Temporal scale dependent interactions between multiple environmental disturbances in microcosm ecosystems

Abstract

Global environmental change has negative impacts on ecological systems, impacting the stable provision of functions, goods, and services. Whereas effects of individual environmental changes (e.g. temperature change or change in resource availability) are reasonably well understood, we lack information about if and how multiple changes interact. We examined interactions among four types of environmental disturbance (temperature, nutrient ratio, carbon enrichment, and light) in a fully factorial design using a microbial aquatic ecosystem and observed responses of dissolved oxygen saturation at three temporal scales (resistance, resilience, and return time). We tested whether multiple disturbances combine in a dominant, additive, or interactive fashion, and compared the predictability of dissolved oxygen across scales. Carbon enrichment and shading reduced oxygen concentration in the short term (i.e. resistance); although no other effects or interactions were statistically significant, resistance decreased as the number of disturbances increased. In the medium term, only enrichment accelerated recovery, but none of the other effects (including interactions) were significant.In the long term, enrichment and shading lengthened return times, and we found significant two-way synergistic interactions between disturbances. The best performing model (dominant, additive, or interactive) depended on the temporal scale of response.In the short term (i.e. for resistance), the dominance model predicted resistance of dissolved oxygen best, due to a large effect of carbon enrichment, whereas none of the models could predict the medium term (i.e. resilience). The long-term response was best predicted by models including interactions among disturbances. Our results indicate the importance of accounting for the temporal scale of responses when researching the effects of environmental disturbances on ecosystems.

Interactions between predation and disturbances shape prey communities

“…Our study demonstrates importance of following the prey community over time, because both prey abundance and community composition changed during and after disturbance 64 . Moreover, the effect of disturbance types and resource deprivation on the prey community was phase-dependent (Figs 2 – 4 ).…”

Disturbance Size Can Be Compensated for by Spatial Fragmentation in Soil Microbial Ecosystems

“…In a microcosm experiment with cyanobacteria, Veraart et al observed patterns of "critical slowing down" resulting in population collapse after several disturbances due to slower recovery with increasing disturbances (Veraart et al, 2011). Another experimental study also finds indications for cumulative effects, by assessing the recovery time of an aquatic microbial community with increasing number of disturbances (Garnier et al, 2017). Similarly, Jurburg et al (2017) observed multiplicative effects of various temperature shocks on the recovery of soil microbial communities.…”

The dimensionality of stability depends on disturbance type

“…Importantly, understanding the mechanisms underpinning the responses of DS requires that future experiments on real and in-silico systems manipulate potential mechanisms, generally the strength and sign of species interactions, and the stochasticity of the system's dynamics (which may be achieved by manipulating levels of demographic and environmental stochasticity, response diversity, dispersal abilities and environmental sensitivities of the species in the community). For such experiments the use of modelling studies, as done here, seems a useful way forward, because collection of such data empirically is feasible only in micro-and mesocosm settings (Baert et al 2016b;Garnier et al 2017;Karakoc ß et al 2018;Pennekamp et al 2018). Importantly, although measuring DS was rather easy in our modelling study, empirical studies may be limited because of the difficulty to measure multiple stability properties in natural systems.…”