Biology subjects

Cant, J.

Publications and source records attributed to Cant, J..

5 recordsLinked to original sources

bioRxiv2022

Evolutionary processes, not environmental drivers, determine the resilience of natural populations

Escalating climatic and anthropogenic pressures expose ecosystems worldwide to increasingly frequent disturbances. Yet, our ability to forecast the responses of natural populations to these disturbances is impeded by a limited understanding for how exposure to stochastic environments shapes population resilience. Instead, the resilience, and vulnerability, of natural populations to ongoing global change is often presumed based on their contemporary exposure to environmental stochasticity. To test the validity of this assumption, we investigated the association between the resilience attributes (e.g., resistance and recovery) of natural animal and plant populations, and measures of local environmental stochasticity (e.g., spectral frequency and abiotic range); collating data from 2,242 populations across 369 animal, plant, and algal species. Unexpectedly, recent abiotic stochasticity regimes from the past 50 years do not predict the inherent ability of populations to resist or recover from disturbances. Instead, population resilience is strongly affected by phylogenetic relationships among species, with survival and developmental investments shaping their responses to stochastic regimes. Contrary to the classical assumption that exposure to recent environmental shifts confers a greater ability to cope with current and future global change, our findings suggest that population resilience is a consequence of evolutionary processes and/or deep-time environmental regimes. Significance statementPopulations that currently endure more variable abiotic conditions are often expected to be less vulnerable to future increases in climatic variability. However, without defining the link between abiotic variability and the capacity for populations to resist and recover following disturbances (i.e., their resilience), we cannot predict the consequences of ongoing community reassembly. Evaluating the association between measures of abiotic variability and the resilience attributes of 2,242 animal, plant, and algae populations, we discredit the assumption that contemporary exposure to more frequent environmental shifts confers a greater ability to cope with future global change. Instead, the resilience attributes of natural populations appear to have been moulded over longer-term evolutionary timeframes and are thus not a response to more recent experiences.

ecology↗

bioRxiv2021

Coral assemblages at higher latitudes favour short-term potential over long-term performance

The persistent exposure of coral communities to more variable abiotic regimes is assumed to augment their resilience to future climatic variability. Yet, while the determinants of coral population resilience across species remain unknown, we are unable to predict the winners and losers across reef ecosystems exposed to increasingly variable conditions. Using annual surveys of 3171 coral individuals across Australia and Japan (2017-2019), we explore spatial variation across the short- and long-term dynamics of competitive, stress-tolerant, and weedy assemblages to evaluate how thermal variability mediates the structural composition of coral communities. We illustrate how, by promoting short-term potential over long-term performance, coral assemblages can reduce their vulnerability to stochastic environments. However, compared to stress-tolerant, and weedy assemblages, competitive coral taxa display a reduced capacity for elevating their short-term potential. Accordingly, future climatic shifts threaten the structural complexity of coral assemblages in variable environments, emulating the degradation expected across global tropical reefs.

ecology↗

bioRxiv2021

Life history mediates the trade-offs among different components of demographic resilience

Summary paragraphAccelerating rates of biodiversity loss underscore the need to understand how species achieve resilience -their ability to resist and recover from a/biotic disturbances. Yet, the factors determining the resilience of species remain poorly understood, due to disagreements on its definition and the lack of large-scale analyses. Here, we investigate how the life history of 785 natural populations of animals and plants predict their intrinsic ability to be resilient. We show that demographic resilience can be achieved through different combinations of compensation, resistance, and recovery after a disturbance. We demonstrate that these resilience components are highly correlated with life history traits related to the species pace of life and reproductive strategy. Species with longer generation times require longer recovery times post-disturbance, while those with greater reproductive capacity have greater resistance and compensation. Our findings highlight the key role of life history traits to understand species resilience, improving our ability to predict how natural populations cope with disturbance regimes.

ecology↗

bioRxiv2021

Transient amplification enhances the persistence of tropicalising coral populations in marginal high latitude environments.

Predicting the viability of species exposed to increasing climatic stress requires an appreciation for the mechanisms underpinning the success or failure of marginal populations. Rather than traditional metrics of long-term population performance, here we illustrate that short-term (i.e. transient) demographic characteristics, including measures of resistance, recovery, and compensation, are fundamental in the poleward range expansion of hard corals, facilitating the establishment of coral populations at higher-latitudes. Through the annual census of tropical and subtropical Acropora spp. colonies in Japan, between 2017-2019, we show how the transient amplification potential of a subtropical coral population supports its enhanced growth within unstable environmental conditions. The transient dynamics of both the tropical and subtropical populations were strongly influenced by their corresponding recruitment patterns. However, we demonstrate that variation in colony survival and fragmentation patterns between the two populations determines their relative capacities for transient amplification. This latitudinal variation in the transient dynamics of Acropora spp. populations emphasizes that coral populations can possess the demographic plasticity necessary for exploiting more variable, marginal conditions.

ecology↗

bioRxiv2021

Transient demographic approaches can drastically expand the toolbox of coral reef science

Coral communities are threatened by an increasing plethora of abiotic and biotic disturbances. Preventing the ensuing loss of coral coverage and diversity calls for a mechanistic understanding of resilience across coral species and populations that is currently lacking in coral reef science. Assessments into the dynamics of coral populations typically focus on their long-term (i.e. asymptotic) characteristics, tacitly assuming stable environments in which populations can attain their long-term characteristics. Instead, we argue that greater focus is needed on investigating the transient (i.e. short-term) dynamics of coral populations to describe and predict their characteristics and trajectories within unstable environments. Applying transient demographic approaches to the evaluation and forecasting of the responses of coral populations to disturbance holds promise for expediting our capacity to predict and manage the resilience of coral populations, species, and communities.

ecology↗