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1.
Glob Chang Biol ; 30(1): e17140, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38273497

RESUMO

Growing evidence suggests that liana competition with trees is threatening the global carbon sink by slowing the recovery of forests following disturbance. A recent theory based on local and regional evidence further proposes that the competitive success of lianas over trees is driven by interactions between forest disturbance and climate. We present the first global assessment of liana-tree relative performance in response to forest disturbance and climate drivers. Using an unprecedented dataset, we analysed 651 vegetation samples representing 26,538 lianas and 82,802 trees from 556 unique locations worldwide, derived from 83 publications. Results show that lianas perform better relative to trees (increasing liana-to-tree ratio) when forests are disturbed, under warmer temperatures and lower precipitation and towards the tropical lowlands. We also found that lianas can be a critical factor hindering forest recovery in disturbed forests experiencing liana-favourable climates, as chronosequence data show that high competitive success of lianas over trees can persist for decades following disturbances, especially when the annual mean temperature exceeds 27.8°C, precipitation is less than 1614 mm and climatic water deficit is more than 829 mm. These findings reveal that degraded tropical forests with environmental conditions favouring lianas are disproportionately more vulnerable to liana dominance and thus can potentially stall succession, with important implications for the global carbon sink, and hence should be the highest priority to consider for restoration management.


Des preuves de plus en plus nombreuses suggèrent que la competition entre lianes et les arbres menace le puits de carbone mondial en ralentissant la récupération des forêts après une perturbation. Une théorie récente, fondée sur des observations locales et régionales, propose en outre que le succès compétitif des lianes sur les arbres est dû aux interactions entre la perturbation forestière et le climat. Nous présentons la première évaluation mondiale de la performance relative des lianes par rapport aux arbres en réponse aux perturbations forestières et aux facteurs climatiques. En utilisant un ensemble de données sans précédent, nous avons analysé 651 échantillons de végétation représentant 26,538 lianes et 82,802 arbres, issus de 556 emplacements uniques dans le monde entier, tirés de 83 publications. Les résultats montrent que les lianes ont de meilleure performances par rapport aux arbres (augmentation du ratio liane-arbre) lorsque les forêts sont perturbées, sous des zones chaudes aves précipitations faibles, et vers les basses altitudes tropicales. Nous avons également constaté que les lianes peuvent être un facteur critique entravant la récupération des forêts dans les forêts perturbées connaissant des climats favorables aux lianes, car les données de chronoséquence montrent que le succès compétitif élevé des lianes sur les arbres peut persister pendant des décennies après les perturbations, surtout lorsque la température annuelle moyenne dépasse 27.8°C, que les précipitations sont inférieures à 1614 mm et que le déficit hydrique climatique est supérieur à 829 mm. Ces découvertes révèlent que les forêts tropicales dégradées avec des conditions environnementales favorables aux lianes sont disproportionnellement plus vulnérables à la dominance des lianes, et peuvent ainsi potentiellement entraver la succession, avec d'importantes implications pour le puits de carbone mondial et devraient donc être la plus haute priorité à considérer pour la gestion de la restauration.


Assuntos
Árvores , Clima Tropical , Árvores/fisiologia , Florestas , Sequestro de Carbono , Água
2.
Trends Ecol Evol ; 38(9): 843-858, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37179171

RESUMO

For each assessment cycle of the Intergovernmental Panel on Climate Change (IPCC), researchers in the life sciences are called upon to provide evidence to policymakers planning for a changing future. This research increasingly relies on highly technical and complex outputs from climate models. The strengths and weaknesses of these data may not be fully appreciated beyond the climate modelling community; therefore, uninformed use of raw or preprocessed climate data could lead to overconfident or spurious conclusions. We provide an accessible introduction to climate model outputs that is intended to empower the life science community to robustly address questions about human and natural systems in a changing world.


Assuntos
Mudança Climática , Modelos Climáticos , Humanos , Previsões
3.
Ecol Appl ; 33(4): e2852, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36946332

RESUMO

Climate change is already having profound effects on biodiversity, but climate change adaptation has yet to be fully incorporated into area-based management tools used to conserve biodiversity, such as protected areas. One main obstacle is the lack of consensus regarding how impacts of climate change can be included in spatial conservation plans. We propose a climate-smart framework that prioritizes the protection of climate refugia-areas of low climate exposure and high biodiversity retention-using climate metrics. We explore four aspects of climate-smart conservation planning: (1) climate model ensembles; (2) multiple emission scenarios; (3) climate metrics; and (4) approaches to identifying climate refugia. We illustrate this framework in the Western Pacific Ocean, but it is equally applicable to terrestrial systems. We found that all aspects of climate-smart conservation planning considered affected the configuration of spatial plans. The choice of climate metrics and approaches to identifying refugia have large effects in the resulting climate-smart spatial plans, whereas the choice of climate models and emission scenarios have smaller effects. As the configuration of spatial plans depended on climate metrics used, a spatial plan based on a single measure of climate change (e.g., warming) will not necessarily be robust against other measures of climate change (e.g., ocean acidification). We therefore recommend using climate metrics most relevant for the biodiversity and region considered based on a single or multiple climate drivers. To include the uncertainty associated with different climate futures, we recommend using multiple climate models (i.e., an ensemble) and emission scenarios. Finally, we show that the approaches we used to identify climate refugia feature trade-offs between: (1) the degree to which they are climate-smart, and (2) their efficiency in meeting conservation targets. Hence, the choice of approach will depend on the relative value that stakeholders place on climate adaptation. By using this framework, protected areas can be designed with improved longevity and thus safeguard biodiversity against current and future climate change. We hope that the proposed climate-smart framework helps transition conservation planning toward climate-smart approaches.


Assuntos
Conservação dos Recursos Naturais , Água do Mar , Conservação dos Recursos Naturais/métodos , Concentração de Íons de Hidrogênio , Biodiversidade , Incerteza , Mudança Climática , Ecossistema
4.
Sci Rep ; 11(1): 13566, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193910

RESUMO

Collecting quantitative information on animal behaviours is difficult, especially from cryptic species or species that alter natural behaviours under observation. Using harness-mounted tri-axial accelerometers free-roaming domestic cats (Felis Catus) we developed a methodology that can precisely classify finer-scale behaviours. We further tested the effect of a prey-protector device designed to reduce prey capture. We aligned accelerometer traces collected at 50 Hz with video files (60 fps) and labelled 12 individual behaviours, then trained a supervised machine-learning algorithm using Kohonen super self-organising maps (SOM). The SOM was able to predict individual behaviours with a ~ 99.6% overall accuracy, which was slightly better than for random forest estimates using the same dataset (98.9%). There was a significant effect of sample size, with precision and sensitivity decreasing rapidly below 2000 1-s observations. We were also able to detect a behaviour specific reduction in the predictability when cats were fitted with the prey-protector device indicating it altered biomechanical gait. Our results can be applied in movement ecology, zoology and conservation, where habitat specific movement performance between predators or prey may be critical to managing species of conservation significance, or in veterinary and agricultural fields, where early detection of movement pathologies can improve animal welfare.


Assuntos
Acelerometria , Comportamento Animal/fisiologia , Ecossistema , Aprendizado de Máquina Supervisionado , Animais , Gatos , Feminino , Masculino
5.
Parasitol Res ; 120(7): 2493-2503, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34115215

RESUMO

Recent anecdotal reports from seafood processors in eastern Australia have described an increased occurrence of post-mortem myoliquefaction ('jellymeat') in broadbill swordfish Xiphias gladius, and macroscopic cysts throughout the musculature of yellowfin tuna Thunnus albacares. A genus of parasitic cnidarians, Kudoa (Myxosporea, Multivalvulida), species of which are known to occur in economically important wild-caught fish species globally, can cause similar quality-deterioration issues. However, Kudoa sp. epizootiology within commercially harvested, high-value fish caught within Australia is poorly understood, despite the parasite's economic importance. To determine the causative agent responsible for the observed quality deterioration in swordfish and yellowfin tuna, muscle-tissue samples from seafood processors in Mooloolaba, Australia, collected from October 2019-February 2020, were examined for parasitic infection. Kudoid myxospores were identified from both hosts and were subquadrate in shape, with four equal-sized polar capsules. The SSU rDNA sequences from both fish shared > 99% identity to Kudoa species. Kudoa musculoliquefaciens was isolated from 87.1% of swordfish sampled, suggesting that it is a widespread parasite in swordfish from the southwest Pacific Ocean. This study provides the first molecular and morphological characterisation of Kudoa thunni in yellowfin tuna and K. musculoliquefaciens in swordfish harvested from the waters of eastern Australia, expanding the geographical distribution of K. thunni and K. musculoliquefaciens to include the Coral and Tasman Seas. We demonstrate that not all infected swordfish progress to jellymeat, show the usefulness of molecular tools for reliably identifying infection by Kudoa spp., and add to the overall knowledge of kudoid epizootiology in wild-caught fish.


Assuntos
Peixes/parasitologia , Myxozoa/classificação , Atum/parasitologia , Animais , Austrália , DNA Ribossômico/genética , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Músculos/parasitologia , Myxozoa/anatomia & histologia , Myxozoa/genética , Oceano Pacífico , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , Filogenia , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Alimentos Marinhos/parasitologia , Especificidade da Espécie
6.
Proc Natl Acad Sci U S A ; 118(15)2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33876750

RESUMO

The latitudinal gradient in species richness, with more species in the tropics and richness declining with latitude, is widely known and has been assumed to be stable over recent centuries. We analyzed data on 48,661 marine animal species since 1955, accounting for sampling variation, to assess whether the global latitudinal gradient in species richness is being impacted by climate change. We confirm recent studies that show a slight dip in species richness at the equator. Moreover, richness across latitudinal bands was sensitive to temperature, reaching a plateau or declining above a mean annual sea surface temperature of 20 °C for most taxa. In response, since the 1970s, species richness has declined at the equator relative to an increase at midlatitudes and has shifted north in the northern hemisphere, particularly among pelagic species. This pattern is consistent with the hypothesis that climate change is impacting the latitudinal gradient in marine biodiversity at a global scale. The intensification of the dip in species richness at the equator, especially for pelagic species, suggests that it is already too warm there for some species to survive.


Assuntos
Organismos Aquáticos/fisiologia , Biodiversidade , Aquecimento Global , Biomassa
7.
J Anim Ecol ; 90(3): 615-627, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33232514

RESUMO

Climate change is altering the latitudinal distributions of species, with their capacity to keep pace with a shifting climate depending on the stochastic expression of population growth rates, and the influence of compensatory density feedback on age-specific survival rates. We use population-abundance time series at the leading edge of an expanding species' range to quantify the contribution of stochastic environmental drivers and density feedbacks to the dynamics of life stage-specific population growth. Using a tropical, range-shifting Indo-Pacific damselfish (Abudefduf vaigiensis) as a model organism, we applied variants of the phenomenological Gompertz-logistic model to a 14-year dataset to quantify the relative importance of density feedback and stochastic environmental drivers on the separate and aggregated population growth rates of settler and juvenile life stages. The top-ranked models indicated that density feedback negatively affected the growth of tropical settlers and juveniles. Rates of settlement were negatively linked to temperatures experienced by parents at potential source populations in the tropics, but their subsequent survival and that of juveniles increased with the temperatures experienced at the temperate sink. Including these stochastic effects doubled the deviance explained by the models, corroborating an important role of temperature. By incorporating sea-surface temperature projections for the remainder of this century into these models, we anticipate improved conditions for the population growth of juvenile coral-reef fishes, but not for settlers in temperate ecosystems. Previous research has highlighted the association between temperature and the redistribution of species. Our analyses reveal the contrasting roles of different life stages in the dynamics of range-shifting species responding to climate change, as they transition from vagrancy to residency in their novel ranges.


Assuntos
Antozoários , Ecossistema , Animais , Mudança Climática , Recifes de Corais , Peixes , Oceanos e Mares
8.
Glob Chang Biol ; 26(10): 5564-5573, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32530107

RESUMO

Climate change is redistributing marine and terrestrial species globally. Life-history traits mediate the ability of species to cope with novel environmental conditions, and can be used to gauge the potential redistribution of taxa facing the challenges of a changing climate. However, it is unclear whether the same traits are important across different stages of range shifts (arrival, population increase, persistence). To test which life-history traits most mediate the process of range extension, we used a 16-year dataset of 35 range-extending coral-reef fish species and quantified the importance of various traits on the arrival time (earliness) and degree of persistence (prevalence and patchiness) at higher latitudes. We show that traits predisposing species to shift their range more rapidly (large body size, broad latitudinal range, long dispersal duration) did not drive the early stages of redistribution. Instead, we found that as diet breadth increased, the initial arrival and establishment (prevalence and patchiness) of climate migrant species in temperate locations occurred earlier. While the initial incursion of range-shifting species depends on traits associated with dispersal potential, subsequent establishment hinges more on a species' ability to exploit novel food resources locally. These results highlight that generalist species that can best adapt to novel food sources might be most successful in a future ocean.


Assuntos
Antozoários , Mudança Climática , Animais , Recifes de Corais , Dieta , Peixes
10.
Nature ; 569(7754): 50-51, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31036966
11.
Trends Ecol Evol ; 33(6): 441-457, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29716742

RESUMO

Climate change is shifting the ranges of species. Simple predictive metrics of range shifts such as climate velocity, that do not require extensive knowledge or data on individual species, could help to guide conservation. We review research on climate velocity, describing the theory underpinning the concept and its assumptions. We highlight how climate velocity has already been applied in conservation-related research, including climate residence time, climate refugia, endemism, historic and projected range shifts, exposure to climate change, and climate connectivity. Finally, we discuss ways to enhance the use of climate velocity in conservation through tailoring it to be more biologically meaningful, informing design of protected areas, conserving ocean biodiversity in 3D, and informing conservation actions.


Assuntos
Biodiversidade , Mudança Climática , Conservação dos Recursos Naturais , Aquecimento Global , Oceanos e Mares
12.
PLoS One ; 12(5): e0177116, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28481897

RESUMO

Predicting responses of coastal ecosystems to altered sea surface temperatures (SST) associated with global climate change, requires knowledge of demographic responses of individual species. Body size is an excellent metric because it scales strongly with growth and fecundity for many ectotherms. These attributes can underpin demographic as well as community and ecosystem level processes, providing valuable insights for responses of vulnerable coastal ecosystems to changing climate. We investigated contemporary macroscale patterns in body size among widely distributed crustaceans that comprise the majority of intertidal abundance and biomass of sandy beach ecosystems of the eastern Pacific coasts of Chile and California, USA. We focused on ecologically important species representing different tidal zones, trophic guilds and developmental modes, including a high-shore macroalga-consuming talitrid amphipod (Orchestoidea tuberculata), two mid-shore scavenging cirolanid isopods (Excirolana braziliensis and E. hirsuticauda), and a low-shore suspension-feeding hippid crab (Emerita analoga) with an amphitropical distribution. Significant latitudinal patterns in body sizes were observed for all species in Chile (21° - 42°S), with similar but steeper patterns in Emerita analoga, in California (32°- 41°N). Sea surface temperature was a strong predictor of body size (-4% to -35% °C-1) in all species. Beach characteristics were subsidiary predictors of body size. Alterations in ocean temperatures of even a few degrees associated with global climate change are likely to affect body sizes of important intertidal ectotherms, with consequences for population demography, life history, community structure, trophic interactions, food-webs, and indirect effects such as ecosystem function. The consistency of results for body size and temperature across species with different life histories, feeding modes, ecological roles, and microhabitats inhabiting a single widespread coastal ecosystem, and for one species, across hemispheres in this space-for-time substitution, suggests predictions of ecosystem responses to thermal effects of climate change may potentially be generalised, with important implications for coastal conservation.


Assuntos
Tamanho Corporal , Mudança Climática , Crustáceos , Animais
13.
PLoS One ; 11(10): e0164934, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27764164

RESUMO

Management authorities seldom have the capacity to comprehensively address the full suite of anthropogenic stressors, particularly in the coastal zone where numerous threats can act simultaneously to impact reefs and other ecosystems. This situation requires tools to prioritise management interventions that result in optimum ecological outcomes under a set of constraints. Here we develop one such tool, introducing a Bayesian Belief Network to model the ecological condition of inshore coral reefs in Moreton Bay (Australia) under a range of management actions. Empirical field data was used to model a suite of possible ecological responses of coral reef assemblages to five key management actions both in the sea (e.g. expansion of reserves, mangrove & seagrass restoration, fishing restrictions) and on land (e.g. lower inputs of sediment and sewage from treatment plants). Models show that expanding marine reserves (a 'marine action') and reducing sediment inputs from the catchments (a 'land action') were the most effective investments to achieve a better status of reefs in the Bay, with both having been included in >58% of scenarios with positive outcomes, and >98% of the most effective (5th percentile) scenarios. Heightened fishing restrictions, restoring habitats, and reducing nutrient discharges from wastewater treatment plants have additional, albeit smaller effects. There was no evidence that combining individual management actions would consistently produce sizeable synergistic until after maximum investment on both marine reserves (i.e. increasing reserve extent from 31 to 62% of reefs) and sediments (i.e. rehabilitating 6350 km of waterways within catchments to reduce sediment loads by 50%) were implemented. The method presented here provides a useful tool to prioritize environmental actions in situations where multiple competing management interventions exist for coral reefs and in other systems subjected to multiple stressor from the land and the sea.


Assuntos
Conservação dos Recursos Naturais/métodos , Recifes de Corais , Oceanos e Mares , Teorema de Bayes , Modelos Estatísticos
14.
PeerJ ; 4: e2460, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27672510

RESUMO

Coastal birds are critical ecosystem constituents on sandy shores, yet are threatened by depressed reproductive success resulting from direct and indirect anthropogenic and natural pressures. Few studies examine clutch fate across the wide range of environments experienced by birds; instead, most focus at the small site scale. We examine survival of model shorebird clutches as an index of true clutch survival at a regional scale (∼200 km), encompassing a variety of geomorphologies, predator communities, and human use regimes in southeast Queensland, Australia. Of the 132 model nests deployed and monitored with cameras, 45 (34%) survived the experimental exposure period. Thirty-five (27%) were lost to flooding, 32 (24%) were depredated, nine (7%) buried by sand, seven (5%) destroyed by people, three (2%) failed by unknown causes, and one (1%) was destroyed by a dog. Clutch fate differed substantially among regions, particularly with respect to losses from flooding and predation. 'Topographic' exposure was the main driver of mortality of nests placed close to the drift line near the base of dunes, which were lost to waves (particularly during storms) and to a lesser extent depredation. Predators determined the fate of clutches not lost to waves, with the depredation probability largely influenced by region. Depredation probability declined as nests were backed by higher dunes and were placed closer to vegetation. This study emphasizes the scale at which clutch fate and survival varies within a regional context, the prominence of corvids as egg predators, the significant role of flooding as a source of nest loss, and the multiple trade-offs faced by beach-nesting birds and those that manage them.

15.
J Anim Ecol ; 85(2): 437-44, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26476209

RESUMO

Connectivity is a pivotal feature of landscapes that affects the structure of populations and the functioning of ecosystems. It is also a key consideration in conservation planning. But the potential functional effects of landscape connectivity are rarely evaluated in a conservation context. The removal of algae by herbivorous fish is a key ecological function on coral reefs that promotes coral growth and recruitment. Many reef herbivores are harvested and some use other habitats (like mangroves) as nurseries or feeding areas. Thus, the effects of habitat connectivity and marine reserves can jointly promote herbivore populations on coral reefs, thereby influencing reef health. We used a coral reef seascape in eastern Australia to test whether seascape connectivity and reserves influence herbivory. We measured herbivore abundance and rates of herbivory (on turf algae and macroalgae) on reefs that differed in both their level of connectivity to adjacent mangrove habitats and their level of protection from fishing. Reserves enhanced the biomass of herbivorous fish on coral reefs in all seascape settings and promoted consumption of turf algae. Consumption of turf algae was correlated with the biomass of surgeonfish that are exploited outside reserves. By contrast, both reserve status and connectivity influenced herbivory on macroalgae. Consumption of macroalgae was greatest on fished reefs that were far from mangroves and was not strongly correlated with any fish species. Our findings demonstrate that landscape connectivity and reserve status can jointly affect the functioning of ecosystems. Moreover, we show that reserve and connectivity effects can differ markedly depending on resource type (in this case turf algae vs. macroalgae). The effectiveness of conservation initiatives will therefore depend on our ability to understand how these multiple interactive effects structure the distribution of ecological functions. These findings have wider implications for the spatial conservation of heterogeneous environments and strengthen the case that the impact of conservation on ecosystem functioning is contingent on how reserves are positioned in landscapes.


Assuntos
Conservação dos Recursos Naturais , Recifes de Corais , Peixes/fisiologia , Herbivoria , Animais , Antozoários , Cadeia Alimentar , Microalgas/crescimento & desenvolvimento , Queensland , Alga Marinha/crescimento & desenvolvimento
16.
Glob Chang Biol ; 22(4): 1548-60, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26661135

RESUMO

Climate change is shifting species' distribution and phenology. Ecological traits, such as mobility or reproductive mode, explain variation in observed rates of shift for some taxa. However, estimates of relationships between traits and climate responses could be influenced by how responses are measured. We compiled a global data set of 651 published marine species' responses to climate change, from 47 papers on distribution shifts and 32 papers on phenology change. We assessed the relative importance of two classes of predictors of the rate of change, ecological traits of the responding taxa and methodological approaches for quantifying biological responses. Methodological differences explained 22% of the variation in range shifts, more than the 7.8% of the variation explained by ecological traits. For phenology change, methodological approaches accounted for 4% of the variation in measurements, whereas 8% of the variation was explained by ecological traits. Our ability to predict responses from traits was hindered by poor representation of species from the tropics, where temperature isotherms are moving most rapidly. Thus, the mean rate of distribution change may be underestimated by this and other global syntheses. Our analyses indicate that methodological approaches should be explicitly considered when designing, analysing and comparing results among studies. To improve climate impact studies, we recommend that (1) reanalyses of existing time series state how the existing data sets may limit the inferences about possible climate responses; (2) qualitative comparisons of species' responses across different studies be limited to studies with similar methodological approaches; (3) meta-analyses of climate responses include methodological attributes as covariates; and (4) that new time series be designed to include the detection of early warnings of change or ecologically relevant change. Greater consideration of methodological attributes will improve the accuracy of analyses that seek to quantify the role of climate change in species' distribution and phenology changes.


Assuntos
Mudança Climática , Ecologia/métodos , Organismos Aquáticos , Modelos Teóricos , Dinâmica Populacional , Estações do Ano
17.
Ecology ; 96(10): 2715-25, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26649392

RESUMO

Species composition is expected to alter ecological function in assemblages if species traits differ strongly. Such effects are often large and persistent for nonnative carnivores invading islands. Alternatively, high similarity in traits within assemblages creates a degree of functional redundancy in ecosystems. Here we tested whether species turnover results in functional ecological equivalence or complementarity, and whether invasive carnivores on islands significantly alter such ecological function. The model system consisted of vertebrate scavengers (dominated by raptors) foraging on animal carcasses on ocean beaches on two Australian islands, one with and one without invasive red foxes (Vulpes vulpes). Partitioning of scavenging events among species, carcass removal rates, and detection speeds were quantified using camera traps baited with fish carcasses at the dune-beach interface. Complete segregation of temporal foraging niches between mammals (nocturnal) and birds (diurnal) reflects complementarity in carrion utilization. Conversely, functional redundancy exists within the bird guild where several species of raptors dominate carrion removal in a broadly similar way. As predicted, effects of red foxes were large. They substantially changed the nature and rate of the scavenging process in the system: (1) foxes consumed over half (55%) of all carrion available at night, compared with negligible mammalian foraging at night on the fox-free island, and (2) significant shifts in the composition of the scavenger assemblages consuming beach-cast carrion are the consequence of fox invasion at one island. Arguably, in the absence of other mammalian apex predators, the addition of red foxes creates a new dimension of functional complementarity in beach food webs. However, this functional complementarity added by foxes is neither benign nor neutral, as marine carrion subsidies to coastal red fox populations are likely to facilitate their persistence as exotic carnivores.


Assuntos
Aves/fisiologia , Cadeia Alimentar , Raposas , Espécies Introduzidas , Comportamento Predatório/fisiologia , Animais , Austrália , Ilhas , Ratos , Suínos
18.
PLoS One ; 10(11): e0141976, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26524471

RESUMO

Determining the position of range edges is the first step in developing an understanding of the ecological and evolutionary dynamics in play as species' ranges shift in response to climate change. Here, we study the leading (poleward) range edge of Ocypode cordimanus, a ghost crab that is common along the central to northern east coast of Australia. Our study establishes the poleward range edge of adults of this species to be at Merimbula (36.90°S, 149.93°E), 270 km (along the coast) south of the previous southernmost museum record. We also establish that dispersal of pelagic larvae results in recruitment to beaches 248 km (along the coast; 0.9° of latitude) beyond the adult range edge we have documented here. Although we cannot conclusively demonstrate that the leading range edge for this species has moved polewards in response to climate change, this range edge does fall within a "hotspot" of ocean warming, where surface isotherms are moving southwards along the coast at 20-50 km.decade-1; coastal air temperatures in the region are also warming. If these patterns persist, future range extensions could be anticipated. On the basis of their ecology, allied with their occupancy of ocean beaches, which are home to taxa that are particularly amenable to climate-change studies, we propose that ghost crabs like O. cordimanus represent ideal model organisms with which to study ecological and evolutionary processes associated with climate change. The fact that "hotspots" of ocean warming on four other continents correspond with poleward range edges of ghost crab species suggests that results of hypothesis tests could be generalized, yielding excellent opportunities to rapidly progress knowledge in this field.


Assuntos
Braquiúros/crescimento & desenvolvimento , Animais , Austrália , Mudança Climática , Ecossistema , Oceanos e Mares
19.
J Environ Manage ; 152: 201-9, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25684567

RESUMO

Oceans, particularly coastal areas, are getting busier and within this increasingly human-dominated seascape, marine biodiversity continues to decline. Attempts to maintain and restore marine biodiversity are becoming more spatial, principally through the designation of marine protected areas (MPAs). MPAs compete for space with other uses, and the emergence of new industries, such as marine renewable energy generation, will increase competition for space. Decision makers require guidance on how to zone the ocean to conserve biodiversity, mitigate conflict and accommodate multiple uses. Here we used empirical data and freely available planning software to identified priority areas for multiple ocean zones, which incorporate goals for biodiversity conservation, two types of renewable energy, and three types of fishing. We developed an approached to evaluate trade-offs between industries and we investigated the impacts of co-locating some fishing activities within renewable energy sites. We observed non-linear trade-offs between industries. We also found that different subsectors within those industries experienced very different trade-off curves. Incorporating co-location resulted in significant reductions in cost to the fishing industry, including fisheries that were not co-located. Co-location also altered the optimal location of renewable energy zones with planning solutions. Our findings have broad implications for ocean zoning and marine spatial planning. In particular, they highlight the need to include industry subsectors when assessing trade-offs and they stress the importance of considering co-location opportunities from the outset. Our research reinforces the need for multi-industry ocean-zoning and demonstrates how it can be undertaken within the framework of strategic conservation planning.


Assuntos
Conservação dos Recursos Naturais/métodos , Pesqueiros/métodos , Oceanos e Mares , Energia Renovável , Irlanda do Norte
20.
Glob Chang Biol ; 20(8): 2383-92, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25121188

RESUMO

Sandy ocean beaches are iconic assets that provide irreplaceable ecosystem services to society. Despite their great socioeconomic importance, beaches as ecosystems are severely under-represented in the literature on climate-change ecology. Here, we redress this imbalance by examining whether beach biota have been observed to respond to recent climate change in ways that are consistent with expectations under climate change. We base our assessments on evidence coming from case studies on beach invertebrates in South America and on sea turtles globally. Surprisingly, we find that observational evidence for climate-change responses in beach biota is more convincing for invertebrates than for highly charismatic turtles. This asymmetry is paradoxical given the better theoretical understanding of the mechanisms by which turtles are likely to respond to changes in climate. Regardless of this disparity, knowledge of the unique attributes of beach systems can complement our detection of climate-change impacts on sandy-shore invertebrates to add rigor to studies of climate-change ecology for sandy beaches. To this end, we combine theory from beach ecology and climate-change ecology to put forward a suite of predictive hypotheses regarding climate impacts on beaches and to suggest ways that these can be tested. Addressing these hypotheses could significantly advance both beach and climate-change ecology, thereby progressing understanding of how future climate change will impact coastal ecosystems more generally.


Assuntos
Praias , Mudança Climática , Animais , Biota , Ecossistema , Invertebrados , Comportamento de Nidação , América do Sul , Tartarugas
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