Species life-history traits and population stability
Understanding the factors that regulate temporal changes in population size (i.e., population stability) is a central aspiration for ecology and is critical for conservation. Theoretical studies have long suggested that life-history traits regulate population stability, but empirical support remains limited, especially for species-rich environments. In this study, we analyzed the population stability and its relationship with species life-history traits for 70 Amazonian freshwater fish species sampled at four floodplain lakes during five up to 15 consecutive years. Temporal stability was measured as coefficient of variation in species abundance based on annual captures using gillnets. Six life history traits were obtained (maximun standard length- SLMax; medium size of first reproduction -L50; fecundity, log transformed; oocyte diameter- ODIAM; and Parental care; detaild methods for these atributes can be found in Röpke et al. 2017). We also estimated the importance of fishes for fisheries (FISHERY INTENSITY). Two life-history traits had significant and interactive relationship with population temporal stability. Species that have high fecundity and low somatic investment before sexual maturation (SIBSM) display low stability; the opposite happens to species that invest highly in somatic tissue before first reproduction. Our results highlight the importance of the trade-off between growth and reproduction in controlling population stability. We stress the importance of life-history traits in controlling an essential part of variation in population sizes, in a complex and species-rich assemblage such as the Amazon floodplains.