Spatial patterns of zooplankton diversity in floodplains

Understanding the spatial distribution of diversity is a main interest of ecology and its relevance is enhanced under the current scenario of progressive diversity loss. Measures of species diversity are dependent on the spatial scale considered, mainly because environmental factors that affect species composition show different ranges of variation among spatial scales. Despite the relevance of spatial scale is increasingly recognized in biodiversity studies, there is still a lack of understanding on how combined environmental variations at smaller and broader scales influence diversity in a certain region. Riverine floodplains host an exceptional high diversity and the hierarchical arrangement of their environments offers a great opportunity to study how spatial heterogeneity affects patterns of communities composition and diversity at multiple scales. These ecosystems are endangered because of human alterations of the natural flood regime. A comprehensive understanding of diversity distribution will contribute to plan conservation, management and restoration measures. The objectives of the present project are: 1- to determine the relevance of alpha-diversity, beta-diversity among habitats within water bodies, and beta-diversity among water bodies as contributors to zooplankton regional diversity in semi-natural and isolated floodplain wetlands; 2- to establish the association between beta-diversity and environmental heterogeneity among and within water bodies, and determine which are the main environmental factors involved; 3- to evaluate the effects of macrophyte`s structural complexity on zooplankton local diversity in vegetated habitats. I will perform field samplings with a hierarchical design across spatial scales in floodplain wetlands from the Danube River in Austria. It will comprise 1- distinct habitats types (open waters, submerged, emergent and floating-leaved macrophytes) to account for the variability within water bodies and 2- different water bodies to account for the variability among water bodies. It will be performed in floodplain wetlands with influence of river flooding (semi-natural ones) and in wetlands mostly disconnected from the river (isolated ones). This project will contribute to a better comprehension on how regional diversity is composed, on which are the main environmental factors that influence diversity patterns at each spatial scale and on the relationship between habitat complexity and local diversity. The comparison between wetlands with influence of river flooding and wetlands that were isolated from the river will contribute to get a better understanding of the relevance of fluvial processes for diversity maintenance in more pristine ecosystems and will provide detailed evidence on the consequences of wetlands degradation. The sound scientific findings from this research will be of major relevance within the fields of aquatic ecology, restoration and conservation biology.

Understanding the spatial distribution of diversity is a main interest of ecology and its relevance is enhanced under the current scenario of progressive diversity loss and massive change of ecosystems. Measures of species diversity are dependent on the spatial scale considered, mainly because environmental factors that affect species composition show different ranges of variation among spatial scales. Despite the relevance of spatial scale is increasingly recognized in biodiversity studies, there is still a lack of understanding on how combined environmental variations at smaller and broader scales influence diversity in a certain region. Riverine floodplains host an exceptional high diversity and the hierarchical arrangement of their environments offers a great opportunity to study how spatial heterogeneity affects patterns of community composition and diversity at multiple scales. These ecosystems are highly endangered because of human alterations of the natural flow regime. A comprehensive understanding of diversity distribution will contribute to improve planning of conservation, management and restoration measures. The objectives of the present project are:1- to determine the relevance of alpha-diversity, beta-diversity among habitats, within water bodies, and beta-diversity among water bodies as contributors to zooplankton regional diversity in semi-natural and isolated floodplain wetlands; 2- to establish the association between beta-diversity and environmental heterogeneity among and within water bodies, and determine which are the main environmental factors involved; 3- to evaluate the effects of macrophyte?s structural complexity on zooplankton local diversity in vegetated habitats. We performed field samplings with a hierarchical design across spatial scales in floodplain wetlands from the Danube River in Austria. It comprised 1- distinct habitats types (open waters, submerged, emergent and floating-leaved macrophytes) to account for the variability within water bodies and 2- different water bodies along a gradient of connectivity. We included wetlands with influence of river flooding (semi-natural ones) and one more isolated wetland. We performed the sampling in summer 2014 and 2015 under contrasting hydrological conditions (after flood vs no flood). This project contributes to a better comprehension on how regional diversity is composed, on which are the main environmental factors that influence diversity patterns at each spatial scale and on the relationship between diversity, environmental heterogeneity and spatial factors. The comparison between wetlands with influence of river flooding and wetlands that were isolated from the river will contribute to get a better understanding of the relevance of fluvial processes for diversity maintenance.