Understanding how species' thermal limits have evolved across the tree of life is central to predicting species' responses to climate change. Here, using experimentally-derived estimates of thermal ...tolerance limits for over 2000 terrestrial and aquatic species, we show that most of the variation in thermal tolerance can be attributed to a combination of adaptation to current climatic extremes, and the existence of evolutionary 'attractors' that reflect either boundaries or optima in thermal tolerance limits. Our results also reveal deep-time climate legacies in ectotherms, whereby orders that originated in cold paleoclimates have presently lower cold tolerance limits than those with warm thermal ancestry. Conversely, heat tolerance appears unrelated to climate ancestry. Cold tolerance has evolved more quickly than heat tolerance in endotherms and ectotherms. If the past tempo of evolution for upper thermal limits continues, adaptive responses in thermal limits will have limited potential to rescue the large majority of species given the unprecedented rate of contemporary climate change.
Process, Mechanism, and Modeling in Macroecology Connolly, Sean R.; Keith, Sally A.; Colwell, Robert K. ...
Trends in ecology & evolution,
November 2017, 2017-11-00, 20171101, Volume:
32, Issue:
11
Journal Article
Peer reviewed
Open access
Macroecology has traditionally relied on descriptive characterization of large-scale ecological patterns to offer narrative explanations for the origin and maintenance of those patterns. Only ...recently have macroecologists begun to employ models termed ‘process-based’ and ‘mechanistic’, in contrast to other areas of ecology, where such models have a longer history. Here, we define and differentiate between process-based and mechanistic features of models, and we identify and discuss important advantages of working with models possessing such features. We describe some of the risks associated with process-based and mechanistic model-centered research programs, and we propose ways to mitigate these risks. Giving process-based and mechanistic models a more central role in research programs can reinvigorate macroecology by strengthening the link between theory and data.
Macroecologists are increasingly using process-based and mechanistic models.
Process-based models need not be reductionistic.
Such models can be used for theoretical, statistical, and virtual-worlds modelling.
These innovations allow stronger inferences about causes of ecological patterns.
Coral reefs are biologically diverse and ecologically complex ecosystems constructed by stony corals. Despite decades of research, basic coral population biology and community ecology questions ...remain. Quantifying trait variation among species can help resolve these questions, but progress has been hampered by a paucity of trait data for the many, often rare, species and by a reliance on nonquantitative approaches. Therefore, we propose filling data gaps by prioritizing traits that are easy to measure, estimating key traits for species with missing data, and identifying ‘supertraits’ that capture a large amount of variation for a range of biological and ecological processes. Such an approach can accelerate our understanding of coral ecology and our ability to protect critically threatened global ecosystems.
Characterizing trait variation between species helps quantify fundamental biological, ecological, and evolutionary processes.
Hampered by a paucity of trait data, novel approaches are needed to fill data gaps by prioritizing traits that are easy to measure.
‘Supertraits’ capture a large amount of process variation. Their discovery will accelerate understanding of coral ecology and our ability to protect a critically threatened global ecosystem.
The direct and indirect effects of climate change can affect, and are mediated by, changes in animal behaviour. However, we often lack sufficient empirical data to assess how large‐scale disturbances ...affect the behaviour of individuals, which scales up to influence communities.
Here, we investigate these patterns by focusing on the foraging behaviour of butterflyfishes, prominent coral‐feeding fishes on coral reefs, before and after a mass coral bleaching event in Iriomote, Japan.
In response to 65% coral mortality, coral‐feeding fishes broadened their diets, showing a significant weakening of dietary preferences across species.
Multiple species reduced their consumption of bleaching‐sensitive Acropora corals, while expanding their diets to consume a variety of other coral genera. This resulted in decreased dietary overlap among butterflyfishes.
Behavioural changes in response to bleaching may increase resilience of coral reef fishes in the short term. However, coral mortality has reduced populations of coral‐feeders world‐wide, indicating the changes in feeding behaviour we document here may not be sufficient to ensure long‐term resilience of butterflyfishes on coral reefs.
This work highlights important bottom‐up effects of coral bleaching on the specificity of reef fish diets. This simultaneous dietary expansion across species follows expectations from optimal foraging theory and is driven by a weakening of dietary preferences in response to food loss. These changes can significantly alter resource overlap. Photo of a feeding Chaetodon trifascialis individual (credit: Sally Keith).
A key goal of conservation is to protect biodiversity by supporting the long-term persistence of viable, natural populations of wild species. Conservation practice has long been guided by genetic, ...ecological and demographic indicators of risk. Emerging evidence of animal culture across diverse taxa and its role as a driver of evolutionary diversification, population structure and demographic processes may be essential for augmenting these conventional conservation approaches and decision-making. Animal culture was the focus of a ground-breaking resolution under the Convention on the Conservation of Migratory Species of Wild Animals (CMS), an international treaty operating under the UN Environment Programme. Here, we synthesize existing evidence to demonstrate how social learning and animal culture interact with processes important to conservation management. Specifically, we explore how social learning might influence population viability and be an important resource in response to anthropogenic change, and provide examples of how it can result in phenotypically distinct units with different, socially learnt behavioural strategies. While identifying culture and social learning can be challenging, indirect identification and parsimonious inferences may be informative. Finally, we identify relevant methodologies and provide a framework for viewing behavioural data through a cultural lens which might provide new insights for conservation management.
AIM: Marine macroalgae provide an excellent opportunity to test hypotheses about latitudinal diversity gradients because macroalgal richness decreases towards the tropics, contrary to classic ...patterns, and because three evolutionarily distinct macroalgal clades (Rhodophyta, Chlorophyta, Phaeophyceae) have converged ecologically. Specifically, we determine the extent to which environmental conditions can predict genus richness in macroalgae. We also evaluate whether the magnitude or direction of the effect of environmental factors, or their ability to explain variation in macroalgal diversity, varies geographically. LOCATION: Global oceans. METHODS: We formulated and fitted global spatial regression models and geographically weighted regression (GWR) models to determine the extent to which environmental conditions could predict genus richness in macroalgae. GWR allowed us to determine how the role of environmental conditions varied amongst geographical regions. RESULTS: The global regression model showed that sea surface temperature and nutrients were important predictors of macroalgal genus richness at a global scale. However, GWR revealed that environmental factors explained less variability in richness in the tropics than elsewhere. MAIN CONCLUSIONS: Our results show that whilst environmental conditions influence marine macroalgal diversity, the strength of this influence shows considerable geographical variation. In particular, environmental conditions explain more of the observed variation in diversity at high latitudes than at low latitudes. This finding is consistent with the hypothesis that environmental tolerances influence species distributions more strongly at high latitudes, whereas other factors, such as biotic interactions, play a more prominent role in the tropics.
Aim
Biodiversity loss is impacting essential ecosystem functions and services across the globe. Recently, our interest in the benefits of biodiversity for ecosystem function has shifted focus from ...measurements of species richness to functional diversity and composition. However, the additional importance of other community characteristics, such as species evenness and co‐occurrence, for diversity‐driven ecosystem function is less known. We used herbivorous coral reef fish as a model system to investigate how co‐occurrence of different functional groups, rather than purely functional diversity, within an assemblage might affect the coral reef benthic state.
Location
Western Atlantic.
Time period
2007–2017.
Major taxa studied
Herbivorous reef fish.
Methods
We analysed benthic and fish assemblage data from 601 sites across 12 countries in the western Atlantic. Using diversity–interaction models, we investigated how the composition and relative abundances of reef fish functional groups were correlated with benthic cover and estimates of coral calcification rates. We used statistical interactions to explore the importance of co‐occurrence of herbivorous fish functional groups for the coral reef benthic state.
Results
We found that co‐occurrence of herbivorous fish functional groups, in addition to functional diversity, was correlated with reduced algal cover and increased coral accretion. Moreover, pairwise statistical interactions between functional groups were significantly correlated with an improvement in the coral reef benthic state.
Main conclusions
Our results support the idea that functional group co‐occurrence, in addition to functional diversity, within herbivorous fish offers additional benefits to the coral reef benthic state. We identify farming damselfish and excavating parrotfish as potential key determinants of the coral reef benthic state and highlight that co‐occurrence of cropping and scraping herbivores might promote coral accretion. Our findings support the argument that protecting herbivore abundance without regard to the species and functional groups present is not enough to preserve coral reef health and that fine‐scale community composition must be considered.
Behaviour is often the first response of organisms to rapid environmental change and can be a key mediator of ecological responses at higher organisational levels.Macroecology seeks to understand ...patterns and processes that emerge from the interaction of many smaller components, and behaviour is an important but understudied category of component.We propose the new field of macrobehaviour, which aims to unify behavioural ecology and macroecology. Researchers from both disciplines can take advantage of new tools, approaches, concepts, and data, and ultimately ask new interdisciplinary questions.
We explore how integrating behavioural ecology and macroecology can provide fundamental new insight into both fields, with particular relevance for understanding ecological responses to rapid environmental change. We outline the field of macrobehaviour, which aims to unite these disciplines explicitly, and highlight examples of research in this space. Macrobehaviour can be envisaged as a spectrum, where behavioural ecologists and macroecologists use new data and borrow tools and approaches from one another. At the heart of this spectrum, interdisciplinary research considers how selection in the context of large-scale factors can lead to systematic patterns in behavioural variation across space, time, and taxa, and in turn, influence macroecological patterns and processes. Macrobehaviour has the potential to enhance forecasts of future biodiversity change.
We explore how integrating behavioural ecology and macroecology can provide fundamental new insight into both fields, with particular relevance for understanding ecological responses to rapid environmental change. We outline the field of macrobehaviour, which aims to unite these disciplines explicitly, and highlight examples of research in this space. Macrobehaviour can be envisaged as a spectrum, where behavioural ecologists and macroecologists use new data and borrow tools and approaches from one another. At the heart of this spectrum, interdisciplinary research considers how selection in the context of large-scale factors can lead to systematic patterns in behavioural variation across space, time, and taxa, and in turn, influence macroecological patterns and processes. Macrobehaviour has the potential to enhance forecasts of future biodiversity change.
Aim
Ecological refuges buffer organisms against stressors and mediate a range of species interactions. However, their role in the context of biological invasions has yet to be synthesized, despite ...the increasing prevalence and impact of non‐native species. To address this, we conducted a systematic review aiming to determine the extent to which refuges are considered explicitly in the invasion literature and to synthesize their function.
Location
Global.
Time period
Present day.
Major taxa studied
All.
Methods
Our search of the literature was conducted using the SCOPUS and Web of Science databases and followed the preferred reporting items for systematic reviews and meta‐analyses (PRISMA) protocol. We obtained 315 records of refuge use in biological invasions from 300 studies. From each record, we extracted information relating to the experimental design, species characteristics and refuge type, where available.
Results
Refuges and refuge‐mediated processes are widely reported in the invasion literature. Native species commonly use refuges to avoid non‐native predation and competition, with spatial complexity and habitat heterogeneity key factors in facilitating their coexistence. Records show that artificial structures safeguard non‐natives in their introduced range. However, there were key differences in the use of such structures in marine and terrestrial environments. Moreover, the enhanced structural complexity created by non‐native plants and bivalves is often reported to act as a predation refuge for other species.
Main conclusions
The ubiquity of refuge‐based processes suggests that refuges can play an important role in affecting the persistence, spread and impacts of non‐native species, either through previously described mechanisms (i.e. refuge‐mediated apparent competition and the persistent pressure scenario) or through a mechanism we describe (i.e. when non‐native species use existing refuges), or both.
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