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1.
J Mammal ; 104(5): 1047-1061, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37800101

ABSTRACT

Captive breeding is often used to produce individuals for reintroduction programs in order to reestablish a species in an area where it has become locally extinct. To maximize the likelihood of establishing a self-sustaining population in the wild, an analysis of data from captive breeding programs is commonly undertaken to (1) increase the quantity of individuals and rate at which they can be released, and (2) maintain or improve the genetic and phenotypic quality of individuals. Here we demonstrate how the knowledge gained from these analyses can also be applied to decision-making during the design of subsequent reintroductions to further advance a reintroduction program toward success. We conducted an analysis of data from a captive breeding program for the threatened pookila (Pseudomys novaehollandiae, New Holland mouse) spanning 6 years. We found evidence for relationships between the reproductive output of pookila and behavioral, demographic, experiential, health, and physiological predictors. Based on a biological interpretation of these results, and with reference to a checklist of all known translocation tactics, we recommend 11 specific design elements to maximize the probability of pookila reproduction postrelease (thereby improving the likelihood of reintroduction success). These recommendations should be interpreted as hypotheses to be evaluated and refined in future reintroduction trials for the pookila. The uncertainty around the postrelease survival and reproduction of a species that is common in reintroduction practice warrants the creative use of existing data to inform adaptive management. Indeed, there is a wealth information in well-kept captive breeding records that is currently underused by reintroduction practitioners. The direct integration of knowledge derived from captive breeding (where available) with decision-making for reintroductions, as described here, will help navigate these uncertainties, which would benefit the conservation of both understudied and well-known species around the world.

2.
Ecol Evol ; 13(7): e10251, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37404705

ABSTRACT

Invasive species have established populations around the world and, in the process, characteristics of their realized environmental niches have changed. Because of their popularity as a source of game, deer have been introduced to, and become invasive in, many different environments around the world. As such, deer should provide a good model system in which to test environmental niche shifts. Using the current distributions of the six deer species present in Australia, we quantified shifts in their environmental niches that occurred since introduction; we determined the differences in suitable habitat between their international (native and invaded) and their Australian ranges. Given knowledge of their Australian habitat use, we then modeled the present distribution of deer in Australia to assess habitat suitability, in an attempt to predict future deer distributions. We show that the Australian niches of hog (Axis porcinus), fallow (Dama dama), red (Cervus elaphus), rusa (C. timorensis), and sambar deer (C. unicolor), but not chital deer (A. axis), were different to their international ranges. When we quantified the potential range of these six species in Australia, chital, hog, and rusa deer had the largest areas of suitable habitat outside their presently occupied habitat. The other three species had already expanded outside the ranges that we predicted as suitable. Here, we demonstrate that deer have undergone significant environmental niche shifts following introduction into Australia, and these shifts are important for predicting the future spread of these invasive species. It is important to note that current Australian and international environmental niches did not necessarily predict range expansions, thus wildlife managers should treat these analyses as conservative estimates.

3.
Ambio ; 52(3): 585-597, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36580270

ABSTRACT

Rewilding is a restoration strategy that aims to return anthropogenic ecosystems to a "self-organized" state, by reinstating trophic complexity through disturbance (e.g. predation, herbivory), dispersal and connectivity. In depopulated areas of Europe, lite versions of rewilding, that maintain but minimize the management of rewilding species (e.g. predators, large herbivores) is gaining support. Livestock rewilding (LR) is a form of rewilding-lite, that uses livestock landraces as keystone species in the restoration of herbivory (the functional integrity of ecosystems) offering ecosystem services, such as ecotourism and the sale of livestock population surpluses, that can mitigate the economic and social effects of rural depopulation. Many challenges remain to implementing LR, including (i) more empirical evidence is required of the feasibility of LR across a variety of habitats and conditions, and (ii) understanding the hurdles that legislation poses for LR, the latter being the aim of this study. To accomplish this, we reviewed the EU legislation on environmental protection, animal health and welfare, identification and traceability, and ownership and civil responsibility, to assess how this might apply to LR. Although there is no specific EU legislation prohibiting LR, the review indicates that it is not clear what legislation applies to LR, as LR's status lies between that of livestock and wild species. As such the existing legislation can be a serious impediment to the development of LR programmes. We highlight the needs for a legal definition, and status of LR species and their ownership. We propose ways to adapt this legislation to support the application of LR programmes in abandoned areas of EU, for example, by using legal exceptions intended for livestock under extensive animal farming systems.


Subject(s)
Conservation of Natural Resources , Ecosystem , Livestock , Animals , Biodiversity , Conservation of Natural Resources/legislation & jurisprudence , Europe , European Union
4.
Biodivers Conserv ; 32(1): 203-225, 2023.
Article in English | MEDLINE | ID: mdl-36405571

ABSTRACT

In response to the ongoing decline of fauna worldwide, there has been growing interest in the rewilding of whole ecosystems outside of fenced sanctuaries or offshore islands. This interest will inevitably result in attempts to restore species where eliminating threats from predators and competitors is extremely challenging or impossible, or reintroductions of predators that will increase predation risk for extant prey (i.e., coexistence conservation). We propose 'Mini Safe Havens' (MSHs) as a potential tool for managing these threats. Mini Safe Havens are refuges that are permanently permeable to the focal species; allowing the emigration of individuals while maintaining gene flow through the boundary. Crucial to the effectiveness of the approach is the ongoing maintenance and monitoring required to preserve a low-to-zero risk of key threats within the MSH; facilitating in-situ learning and adaptation by focal species to these threats, at a rate and intensity of exposure determined by the animals themselves. We trialled the MSH approach for a pilot reintroduction of the Australian native New Holland mouse (Pseudomys novaehollandiae), in the context of a trophic rewilding project to address potential naïveté to a reintroduced native mammalian predator. We found that mice released into a MSH maintained their weight and continued to use the release site beyond 17 months (525 days) post-release. In contrast, individuals in temporary soft-release enclosures tended to lose weight and became undetectable approximately 1-month post-release. We discuss the broad applicability of MSHs for population recovery and reintroductions 'beyond-the-fence' and recommend avenues for further refinement of the approach. Supplementary Information: The online version contains supplementary material available at 10.1007/s10531-022-02495-6.

5.
Oecologia ; 200(3-4): 285-294, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35962285

ABSTRACT

Male and female reproductive behaviour is typically synchronised. In species such as those in the family Cervidae, reproductive timing is often cued by photoperiod, although in females, it can be dependent on body condition. When a species is introduced to a novel environment, the environment changes, or responses of the sexes to such cues differ, asynchronous reproductive behaviour between males and females may occur. We investigated the seasonality of reproductive behaviour in introduced chital deer in northern Queensland by examining male antler phase in relation to female conception rates. We then analysed the influence of different variables likely to affect the timing of male and female reproductive physiology. The lowest percentage of chital in hard antler in any 1 month in this study was 35% (Fig. 1), but the average value was closer to 50%, thus there was a seasonal peak in antler phase linked with photoperiod. Females conceived at any time of year, but were strongly influenced by the amount of rainfall 3 months prior to conception. This resulted in varying conception peaks year-to-year that often did not correspond to the male's peak in hard antler. In this system, a proportion of males and females were physiologically and behaviourally ready to mate at any time of the year. We predict that differences in the timing of the peaks between the males and females will lead to increased reproductive skew (variation in reproductive success among individual males). This pattern may select for different mating strategies or physiological mechanisms to increase reproductive success. Fig. 1 The average percentage of male chital deer in hard antler by month from 2014 to 2019 in north Queensland. Values above the bars indicate the total number of males that were sampled in each month and the error bars indicate the standard error. In the month with the lowest % males in hard antler in the entire study (November, 2017), 35% of males were in hard antler.


Subject(s)
Deer , Animals , Female , Male , Reproduction , Fertilization , Cues
6.
Ecol Evol ; 11(9): 4577-4587, 2021 May.
Article in English | MEDLINE | ID: mdl-33976832

ABSTRACT

When introduced to new ecosystems, species' populations often grow immediately postrelease. Some introduced species, however, maintain a low population size for years or decades before sudden, rapid population growth is observed. Because exponential population growth always starts slowly, it can be difficult to distinguish species experiencing the early phases of slow exponential population growth (inherent lags) from those with actively delayed growth rates (prolonged lags). Introduced ungulates provide an excellent system in which to examine lags, because some introduced ungulate populations have demonstrated rapid population growth immediately postintroduction, while others have not. Using studies from the literature, we investigated which exotic ungulate species and populations (n = 36) showed prolonged population growth lags by comparing the doubling time of real ungulate populations to those predicted from exponential growth models for theoretical populations. Having identified the specific populations that displayed prolonged lags, we examined the impacts of several environmental and biological variables likely to influence the length of lag period. We found that seventeen populations (47%) showed significant prolonged population growth lags. We could not, however, determine the specific factors that contributed to the length of these lag phases, suggesting that these ungulate populations' growth is idiosyncratic and difficult to predict. Introduced species that exhibit delayed growth should be closely monitored by managers, who must be proactive in controlling their growth to minimize the impact such populations may have on their environment.

7.
Sustain Sci ; 15(6): 1723-1733, 2020.
Article in English | MEDLINE | ID: mdl-32837574

ABSTRACT

Urgent sustainability challenges require effective leadership for inter- and trans-disciplinary (ITD) institutions. Based on the diverse experiences of 20 ITD institutional leaders and specific case studies, this article distills key lessons learned from multiple pathways to building successful programs. The lessons reflect both the successes and failures our group has experienced, to suggest how to cultivate appropriate and effective leadership, and generate the resources necessary for leading ITD programs. We present two contrasting pathways toward ITD organizations: one is to establish a new organization and the other is to merge existing organizations. We illustrate how both benefit from a real-world focus, with multiple examples of trajectories of ITD organizations. Our diverse international experiences demonstrate ways to cultivate appropriate leadership qualities and skills, especially the ability to create and foster vision beyond the status quo; collaborative leadership and partnerships; shared culture; communications to multiple audiences; appropriate monitoring and evaluation; and perseverance. We identified five kinds of resources for success: (1) intellectual resources; (2) institutional policies; (3) financial resources; (4) physical infrastructure; and (5) governing boards. We provide illustrations based on our extensive experience in supporting success and learning from failure, and provide a framework that articulates the major facets of leadership in inter- and trans-disciplinary organizations: learning, supporting, sharing, and training.

8.
PLoS One ; 15(6): e0234455, 2020.
Article in English | MEDLINE | ID: mdl-32598368

ABSTRACT

Threatened species recovery programs are increasingly turning to reintroductions to reverse biodiversity loss. Here we present a real-world example where tactics (techniques which influence post-release performance and persistence) and an adaptive management framework (which incorporates feedback between monitoring and future actions) improved reintroduction success. Across three successive trials we investigated the influence of tactics on the effective survival and post-release dispersal of endangered eastern quolls (Dasyurus viverrinus) reintroduced into Mulligans Flat Woodland Sanctuary, Australian Capital Territory. Founders were monitored for 42 days post-release, and probability of survival and post-release dispersal were tested against trial, origin, sex, den sharing and presence of pouch young. We adopted an adaptive management framework, using monitoring to facilitate rapid learning and to implement interventions that improved reintroduction success. Founders released in the first trial were less likely to survive (28.6%, n = 14) than those founders released the second (76.9%, n = 13) and third trials (87.5%, n = 8). We adapted several tactics in the second and third trials, including the selection of female-only founders to avoid elevated male mortality, and post-mating releases to reduce stress. Founders that moved dens between consecutive nights were less likely to survive, suggesting that minimising post-release dispersal can increase the probability of survival. The probability of moving dens was lower in the second and third trials, for females, and when den sharing with another founder. This study demonstrates that, through iterative trials of tactics involving monitoring and learning, adaptive management can be used to significantly improve the success of reintroduction programs.


Subject(s)
Carnivora/physiology , Ecology/methods , Endangered Species , Marsupialia/physiology , Animal Distribution , Animals , Australia , Australian Capital Territory , Ecological Parameter Monitoring/methods , Female , Male , Population Dynamics , Probability , Research Design
9.
J Wildl Dis ; 56(3): 547-559, 2020 07.
Article in English | MEDLINE | ID: mdl-32017663

ABSTRACT

We evaluated the health of 31 (eight males, 23 females) founder eastern quolls (Dasyurus viverrinus), translocated to a fenced reserve in the Australian Capital Territory between February 2016 and July 2017. Quolls were wild caught in Tasmania (16 animals) or captive bred at Mount Rothwell Biodiversity Interpretation Centre, Victoria (15 animals). Quolls were assessed for the presence of selected potential pathogens (Toxoplasma gondii, herpesviruses, Salmonella serovars, hemoprotozoa, and ectoparasites). We assessed the relationships among sex, provenance (captive or free ranging), T. gondii or herpesvirus infection, weight, and hematologic and biochemical variables. Six of 21 quolls (29%) tested were seropositive for antibodies to T. gondii. Seropositive quolls weighed significantly more and had significantly lower potassium levels, anion gaps, and urea and triglyceride levels than seronegative quolls had. Eighteen of 31 (58%) combined conjunctival-pharyngeal-cloacal swabs collected from quolls were PCR positive for a newly identified gammaherpesvirus, tentatively named dasyurid gammaherpesvirus 3. There were no significant differences among hematologic and biochemical variables or body weights from PCR-positive and PCR-negative quolls. Eighteen of 18 (100%) of rectal-swab samples were culture negative for Salmonella serovars. Three species of tick (Ixodes tasmani, Ixodes fecialis, and Ixodes holocyclus), two species of mite (Andreacus radfordi, one unidentified), and four species of flea (Pygiopsylla hoplia, Acanthopsylla rothschildi rothschildi, Uropsylla tasmanica, and Stephanocircus dasyuri), were detected on wild-caught quolls, whereas a fifth species of flea, Echidnophaga myremecobii, was detected only on captive-bred quolls. Five of 15 blood samples (33%) were positive for hemoprotozoan DNA via PCR, a novel Hepatozoon species, a novel Theileria species, Theileria paparinii, and Trypanosoma copemani were detected. Despite the presence of several potential pathogens known to be associated with disease in other marsupials, the quolls were considered to be in good general health, suitable for translocation, and a viable population was subsequently established.


Subject(s)
Communicable Diseases/veterinary , Conservation of Natural Resources , Marsupialia , Parasitic Diseases, Animal/parasitology , Animals , Female , Humans , Male , Parasitic Diseases, Animal/diagnosis , Parasitic Diseases, Animal/epidemiology , Tasmania , Victoria
10.
Front Public Health ; 8: 616328, 2020.
Article in English | MEDLINE | ID: mdl-33585387

ABSTRACT

The past two decades have seen an accumulation of theoretical and empirical evidence for the interlinkages between human health and well-being, biodiversity and ecosystem services, and agriculture. The COVID-19 pandemic has highlighted the devastating impacts that an emerging pathogen, of animal origin, can have on human societies and economies. A number of scholars have called for the wider adoption of "One Health integrated approaches" to better prevent, and respond to, the threats of emerging zoonotic diseases. However, there are theoretical and practical challenges that have precluded the full development and practical implementation of this approach. Whilst integrated approaches to health are increasingly adopting a social-ecological system framework (SES), the lack of clarity in framing the key concept of resilience in health contexts remains a major barrier to its implementation by scientists and practitioners. We propose an operational framework, based on a transdisciplinary definition of Socio-Ecological System Health (SESH) that explicitly links health and ecosystem management with the resilience of SES, and the adaptive capacity of the actors and agents within SES, to prevent and cope with emerging health and environmental risks. We focus on agricultural transitions that play a critical role in disease emergence and biodiversity conservation, to illustrate the proposed participatory framework to frame and co-design SESH interventions. Finally, we highlight critical changes that are needed from researchers, policy makers and donors, in order to engage communities and other stakeholders involved in the management of their own health and that of the underpinning ecosystems.


Subject(s)
Agriculture , Conservation of Natural Resources , Ecosystem , Public Health , Animals , Biodiversity , Communicable Diseases, Emerging , Humans , Zoonoses/prevention & control
11.
Ambio ; 49(9): 1530-1548, 2020 Sep.
Article in English | MEDLINE | ID: mdl-31808107

ABSTRACT

A debt-based economy requires the accumulation of more and more debt to finance economic growth, while future economic growth is needed to repay the debt, and so the cycle continues. Despite global debt reaching unprecedented levels, little research has been done to understand the impacts of debt dynamics on environmental sustainability. Here, we explore the environmental impacts of the debt-growth cycle in Indonesia, the world's largest debt-based producer of palm oil. Our empirical Agent-Based Model analyses the future effects (2018-2050) of power (im)balance scenarios between debt-driven economic forces (i.e. banks, firms), and conservation forces, on two ecosystem services (food production, climate regulation) and biodiversity. The model shows the trade-offs and synergies among these indicators for Business As Usual as compared to alternative scenarios. Results show that debt-driven economic forces can partially support environmental conservation, provided the state's role in protecting the environment is reinforced. Our analysis provides a lesson for developing countries that are highly dependent on debt-based production systems: sustainable development pathways can be achievable in the short and medium terms; however, reaching long-term sustainability requires reduced dependency on external financial powers, as well as further government intervention to protect the environment from the rough edges of the market economy.


Subject(s)
Conservation of Natural Resources , Ecosystem , Biodiversity , Indonesia , Palm Oil
12.
PeerJ ; 7: e6622, 2019.
Article in English | MEDLINE | ID: mdl-31179166

ABSTRACT

The eastern bettong (Bettongia gaimardi), a medium-sized digging marsupial, was reintroduced to a predator-free reserve after 100 years of absence from the Australian mainland. The bettong may have the potential to restore temperate woodlands degraded by a history of livestock grazing, by creating numerous small disturbances by digging. We investigated the digging capacity of the bettong and compared this to extant fauna, to answer the first key question of whether this species could be considered an ecosystem engineer, and ultimately if it has the capacity to restore lost ecological processes. We found that eastern bettongs were frequent diggers and, at a density of 0.3-0.4 animals ha-1, accounted for over half the total foraging pits observed (55%), with echidnas (Tachyglossus aculeatus), birds and feral rabbits (Oryctolagus cuniculus) accounting for the rest. We estimated that the population of bettongs present dug 985 kg of soil per ha per year in our study area. Bettongs dug more where available phosphorus was higher, where there was greater basal area of Acacia spp. and where kangaroo grazing was less. There was no effect on digging of eucalypt stem density or volume of logs on the ground. While bettong digging activity was more frequent under trees, digging also occurred in open grassland, and bettongs were the only species observed to dig in scalds (areas where topsoil has eroded to the B Horizon). These results highlight the potential for bettongs to enhance soil processes in a way not demonstrated by the existing fauna (native birds and echidna), and introduced rabbit.

13.
J Environ Manage ; 231: 940-952, 2019 Feb 01.
Article in English | MEDLINE | ID: mdl-30602255

ABSTRACT

Tropical countries lie at the nexus of three pressing issues for global sustainability: agricultural production, climate change mitigation and biodiversity conservation. The forces that drive forest protection do not necessarily oppose those that drive forest clearance for development. This decoupling, enhanced by the stronger economic forces compared to conservation, is detrimental for the social-ecological sustainability of forested tropical landscapes. This paper presents an integrated, and spatially-explicit, Agent-Based Model that examines the future impacts of land-use change scenarios on the sustainability of the Wet Tropics region of tropical Queensland, Australia. In particular, the model integrates Bayesian Belief Networks, Geographical Information Systems, empirical data and expert knowledge, under a land-sharing/land-sparing analysis, to study the impact of different landscape configurations on trade-offs and synergies among biodiversity and two ecosystem services (sugarcane production and carbon sequestration). Contrary to most tropical regions, model simulations show that Business As Usual is helping to reconcile these contrasting goals in the forested landscape of the Wet Tropics. The paper analyses which combination of governance and socio-economic factors is causing these positive results. This is an outstanding achievement for a tropical region, considering that most tropical areas are characterized for having stronger economic-land clearing forces compared to conservation forces, which reduce important ecosystem services for human wellbeing and the health of ecosystems.


Subject(s)
Conservation of Natural Resources , Ecosystem , Australia , Bayes Theorem , Forests , Humans , Queensland
14.
PLoS One ; 13(8): e0202509, 2018.
Article in English | MEDLINE | ID: mdl-30102738

ABSTRACT

[This corrects the article DOI: 10.1371/journal.pone.0201141.].

15.
PLoS One ; 13(7): e0201141, 2018.
Article in English | MEDLINE | ID: mdl-30028881

ABSTRACT

A debt-based economy cannot survive without economic growth. However, if private debt consistently grows faster than GDP, the consequences are financial crises and the current unprecedented level of global debt. This policy dilemma is aggravated by the lack of analyses factoring the impact of debt-growth cycles on the environment. What is really the relationship between debt and natural resource sustainability, and what is the role of debt in decoupling economic growth from natural resource availability? Here we present a conceptual Agent-Based Model (ABM) that integrates an environmental system into an ABM representation of Steve Keen's debt-based economic models. Our model explores the extent to which debt-driven processes, within debt-based economies, enhance the decoupling between economic growth and the availability of natural resources. Interestingly, environmental and economic collapse in our model are not caused by debt growth, or the debt-based nature of the economic system itself (i.e. the 'what'), but rather, these are due to the inappropriate use of debt by private actors (i.e. the 'how'). Firms inappropriately use bank credits for speculative goals-rather than production-oriented ones-and for exponentially increasing rates of technological development. This context creates temporal mismatches between natural resource growth and firms' resource extraction rates, as well as between economic growth and the capacity of the government to effectively implement natural resource conservation policies. This paper discusses the extent to which economic growth and the availability of natural resources can be re-coupled through a more sustainable use of debt, for instance by shifting mainstream banking forces to partially support environmental conservation as well as economic growth.


Subject(s)
Conservation of Natural Resources/economics , Models, Economic , Algorithms , Computer Simulation , Government Regulation , Humans , Sustainable Development/economics
16.
Sci Adv ; 1(1): e1400039, 2015 Feb.
Article in English | MEDLINE | ID: mdl-26601127

ABSTRACT

China's increasingly urbanized and wealthy population is driving a growing and changing demand for food, which might not be met without significant increase in agricultural productivity and sustainable use of natural resources. Given the past relationship between lack of access to affordable food and political instability, food security has to be given a high priority on national political agendas in the context of globalization. The drive for increased food production has had a significant impact on the environment, and the deterioration in ecosystem quality due to historic and current levels of pollution will potentially compromise the food production system in China. We discuss the grand challenges of not only producing more food but also producing it sustainably and without environmental degradation. In addressing these challenges, food production should be considered as part of an environmental system (soil, air, water, and biodiversity) and not independent from it. It is imperative that new ways of meeting the demand for food are developed while safeguarding the natural resources upon which food production is based. We present a holistic approach to both science and policy to ensure future food security while embracing the ambition of achieving environmental sustainability in China. It is a unique opportunity for China to be a role model as a new global player, especially for other emerging economies.

17.
PLoS One ; 10(6): e0130626, 2015.
Article in English | MEDLINE | ID: mdl-26111037

ABSTRACT

Australia has experienced dramatic declines and extinctions of its native rodent species over the last 200 years, particularly in southern Australia. In the tropical savanna of northern Australia significant declines have occurred only in recent decades. The later onset of these declines suggests that the causes may differ from earlier declines in the south. We examine potential regional effects (northern versus southern Australia) on biological and ecological correlates of range decline in Australian rodents. We demonstrate that rodent declines have been greater in the south than in the tropical north, are strongly influenced by phylogeny, and are consistently greater for species inhabiting relatively open or sparsely vegetated habitat. Unlike in marsupials, where some species have much larger body size than rodents, body mass was not an important predictor of decline in rodents. All Australian rodent species are within the prey-size range of cats (throughout the continent) and red foxes (in the south). Contrary to the hypothesis that mammal declines are related directly to ecosystem productivity (annual rainfall), our results are consistent with the hypothesis that disturbances such as fire and grazing, which occur in non-rainforest habitats and remove cover used by rodents for shelter, nesting and foraging, increase predation risk. We agree with calls to introduce conservation management that limits the size and intensity of fires, increases fire patchiness and reduces grazing impacts at ecological scales appropriate for rodents. Controlling feral predators, even creating predator-free reserves in relatively sparsely-vegetated habitats, is urgently required to ensure the survival of rodent species, particularly in northern Australia where declines are not yet as severe as those in the south.


Subject(s)
Conservation of Natural Resources/methods , Ecosystem , Food Chain , Animals , Australia , Foxes , Marsupialia , Population Dynamics , Predatory Behavior , Rodentia , South Australia
18.
PLoS One ; 9(12): e105966, 2014.
Article in English | MEDLINE | ID: mdl-25501680

ABSTRACT

Large mammalian grazers can alter the biotic and abiotic features of their environment through their impacts on vegetation. Grazing at moderate intensity has been recommended for biodiversity conservation. Few studies, however, have empirically tested the benefits of moderate grazing intensity in systems dominated by native grazers. Here we investigated the relationship between (1) density of native eastern grey kangaroos, Macropus giganteus, and grass structure, and (2) grass structure and reptiles (i.e. abundance, richness, diversity and occurrence) across 18 grassland and grassy Eucalyptus woodland properties in south-eastern Australia. There was a strong negative relationship between kangaroo density and grass structure after controlling for tree canopy cover. We therefore used grass structure as a surrogate for grazing intensity. Changes in grazing intensity (i.e. grass structure) significantly affected reptile abundance, reptile species richness, reptile species diversity, and the occurrence of several ground-dwelling reptiles. Reptile abundance, species richness and diversity were highest where grazing intensity was low. Importantly, no species of reptile was more likely to occur at high grazing intensities. Legless lizards (Delma impar, D. inornata) were more likely to be detected in areas subject to moderate grazing intensity, whereas one species (Hemiergis talbingoensis) was less likely to be detected in areas subject to intense grazing and three species (Menetia greyii, Morethia boulengeri, and Lampropholis delicata) did not appear to be affected by grazing intensity. Our data indicate that to maximize reptile abundance, species richness, species diversity, and occurrence of several individual species of reptile, managers will need to subject different areas of the landscape to moderate and low grazing intensities and limit the occurrence and extent of high grazing.


Subject(s)
Eating , Forests , Grassland , Macropodidae/physiology , Reptiles/physiology , Animals , Australia , Biodiversity , Conservation of Natural Resources , Eucalyptus , Poaceae , Principal Component Analysis , South Australia
19.
ISME J ; 5(5): 801-9, 2011 May.
Article in English | MEDLINE | ID: mdl-21124491

ABSTRACT

We applied constrained ordination numerical ecology methods to data produced with a human intestinal tract-specific phylogenetic microarray (the Aus-HIT Chip) to examine the microbial diversity associated with matched biopsy tissue samples taken from the caecum, transverse colon, sigmoid colon and rectum of 10 healthy patients. Consistent with previous studies, the profiles revealed a marked intersubject variability; however, the numerical ecology methods of analysis allowed the subtraction of the subject effect from the data and revealed, for the first time, evidence of a longitudinal gradient for specific microbes along the colorectum. In particular, probes targeting Streptococcus and Enterococcus spp. produced strongest signals with caecal and transverse colon samples, with a gradual decline through to the rectum. Conversely, the analyses suggest that several members of the Enterobacteriaceae increase in relative abundance towards the rectum. These collective differences were substantiated by the multivariate analysis of quantitative PCR data. We were also able to identify differences in the microarray profiles, especially for the streptococci and Faecalibacterium prausnitzii, on the basis of gender. The results derived by these multivariate analyses are biologically intuitive and suggest that the biogeography of the colonic mucosa can be monitored for changes through cross-sectional and/or inception cohort studies.


Subject(s)
Bacteria/classification , Colon/microbiology , Intestinal Mucosa/microbiology , Phylogeography , Aged , Bacteria/genetics , Biodiversity , Cluster Analysis , Female , Humans , Male , Middle Aged , Oligonucleotide Array Sequence Analysis , Polymerase Chain Reaction , Prospective Studies , Rectum/microbiology , Sex Factors
20.
J Environ Manage ; 90(1): 120-30, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18082928

ABSTRACT

Vicuña provide an excellent case study for examining the sustainable use of wildlife outside protected areas: the community-based conservation approach. Vicuña populations in the high Andes of Argentina, Bolivia, Chile, Ecuador and Perú fell to a critically low level, but a Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) ban on trade in their fiber has seen numbers recover dramatically, and now live shearing of vicuña for a high-value international market is being promoted as a mechanism to secure both sustainable vicuña populations and local livelihoods. We used a dynamic optimization model to explore the consequences of legalizing markets, including the consequences for poaching which is critical in vicuña dynamics. Using parameters obtained from the literature and expert knowledge, we explored different scenarios for the Argentine region of Cieneguillas. Our results showed that the role of the international market is ambiguous; live shearing for an international market can provide the very best of outcomes for both vicuña and local people, with large herds generating high revenues. But an international market also creates a market for poached vicuña fiber; as a result, vicuña numbers risk once again falling to critically low levels, resulting also in minimal revenues from sale of fiber. The message for the international community is that if community-based conservation is not implemented carefully then its impact can easily be perverse.


Subject(s)
Animals, Wild , Camelids, New World , Conservation of Natural Resources/legislation & jurisprudence , Crime/legislation & jurisprudence , Animals , Ecosystem , Humans , Population Density , South America
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