Net effect of environmental fluctuations in multiple global-change drivers across the tree of life

Abstract

Jensen’s inequality predicts that the response of any given system to average constant conditions is different from its average response to varying ones. Environmental fluctuations in abiotic conditions are pervasive on Earth; yet until recently, most ecological research has addressed the effects of multiple environmental drivers by assuming constant conditions. One could thus expect to find significant deviations in the magnitude of their effects on ecosystems when environmental fluctuations are considered. Drawing on experimental studies published during the last 30 years reporting more than 950 response ratios ( n = 5,700), we present a comprehensive analysis of the role that environmental fluctuations play across the tree of life. In contrast to the predominance of interactive effects of global-change drivers reported in the literature, our results show that their cumulative effects were additive (58%), synergistic (26%), and antagonistic (16%) when environmental fluctuations were present. However, the dominant type of interaction varied by trophic level (autotrophs: interactive; heterotrophs: additive) and phylogenetic group (additive in Animalia; additive and positive antagonism in Chromista; negative antagonism and synergism in Plantae). In addition, we identify the need to tackle how complex communities respond to fluctuating environments, widening the phylogenetic and biogeographic ranges considered, and to consider other drivers beyond warming and acidification as well as longer timescales. Environmental fluctuations must be taken into account in experimental and modeling studies as well as conservation plans to better predict the nature, magnitude, and direction of the impacts of global change on organisms and ecosystems.

Accurate photosynthetic parameter estimation at low stomatal conductance: effects of cuticular conductance and instrumental noise

“…Leaf conductance and stomatal behavior are known to vary across environmental conditions and species (Jones et al 2009 ; Cabrerizo and Marañón 2022 ). Through the characterization of species-specific leaf conductance, researchers can gain valuable insights into the functional traits and adaptations that contribute to the successful adaptation of plants in diverse environments (Mott and Buckley 2000 ; Franks et al 2009 ).…”