Realized ecological niche-based occupancy–abundance patterns of benthic diatom traits

Abstract

AbstractNowadays, when aquatic habitats are threatened by human and climatic disturbances leading to reductions in biodiversity and ecosystem functions, the study of the abundance–occupancy relationships of species traits and their underlying mechanisms is of great importance to future conservation management. To study the distribution patterns of benthic diatom traits, lakes were sampled during the summer and early autumn. Niche breadth, niche position (NP), regional occupancy and local abundances (LAs) of benthic diatom traits and their combinations were determined along different environmental gradients. Benthic diatom traits were identified in all possible niche types (14% non-marginal–narrow, 37% non-marginal–broad, 8% marginal–narrow and 41% marginal–broad niche). On the basis of increased niche differentiation, it is possible to achieve an improved and more effective utilization of the eco-morphological concept of diatom traits. The relationships between the occupancy, abundance and niche characteristics suggest that the broader the niche, the wider the distribution and the greater the LA; the more marginal the NP, the more restricted spatially the distribution and the lower the LA. With regard to the key factors driving the occupancy of benthic diatom traits in lentic ecosystems, the NP hypothesis proves to be the best predictor of its variation.