Abstract Listing by Session

Conservation on private lands

Parnell      Wednesday, December 7th 2011

Presentation #1   16:30  Landscape composition and scale determine butterfly richness in gardens: evidence from citizen-scientist garden counts in Belgium Maes, D*, Research Institute for Nature and Forest (INBO ; Vanreusel, W, Natuurpunt; Van Dyck, H, UCL
Butterflies are among the best-known invertebrates by the general public. Making use of this social basis, the largest volunteer nature organisation in Belgium, organised monthly garden butterfly counts since 2007. To do so, volunteer citizen-scientists observed 19 easily recognisable and common butterflies species in their gardens. In total, 1140 gardens were counted in which almost 92000 individuals were observed. We analyzed the effect of both structural (area of 8 different land use types) and functional (composition and number of patches of land use types) landscape heterogeneity on butterfly species richness in gardens at 5 different spatial scales (radius 500-2500m). The smallest spatial scale (radius 500m) best explained the variation in the number of species in the gardens. Species richness was highest in gardens surrounded by a large total area of unfragmented semi-natural biotopes and a low area of densely build-on areas. Additionally, we examined the effect of the amount and the configuration of biotopes beyond 500m on butterfly species richness. A positive effect was observed for the number of deciduous woodland patches >1ha in the ring between 500- 1000m and for the area of meadows in the ring of 1000-1500m, while a negative effect of the number of densely build-on patches in the ring of 2000-2500m was demonstrated. In a next stage, we will also focus on the gardens characteristics itself and on the interaction between garden and the surrounding landscape.
Presentation #2   16:45  Comparing environmental performance of organic and integrated management kiwifruit orchards MACLEOD, CJ*, Landcare Research
Organic farming is often promoted as a solution for counteracting the adverse impacts of agricultural intensification on biodiversity. However, it is unclear whether the biodiversity benefits derived from organic farming require an adoption of organic farming in its entirety (i.e. a systems-level approach) or whether the benefits derived are due to just a small subset of the associated management practices. Using data collected from kiwifruit orchards in New Zealand, we assess whether orchards managed under an organic system support enhanced biodiversity and soil quality than those under integrated management systems. We then test whether variation in specific land management practices among kiwifruit orchards better predicts biodiversity and soil quality than overall differences in management system, to determine whether environmental gains can also be achieved on non-organic orchards. We conclude with a power analysis investigating whether our current study design has the power to detect significant changes in environmental performance.
Presentation #3   17:00  Effects of pond draining on farm pond biodiversity and water quality USIO, NISIKAWA*, Niigata University, Japan ; Miho Imada, National Institute for Environmental Studies, Japan; Megumi Nakagawa , National Institute for Environmental Studies, Japan; Munemitsu Akasaka , National Institute for Environmental Studies, Japan; Noriko Takamura, National Institute for Environmental Studies, Japan
Farm ponds have high conservation values because they contribute significantly to regional biodiversity and ecosystem services. In Japan, pond draining is a traditional management method that is widely believed to improve water quality and to eradicate invasive fish. On the other hand, pond draining may reduce freshwater biodiversity through extirpation of immobile aquatic animals. However, scientific evaluation of the effects of pond draining is lacking. Here, we evaluated through a natural experiment the effects of pond draining on freshwater biodiversity and water quality with regards to differential pond management practices and heterogeneous landscapes. Sixty four farm ponds were surveyed for various aquatic animals and plants. Macroinvertebrates and bloom-forming Cyanobacteria were used as indicators for freshwater biodiversity and water quality, respectively, and these variables were related to pond management practice and land use variables. The key findings are that: 1) contrary to the expectations, pond draining was neither effective in eradicating invasive animals (i.e. bluegill sunfish and red swamp crayfish) nor improving water quality and 2) pond draining can have adverse effects on red list species (mainly snails) in forest-dominated landscapes. Overall, our results indicate that pond draining is not effective at least for the selected variables. There is a pressing need for developing target-specific management methods of farm pond ecosystems.
Presentation #4   17:15  Herbivory as an indirect driver of change in fragmented eucalypt forests Farmilo, BJ*, La Trobe University ; Morgan, JW, La Trobe University
Current fragmentation research lacks investigations on biotic interactions between species, particularly herbivory. Utilising the Wog Wog Fragmentation Experiment in south-eastern Australia, we aim to better understand the plant-herbivore interactions in fragmented landscapes and whether it is an important, but overlooked, agent of change. Herbivore impacts on four common plant species were compared in eucalypt forest that varied in fragment size (0.25 ha, 0.88 ha, 3.06 ha) using vertebrate herbivore exclusion plots. We recorded key measures of growth, reproduction and survival that will infer the role of herbivores in this fragmented environment. Initial results indicate herbivory impacts are species-specific and increase with increasing fragment size. Hence, plants in small fragments are not impacted in the same way that they are in larger fragments, and control forests. Herbivores can exert a strong influence on community dynamics and alterations to herbivore activity will most likely result in indirect changes in community composition via fragmentation.
Presentation #5   17:30  Elevational distribution pattern and conservation of amphibians in the eastern Himalaya, India Chettri, Basundhara, Sikkim Government College, Tadong ; ACHARYA, BK*, Sikkim Government College, Tadong
Eastern Himalaya harbors diversity of habitats resulting in diverse life forms with high endemicity. Recently, these habitats have experienced various anthropogenic pressures posing serious threat to biodiversity. Here we examine elevational distribution pattern of amphibians to identify high diverse areas along elevation gradient (300-4800 m) in Sikkim, Eastern Himalaya, India. We also evaluate threats to amphibians and suggest measures for conservation. We used Visual Encounter and Night Stream Survey methods for data on amphibian population, and field surveys, home visits and interviews for data on threats. Amphibian species richness depicted mid-elevation peak showing maximum richness at 1500-2000 m with a four-fold decline from middle to the highest elevation. Upcoming hydro power projects possess major threat to amphibian habitat along the river valleys. Rampant extraction of amphibians by local communities for food and medicine caused population decline. As conservation measures, we extensively raised awareness at various levels on role of amphibians in ecosystems and their conservation need. We conclude that river valleys all along the elevation, more importantly mid-elevation, are crucial for amphibian conservation in the eastern Himalaya and needs immediate conservation attention. Empowerment of panchayat members (governance at village level) for taking legal action at local level is suggested so that collection of amphibians and habitat destruction is reduced.
Presentation #6   17:45  Contribution of land use types to regional plant diversity in temperate Australian agricultural landscapes Schultz, Nick*, School of Environmental & Rural Science, University of New England, Armidale NSW 2351, AUSTRALIA ; Reid, Nick, School of Environmental & Rural Science, University of New England, Armidale NSW 2351, AUSTRALIA; Lodge, Greg, Department of Trade & Investment, Regional Infrastructure and Services, Primary Industries, Tamworth Agricultural Institute, Calala NSW 2340, AUSTRALIA
Plant diversity is threatened in Australia’s agricultural landscapes. While there is a good understanding of the effects of grazing and agricultural management on plant diversity at the site scale, our understanding of diversity patterns across multiple spatial scales is less developed. On the North West Slopes of New South Wales, Australia, we compared species accumulation curves and habitat specificity indices of three major land uses in the region; native pastures, woodlands grazed by livestock, and woodlands not grazed by livestock. Despite similar species densities at local scales (i.e. 400 m^2), regional species accumulation and habitat specificity were highest in ungrazed woodlands and lowest in native perennial grass dominated pastures. Native species that persisted in native pastures were largely a subset of the suite of species found elsewhere in the landscape. We propose that tree removal and livestock grazing have both reduced habitat heterogeneity in the landscape. Therefore conservation efforts should focus on the protection, restoration and regeneration of ungrazed patches of woodlands in the landscape. Our results contrast with some other studies in Australian agricultural landscapes that showed that native pastures grazed by livestock support a suite of species not found elsewhere in the landscape. Hence, it is likely that not all agricultural landscapes are similar in their landscape diversity patterns.
Presentation #7   18:00  The Satoyama Index: A biodiversity indicator for agricultural landscapes Kadoya, T*, National Institute for Environmental Studies ; Washitani, I, The University of Tokyo
Agricultural development to meet rapidly growing demands for food and biofuel and the abandonment of traditional land use have had major impacts on biodiversity. Habitat diversity is one of the most important factors influencing biodiversity in agricultural landscapes. In this study we propose an ecological index of ecosystem or habitat diversity in agricultural landscapes – the Satoyama Index (SI) – that is discernible under appropriate spatial units (e.g., 6 km×6 km) from 1 km×1 km gridded land-cover data available from an open-access web site. A high SI value is an indicator of high habitat diversity, which is characteristic of traditional agricultural systems, including Japanese satoyama landscapes, while a low value indicates a monotonic habitat condition typical of extensive monoculture landscapes. The index correlated well with the spatial patterns of occurrence of a bird of prey (Butastur indicus) and species richness of amphibians and damselflies in Japan. The values of the SI also corresponded well to the spatial patterns of typical traditional agricultural landscapes with high conservation value in other countries, for example, the dehesas of the Iberian Peninsula and shade coffee landscapes in Central America. Globally, the pattern of East/South-East Asian paddy belts with their high index values contrasts markedly with the low values of the Eurasian, American, and Australian wheat or corn belts. The SI, which correlates landscapes with biodiversity through potential habitat availability, is highly promising for assessing and monitoring the status of biodiversity irrespective of scale.
Presentation #8   18:15  Matrix heterogeneity affects population size of Harvest mice in fragmented landscape Misako Kuroe*, Akita Prefectural University
In a highly fragmented landscape, not only habitat size and arrangement but also heterogeneity of landscape matrix affects population sizes through dispersal process. Most previous studies estimated matrix-dependent dispersal parameters using radio-tracking data or mark-recapture data which were difficult to obtain. In this study, I demonstrated that matrix resistances can be estimated by using distribution data. I investigated nest distributions of Harvest mice (Micomys minutes), which inhabits tall grassland in agricultural landscape. First, statistical modeling by Bayesian estimation showed that patch size and patch connectivity including matrix heterogeneity were important for nest distributions. Estimated values of matrix resistance depend on landscape elements; rice and crop field showed low resistances, and forest, creak, road and residential area showed high resistances. Second, to test the effectiveness of the pattern-oriented Bayesian modeling, I conducted field experiments and model validations. The field experiments of habitat loss showed that the colonization rates were also depended on matrix compositions, which were consistent with estimated matrix resistances. The model validation showed that the model including matrix heterogeneity well predicted the population sizes in more fragmented landscapes, while the model without matrix heterogeneity could not. These results suggest that matrix resistances estimated by distribution data were applicable for predicting population size, and in addition to habitat management, matrix restoration will be an effective strategy to enhance population size in fragmented landscape.