The relative role of environmental, spatial, and land-use patterns in explaining aquatic macrophyte community composition

Abstract

Quantifying the relative role of environmental and spatial factors to understand patterns in community composition is a fundamental goal of community ecology. We applied a tested and repeatable point-intercept sampling method to aquatic macrophyte assemblages in 225 Wisconsin lakes to understand the ability of environmental, land-use, and spatial patterns to explain aquatic plant distribution and abundance. Using a variation partitioning framework in conjunction with Moran eigenvector maps we found that environmental, land-use, and spatial patterns explained 31% of total adjusted variation in aquatic macrophyte assemblages across the landscape. Environmental factors were the most important (contributing 34% of the total explained variation), but all sources of variation were statistically significant. Community composition varied from north to south along a gradient of alkalinity and from disturbed to undisturbed lakes, diverging according to whether disturbance was urban or agricultural. The large amount of shared variation among predictor variables suggests causal relationships are complex and emphasizes the importance of considering space and land-use in addition to environmental factors when characterizing macrophyte assemblages. This work is the first to examine the joint and unique effects of environment, land-use, and spatial patterns on aquatic plant communities.

Spatial Distribution of Benthic Macroinvertebrate Assemblages in Relation to Environmental Variables in Korean Nationwide Streams

“…We revealed that the variables associated with altitude and in-stream habitats best accounted for the largest amount of variability in our macroinvertebrate data set, supporting the more important determinants of local environmental factors than broad or regional parameters [16,44]. The importance and role of local environmental variables have also been highlighted in other aquatic communities: aquatic macrophytes [45], freshwater phytoplankton [46], benthic diatoms [44], intertidal macroinvertebrates [47], and fish [48]. However, a comprehensive understanding of multispatial scales is needed because of significant correlations between macrohabitat and microhabitat characteristics, depending on the relative size of the area studied [3].…”

Global patterns in the metacommunity structuring of lake macrophytes: regional variations and driving factors

“…One biological group showing context dependency has been aquatic macrophytes, many of which are distributed around the world due to efficient dispersal abilities and colonization strategies (Santamaría 2002; Chambers et al 2008). Environmental filtering has thus often overruled spatial factors in explaining variation in macrophyte community structure (Capers et al 2010; Mikulyuk et al 2011; Alahuhta et al 2013; Viana et al 2014), although opposite patterns have been found in some metacommunities (Hájek et al 2011; Padial et al 2014). These conflicting patterns for aquatic macrophyte metacommunities call for a more holistic comparative analysis including data sets with identical explanatory variables from different regions globally.…”

Environmental drivers of aquatic macrophyte assemblages in ponds along an altitudinal gradient

“…Many factors are known to have an influence on the presence and abundance of aquatic macrophytes, for instance, herbivorism (Lodge, 1991;Pipalová, 2002), substrate characteristics (Lacoul & Freedman, 2006b;Mikulyuk et al, 2011), water-level fluctuations (Fernández-Aláez et al, 1999Van Geest et al, 2005), land uses in the catchment (Capers et al, 2010;Akasaka et al, 2010) or propagule dispersal (Dahlgren & Ehrlén, 2005). In organisms with high dispersion capacity, local environmental conditions can be expected to explain a large proportion of the assemblage composition (Capers et al, 2010).…”