Green K.,National Parks and Wildlife Service
Journal of Mountain Science | Year: 2010
The phenologies of plants and animals in snow-covered landscapes are expected to accelerate with global warming. However, there are few studies that have examined a range of unrelated taxa in alpine environments to determine whether there is commonality in the proximate causes, synchrony in timing, or the direction of any changes. Records for five alpine animal species and two alpine plant species, chosen primarily for their visibility, were examined to determine their temporal response to regional climate warming. Over the 30-year period studied, they showed an array of different phenological responses. Plant flowering appeared linked to date of snow melt, whereas animal responses varied. Although having accelerated phenologies, two migratory bird species exhibited contrary changes; one to low-altitude warming regardless of snow conditions in the alpine zone (flame robin) and the other to state of the snowpack regardless of low-altitude temperatures (Richard's pipit). By contrast, the migratory bogong moth arrived significantly later over the years with no apparent explanatory climatic cause. Although bogong moths are not responding to earlier snow melt, insectivorous predators on the ground are. This could lead to a serious mismatch in timing at different trophic levels, putting pressure on endangered vertebrates. Emergence of locally wintering insect species, March flies and Macleay's swallowtails, were not significantly related to measured climatic parameters over the study period. A consequence of the disparate responses to climate warming recorded here is the questionable value of 'indicator species' to examine the impact of climate warming on alpine ecosystems. © 2010 Science Press, Institute of Mountain Hazards and Environment, CAS and Springer-Verlag Berlin Heidelberg.
Muir C.,Australian National University |
Rose D.,Macquarie University |
Sullivan P.,National Parks and Wildlife Service
Rangeland Journal | Year: 2010
A river is like a mirror: it reflects the care given by people whose lives depend upon it. A scald on red ground or the slow death of a river reveals more than troubled ecological relationships they are signs of broken social relationships. How people take care of social relationships and how they take care of ecological relationships are the same question. In this paper we emphasise the importance that Aboriginal people place on social relationships for good ecological relationships. In the past few decades natural resource managers have sought Indigenous knowledge relevant to Western ideas of environment, and in doing so, created distinctions between 'ecological' and 'social' knowledge this is an artificial 'white-fella' separation. Additionally, Indigenous knowledge has been treated as if it were a static archive that need only be extracted and applied to resource development and planning. Instead it is dynamic, adaptive and contextual. As a consequence of compartmentalisation and the assumption of timelessness, the importance of social relationships in ecological relationships has been overlooked. Some research has explored similarities between Indigenous knowledge and the Western concept of adaptive management, and raised the possibility of synergy between them. We agree there are possible connections and opportunities for exchange and further learning between Indigenous knowledge and ecological resilience and adaptive management. However, Indigenous knowledge and Western science belong to different world views. An important task is to explore ways of grappling with this ontological challenge. We suggest a conceptual turn around that we believe could assist in opening a dialogue as well as creating a set of foundational principles for robust ecological and social relationships. © 2010 Australian Rangeland Society.
Green K.,National Parks and Wildlife Service |
Pickering C.,Griffith University
Plant Ecology and Diversity | Year: 2013
Background: In the alpine zone of the Snowy Mountains, grazing by mammals is limited. However, introduced European hare numbers have increased since the 1970s. Aims: To estimate the density of hares and hence grazing pressure among years. To assess the response of biomass, vegetation height and composition to a cessation of hare grazing. Methods: We used indices of hare abundance based on spotlighting and counts of hare pellets on a transect. The effect of hare grazing on tall alpine herbfield was assessed by using 15 paired exclosure and control quadrats for six years. Results: The indices of hare abundance suggested densities similar to those in upland areas of Britain. Grazing did not affect the composition, cover of herbs or graminoids or, for 2010, vegetation height or biomass. Variation in vegetation and hare numbers among years was not correlated with climatic variables. Observations of selective grazing suggested that impacts on vegetation may be localised and restricted to certain species. Prior analyses of hare pellets indicated that hares might spread seed of native and exotic species. Conclusions: Hares are having no general effect on tall alpine herbfield but may affect certain plant species via selective grazing or by spread of viable seed. © 2013 Copyright 2013 Botanical Society of Scotland and Taylor & Francis.
Fox A.D.,University of Aarhus |
Walsh A.,National Parks and Wildlife Service
Hydrobiologia | Year: 2012
Migratory geese accumulate energy and nutrient stores in winter to fly to refuelling spring staging areas before onward migration to breeding areas. Mean ground temperatures at two important Greenland White-fronted Geese wintering sites rose in winter and spring by 1.0-1.3°C during 1973-2007. Greenland White-fronted Geese departed the Wexford winter quarters on 3rd April 2007 for Icelandic spring staging areas, the earliest on record, representing a mean advancement of 15 days since 1973, mirrored amongst mean dates of departure amongst Scottish wintering birds that have advanced by 12 days during 1973-2007. Icelandic temperatures at critical midway staging areas en route to Greenland showed no significant change since 1973, suggesting that it is warming on the winter quarters that enable geese to depart earlier, rather than elevated temperatures at ultimate spring staging areas. However, Wexford departure date did not correlate with spring temperature. Data presented here show that Greenland White-fronted Geese have accumulated threshold body stores progressively earlier in spring migration, especially during 1995-2007. Although this did not correlate with ambient temperature, the mean degree of accumulated fat stored by 1st April in each year was a statistically significant predictor of departure date for the wintering population at Wexford. These data support the hypothesis that it is intrinsic factors (i. e. improvements in internal body state resulting from better feeding conditions) that has permitted progressively earlier departure of these geese from Wexford on spring migration, rather than amelioration of spring conditions in Iceland or solely the result of warming of the winter quarters. © 2012 Springer Science+Business Media B.V.
Monteiro N.M.,Fernando Pessoa University |
Lyons D.O.,National Parks and Wildlife Service
PLoS ONE | Year: 2012
In order to answer broader questions about sexual selection, one needs to measure selection on a wide array of phenotypic traits, simultaneously through space and time. Nevertheless, studies that simultaneously address temporal and spatial variation in reproduction are scarce. Here, we aimed to investigate the reproductive dynamics of a cold-water pipefish simultaneously through time (encompassing variation within each breeding cycle and as individuals grow) and space (by contrasting populations experiencing distinct water temperature regimes) in order to test hypothesized differences in sexual selection. Even though the sampled populations inhabited locations with very different water temperature regimes, they exhibited considerable similarities in reproductive parameters. The most striking was the existence of a well-defined substructure in reproductive activity, where larger individuals reproduce for longer periods, which seemed dependent on a high temperature threshold for breeding rather than on the low temperatures that vary heavily according to latitude. Furthermore, the perceived disparities among populations, such as size at first reproduction, female reproductive investment, or degree of sexual size dimorphism, seemed dependent on the interplay between seawater temperature and the operational sex ratio (OSR). Contrary to our expectations of an enhanced opportunity for sexual selection in the north, we found the opposite: higher female reproductive investment coupled with increased sexual size dimorphism in warmer waters, implying that a prolonged breeding season does not necessarily translate into reduced sexual selection pressure. In fact, if the limited sex has the ability to reproduce either continuously or recurrently during the entire breeding season, an increased opportunity for sexual selection might arise from the need to compete for available partners under strongly biased OSRs across protracted breeding seasons. A more general discussion on the effects of climate change in the pressure of sexual selection is also presented. © 2012 Monteiro, Lyons.