The Temporal Dynamics of Multiple Stressor Effects: From Individuals to Ecosystems

Multiple anthropogenic stressors rarely overlap in perfect synchrony time, yet most research quantifying how they interact assumes that do.Stressor sequence and the degree of temporal will have implications for ecological memory – influence past on future responses from genes to ecosystems.Adding this complexity, organisms with different generation times experience multiple (and which time) ways.We propose lifespan associated metabolic rates can be used define stressor type (continuous or discrete) focal organisms.Moving forward, we need embrace complexity quantify various realistic asynchronous scenarios alter their cumulative impacts across ecosystems. stressors, such as warming invasions, often occur together nonadditive effects. Most studies date assume operate synchrony, but case reality. Stressor ability responses. Moreover, are usually defined an anthropocentric context: what consider a short-term stressor, flood, span generations microbes. We argue predict individuals whole ecosystem, it is necessary rates, determine timescales at therefore, ultimately, levels organization. Predicting pollution events, warming, novel pathogens, affect natural ecosystems major challenge contemporary ecology. The presence, frequency, magnitude varies over time space, however, independent combined effects individual behavior entire ecosystem processes [1.Ryo M. et al.Basic principles dynamics.Trends Ecol. Evol. 2019; 34: 723-733Abstract Full Text PDF PubMed Scopus (51) Google Scholar]. Here, timing duration both initial recovery particularly critical, least important spatial component has been primary focus date. In particular, dynamics events largely overlooked, critically because rarely, if ever, act order shape impacts. Furthermore, do not effects, since ‘legacy’ previous response its populations) stress. 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Theor. 2007; 247 (213–212)Crossref (77) currently cannot nontrophic populations. truly multistressor time-varying, nonlinear food-web mediated) needs (Box 1).Box 1Species Temporal StressorsIn addition considering dimension, cascading mediated; I). Nonlinearities generate unpredictable fluctuations interacting propagation stressor-induced producers top consumers). attenuate directionally move differences species. systems (small-bodied fast-lived) algae, observe very base web, time-lagged aggregated (which larger-bodied longer-lived; body-mass I), status abundance.As know affects put bounds ‘ripple’ upwards (to account dimension effects) disentangle direct IB). Of course, webs simply unidirectional networks: consumers exert top-down control. modulate seen pesticides, nutrients, acidification, change, instance; yet, remains understood. abundance. complexities, nascent state theoretical development field, make empirically predictions about qualitatively mapping onto organisms’ ecosystem. hypothesize every depending proportions it, each perceived event) compare ‘slow’ comprising large, trees) versus ‘fast’ dominated oceanic phytoplankton), ‘zeroth-order’ model biomass-weighted expect fundamentally community-level slow fast experiencing another, adding goal, group broad typologies hence capacity envelopes response, (extreme exemplar) cases earlier. How precisely maps open question, progress made decades fairly rules narrow field. strongly size-structured flowing small, abundant, algae) rarer, longer-lived predatory fishes; Box ‘trophic-level’ there approximate drop transfer 1) similar degrees listed above many well-described allometric here shifts map One could involve resolution spectra techniques next-generation sequencing metabarcoding DNA bulk-sample DNA) obtain detailed information, machine learning images gain complementary distributions [51.Jackson al.Recommendations next monitoring tools.Adv. 55: 615-636Crossref calculate distributed ecologists decide accurately measure Moving effort unraveling temporally occurring points, full resolve ‘temporal types’ testing models. taken off few Scholar,25.Orr Scholar,52.Tockner coupled river–floodplain ecosystems.Freshw. 2010; 135-151Crossref (288) Scholar,53.Birk al.Impacts biota ecosystems.Nat. 4: 1060-1068Crossref (154) chasm bridged bring greater realism some biggest rapidly world shown beyond perfectly overlapping stressors: sequences, overlap, Outstanding Questions). unrealistic scenarios. dramatically memory, prevalence extension, management conservation ecosystems.Outstanding QuestionsHow order, populations?Does exposure promote erode resilience (through memory) does similarity?Do outcomes dominance affects) comparable acting synchrony?If rescale (rather time), lifespans?How population-level variable ecosystems? populations? Does similarity? Do synchrony? If lifespans? All authors supported Natural Environment Research Council (NERC) grants NE/M020843/1 NE/S000348/1 . M.C.J. NERC grant NE/V001396/1 No interests declared. exists any processes. acquisition recombination improve performance survival generations. physiological, morphological, behavioral adjustments certain conditions. effect parts. throughout organism. part experiences consecutive lineages population. phenotype affected parents.