Adsorption/Desorption of Polyvinyl Alcohol on Solid Substrates and Relevant Biodegradation

The rates and extents of absorption and desorption of polyvinyl alcohol (PVA) samples on different solid substrates comprising montmorillonite, quartz sand, and farm soil, as well as humic acid mixture are reported. The uptake of PVA by the substrates was analyzed as a function of PVA hydrolysis (72–98%), molecular weight, and molecular weight distribution. Higher adsorption was detected on montmorillonite followed by farm soil, whereas the quartz sand did not display any specific adsorption affinity for the PVA. An increase in the hydrolysis degree of PVA increased the adsorption rate and extent whereas this feature was reversed by an increase in PVA molecular weight. The desorption of PVA samples from the different substrates was performed both under various pH conditions and in the presence of concentrated HF that was used to dissolve the silicon derivatives present in the substrates. Biodegradation experiments carried out in liquid cultures of PVA adsorbed on montmorillonite showed that the mineralization of the adsorbed PVA was much lower than that detected for the nonadsorbed PVA. This investigation suggests that irreversible adsorption of PVA on the clay component occurs in soil, thus substantially inhibiting PVA biodegradation.     

Human disturbance and shifts in vertebrate community composition in a biodiversity hotspot

Understanding how human modification of the landscape shapes vertebrate community composition is vital to understanding the current status and future trajectory of wildlife. Using a participatory approach, we deployed the largest camera-trap network in Mesoamerica to date to investigate how anthropogenic disturbance shapes the occupancy and co-occurrence of terrestrial vertebrate species in a tropical biodiversity hotspot: the Osa Peninsula, Costa Rica. We estimated species richness in different categories of land protection with rarefaction analysis and estimated the expected occupancy with a joint species distribution model that included covariates for anthropogenic disturbance, land protection, habitat quality, and habitat availability. Areas with the most stringent land-use protections (e.g., Corcovado National Park, 24 species [95% CI 23–25]) harbored significantly more species than unprotected areas (20 species [19.7–20.3]), mainly due to a reduced presence of large-bodied species of conservation concern in unprotected areas (e.g., jaguar Panthera onca and white-lipped peccary Tayassu pecari). Small-bodied generalist species, such as opossums (Didelphidae) and armadillos (Dasypus novemcinctus), in contrast, were more common at disturbed sites, resulting in a significant difference in vertebrate community composition between sites with low and high disturbance. Co-occurrence of species was also mainly associated with response to disturbance. Similar responses to disturbance create two groups of species, those whose site-level occupancy usually increased as anthropogenic disturbance increased and those whose estimated occupancy decreased. The absence of large-bodied species entails an important loss of ecological function in disturbed areas and can hinder forest development and maintenance. Efforts to protect and restore forested landscapes are likely having a positive effect on the abundance of some threatened species. These efforts, however, must be sustained and expanded to increase connectivity and ensure the long-term viability of the wildlife community.     

A statistical methodology for the evaluation of long-range dispersion models: an application to the ETEX exercise

This paper describes the statistical methodology applied to evaluate the performance of the long-range dispersion models that were used in the modelling activities of ETEX (European Tracer EXperiment). The availability of a large number of models makes this exercise rather unique. These models are used for the practical purpose to quantify the contamination effects over a vast area, following a hypothetical accidental release of harmful material. This makes the quality judgement that could be attributed to the results of each model particularly important.The statistical indicators considered to be the most effective for the evaluation of long-range dispersion models are introduced and commented, with specific examples in the frame of ETEX simulations. The importance of using several indices and critically interpreting the results is discussed.     

Variability in environmental impacts of Brazilian soybean according to crop production and transport scenarios

Soybean production and its supply chain are highly dependent on inputs such as land, fertilizer, fuel, machines, pesticides and electricity. The expansion of this crop in Brazil in recent decades has generated concerns about its environmental impacts. To assess these impacts, two representative chains supplying soybeans to Europe were identified: Center West (CW) and Southern (SO) Brazil. Each supply chain was analyzed using Life Cycle Assessment methodology. We considered different levels of use of chemical and organic fertilizers, pesticides and machinery, different distances for transportation of inputs and different yield levels. Because transportation contributed strongly to environmental impacts, a detailed study was performed to identify the routes used to transport soybeans to seaports. Additionally, we considered different levels of land occupation and land transformation to represent the impact of deforestation in the CW region. Environmental impacts were calculated for 1000 kg of soybean up to and including the delivery to Europe at the seaport in Rotterdam, at 13% humidity. Overall results showed that the impacts are greater for CW than for SO for all impact categories studied, including acidification (7.7 and 5.3 kg SO₂ eq., respectively), climate change (959 and 510 kg CO₂ eq.), cumulative energy demand (12,634 and 6,999 MJ) and terrestrial ecotoxicity (4.9 and 3.1 kg 1,4-DCB eq.), except eutrophication and land occupation. The same trend was observed for the crop-production stage. Efforts to reduce chemical fertilizers and diesel consumption can reduce CO₂ emissions. Although deforestation for crop production has decreased in recent years, the contribution of deforestation to climate change and cumulative energy demand remains significant. In the CW scenario deforestation contributed 29% to climate change and 20% to cumulative energy demand. Results also showed that although there are different transportation options in Brazil, the current predominance of road transport causes severe environmental impacts. In CW, road transport contributed 19% to climate change and 24% to cumulative energy demand, while in SO it contributed 12% and 15% to these impacts, respectively. Improvements in the logistics of transportation, giving priority to rail and river transports over road transport, can contribute significantly to reducing greenhouse gas emissions and decreasing energy use. Future studies involving Brazilian soybeans should take into account the region of origin as different levels of environmental impact are predicted.     

Factors Affecting Flood Disasters in Small Island Developing States and Potential Adaptation Measures: The Case of Funchal City,Portugal

This work highlights the evolution of flood disasters and their impacts upon environmental and socioeconomic aspects both worldwide and in Small Island Developing States (SIDS) in particular. For our research, we reviewed the stress factors affecting flood disasters and performed surveys of two focus groups in Funchal municipality on Madeira Island (Portugal). Our research identifies the main causes of the serious impacts that flash floods can have on Funchal city. These include:

• The occupation of floodplain areas,
• Canalization of water courses,
• Erosion and transport of soil from upstream hillslopes due to deforestation, and
• Intensive precipitation of long duration.

     

Implementing SDG 15: Can large‐scale public programs help deliver biodiversity conservation,restoration and management,while assisting human development?

Among the Sustainable Development Goals (SDGs), the proposed SDG 15 promotes activities that, inter alia, “Protect, restore and promote sustainable use of terrestrial ecosystems”. An important potential contribution in achieving SDG 15 is through public programmes designed to jointly promote human development through poverty alleviation and improvement of human livelihoods and biodiversity conservation/management/restoration. An analysis of twenty public programmes with such joint objectives yielded twelve lessons learned. In addition to financial commitments, government and intergovernmental agency input for such public programmes includes ensuring political will and appropriate legal frameworks. Local communities and civil society provide input through traditional and indigenous ecological knowledge and stewardship. Appropriate shared inputs in development and the implementation of such public programmes, with communication between local community, broader civil society, the scientific community and governments will result in: better use and management of biodiversity; alleviation of poverty; security of livelihoods and better governance systems. The Ecosystem Approach of the Convention on Biological Diversity provides an ideal framework when planning and implementing new programmes. Application of the lessons learned to new public programmes will ensure that the answer to the question posed in the title is an emphatic “Yes”, and assist with the achievement of SDG 15.     

Alternative approaches to dealing with respondent uncertainty in contingent valuation: a comparative analysis

Several strategies have been proposed to deal with response uncertainty in contingent valuation. One approach, often applied to address issues of hypothetical bias, recodes and/or reweights responses according to stated levels of certainty but so far few analyses compare alternative recoding and reweighting strategies. We explore the choice among alternative strategies that exploit a numerical certainty scale obtained from a follow-up to the payment question in a valuation survey about a whale conservation program. Two novel variations of previously followed approaches perform best on our dataset in terms of the efficiency of estimates. The first one uses an exponential transformation of the numerical certainty scale as a weight in the willingness to pay regression. The other one is based on constructing a continuous willingness to pay variable with the highly certain "yes" and "no" original responses to the payment question as extreme values and with mid-point values that correspond to the original "don't know" responses. We find, though, that the effect of using different treatment strategies on mean willingness to pay is rarely statistically significant and we fail to detect a consistent effect on the efficiency of the estimation regardless of the strategy applied.