26 research outputs found

    Modelling future range shift gaps in a biodiversity hotspot : a case study of critically endangered plants in Madagascar

    Get PDF
    The synergy between climate and land use land cover change is expected to influence species distribution at local and regional scales in tropical regions. However, robust quantification of species responses and species-specific dispersal rates is lacking for most of Sub-Saharan Africa. This project aims to model range-shift gaps for 84 endangered or critically endangered plant species due to environmental change in Madagascar. To achieve this deforestation and forest degradation rates were quantified from Landsat imagery using sub-pixel analysis in two intervals (i.e, 1994-2002 and 2002-2014). Next, intensity analysis was used to determine processes of LULCC at eco-regional scale, while morphological spatial pattern analysis was applied for the determination of protected areas connectivity. Furthermore, species distribution models were constructed using hierarchical Bayesian modelling approach that included corridor connectivity and uncertainties in the derived predictions of species distribution under current and future scenarios. Finally, six spatial indices that quantified vulnerabilities, species range-shifts and displacement were derived from these predictions. The results showed differentiation in rates of deforestation and forest degradation across eco-regions. On average plant species' range were predicted to shift by approximately 300 km under future scenarios with and without connectivity. Corridor connectivity will facilitate more species upward displacements under low emission scenarios compared to high emission scenarios. Eastern humid forest were identified as 'range shift hotspots' and will be characterised by substantial species' range contractions in future scenarios. Biodiveristy in the region will experience novel threats from climate and land use cover change. Conservationist need to adapt on-going intervention programmes to prepare for the potential risks of species extinctions due to environmental change through the integration of spatial conservation planning concepts in policy formulation

    Assessment of variability of peat physicochemical properties, subsidence and their interactions within Selangor forests

    Get PDF
    Tropical peat swamp forests are carbon-rich ecosystems both above- and belowground, which play a major role in the climate balance of the earth. The majority of the world's tropical peat forest cover is located in Southeast Asia and is increasingly threatened by anthropogenic disturbances. Despite their importance for biodiversity conservation and climatic balance of the earth, pristine peatlands are almost extinct in many parts of Southeast Asia. Peninsular Malaysia is one such region, where there are no undisturbed peatlands left in the west coast. We studied the largest peat forest area in the west coast of Malaysia, located in the state of Selangor. We evaluated variability of peat subsidence (for 1 year), peat physicochemical properties and macronutrient contents between forest regions and between different depths (not for subsidence) covering the top 50 cm, and the complex interactions between them. We found that there was significant peat subsidence in all the studied regions, however, there was no significant difference in subsidence between different forest regions. Physicochemical properties such as peat moisture, pH and carbon (C) content and all macronutrient contents except phosphorus (P), either varied between regions, or showed significant interactions between region and depth in Selangor peat forests. All the measured peat physicochemical properties varied with depth. Among macronutrients, only nitrogen (N), P and calcium (Ca) showed significant change with depth, while there were no changes with depth for sulphur (S), potassium (K) and magnesium (Mg) contents. These changes in each peat physicochemical property and macronutrient contents correlated with changes in other peat physicochemical properties and nutrient contents; however, there is a need for controlled experiments to further understand these significant interactions. The findings show continued carbon loss in secondary peat swamp forests through subsidence, indicating the long-term impact of selective logging and associated historical drainage. The significant variability of peat physicochemical properties and macronutrient contents with region and depth, also show the need for intensive sampling to characterise large secondary peat swamp forests

    Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980-2017: a systematic analysis for the Global Burden of Disease Study 2017.

    Get PDF
    BACKGROUND: Global development goals increasingly rely on country-specific estimates for benchmarking a nation's progress. To meet this need, the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 estimated global, regional, national, and, for selected locations, subnational cause-specific mortality beginning in the year 1980. Here we report an update to that study, making use of newly available data and improved methods. GBD 2017 provides a comprehensive assessment of cause-specific mortality for 282 causes in 195 countries and territories from 1980 to 2017. METHODS: The causes of death database is composed of vital registration (VR), verbal autopsy (VA), registry, survey, police, and surveillance data. GBD 2017 added ten VA studies, 127 country-years of VR data, 502 cancer-registry country-years, and an additional surveillance country-year. Expansions of the GBD cause of death hierarchy resulted in 18 additional causes estimated for GBD 2017. Newly available data led to subnational estimates for five additional countries-Ethiopia, Iran, New Zealand, Norway, and Russia. Deaths assigned International Classification of Diseases (ICD) codes for non-specific, implausible, or intermediate causes of death were reassigned to underlying causes by redistribution algorithms that were incorporated into uncertainty estimation. We used statistical modelling tools developed for GBD, including the Cause of Death Ensemble model (CODEm), to generate cause fractions and cause-specific death rates for each location, year, age, and sex. Instead of using UN estimates as in previous versions, GBD 2017 independently estimated population size and fertility rate for all locations. Years of life lost (YLLs) were then calculated as the sum of each death multiplied by the standard life expectancy at each age. All rates reported here are age-standardised

    Madagascar protected area prioritization: a road map for conservation

    No full text
    corecore