Coastal biophysical processes and the biogeography of rocky intertidal species along the south‐eastern Pacific

Abstract

Aim:We assess the spatial distribution of a suite of coastal biophysical characteristics and how their variability is related to the distribution and geographic range of a diverse assemblage of coastal benthic species with different larval dispersal strategies.Location: South-eastern Pacific (SEP) coast between 18°20′S and 42°35′S.Methods: Biophysical variability was assessed using chlorophyll-a concentration, sea surface temperature and the signal of turbid river plumes derived from MODIS onboard the Aqua satellite. We established the dominant spatial components using wavelet and coherence analysis, and evaluated the biogeographic structure of 51 rocky intertidal species sampled over~2,600 km along the SEP using multivariate classification and regression trees.Results: Biogeographic breaks detected here were consistent with recent biogeographic classification schemes. Distribution breakpoints for species with lecithotrophic larvae clustered around 30°S. We observed a previously unreported break in the distribution of species with planktotrophic larval dispersal strategies around 35°S. These breaks are related to coherence in the spatial structure of sea surface temperature, chlorophyll-a and river outflow over different temporal scales. Regions with similar biophysical characteristics, and the breaks the separate them, are in striking agreement with the biogeographic patterns revealed by the multivariate classification trees. Main conclusions:Our results reconcile patterns of biogeographic structure reported for other groups of species along the SEP coast. We suggest that river outflow, a poorly studied coastal environmental forcing, may play an important role

Geographical variation of multiplex ecological networks in marine intertidal communities

“…LT SST has been shown before to be a robust indicator of the role of environmental variability on ecological processes across coastal upwelling ecosystems (Broitman et al 2001, Menge et al 2003, Navarrete et al 2005, Wieters et al 2009, Valdivia et al 2013). This generalization seems to hold well along our study region (Lara et al 2019).…”

Latitudinal patterns of species diversity on South American rocky shores: Local processes lead to contrasting trends in regional and local species diversity

“…Here, the highest γ-diversity was observed in ecoregions influenced by the convergence of oceanic currents or upwelling systems (i.e. Guayaquil, Humboldtian, Eastern Brazil; see also Coutinho et al, 2016;Lara et al, 2019;Rivadeneira et al, 2015). Yet, site-scale β-diversity was also the high- production, was also a significant factor explaining variability in biodiversity on all coasts, which supports the hypothesis that convergence of oceanic currents and upwelling systems promote high biological diversity at the regional scale (Miloslavich et al, 2011).…”

High dimensionality of the stability of a marine benthic ecosystem

“…The study was conducted at multiple field sites on the extremes of a large transitional biogeographic province that extends between the Peruvian and Magellan provinces along the Chilean sector of the South East Pacific (Camus, 2001;Thiel et al, 2007;Lara et al, 2019). We used eight study sites that where evenly split between the northern and southern extremes of the province (around 30.23ºS and 39.9º, respectively)-each region encompassing ca.…”

“…The southern region presents a persistent relationship between Chlorophyll-a concentration, riverine inputs, and runoff from forestry and agricultural activities (Van Holt et al, 2012;Lara et al, 2019). In this region, upwelling activity is weaker and more intermittent than the sector equatorward from Concepción, which is dominated by strong seasonal upwelling (ca.…”

“…Colour scales denote long-term temporal mean (2003-2018) of (A) sea surface temperature and (B) log10 Chlorophyll-a concentration using L3 MODIS-aqua data (Lara et al, 2019).…”