Data for: Stronger niche than dispersal effects on α- and β-diversity of stream algae, insects, and fish across latitudes in the US

Aim: Niche and dispersal processes influence biodiversity, but their relative importance along latitude is unclear. We predicted that: i) niche processes would dominate at high latitudes due to increased climatic stress, consistent with the physiological tolerance hypothesis and the Dobzhansky-MacArthur hypothesis and ii) dispersal limitation would prevail at low latitudes due to narrower niches and smaller range sizes, as postulated by the dispersal-ecological specialization tradeoff hypothesis, the latitude-niche breadth hypothesis, and Rapoport’s rule. 
Location: Central United States
Time Period: 1993-2019
Major taxa studied: Stream algae, insects, and fish
Methods: We examined the relative effects of environment (climate and physicochemistry) vs. space on stream biodiversity in seven latitudinal zones, spanning 19 latitudinal degrees. In each zone, species richness (α-diversity) was analyzed with multiple regression and variance partitioning. Compositional dissimilarity (β-diversit...