45,891 research outputs found

    First Report of \u3ci\u3eAllonemobius Griseus\u3c/i\u3e and \u3ci\u3ePsinidia Fenestralis\u3c/i\u3e in Ohio (Orthoptera: Gryllidae and Acrididae)

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    Occurrences of Allonemobius griseus and Psinidia fenestralis in Ohio are pub- lished for the first time. Apparent restriction of these species to the sand deposits of northwestern Ohio, their localized distribution in scattered, non-contiguous blow- outs, and habitat loss presently occurring from residential and commercial development nearby, are justifications provided for the formal state listing and conservation of these Orthoptera in Ohio

    Deforestation and Habitat Loss: Human Causes, Consequences and Possible Solutions

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    Deforestation leads to habitat loss while preservation and conservation of the natural forest increase biological diversity. Multiple factors have been reported to be responsible for deforestation and habitat loss, which could either be of human or natural origin.Natural causes of deforestation could be as a result of forest fires, droughts, exotic animals, floods, overpopulation of foreign animals and climate change. That notwithstanding, human activities are among the principal causes of global deforestation and habitat loss with agricultural expansion, cattle breeding, timber extraction, mining,oil extraction, dam construction and infrastructure development as some examples of these human influences. This study identifies agricultural activities and urbanization as the chief causes of human induced deforestation and habitat loss on a large scale. The simple and more practicable approach to curb the already alarming effects of deforestation and habitat loss is through environmental education of everyone still surviving on our planet.Environmental education is the key to reversing continuous and deliberate human actions through the protection of every natural forest and afforestation where necessary

    Anticipated climate and land-cover changes reveal refuge areas for Borneo's orang-utans

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    Habitat loss and climate change pose a double jeopardy for many threatened taxa, making the identification of optimal habitat for the future a conservation priority. Using a case study of the endangered Bornean orang-utan, we identify environmental refuges by integrating bioclimatic models with projected deforestation and oil-palm agriculture suitability from the 1950s to 2080s. We coupled a maximum entropy algorithm with information on habitat needs to predict suitable habitat for the present day and 1950s. We then projected to the 2020s, 2050s and 2080s in models incorporating only land-cover change, climate change or both processes combined. For future climate, we incorporated projections from four model and emission scenario combinations. For future land cover, we developed spatial deforestation predictions from 10 years of satellite data. Refuges were delineated as suitable forested habitats identified by all models that were also unsuitable for oil palm – a major threat to tropical biodiversity. Our analyses indicate that in 2010 up to 260 000 km2 of Borneo was suitable habitat within the core orang-utan range; an 18–24% reduction since the 1950s. Land-cover models predicted further decline of 15–30% by the 2080s. Although habitat extent under future climate conditions varied among projections, there was majority consensus, particularly in northeastern and western regions. Across projections habitat loss due to climate change alone averaged 63% by 2080, but 74% when also considering land-cover change. Refuge areas amounted to 2000–42 000 km2 depending on thresholds used, with 900–17 000 km2 outside the current species range. We demonstrate that efforts to halt deforestation could mediate some orang-utan habitat loss, but further decline of the most suitable areas is to be expected given projected changes to climate. Protected refuge areas could therefore become increasingly important for ongoing translocation efforts. We present an approach to help identify such areas for highly threatened species given environmental changes expected this century

    Threats of future climate change and land use to vulnerable tree species native to Southern California

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    Climate and land-use changes are expected to drive high rates of environmental change and biodiversity loss in Mediterranean ecosystems this century. This paper compares the relative future impacts of land use and climate change on two vulnerable tree species native to Southern California (Juglans californica and Quercus engelmannii) using species distribution models. Under the Intergovernmental Panel for Climate Change's A1B future scenario, high levels of both projected land use and climate change could drive considerable habitat losses on these two already heavily-impacted tree species. Under scenarios of no dispersal, projected climate change poses a greater habitat loss threat relative to projected land use for both species. Assuming unlimited dispersal, climate-driven habitat gains could offset some of the losses due to both drivers, especially in J. californica which could experience net habitat gains under combined impacts of both climate change and land use. Quercus engelmannii, in contrast, could experience net habitat losses under combined impacts, even under best-case unlimited dispersal scenarios. Similarly, projected losses and gains in protected habitat are highly sensitive to dispersal scenario, with anywhere from > 60% loss in protected habitat (no dispersal) to > 170% gain in protected habitat (unlimited dispersal). The findings underscore the importance of dispersal in moderating future habitat loss for vulnerable species

    Measuring the Meltdown: Drivers of Global Amphibian Extinction and Decline

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    Habitat loss, climate change, over-exploitation, disease and other factors have been hypothesised in the global decline of amphibian biodiversity. However, the relative importance of and synergies among different drivers are still poorly understood. We present the largest global analysis of roughly 45% of known amphibians (2,583 species) to quantify the influences of life history, climate, human density and habitat loss on declines and extinction risk. Multi-model Bayesian inference reveals that large amphibian species with small geographic range and pronounced seasonality in temperature and precipitation are most likely to be Red-Listed by IUCN. Elevated habitat loss and human densities are also correlated with high threat risk. Range size, habitat loss and more extreme seasonality in precipitation contributed to decline risk in the 2,454 species that declined between 1980 and 2004, compared to species that were stable (n = 1,545) or had increased (n = 28). These empirical results show that amphibian species with restricted ranges should be urgently targeted for conservation

    Climate change and the selective signature of the Late Ordovician mass extinction

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    Selectivity patterns provide insights into the causes of ancient extinction events. The Late Ordovician mass extinction was related to Gondwanan glaciation; however, it is still unclear whether elevated extinction rates were attributable to record failure, habitat loss, or climatic cooling. We examined Middle Ordovician-Early Silurian North American fossil occurrences within a spatiotemporally explicit stratigraphic framework that allowed us to quantify rock record effects on a per-taxon basis and assay the interplay of macrostratigraphic and macroecological variables in determining extinction risk. Genera that had large proportions of their observed geographic ranges affected by stratigraphic truncation or environmental shifts at the end of the Katian stage were particularly hard hit. The duration of the subsequent sampling gaps had little effect on extinction risk, suggesting that this extinction pulse cannot be entirely attributed to rock record failure; rather, it was caused, in part, by habitat loss. Extinction risk at this time was also strongly influenced by the maximum paleolatitude at which a genus had previously been sampled, a macroecological trait linked to thermal tolerance. A model trained on the relationship between 16 explanatory variables and extinction patterns during the early Katian interval substantially underestimates the extinction of exclusively tropical taxa during the late Katian interval. These results indicate that glacioeustatic sea-level fall and tropical ocean cooling played important roles in the first pulse of the Late Ordovician mass extinction in Laurentia

    Habitat loss exacerbates pathogen spread : An Agent-based model of avian influenza infection in migratory waterfowl

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    Habitat availability determines the distribution of migratory waterfowl along their flyway, which further influences the transmission and spatial spread of avian influenza viruses (ATVs). The extensive habitat loss in the East Asian-Australasian Flyway (EAAF) may have potentially altered the virus spread and transmission, but those consequences are rarely studied. We constructed 6 fall migration networks that differed in their level of habitat loss, wherein an increase in habitat loss resulted in smaller networks with fewer sites and links. We integrated an agent-based model and a susceptible-infected-recovered model to simulate waterfowl migration and AIV transmission. We found that extensive habitat loss in the EAAF can 1) relocate the outbreaks northwards, responding to the distribution changes of wintering waterfowl geese, 2) increase the outbreak risk in remaining sites due to larger goose congregations, and 3) facilitate AIV transmission in the migratory population. In addition, our modeling output was in line with the predictions from the concept of "migratory escape", i.e., the migration allows the geese to "escape" from the location where infection risk is high, affecting the pattern of infection prevalence in the waterfowl population. Our modeling shed light on the potential consequences of habitat loss in spreading and transmitting AIV at the flyway scale and suggested the driving mechanisms behind these effects, indicating the importance of conservation in changing spatial and temporal patterns of AIV outbreaks.Peer reviewe

    Five main phases of landscape degradation revealed by a dynamic mesoscale model analysing the splitting, shrinking, and disappearing of habitat patches

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    The ecological consequences of habitat loss and fragmentation have been intensively studied on a broad, landscape-wide scale, but have less been investigated on the finer scale of individual habitat patches, especially when considering dynamic turnovers in the habitability of sites. We study changes to individual patches from the perspective of the inhabitant organisms requiring a minimum area for survival. With patches given by contiguous assemblages of discrete habitat sites, the removal of a single site necessarily causes one of the following three elementary local events in the affected patch: splitting into two or more pieces, shrinkage without splitting, or complete disappearance. We investigate the probabilities of these events and the effective size of the habitat removed by them from the population's living area as the habitat landscape gradually transitions from pristine to totally destroyed. On this basis, we report the following findings. First, we distinguish four transitions delimiting five main phases of landscape degradation: (1) when there is only a little habitat loss, the most frequent event is the shrinkage of the spanning patch; (2) with more habitat loss, splitting becomes significant; (3) splitting peaks; (4) the remaining patches shrink; and (5) finally, they gradually disappear. Second, organisms that require large patches are especially sensitive to phase 3. This phase emerges at a value of habitat loss that is well above the percolation threshold. Third, the effective habitat loss caused by the removal of a single habitat site can be several times higher than the actual habitat loss. For organisms requiring only small patches, this amplification of losses is highest during phase 4 of the landscape degradation, whereas for organisms requiring large patches, it peaks during phase 3

    How to protect estuaries in Durham, NH

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    Estuaries are some of the most diverse and fragile ecosystems on our planet. All over the nation, along the coastal states, half of the wetlands, about 55 million acres, have been destroyed (“Habitat Loss Nationwide,” n.d.). Most of these wetlands get Dutton 3 cleared and drained for development, agriculture, etc. In the estuaries located in the Gulf of Maine, development has doubled in the last forty years in the lower watershed (“Habitat Loss Nationwide,” n.d.). This has resulted in an increase in population and impervious surfaces, which correlates with the negative impacts to the watershed, such as runoff and sedimentation (National Research Council, 1987). Other factors have contributed to the degradation of the estuaries in the Piscataqua region such as sealevel rise and an increase in fertilizer use (citations). Some changes have been made to protect these estuaries, however, solving the cumulative impacts need to be included in the protection. Each individual activity is not independent of each other. Their activities work together to decrease the productivity and health of the estuaries. We have policies that have been created, and zoning that has been changed to improve estuaries, however, we need to take that next step forward to fill in the gaps. The goal of this paper is to analyze the current policies and programs, identify the gaps to improve and enhance the programs to be in line with the longstanding ideals of protection and conservation of Durham’s estuaries
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