Pressure cookers or pressure valves: Do roads lead to deforestation in China?

The effect of roads on forests is ambiguous. Many studies conclude that building and upgrading roads increases pressure on forests but some find that new and better roads may reduce the rate of deforestation. In this paper we use satellite remote sensing images of forest cover in Jiangxi Province, China, to test whether the existence and the size of roads (ranging from expressways to tertiary roads) in 1995 affected the level of forest cover in 2000 or the rate of change between 1995 and 2000. To account for road access for each of our 1 km² (“pixel”) units of forest cover we measure whether or not and what type of roads penetrate the “watershed” in which the pixel lies. These watersheds allow more plausible measures of accessibility than do traditional “crowfly” distance measures that ignore topography. To account for possible confounding we also use 12 additional covariates: geographic and climatic variables (e.g., elevation, slope, rainfall, temperature, soil properties); demographic and economic variables (e.g., local population and GDP per square kilometer); and distance variables (e.g., distance to the nearest provincial capital). Although simple univariate OLS regressions show that forest levels are lower and deforestation rates higher either when there is a road, or when there is a higher quality road, these results are not robust. Controlling for all of the covariates and also using recently developed covariate matching techniques to estimate treatment effects, we find that roads in China’s Jiangxi Province can most safely be described as having no impact on the level of forests and no impact on the rate of deforestation.     

Catalytic ozonation of reactive red X-3B in aqueous solution under low pressure: decolorization and OH· generation

Catalytic ozonation of Reactive Red X-3B in aqueous solution had been carried out in an ozone oxidation reactor where Mn-Fe-ceramic honeycomb was used as the catalysts. The presence of Mn-Fe-ceramic honeycomb catalyst could obviously improve the decoloration efficiency of Reactive Red X-3B and the utilization efficiency of ozone compared to the results from non-catalytic ozonation. Adsorption of Reactive Red X-3B had no obviously influence on the degradation efficiency. Addition of tert-butanol significantly decreased the degradation efficiency, indicating that the degradation of Reactive Red X-3B followed the mechanism of hydroxyl radical (OH·) oxidation. The operating variables such as reaction pressure and ozone supply had a positive influence on the degradation efficiency, mainly attributing to facilitate the ozone decomposition and OH· formation.     

Investigating Potential for Depensation in Marine Turtles: How Low Can You Go?

Abstract:  Where mechanisms inherent within the biology of a species affect individual fitness at low density, demographic-scale depensation may occur, hastening further decline and leading ultimately to population extirpation and species extinction. Reduction in fertility at low population densities has been identified in marine and terrestrial species. Using data on hatch success and hatchling-emergence success as proxies for fertilization success, we conducted a global meta-analysis of data from breeding aggregations of green turtles ( Chelonia mydas ) and loggerhead turtles ( Caretta caretta ). We found that there has been no reduction in fertility in small nesting aggregations in either of these species worldwide. We considered mechanisms within the mating strategies and reproductive biology of marine turtles that may allow for novel genetic input and facilitate enhanced gene flow among rookeries. Behavioral reproductive mechanisms, such as natal philopatry and polyandry, may mitigate potential impacts of depensation and contribute to the resilience of these species.     

Irrigation projects in Ethiopia: what can be done to enhance effectiveness under ‘challenging contexts’?

Investment in small scale irrigation (SSI) is crucial to sustain food security and livelihoods of smallholders. In Ethiopia, the government and development partners show a growing interest in developing irrigation projects. The success of irrigation projects is determined by governance and socio-cultural contexts. Yet the lack of thorough understanding of the challenging contexts undermines the efforts to achieve sustainability outcomes in irrigation projects. This article identifies the challenging contexts to irrigation projects, examines how the challenging contexts influence the effectiveness of irrigation projects, and indicates ways of improving the effectiveness of irrigation projects under the existing challenging contexts. Data were collected between April and December 2011 in three regional states of Ethiopia using in-depth interviews and focus group discussions. The lack of governance capacity and accountability are critical challenges for the sustainability of the irrigation projects. In addition, the poor consideration of local knowledge and the use of top-down approaches in planning and implementing the irrigation projects, and lack of equitable access to the irrigation schemes result in poor ownership of projects among farmers. Improving the funding scheme to support long-term capacity building at national and local levels, and in understanding the socio-cultural contexts of the intervention areas; planning irrigation projects with due consideration of the existing challenging contexts, and with active engagement of the local community, are important for the long-term viability and sustainability of irrigation projects.     

Exploring thermal and trophic preference of Balaenoptera physalus in the central Tyrrhenian Sea: a new summer feeding ground?

In the 1990s, the central Tyrrhenian Sea was regarded as a transit region for fin whales’ (Balaenoptera physalus) summer migration. In recent years, a much higher presence of fin whales during the entire summer season was reported in the region. The hypothesis that the central Tyrrhenian Sea may have become a summer feeding ground was tested gathering data from summer presence of whales in the region (40–42.5°N; 9–13°E) and investigating whether it might be related to sea surface temperature and chlorophyll-a concentration, considered as proxies of food availability. Results showed that whales always aggregate in the more productive portions of the investigated area; the general productivity of the area, however, did not directly influence the frequency of occurrence of whales. We concluded that the complex dynamics of the balance between feeding activities and avoiding pressures may have led fin whales to use the region as an opportunistic feeding ground.