John Winter

Bio: John Winter is an academic researcher from James Cook University. The author has contributed to research in topics: Endangered species & Threatened species. The author has an hindex of 9, co-authored 12 publications receiving 574 citations. Previous affiliations of John Winter include Commonwealth Scientific and Industrial Research Organisation.

Spatial scale, species diversity, and habitat structure: small mammals in Australian tropical rain forest

Abstract: We investigated patterns of mammal assemblage structure on the Atherton Tableland in the Wet Tropics biogeographic region of northeastern Australia. We used live trapping and quantitative estimates of stratified vegetation density to examine the relationships between the structure of the mammal assemblage and habitat structure over three nested spatial scales across a natural vegetation gradient from rain forest to dry, open forest. The narrow transition zone enabled us to examine the relationships between mammal assemblage structure and habitat structure while minimizing the confounding effects of distance, climate, and biogeographic history. The structure of the mammal assemblages was closely related to vegetation structure across and within habitats, and over all spatial scales examined. Vegetation complexity and heterogeneity both influenced assemblage structure, but the relationships varied with spatial scale. Species richness was highest in the open forest and decreased across the gradient into the rain forest. Point diversity was only weakly explained by vegetation structure, whereas >80% of the variation in species richness at the local scale could be explained by vegetation structure. Local-scale species richness of ground-dwelling mammals was mostly a product of the spatial variability in assemblage structure (β diversity), which was associated with the spatial variability in vegetation structure. Local-scale habitat heterogeneity thus promoted local-scale species richness via the close ecological interaction between mammals and habitat structure. The multiscale approach used here, and the nesting of spatial variability in within-habitat vegetation structure, enabled us to demonstrate the scale-dependent effects of spatial habitat heterogeneity and complexity on the structure and diversity of the small-mammal assemblage.

Optimizing Allocation of Management Resources for Wildlife

Abstract: Allocating money for species conservation on the basis of threatened species listings is not the most cost-effective way of promoting recovery or minimizing extinction rates. Using ecological and social factors in addition to threat categories, we designed a decision-support process to assist policy makers in their allocation of resources for the management of native wildlife and to clarify the considerations leading to a priority listing. Each species is scored on three criteria at the scale of the relevant jurisdiction: (1) threat category, (2) consequences of extinction, and (3) potential for successful recovery. This approach provides opportunity for independent input by policy makers and other stakeholders (who weight the relative importance of the criteria) and scientists (who score the species against the criteria). Thus the process explicitly separates societal values from the technical aspects of the decision-making process while acknowledging the legitimacy of both inputs. We applied our technique to two Australian case studies at different spatial scales: the frogs of Queensland (1,728,000 square km; 116 species) and the mammals of the Wet Tropics bioregion (18,500 km2; 96 species). We identified 7 frog and 10 mammal species as priorities for conservation. The frogs included 1 of the 9 species classified as endangered under Queensland legislation, 3 of the 10 species classified as vulnerable, 2 of the 22 species classified as rare, and 1 of the 75 species classified as least concern. The mammals identified included 3 of the 6 species classified as endangered, 1 of the 4 species classified as vulnerable, 5 of the 11 species classified as rare, and 1 of the 75 species classified as least concern. The methods we used to identify species were robust to comparisons across the two taxonomic groups. We concluded that (1) our process facilitates comparisons of data required to make transparent, cost-effective, and strategic management decisions across taxonomic groups and (2) the process should be used to short-list species for further discussion rather than for allocating resources per se.

Importance of canopy connectivity for home range and movements of the rainforest arboreal ringtail possum (Hemibelideus lemuroides)

Abstract: Roads and powerline corridors destroy canopy connectivity in the rainforest of north-east Australia. We tested the hypotheses that linear barriers affect (a) the alignment of home ranges, (b) use of habitat either side of linear barriers, and (c) the crossing of them by the strictly arboreal lemuroid ringtail possum (Hemibelideus lemuroides), which is known to be vulnerable to habitat fragmentation. Radio-tracking and a translocation experiment were conducted at a narrow 7-m-wide road and an 80-m-wide powerline. Homes ranges of lemuroid ringtails ranged from 0.15 to 1.67 ha (minimum convex polygon) and were aligned with the road but not powerline corridors. When lemuroid ringtails were experimentally translocated, wider canopy clearings over roads reduced their capacity to return to their original home range, and the powerline corridor was a nearly insurmountable barrier. No possums were observed crossing roads or the powerline corridor at ground level or residing in the intervening matrix, indicating that loss of canopy connectivity has a negative impact on their movements.

Ecological correlates of folivore abundance in north Queensland rainforests

Abstract: The ecological factors controlling the distribution and abundance of the folivorous marsupials endemic to the rainforests of northern Australia are not understood. In this study, we surveyed folivore abundance at 40 sites stratified by altitude and geology in rainforests of the Atherton Tableland, north Queensland. All five species of folivore that inhabit the study area were more abundant in highland (800–1200 m) than in upland (400–800 m) forests. Allowing for the effects of altitude, four species of folivore were more abundant in forests on nutrient-rich basalts than in forests on nutrient-poor acid igneous or metamorphic rocks. The abundance of two folivore species also varied inversely with rainfall. Altitudinal variation in folivore abundance in the study area has been attributed to habitat destruction, Aboriginal hunting, the distribution of host plants and climate; however, none of these hypotheses has been tested. Variation in folivore abundance with geology is plausibly explained as a response to the nutritional quality of foliage. Foliage quality may also explain the inverse relationship between two of the folivores and rainfall. The results of this study show that only a relatively small proportion of north Queensland rainforests support abundant populations of the endemic folivorous marsupials.

Community survey of the distribution of Lumholtz's Tree-kangaroo on the Atherton Tablelands, north-east Queensland

Abstract: Lumholtz's Tree-kangaroo Dendrofagus lumholtzi is endemic to the rainforests of north Queensland, Australia. Most records of D. lumholtzi are from upland forests on the Atherton Tablelands, an area -extensively cleared for agriculture. In 1997, residents of the Tablelands formed the Tree Kangaroo and Mammal Group Inc. (TKMG) with the aim of promoting the conservation of the species. The first project of TKMG was an intensive community-based survey of the distribution of D. fumholtzi. Residents of all postal districts encompassing areas of upland rainforest within the range of D. lumholtzi were sent a written questionnaire seeking details of tree-kangaroo sightings. The Malanda postal district was surveyed in 1998 while all other postal districts were surveyed in 1999. In total, 10 122 questionnaires were distributed in the survey. Nearly BOO responses were received to the survey, providing 2 36B Sighting records of D. lumholtzi. Of these, 367 records were of dead tree-kangaroos, mostly road-kills." The survey has provided a much more comprehensive account of the distribution of the species than was previously available. Most records of D. lumholtz; obtained in the survey were from upland forests between Atherton and Ravenshoe, particularly remnant forests in the central and western Tablelands. Although the survey methodology is biased towards areas frequented by humans, these patterns are consistent with independent surveys. The conservation of D. lumholtzi on the Tablelands would benefit from the protection of remnant forests, the restoration of habitat and a reduction in the incidence of road-kills and dog attacks on tree-kangaroos.

Animal species diversity driven by habitat heterogeneity/diversity: the importance of keystone structures

Abstract: Aim In a selected literature survey we reviewed studies on the habitat heterogeneity–animal species diversity relationship and evaluated whether there are uncertainties and biases in its empirical support. Location World-wide. Methods We reviewed 85 publications for the period 1960–2003. We screened each publication for terms that were used to define habitat heterogeneity, the animal species group and ecosystem studied, the definition of the structural variable, the measurement of vegetation structure and the temporal and spatial scale of the study. Main conclusions The majority of studies found a positive correlation between habitat heterogeneity/diversity and animal species diversity. However, empirical support for this relationship is drastically biased towards studies of vertebrates and habitats under anthropogenic influence. In this paper, we show that ecological effects of habitat heterogeneity may vary considerably between species groups depending on whether structural attributes are perceived as heterogeneity or fragmentation. Possible effects may also vary relative to the structural variable measured. Based upon this, we introduce a classification framework that may be used for across-studies comparisons. Moreover, the effect of habitat heterogeneity for one species group may differ in relation to the spatial scale. In several studies, however, different species groups are closely linked to ‘keystone structures’ that determine animal species diversity by their presence. Detecting crucial keystone structures of the vegetation has profound implications for nature conservation and biodiversity management.

Towards an Integrated Framework for Assessing the Vulnerability of Species to Climate Change

Abstract: [Extract] Global climate change threatens global biodiversity, ecosystem function, and human well-being, with thousands of publications demonstrating impacts across a wide diversity of taxonomic groups, ecosystems, economics, and social structure. A review by Hughes [1] identified many of the ways that organisms may be affected by and/or respond to climate change. Since then, there has been a dramatic increase in the number of case studies attesting to ecological impacts [2], prompting several recent reviews on the subject (e.g., [3–6]). Several global meta-analyses confirm the pervasiveness of the global climate change "fingerprint" across continents, ecosystems, processes, and species [7–9]. Some studies have predicted increasingly severe future impacts with potentially high extinction rates in natural systems around the world [10,11]. Responding to this threat will require a concerted, multi-disciplinary, multi-scale, multi-taxon research effort that improves our predictive capacity to identify and prioritise vulnerable species in order to inform governments of the seriousness of the threat and to facilitate conservation adaptation and management [12,13]. If we are to minimise global biodiversity loss, we need significant decreases in global emissions to be combined with environmental management that is guided by sensible prioritisation of relative vulnerability. That is, we need to determine which species, habitats, and ecosystems will be most vulnerable, exactly what aspects of their ecological and evolutionary biology determine their vulnerability, and what we can do about managing this vulnerability and minimising the realised impacts. There is an emerging literature on specific traits that promote vulnerability under climate change (e.g., thermal tolerance [14]) as well as a broad literature on the traits that influence species' vulnerability generally (e.g., review by [15]). Less is known about the various mechanisms for either ecological or evolutionary adaptation to climate change, although it is increasingly recognised as a vital component of assessing vulnerability [16,17].

Impacts of roads and linear clearings on tropical forests.

Abstract: Linear infrastructure such as roads, highways, power lines and gas lines are omnipresent features of human activity and are rapidly expanding in the tropics. Tropical species are especially vulnerable to such infrastructure because they include many ecological specialists that avoid even narrow (<30-m wide) clearings and forest edges, as well as other species that are susceptible to road kill, predation or hunting by humans near roads. In addition, roads have a major role in opening up forested tropical regions to destructive colonization and exploitation. Here, we synthesize existing research on the impacts of roads and other linear clearings on tropical rainforests, and assert that such impacts are often qualitatively and quantitatively different in tropical forests than in other ecosystems. We also highlight practical measures to reduce the negative impacts of roads and other linear infrastructure on tropical species.

The relationship between fish species richness, abundance and habitat complexity in a range of shallow tropical marine habitats

Abstract: A simple habitat assessment score (HAS) was designed to assess habitat complexity across several different shallow tropical marine habitats including sandy patches, algal beds, seagrass beds and reefs. It measured rugosity, variety of growth forms, height, refuge size categories, percentage live cover and percentage hard substratum. Multiple regression models using HAS variables as predictors accounted for 71 and 22% of the variation in observed species richness and total fish abundance respectively. The two most important predictors of observed species richness were rugosity and variety of growth forms, while height was the most important predictor of total fish abundance. The HAS method worked consistently across a variety of habitat types and the complexity map closely mirrored the map of observed species richness, reflecting the patchy habitat mosaic of shallow tropical marine areas. Stations at the mouth of an enclosed lagoon, however, had a higher number of species than might have been expected judging from the habitat complexity scores. It is possible that this was linked to the preferential settling of pelagic fish larvae in this area as tidal water exchanges between the bay and the reef were funnelled through one small gap. This study highlights the need for fish biodiversity studies to take habitat complexity into account.

Climate change in Australian tropical rainforests: an impending environmental catastrophe

Abstract: It is now widely accepted that global climate change is affecting many ecosystems around the globe and that its impact is increasing rapidly. Many studies predict that impacts will consist largely of shifts in latitudinal and altitudinal distributions. However, we demonstrate that the impacts of global climate change in the tropical rainforests of northeastern Australia have the potential to result in many extinctions. We develop bioclimatic models of spatial distribution for the regionally endemic rainforest vertebrates and use these models to predict the effects of climate warming on species distributions. Increasing temperature is predicted to result in significant reduction or complete loss of the core environment of all regionally endemic vertebrates. Extinction rates caused by the complete loss of core environments are likely to be severe, nonlinear, with losses increasing rapidly beyond an increase of 2 degrees C, and compounded by other climate-related impacts. Mountain ecosystems around the world, such as the Australian Wet Tropics bioregion, are very diverse, often with high levels of restricted endemism, and are therefore important areas of biodiversity. The results presented here suggest that these systems are severely threatened by climate change.