A Metacommunity Approach to Improve Biological Assessments in Highly Dynamic Freshwater Ecosystems

Abstract

Rapid shifts in biotic communities due to environmental variability challenge the detection of anthropogenic impacts by current biomonitoring programs. Metacommunity ecology has the potential to inform such programs, because it combines dispersal processes with niche-based approaches and recognizes variability in community composition. Using intermittent rivers—prevalent and highly dynamic ecosystems that sometimes dry—we develop a conceptual model to illustrate how dispersal limitation and flow intermittence influence the performance of biological indices. We produce a methodological framework integrating physical- and organismal-based dispersal measurements into predictive modeling, to inform development of dynamic ecological quality assessments. Such metacommunity-based approaches could be extended to other ecosystems and are required to underpin our capacity to monitor and protect ecosystems threatened under future environmental changes.

Effects of the Temporal Scale of Observation on the Analysis of Aquatic Invertebrate Metacommunities

“…The sampling design in these cases should take into account both spatial and temporal scales together. Therefore, the sampling design should be based on a previous knowledge of the temporal fluctuations of the landscape, this being important to find natural references of stable (such as tropical systems or stable interstitial zones; Hubbell, 2001;Dumas, 2002) and unstable landscapes (such as temporary ponds or intermittent rivers; Castillo-Escrivà et al, 2017;Cid et al, 2020) to test the theoretical predictions. This also encourages the use of more complex landscapes in the simulations for specific cases, taking into account different types of environmental variation (e.g., mosaic, gradient; Viana and Chase, 2019), the type of spatial distribution of localities (e.g., regular, random; Henriques-Silva et al, 2015), and regular or unexpected temporal events (e.g., droughts, seasonality; Tonkin et al, 2017).…”

Metacommunity Structures of Macroinvertebrates and Diatoms in High Mountain Streams, Yunnan, China

“…We found significant associations between diatom and macroinvertebrate community dissimilarity, however, the concrete cause of this association is speculative. Disentangling the local metacommunity structure and the influence of spatial and environmental factors on local areas provides valuable insight into the structuring forces of this high biodiversity region and its vulnerability to human impacts (Chase et al, 2020) and can help improve biological assessments and conservation in these dynamic ecosystems (Cid et al, 2020). Future research should expand metacommunity analysis to include other high mountain areas and use replicated metacommunities at multiple spatial scales to disentangle drivers of this variability for different organismal groups.…”

Spatial modelling of temporal dynamics in stream fish communities under anthropogenic change

“…Mapping of community dynamics highlighted faster changes in lowland streams affected by hydroelectric development and exotic species. Overall, our framework helps to generalize community dynamics from discrete locations to entire watersheds, providing spatial information needed for freshwater ecosystem assessment and management (Cid et al., 2020; Fausch et al., 2002).…”

“…Moreover, we produced maps that helped visualizing community changes across the stream network and that highlighted the effects of a new hydroelectric development in nearby lotic systems. We suggest that our framework may be widely useful to freshwater ecologists aiming to understand spatial variation in local community dynamics under anthropogenic change, while providing a tool for managers to make spatially continuous predictions of community temporal dynamics that can be used in bioassessment and mitigation of anthropogenic impacts on freshwater ecosystems (Cid et al., 2020; Fausch et al., 2002).…”

“…However, relatively few studies have investigated the patterns and drivers of spatial variation in the temporal dynamics of local community, though this would be important to generalize patterns from particular sites to landscapes and regions that are the main focus of management (Erős & Lowe, 2019; Hugueny et al., 2010; Schlosser, 1991; Wiley et al., 1997). Therefore, it is essential to provide conservation and water agencies with spatially continuous views of community dynamics, thereby contributing to assess anthropogenic impacts and to prioritize management action (Cid et al., 2020; Fausch et al., 2002).…”