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

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

Crop expansion and conservation priorities in tropical countries

Expansion of cropland in tropical countries is one of the principal causes of biodiversity loss, and threatens to undermine progress towards meeting the Aichi Biodiversity Targets. To understand this threat better, we analysed data on crop distribution and expansion in 128 tropical countries, assessed changes in area of the main crops and mapped overlaps between conservation priorities and cultivation potential. Rice was the single crop grown over the largest area, especially in tropical forest biomes. Cropland in tropical countries expanded by c. 48,000 km2 per year from 1999–2008. The countries which added the greatest area of new cropland were Nigeria, Indonesia, Ethiopia, Sudan and Brazil. Soybeans and maize are the crops which expanded most in absolute area. Other crops with large increases included rice, sorghum, oil palm, beans, sugar cane, cow peas, wheat and cassava. Areas of high cultivation potential—while bearing in mind that political and socio-economic conditions can be as influential as biophysical ones—may be vulnerable to conversion in the future. These include some priority areas for biodiversity conservation in tropical countries (e.g., Frontier Forests and High Biodiversity Wilderness Areas), which have previously been identified as having ‘low vulnerability’, in particular in central Africa and northern Australia. There are also many other smaller areas which are important for biodiversity and which have high cultivation potential (e.g., in the fringes of the Amazon basin, in the Paraguayan Chaco, and in the savanna woodlands of the Sahel and East Africa). We highlight the urgent need for more effective sustainability standards and policies addressing both production and consumption of tropical commodities, including robust land-use planning in agricultural frontiers, establishment of new protected areas or REDD+ projects in places agriculture has not yet reached, and reduction or elimination of incentives for land-demanding bioenergy feedstock

Mapping and valuation of ecosystems and economic activities along the coast of Cameroon: implications of future sea level rise.

The vulnerability of the coastal zone of Cameroon to flooding from sea level rise (SLR) was quantified using Geographic Information System (GIS) flooding analysis. The main economic activities and ecosystems along this area were iden tified using secondary data. Valuations of non- market values of ecosystems were based on the ecosystem service product method. The low-lying coastal areas were found to be physically and socio-economically susceptible to impacts of SLR due to their high ecological and economic value. A digitised land use/land cover (LULC) classification was produced from low resolution topographic maps and Google Earth images of the area. The digital elevation model (DEM) used was acquired by the shuttle radar topography mission. Evaluation of potential land loss due to inundation was based on empirical approaches using minimum and maximum scenarios of 2 and 10 m flooding. These were estimated considering the best available SLR data for the area, mean high water levels and wave heights during storms. The estimated SLR range from 2.3 m to 9.2 m for the low and high scenarios, respectively, by 2050 and from 2.6 m to 9.7 m for the low and high scenarios, respectively, by the year 2100. Results indicate that 112 km 2 (1.2 %) and 1,216 km 2 (12.6 %) of the coastal area will be lost from a 2 m (equivalent to a low scenario by 2050) and 10 m (equivalent to a high scenario by 2100) flooding, respectively. 0.3 % to 6.3 % of ecosystems worth US$ 12.13 billion/yr could be at risk of flooding by the years 2050 and 2100. The areas under a serious threat cont ain mangroves, sea and airport, residential and industrial areas of Douala. Main plantation crops of banana and palms will be slightly affected. The identification of the soci o-economic impacts of projected SLR on vulnerable coastlines and populations is important for timely actions to be taken in mitigating the effects of natural disasters in the coastal zone

Understanding the past to conserve the future long-term environmental and vegetation change in the Karoo Midlands, South Africa over the 20th century

Includes bibliographical references.This study investigated the nature, extent and rate vegetation change in the Karoo Midlands region of South Africa at multiple spatial and temporal scales in relation to local and global drivers. This is important because changes in land cover have major implications for the conservation and management of biodiversity in the region. The thesis is comprised of an historical analysis of climate as well as three cases studies which use repeat photography and long-term surveys to assess vegetation change in the region

Marginalised herders: social dynamics and natural resource use in the fragile environment of the Richtersveld National Park, South Africa

This research article published by Elsevier B.V., 2018In the contractual Richtersveld National Park (RNP), park officials and neighbouring communities jointly manage resources, with the aim to harmonize biodiversity conservation and human land use. Our socio-ecological approach compared herding practices and livelihoods of 36 livestock owners and 35 hired herders inside and outside RNP, and further assessed soil quality and vegetation characteristics under different livestock grazing patterns and access to natural resources. Hired herders were mainly in charge of animal movement patterns but were not included in formal agreements, which negatively impacted on natural resource management, livelihoods, animal well-being and communication amongst stakeholders. Soil properties and vegetation were generally negatively affected through grazing and herding practices in this fragile semi-arid biodiversity hotspot that encompasses many endangered and endemic species. Our research highlights the complex social relationships and dynamics between diverse stakeholders engaged in the contractual park and accentuates the need to improve herders’ social and economic status