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Voyageurs National Park (VNP) is within the historical distribution of Canada lynx (Lynx canadensis), a federally threatened species. Sightings of lynx in and near VNP have existed since the 1970s, and three recent sightings have been confirmed with DNA analysis. However, population status and habitat suitability for lynx in VNP are unknown. We used remote cameras and snow-tracking to search for lynx in and near VNP in 2007 and 2008 and did not document lynx presence. We estimated the density of the lynx's primary prey, snowshoe hare (Lepus americanus), with hare pellet counts, extrapolated hare density to the landscape level, and compared habitat in VNP to habitat in lynx home ranges in northeastern Minnesota. Hare pellet densities in VNP were about half of hare pellet densities in lynx home ranges in northeastern Minnesota. Even though patches of high-density hare habitat exist in the VNP area, the low density of snowshoe hares at the landscape level would not support resident lynx, and most of the lynx recently documented in and near VNP are, therefore, probably transient animals. A female lynx with a kitten west of VNP in winter of 2010 was the only probable resident lynx confirmed near VNP from 2001 to 2010. Habitat management or natural disturbance processes that increase snowshoe hare densities would be required to support a resident lynx population in VNP.
The amount of forest cover in Jordan is estimated at about one percent of the country's land area. Land-use pressures and altered disturbance regimes have generated concern for the conservation of forests. In this context, Aleppo pine (Pinus halepensis Mill.) is a valuable forest type diminished from its historic extent. Accordingly, to gather information for conservation planning, we used systematic vegetation sampling to evaluate the composition and structure of Aleppo pine communities at the Dibeen Forest Reserve in Jordan. Permanent plot centers were established on a 200-m grid, and 72 of the grid points were selected randomly for an initial sampling of the reserve. An inventory of all live and dead trees was taken on circular plots. Due to their conservation value and growing pattern, the plot size for live Aleppo pine was enlarged to capture additional diameter samples. Relative species abundance, as determined by basal area estimates, ranged from < 1 m2/ha for five of seven tree species captured in our inventory and up to 4.6 m2/ha for P. halepensis. The majority of basal area (41.2%) occurred in diameter classes between 5 and 20 cm. Not counting recruitment trees under 5 cm in diameter, tree density ranged from 0.7 trees per hectare (TPH) for Azarole hawthorn (Crataegus azawlus L. Azarole.) to 504.5 TPH for Palestine oak (Quercus coccifera ssp. calliprinos Holmboe (syn. Quercus calliprinos Webb)). Given the importance of P. halepensis in determining the structure of Dibeen communities, basal area values were further stratified by diameter for the species, over 70% of which were concentrated in diameter classes between 20 and 55 cm. To assess succession and recruitment patterns in the pine, stem density was also stratified by diameter class and ranged from 68.9 TPH in the smallest class to 0.1 in the largest measured class, 140 cm. The distribution of stem densities among diameter cohorts implies a selfsustaining population of P. halepensis at the reserve. Low recruitment of other seral species suggests a need to further monitor tree recruitment and consider conservation strategies.
Protected areas increasingly face degradation from both internal and external stressors. One increasingly relevant external threat is oil contamination, which has well documented negative impacts on terrestrial and aquatic ecosystems. To evaluate such potential threats in environmental management, risk analysis has expanded as a discipline. Here, we derive a risk index for protected areas in British Columbia, Canada, that are located downstream from the proposed Northern Gateway pipeline along its 680 km route across the province. Using a Geographic Information System (GIS) approach, our risk model incorporates both the probability of oil — once spilled — contaminating a park and the consequence of such exposure. We identified 34 protected areas located downstream and potentially at risk. Two were within 50 meters of the proposed pipeline route. Of downstream parks, we found that some were at twice the risk of others. In general, higher risk parks were not any closer to the pipeline but were, on average, of larger areas. The Fraser River watershed, which hosts British Columbia's most economically valuable salmon runs, contained the most parks at risk. From an environmental impact assessment and park management perspective, our results can help identify and evaluate the potential adverse effects of pipeline ruptures. The information can be used to determine, systematically, which parks most urgently require spill response plans and where baseline environmental monitoring might be best deployed. Given that oil transport, a rapidly growing enterprise, is only one of many stressors that threaten natural areas, decisions concerning industrial proposals benefit appreciably from risk analysis.
Cerro El Potosi is a Natural Protected Area under State jurisdiction and it is one of the highest peaks of the Sierra Madre Oriental. It is an interesting area as its flora and fauna are distributed along a 2000–3750 m altitudinal gradient. The purpose of this study was to conduct an inventory of the herpetofauna and to describe its distribution in relation to plant communities and altitude. In addition, we address the risk of extirpation of some of the species. Twenty-five field trips of three to four days each were made between October 2006 and October 2008. A total of 268 individuals of amphibians and reptiles were observed. The sampled plant communities and number of herpetofaunal species found were: farming areas, eight species; submontane scrubland, four; chaparral, five; Quercus spp, six; Pinus pseudostrobus, eight; Pinus ayacahuite-, five; Pseudotsuga menziesii, five; Pinus hartwegii, five; Pinus strobiformis, two; Pinus culminicola, five; and catastrophic fire deforestation areas, three. According to the literature, 41 species are known from the area, while only 16 taxa were found during this study. The non-parametric estimators for species diversity indicated that the number of species tend to rise as sampling increases; the curve has not reached totality. Its asymptote represents 84.21% of herpetofauna for the mountain.
Casuarinas (Casuarina equisetifolia L.) are a problematic invasive plant within the Bahamas, but very little is known about its population dynamics or spread capabilities. This study monitored casuarinas beach populations on San Salvador Island, the Bahamas, over a 2.5 year period to provide basic background data on distribution patterns and degree of spatial variability over time. Casuarinas had a significant clustered distribution along beach transects (P< 0.05). Numerous gaps in between clusters, 20 m or longer, were not colonized during the duration of the study. These patterns occurred among beaches with differing levels of human visitation. It seems that beach populations of casuarinas had low spatial variability within the spatial and temporal context of this study. These results may help guide future research and may be an initial step in developing effective management strategies in the Bahamas and in other areas where it has invaded.
Invasive plants threaten Canada's National Parks, which have a mandate for conservation of native vegetation. In Jasper National Park, Russian thistle (Salsola tragus L.), an introduced annual forb, has invaded Montane grasslands that constitute critical winter range for bighorn sheep (Ovis canadensis Shaw) and other ungulates. A two year study assessed five strategies for controlling Russian thistle: (1) removal of ungulate grazing; (2) spraying with metsulfuron-methyl; (3) manual pulling of Russian thistle plants; (4) broadcast seeding of native plant species; and (5) integrated weed management combining grazing exclusion, herbicide, and seeding. All treatments that included herbicide reduced Russian thistle, but also removed native forbs. Manual removal of thistle plants reduced the cover and density of the weed, but not final biomass, and may be impractical to implement on large areas. Grazing exclusion resulted in a large decline in Russian thistle density and biomass after two years and coincided with recovery of other forbs, suggesting this weed species is responding to competition and could, therefore, be reduced through management of ungulate grazing pressure.
Spotted knapweed (Centaurea stoebe L. ssp. micranthos [Gugler] Hayek) is an exotic plant that displaces native vegetation leading to altered plant and animal communities. We compared small mammal abundance and diversity in areas with, and without, spotted knapweed in Grand Sable Dunes, Michigan, to determine whether presence of this plant affected the small mammal community. We live trapped small mammals in June and August 2003 in six plots in native dune vegetation and in six plots in areas with spotted knapweed and native dune vegetation. Mean number of captures per trap of mice in spotted knapweed plots ( = 0.50 ± 0.31) was nearly double that in native plot ( = 0.27 ± 0.19; F1,20 = 18.251, P < 0.001). Amount of total vegetative cover in spotted knapweed plots ( = 71 ± 12% SD) was almost twice that in native plots ( = 37 ± 11%). Mean number of captures per trap was positively related to percent cover (F1,20 = 5.239, P = 0.033). Mice are seed and insect predators, seed and spore dispersers, and serve as prey for numerous species. Thus, the positive response by mice to the spotted knapweed invasion may have caused additional changes to this community.
Many small, once-rural parcels of land, which were protected to conserve rare plants, now exist as isolated patches of habitat within suburban and urban matrices. Small parcel protection and management are sometimes considered a non-ideal use of scarce conservation resources, but for plants with narrowly-restricted ranges, remnant parcels may still hold significant conservation value. Managing small reserves can be more complicated than tending to a single large reserve; destructive trespass and encroachment are common challenges on small reserves, where edge effects impact a significant portion of the total protected area. Small properties also provide limited space for species to migrate and adapt in the face of climate change. The conservation values and management challenges relevant to many small reserves are exemplified here in a case study from Bear Valley in southern California where The Nature Conservancy has collaborated with various partners to protect rare plants on lands within the San Bernardino Mountains, which later became surrounded by residential development. The San Bernardino Mountains constitute a mere 1% of the land area of California, yet contain about 25% of all of the state's plant species. The history of rare plant conservation in Bear Valley and the current status of The Nature Conservancy's efforts in this region are discussed. In addition, strategies and management recommendations for successful rare plant conservation in the face of global urbanization are presented.
Bunnell et al. (2009) introduced the concept of Stewardship Responsibility (SR) rankings as a tool for conservation planning, using global rankings of rare species in British Columbia. I applied a version of their tool to assess biodiversity distributions in New York State Parks, using records collected by the N.Y. Natural Heritage Program. Comprehensive surveys were conducted among 150 parks over a decade, leading to a database of 1074 records for 312 rare species and 98 significant ecological communities. I applied SR ranks in a nested design — agency-wide — among regions within the agency and across the state (comparisons with other management entities). Subsets of parks and regions ranked more highly than others, but most parks contain at least one rare species and significant ecological community, indicating a broad distribution of important biological resources. Statewide, the agency maintains a very high SR rank profile in proportion to its land area (< 1% of the state), with 43% of all New York rare species found in at least one State Park, and 30 species fully or primarily dependent on the agency for their protection. Taking this information a step further, I developed a set of park-by-park Natural Heritage Biodiversity Profiles, which emphasize unique contributions of each park in ways designed to inform the general public. Although many state and provincial park systems emphasize their recreational features, probably all make critical contributions to biodiversity conservation, and tools like these can be used to illustrate and enhance those contributions.
Restoration and conservation may be enhanced by using ecologically-based methods for prioritizing actions. Efforts are currently underway to restore river flows to the San Joaquin River in California's Central Valley. Although fish are the primary restoration target for restored flows, complementary efforts are being designed to protect, enhance, and restore riparian and floodplain habitats to benefit the larger ecological community. We describe our efforts to use bird habitat distribution models to inform and prioritize conservation activities along the San Joaquin River. We demonstrate the integration of habitat distribution models into an established conservation planning process that illustrates the synergies and tradeoffs of protecting high quality habitat for multiple species-groups and other restoration opportunities on the San Joaquin River. We used quantitative models to develop habitat quality indices for marsh birds, early-successional riparian birds, and mid/late-successional riparian birds, and used these indices to rank 18 sites under consideration along the San Joaquin River. We found little evidence that the rankings of the 18 sites for the three habitats were correlated, suggesting that any prioritization decisions will need to consider the quality of all three habitats, rather than one habitat acting as a surrogate for the others. Considering the habitat model rankings together with expert opinion rankings based on existing habitat quality, restoration potential, and flood management opportunities allowed us to identify sites that ranked high across multiple criteria. These results illustrate a simple process by which quantitative information from habitat models can be combined with expert opinion to inform priorities for protection and restoration.
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