Ecological restoration as a strategy for mitigating and adapting to climate change: lessons and challenges from Brazil

Climate change is a global phenomenon that affects biophysical systems and human well-being. The Paris Agreement of the United Nations Framework Convention on Climate Change entered into force in 2016 with the objective of strengthening the global response to climate change by keeping global temperature rise this century well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 °C. The agreement requires all Parties to submit their “nationally determined contributions” (NDCs) and to strengthen these efforts in the years ahead. Reducing carbon emissions from deforestation and forest degradation is an important strategy for mitigating climate change, particularly in developing countries with large forests. Extensive tropical forest loss and degradation have increased awareness at the international level of the need to undertake large-scale ecological restoration, highlighting the need to identify cases in which restoration strategies can contribute to mitigation and adaptation. Here we consider Brazil as a case study to evaluate the benefits and challenges of implementing large-scale restoration programs in developing countries. The Brazilian NDC included the target of restoring and reforesting 12 million hectares of forests for multiple uses by 2030. Restoration of native vegetation is one of the foundations of sustainable rural development in Brazil and should consider multiple purposes, from biodiversity and ecosystem services conservation to social and economic development. However, ecological restoration still presents substantial challenges for tropical and mega-diverse countries, including the need to develop plans that are technically and financially feasible, as well as public policies and monitoring instruments that can assess effectiveness. The planning, execution, and monitoring of restoration efforts strongly depend on the context and the diagnosis of the area with respect to reference ecosystems (e.g., forests, savannas, grasslands, wetlands). In addition, poor integration of climate change policies at the national and subnational levels and with other sectorial policies constrains the large-scale implementation of restoration programs. The case of Brazil shows that slowing deforestation is possible; however, this analysis highlights the need for increased national commitment and international support for actions that require large-scale transformations of the forest sector regarding ecosystem restoration efforts. Scaling up the ambitions and actions of the Paris Agreement implies the need for a global framework that recognizes landscape restoration as a cost-effective nature-based solution and that supports countries in addressing their remaining needs, challenges, and barriers.

     

Wood burning impact on PM10 in three Austrian regions

Anhydrosugars (levoglucosan, mannosan and galactosan) were investigated during one year in three Austrian regions at three types of sites (city-heavy traffic-impacted, city-residential and background) in order to assess the magnitude of the contribution of wood smoke to the particulate matter load and its organic fraction. The annually averaged concentrations of levoglucosan ranged from 0.12 to 0.48 μg m^?3. The levoglucosan concentration exhibited a strong annual cycle with higher concentrations in the cold season. The minor anhydrosugars had a similar annual trend, but their concentrations were lower by a factor of about 5 and about 25 in the cold season for mannosan and galactosan, respectively. Levoglucosan concentrations were higher at the inner-urban as compared to rural sites. The contribution of wood smoke to organic carbon and PM₁₀ levels was calculated using a constant ratio of levoglucosan and OC, respectively PM₁₀ as derived for fire wood typical for Alpine European regions [Schmidl, C., Marr, I.L., Caseiro, A.e, Kotianová, P., Berner, A., Bauer, H., Kasper-Giebl, A., Puxbaum, H., 2008a. Chemical characterisation of fine particle emissions from wood stove combustion of common woods growing in mid-European Alpine regions. Atmospheric Environment 42, 126–141]. The estimated contribution of wood smoke-OC to the OC of PM₁₀ ranged from one third to more than half in the cold season with higher contributions up to 70% in winter (December, January and February) in the smaller cities and the rural background. This indicates, that wood smoke is the predominant source of organic material at rural and small urban sites in central Europe. Consistently, wood smoke was an important contributor to PM₁₀ during the cold season, with contributions of around 10% in the Vienna larger region and around 20% at rural sites in the densely forested regions of Salzburg and Styria during the winter months. In those regions residential sites exhibited highest relative wood smoke contents in PM₁₀ during autumn (September till November), indicating the use of wood stoves for auxiliary heating in the transition of warm to cold season. Using the relationships between the different anhydrosugars the combustion of softwood was found to be dominant for the wood smoke occurrence in ambient air at the investigated sites. Potassium, a commonly used tracer for biomass burning, correlated well to levoglucosan, with a mass ratio of around 0.80 in the cold season.     

Experimental exposure of juvenile savannah monitors (Varanus exanthematicus) to an environmentally relevant mixture of three contaminants: effects and accumulation in tissues

Using varanids as indicators of pollution in African continental wetlands was previously proposed. The present study aimed at understanding experimentally how monitors absorb and accumulate pollutants and how they are affected. The relevance of non-destructive sampling was also evaluated. Savannah monitors (Varanus exanthematicus) were orally exposed during 6 months to a mixture of lead, 4,4′-dichlorodiphenyltrichloroethane (4,4′-DDT) and chlorpyrifos-ethyl (CPF) or to the vehicle only. Proportionally to their mass, exposed monitors received the same dose: 20 then 10 mg lead?kg^?1, 2 then 0.5 mg CPF?kg^?1 and 4 mg 4,4′-DDT?kg^?1. Individuals surviving contamination were euthanized after 4 or 6 months of experiment. Tissues were analysed for lead by atomic absorption spectrophotometry and for DDT and CPF by gas chromatography. Exposed monitors absorbed all three pollutants but only lead (essentially in bone, tail tips and phalanxes) and 4,4′-DDT plus its main metabolites (essentially in fat and liver) accumulated. CPF killed ten individuals. Clear correlations occurred between the total quantity of lead or 4,4′-DDT administered and concentrations in tissues. Tail tips and skin samples are recommended non-destructive indicators for lead and organochlorine pesticides contamination, respectively. This work confirms that monitors can be used as relevant indicators of environmental pollution by lead and organochlorine pesticides. Although varanids withstand heavy lead and DDT contamination, our results suggest that CPF can be lethal at very low doses to the herpetofauna and emphasize the importance of considering all taxa in impact assessment studies, including reptiles.     

Catalytic and electrocatalytic hydrogenolysis of brominated diphenyl ethers

Polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental contaminants due to their use as additive flame-retardants. Conventional catalytic hydrogenolysis in methanol solution and electrocatalytic hydrogenolysis in aqueous methanol were examined as methods for debrominating mono- and di-bromodiphenyl ethers, as well as a commercial penta-PBDE mixture, in each case using palladium on alumina as the catalyst. Electrocatalytic hydrogenolysis employed a divided flow-through batch cell, with reticulated vitreous carbon cathodes and IrO2/Ti dimensionally stable anodes. Both methods gave efficient sequential debromination, with essentially complete removal of bromine from the PBDEs, but the electrocatalytic method was limited by the poor solubility of PBDEs in aqueous methanol.     

Fungal biodegradation and removal of cyanobacteria and microcystins: potential applications and research needs

Environmental Science and Pollution Research - Harmful cyanobacterial blooms (HCB) have severe impacts on marine and freshwater systems worldwide. They cause oxygen depletion and produce potent...