Diatom diversity patterns over the pastc. 150 years across the conterminous United States of America: Identifying mechanisms behind beta diversity

• DOI: 10.1111/geb.12640
• Publication Date: 2017-10-04T10:13:25Z
• Authors: Amanda K. Winegar...; Pierre Legendre; Beatrix E. Beisner; Irene Gregory‐Eaves
• Keywords: Gamma diversity; Land Cover; Temporal scales

Abstract Aim Understanding the magnitude and drivers of freshwater diversity over last 150 years provides essential insights for developing scenarios future change. Here, we quantify identify spatial temporal beta in diatom assemblages between historical modern times. Location United States America. Major Taxa Studied Diatoms. Tim Period pre‐AD 1850 c. 2007. Methods Using sedimentary genus‐level data from 169 lakes species‐level 52 lakes, computed across all within ecoregions 2007 time points. We also local contributions to (LCBD) analysed them with respect environmental variables. Total was partitioned into replacement abundance difference components mechanisms possibly responsible at each point. Temporal indices (TBI) were lake by comparing TBIs decomposed taxon losses gains facilitate interpretation. their related contemporary land cover. Results varied significantly as a function forest cover, higher watersheds lower Spatial similar Lakes substantial differentiated water quality cover variables scale, but showed no systematic regional pattern. Main conclusions diatoms U.S.A. does not appear have changed 2007, suggesting that broad‐scale use hydrological alteration landscape has homogenized these communities. occurred through genus watersheds. These analyses, pairing diversity, provide insight maintaining diversity.