Spatial impacts on zooplankton communities

Kulkarni et al. (2019) have reported geographic distance to correlate with zooplankton community dissimilarity on a very small geographic scale (1.5 km). In our study, however, there was no such relation between community composition and geographic proximity, arguing against isolation-by-distance as a significant factor in community assembly in our system, at least on the geographic scale we analysed (~14.0 km). Passively dispersed organisms, as zooplankton, are dependent on dispersal vectors (e.g., Fontaneto, 2019). If they are wind-dependent, their dispersal effectiveness strongly depends on the geographic scale (Horvath et al., 2016; Vanschoenwinkel et al., 2009). They can also depend on animals, so called mobile links (Jeltsch et al., 2013; Lundberg & Moberg, 2003) to get dispersed on a landscape scale (Brochet et al., 2009; Frisch et al., 2007; Moreno-Linares et al., 2016; Vanschoenwinkel et al., 2008,2009). These mobile links often do not necessarily create an isolation-by-distance related dispersal framework, as they may not explore habitats in a purely distance-related manner and may have other selective criteria, such as landscape configuration (habitat quality, connectivity, competition etc.). In addition, these factors may change temporally, especially in agricultural landscapes (due to farming/cultivation activities). These complex and confounding factors may result in dynamic and non-linear dispersal dynamics for passive disperses (like zooplankton), which makes it difficult to detect any distance-based patterns, should they exist on the scale of the analysed metacommunity (Burel & Baudry, 2005; Kleyheeg et al., 2017; Kloskowski et al., 2010). Furthermore, individual zooplankton species might have different dispersal rates/abilities (Caceres & Soluk et al., 2002; Frisch et al., 2007; Vanschoenwinkel et al., 2009) and pathways (Lopes et al., 2016), a pattern potentially masked in our community approach.