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.

     

Collection and recycling of electronic scrap: a worldwide overview and comparison with the Brazilian situation

Recycling and the related issue of sustainable development are increasing in importance around the world. In Brazil, the new National Policy on Solid Wastes has prompted discussion on the future of electronic waste (e-waste). Over the last 10 years, different e-waste collection systems and recycling processes have been applied globally. This paper presents the systems used in different countries and compares the world situation to the current Brazilian reality. To establish a recycling process, it is necessary to organize efficient collection management. The main difficulty associated with the implementation of e-waste recycling processes in Brazil is the collection system, as its efficiency depends not only on the education and cooperation of the people but also on cooperation among industrial waste generators, distributors and the government. Over half a million waste pickers have been reported in Brazil and they are responsible for the success of metal scrap collection in the country. The country also has close to 2400 companies and cooperatives involved in recycling and scrap trading. On the other hand, the collection and recycling of e-waste is still incipient because e-wastes are not seen as valuable in the informal sector. The Brazilian challenge is therefore to organize a system of e-waste management including the informal sector without neglecting environmentally sound management principles.     

How an introduced seaweed can affect epibiota diversity in different coastal systems

Invasions by non-indigenous species have the potential to alter the biodiversity of recipient systems. The magnitude of this effect often depends on the nature of the invaded communities and the ecology of the invader. We investigated the impacts of the Japanese seaweed Sargassum muticum (Phaeophyceae, Fucales) on biodiversity in a rocky and sedimentary environment on two islands in the North Sea. In each case, we compared the epibiota of non-indigenous S. muticum with epibiota communities on taxonomically related and structurally similar native seaweed hosts. Total and average species richness on S. muticum were similar on the rocky shore (60 species and 22±6 species, respectively) and the sandy shore (64 species and 20±3 species, respectively). However, community structure and species composition differed significantly between the environments. On the rocky shore, another native fucoid seaweed, Halidrys siliquosa, supported an epibiota community very similar to that of the invader. On the sandy shore, the only other abundant native habitat-providing algal species was Fucus vesiculosus. This species supported a different and less diverse assemblage of associated taxa. We conclude that S. muticum enhances epibiota diversity in the sedimentary environment, probably by increasing the substratum availability and habitat heterogeneity. In contrast, it has negligible impacts on epibiota diversity in the rocky shore environment, where it does not represent a fundamentally new habitat component. We conclude that even within the same region, the consequences of non-indigenous species on biodiversity cannot be generalised but depend on the composition and structural complexity of the species in the recipient community. This paper is dedicated to Udo Schilling, Chief Diving Officer, Alfred Wegener Institute who trained all of the authors in the waters off Helgoland to be scientific divers. The work reported here and in previous publications has been made possible through Udo’s training and support. We remain grateful for his enthusiasm, effort and patience.     

Effect modification of ambient particle mortality by radon: A time series analysis in 108 U.S. cities

Numerous studies have reported a positive association between ambient fine particles and daily mortality, but little is known about the particle properties or environmental factors that may contribute to these effects. This study assessed potential modification of radon on PM_2.5 (particulate matter with an aerodynamic diameter <2.5 μm)-associated daily mortality in 108 U.S. cities using a two-stage statistical approach. First, city- and season-specific PM_2.5 mortality risks were estimated using over-dispersed Poisson regression models. These PM_2.5 effect estimates were then regressed against mean city-level residential radon concentrations to estimate overall PM_2.5 effects and potential modification by radon. Radon exposure estimates based on measured short-term basement concentrations and modeled long-term living-area concentrations were both assessed. Exposure to PM_2.5 was associated with total, cardiovascular, and respiratory mortality in both the spring and the fall. In addition, higher mean city-level radon concentrations increased PM_2.5-associated mortality in the spring and fall. For example, a 10 µg/m³ increase in PM_2.5 in the spring at the 10th percentile of city-averaged short-term radon concentrations (21.1 Bq/m³) was associated with a 1.92% increase in total mortality (95% CI: 1.29, 2.55), whereas the same PM_2.5 exposure at the 90th radon percentile (234.2 Bq/m³) was associated with a 3.73% increase in total mortality (95% CI: 2.87, 4.59). Results were robust to adjustment for spatial confounders, including average planetary boundary height, population age, percent poverty and tobacco use. While additional research is necessary, this study suggests that radon enhances PM_2.5 mortality. This is of significant regulatory importance, as effective regulation should consider the increased risk for particle mortality in cities with higher radon levels.

Implications: In this large national study, city-averaged indoor radon concentration was a significant effect modifier of PM_2.5-associated total, cardiovascular, and respiratory mortality risk in the spring and fall. These results suggest that radon may enhance PM_2.5-associated mortality. In addition, local radon concentrations partially explain the significant variability in PM_2.5 effect estimates across U.S. cities, noted in this and previous studies. Although the concept of PM as a vector for radon progeny is feasible, additional research is needed on the noncancer health effects of radon and its potential interaction with PM. Future air quality regulations may need to consider the increased risk for particle mortality in cities with higher radon levels.     

Lavender essential oil decreases stress response of horses

Simple and soft means are needed to manage horse stress. For instance, essential oils such as lavender oil contain active principles that may mitigate stress responses in humans and animals. Here we developed a protocol to test the effects of essential oil on equine stress response. We tested the effect of lavender oil on horse stress. Twenty-eight Welsh horse fillies were divided into two groups: horses treated with a roll-on with 2 mL of vegetable oil (control) and horses treated with 2 mL of 10% lavender essential oil in vegetable oil. Horses were then subjected to a series of stress tests. Heart rates and stress behavioral indicators were monitored during the 30 min of the stress tests. Saliva was collected. Blood from six horses was sampled after lavender essential oil application to follow plasma linalool content and antioxidant efficiency. Results show that stress indicators such as heart rate, alert postures and defecations are lower in lavender oil-treated horses. Lavender essential oil also modified salivary cortisol. Pharmacokinetics of linalool in plasma displayed a peak 20 min after lavender essential oil application, thus confirming the effect of lavender oil. Overall, our findings demonstrate that lavender essential oil reduces the response to stress of horses placed in stressful situations.     

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

Mitigation and Adaptation Strategies for Global Change - The original version of the article unfortunately contained an error.     

Evaluation of the phytotoxicity of contaminated sediments deposited "on soil". I. Impact of water draining from the deposit on the germination of neighbouring plants

As part of a study of the phytotoxic risk of spreading of contaminated sediments "on soil", we carried out a laboratory experiment assessing the impact of water draining from sediments in a deposit scenario on the peripheral vegetation. The plant tested were the Chinese cabbage (Brassica campestris L. var. chinensis), maize (Zea mays L.) and ryegrass (Lolium perenne L.). The draining water samples (A1, B1 and C1) were obtained after decantation in laboratory of the sediments. The classification of the water sampled in decreasing order of cumulative contamination was C1 > A1 > B1. The B1 and C1 water samples inhibited the germination of seeds tested to various extents. The percentage of seeds that did not germinate was 1.3-fold times higher for Chinese cabbage with B1 than for the control and 2.3-fold times higher for ryegrass with C1 than for the control. Seeds watered with B1 had lower moisture contents than the control: 10% lower for ryegrass and maize and 50% lower for Chinese cabbage. An increase (about 1.5 microg/ml) in total soluble protein (versus the control) was observed for all three plant species tested in the presence of C1. Glutamine synthetase activity was significantly (1.35 times) higher in ryegrass seeds in the presence of C1 than in the control. We also observed changes in the specific activity of phosphoenolpyruvate carboxylase, which increased for ryegrass and decreased for maize as the concentration of contaminants in the water increased. The results show (i) the necessity to use different plant species to evaluate the toxic effect of sediment deposited on soil on the vegetation, and (ii) that soon as on germination an evaluation of an impact is possible.     

Evaluation of the phytotoxicity of contaminated sediments deposited "on soil": II. Impact of water draining from deposits on the development and physiological status of neighbouring plants at growth stage

As part of a study of the phytotoxic risk of spreading contaminated sediments "on soil", a laboratory experiment was carried out to assess the impact of water draining from sediments on peripheral vegetation. Drainage water was obtained in the laboratory by settling three sediments with different pollutants levels, and the supernatant solutions (respectively A1, B1, C1 drainage waters) were used as soaking water for maize (Zea ma?s L.) and ryegrass (Lolium perenne L.). The physicochemical characteristics of the supernatant water, particularly metal contents, showed a pattern of contamination, with C1>A1>B1. The plants tested were grown on soil for 21 days, before being soaked for another 21-day period with drainage water (treatments) and distilled water (control). Biomass parameters (fresh weight, length, etc.), enzymatic activity [glutamine synthetase (GS), phosphoenolpyruvate carboxylase (PEPc)] and Zn, Cu, Cd and Cr contents were measured on both the shoots and roots of each plant. Biomass parameters were stimulated by C1, not affected by A1 and decreased with B1 for maize, whereas they increased for ryegrass in all the treatments. Compared to the control, GS activity was stimulated by C1 in the shoots of both plants and inhibited by treatments B1 and C1 in maize roots. PEPc activity in ryegrass was 1.5-5 times higher with contaminated water treatment, while contrasting effects were observed in maize plants. Both plants showed greater accumulation of chromium and zinc than cadmium and copper. Treatment A1 was found to be less active on plant growth and have a lower impact on the physiological status (enzymatic activities) of both plants. Treatment C1 stimulated the growth and physiological status of the plants, especially in shoots, with higher metal accumulation values in both plants. Treatment B1 was found to show more variable effects on growth indices, enzymatic activity and metal accumulation according to plant species.