variables were used to assess environmental stability at sites on 10 contrasting streams in the Southern Alps of New Zealand. Five spring-fed initially designated "stable", others, which predominantly catchment-fed, "unstable". At each site, depth, current velocity, water temperature measured monthly for 19 mo, distances moved by marked stones three size groups determined over 18 mo. Stone invertebrate communities sampled site intervals. Tractive force measurements Pfankuch index also calculated. Monthly depth variability, range, scores, substrate movement all greater five "unstable" sites, but rank order obtained with measure was not consistent. only that did differ significantly between "stable" streams. Princi...