Rescue effect drives local persistence of fish species in the Upper Paraná River floodplain

Abstract

The interspecific variation in spatial distribution has been frequently studied in macroecology, but cross‐species differences in temporal occupancy (the number of times a species has been recorded in a site, i.e. local persistence) are seldom investigated. Here we aim to determine the relative importance of different predictors of species temporal occupancy, including local abundance, body size, range size, biological traits, environmental niche metrics, and proportion of the sites occupied (mean landscape occurrence). Using 17 years of data on 93 Neotropical fish species collected at the Upper Paraná River floodplain, we modelled temporal occupancy in six floodplain lakes, controlling for phylogenetic dependence, and investigated whether the relative importance of predictors was maintained across sites. Mean landscape occurrence and mean local abundance were the main predictors of temporal occupancy in all six lakes. Body size was also important in most lakes. The concordance in the ranks of predictors was high, indicating consistency in the mechanisms behind temporal occupancy across sites. Our results indicate the importance of metapopulation processes, especially the rescue effect, in determining long‐term persistence of fish local populations in floodplains. The influence of spatial occupancy on local persistence implies that protecting a large number of habitats in the landscape might reduce the risk of local extinction of species, thus maintaining biodiversity levels in the system.

Drivers and spatial patterns of population synchrony of fish species in a floodplain

“…Thus, the high level of synchrony of P. lineatus may be concerning. Similarly, the low spatial synchrony of L. platymetopon is revealing, as this invasive species (Casimiro et al., 2017) is one of the most abundant, widely distributed and locally persistent species in the Upper Paraná River floodplain (Granzotti et al., 2021).…”

“…Dispersal between subpopulations is thought to synchronise populations at small spatial extents (Bunnell et al., 2010; Cavanaugh et al., 2013), although some studies suggest that occasional dispersal may synchronise populations over large areas (Hopson & Fox, 2018; Lande et al., 1999; Stenseth et al., 1999). There is evidence that dispersal is important in determining the dynamics of fish populations in the Upper Paraná River floodplain (Granzotti et al., 2021; Gubiani et al., 2007). The spatial patterns of synchrony can also reveal the relative importance of dispersal in synchronising populations (Larsen et al., 2021; Walter et al., 2017).…”

“…Indeed, interannual variation in P. lineatus abundances is related to flood intensity (Piana et al., 2017). Specifically, because this species generally occupies a large fraction of the floodplain (Granzotti et al., 2021; Gubiani et al., 2007), years with delayed floods may cause recruitment failures which affect most local populations simultaneously (Oliveira et al., 2015), synchronising them. This may also be the case for other species with high synchrony and similar life‐histories, such as P. corruscans and Megaleporinus piavussu .…”

Niche position accounts for the positive occupancy–abundance relationship of lake fishes

“…However, the patterns and determinants of fish OARs remain poorly addressed at different spatial scales. To our knowledge, only 13 studies have documented fish OARs in the freshwater realm (Table S1), among which ten have found positive OARs (Faulks et al., 2015; Gotelli & Taylor, 1999; Granado‐Lorencio et al., 2005; Granzotti et al., 2021; Miranda & Killgore, 2019; Passy, 2012; Tales et al., 2004; Taylor et al., 2006; Ten Caten et al., 2022; Xia et al., 2022), and the other three have found non‐significant and even negative OARs (Gaston & Lawton, 1990; Pyron, 1999; Roney et al., 2015). Further, previous studies were mainly restricted to European and American freshwaters, and only one was conducted in Asia (Xia et al., 2022).…”

Interspecific variations in fish occupancy and abundance are driven by niche characteristics in a monsoon climate river basin

“…To our knowledge, only 11 studies have reported OARs for fish (Table S1). Among these studies, eight have found evidence for positive OARs (Faulks et al, 2015; Gotelli & Taylor, 1999; Granado‐Lorencio et al, 2005; Granzotti et al, 2021; Miranda & Killgore, 2019; Passy, 2012; Tales et al, 2004; Taylor et al, 2006), while the others have reported non‐significant or even negative OARs (Gaston & Lawton, 1990; Pyron, 1999; Roney et al, 2015). Furthermore, few studies have explored the relative roles of multiple mechanisms in driving fish occupancy and abundance (Passy, 2012; Tales et al, 2004).…”