Synergy between climate and human land-use maintained open vegetation in southwest Madagascar over the last millennium

Madagascar experienced environmental change during the Late-Holocene, and the relative importance of climatic and anthropogenic drivers is still the subject of an ongoing debate. Using palaeoecological records from the southwest region at Lake Longiza, we provide additional records to elucidate the complex history of the island and to identify the changes that occurred in the tropical dry forest during the Late-Holocene. The data showed vegetation changes associated with climate variability until AD 900 as reflected by the variation in grass, dry-adapted taxa, deciduous trees, and isotope records. An increasing effect of human activities was recorded, indicated by increased coprophilous spore concentration, as a result of a shift from foraging to pastoralism leading to further opening of the ecosystem from AD 980. At the same time, the regional palaeoclimate record showed drier conditions from around AD 1000, which could have accentuated the changes in vegetation structure. More open vegetation was likely maintained by increased use of fire and herbivory around the area, as indicated by the multiple peaks in the charcoal and spore records. Since AD 1900, the pollen record from the southwest region showed that the ecosystem became increasingly open with an increased abundance of grass, pioneer taxa, and reduced diversity, which was linked to a simultaneous effect of climate and agropastoralism activities. Our study suggests that the dry conditions around AD 950 initiated the replacement of forest-dominant vegetation with grass-dominant communities over the last millennium, depicted as an open ecosystem at present. Subsequent changes in subsistence activities would have further maintained an open-structured ecosystem.university of cape town https://doi.org/10.13039/501100007112The University Research Committee accredited (URC)southern african science service centre for climate change and adaptive land management https://doi.org/10.13039/501100011013neurosciences research foundation https://doi.org/10.13039/100007431African Origins PlatformPeer Reviewe

Linking global drivers of agricultural trade to on-the-ground impacts on biodiversity.

Consumption of globally traded agricultural commodities like soy and palm oil is one of the primary causes of deforestation and biodiversity loss in some of the world's most species-rich ecosystems. However, the complexity of global supply chains has confounded efforts to reduce impacts. Companies and governments with sustainability commitments struggle to understand their own sourcing patterns, while the activities of more unscrupulous actors are conveniently masked by the opacity of global trade. We combine state-of-the-art material flow, economic trade, and biodiversity impact models to produce an innovative approach for understanding the impacts of trade on biodiversity loss and the roles of remote markets and actors. We do this for the production of soy in the Brazilian Cerrado, home to more than 5% of the world´s species. Distinct sourcing patterns of consumer countries and trading companies result in substantially different impacts on endemic species. Connections between individual buyers and specific hot spots explain the disproportionate impacts of some actors on endemic species and individual threatened species, such as the particular impact of European Union consumers on the recent habitat losses for the iconic giant anteater (Myrmecophaga tridactyla). In making these linkages explicit, our approach enables commodity buyers and investors to target their efforts much more closely to improve the sustainability of their supply chains in their sourcing regions while also transforming our ability to monitor the impact of such commitments over time.UK Global Food Security programme (Project 304 BB/N02060X/1

New evidence of megafaunal bone damage indicates late colonization of Madagascar

Copyright: © 2018 Anderson et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The estimated period in which human colonization of Madagascar began has expanded recently to 5000–1000 y B.P., six times its range in 1990, prompting revised thinking about early migration sources, routes, maritime capability and environmental changes. Cited evidence of colonization age includes anthropogenic palaeoecological data 2500–2000 y B.P., megafaunal butchery marks 4200–1900 y B.P. and OSL dating to 4400 y B.P. of the Lakaton’i Anja occupation site. Using large samples of newly-excavated bone from sites in which megafaunal butchery was earlier dated >2000 y B.P. we find no butchery marks until ~1200 y B.P., with associated sedimentary and palynological data of initial human impact about the same time. Close analysis of the Lakaton’i Anja chronology suggests the site dates <1500 y B.P. Diverse evidence from bone damage, palaeoecology, genomic and linguistic history, archaeology, introduced biota and seafaring capability indicate initial human colonization of Madagascar 1350–1100 y B.P

Using Palaeoecology to address mining - Conservation Conflicts in Southeast Madagascar

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Demand for meat is driving deforestation in Brazil – changing the soy industry could stop it

Soy may have a pretty innocuous reputation thanks to its association with vegan food and meat alternatives. But don’t be fooled – crops of this pale legume are behind much of Brazil’s epidemic of deforestation. Since 2000, Brazil has doubled its total area of soy plantation to 36 million hectares and become the world’s largest producer. This expansion has erased vast swathes of forest and other habitats in some of the country’s most biodiverse regions

A probabilistic scenario approach for developing improved Reduced Emissions from Deforestation and Degradation (REDD+) baselines

Performance-based payments are widely seen as a promising tool for Reduced Emissions from Deforestation and forest Degradation (REDD+) in tropical forests. Despite great advances in international REDD+ negotiations, there is a lack of consensus around the development of business-as-usual (BAU) reference scenarios or baselines to derive and quantify net carbon emission reductions. In this paper, we explore a novel approach for developing baselines (point forecasts) using exponential smoothing. Further, we introduce the concept of probabilistic BAU scenario ranges developed using this approach. We compare predictive performance with the linear trend and historical averages approaches conventionally used in policy proposals and REDD+ pilots. We empirically test the relative performance of all three approaches by forecasting BAU baselines and scenario ranges in 36 sites (consisting of 20 countries and 8 Amazonian states with and 8 countries without REDD+ schemes ). Based on two predictive performance measures (the root mean squared error and mean absolute percentage error), we find that exponential smoothing outperforms the linear trend and historical average models at predicting forest cover changes. In addition, we show how prediction intervals based on a desired confidence level generated through exponential smoothing can be used in novel ways to determine likely baseline scenario ranges. In this way it is possible to quantify the degree of variability and uncertainty in datasets. Importantly, this also provides a statistical measure of confidence to determine if REDD+ interventions have been effective. By generating robust probabilistic baseline scenarios, exponential smoothing models can facilitate the effectiveness of REDD+ payments, support a more efficient allocation of scarce conservation resources, and improve our understanding of effective forest conservation investments, also beyond REDD+

Threshold response of Madagascar's littoral forest to sea-level rise

Aim: Coastal biodiversity hotspots are globally threatened by sea-level rise. As such it is important to understand how ecosystems resist, respond and adapt to sea-level rise. Using pollen, geochemistry, charcoal and diatom records in conjunction with previously published palaeoclimatic records, we investigated the mechanism, interactions and ecosystem response and resilience of Madagascar's littoral forest to late Holocene sea-level rise. Location: Sediment sequences were collected along the south-east coast of Madagascar in two adjacent habitats in Mandena; the highly diverse littoral forest fragment and species-poor Erica-matrix. Methods: We used a multi-proxy approach to investigate the relative influence of environmental changes on the littoral ecosystem. We reconstructed past vegetation and fire dynamics over the past 6500 years at two sites in the littoral forest using fossil pollen and macrofossil charcoal contained in sedimentary sequences. Alongside these records we reconstructed past marine transgressions from the same sedimentary sequences using geochemical analyses, and a salinity and drought index through the analysis of fossil diatoms. Results: Our findings indicated that it was the synergistic effect of sea-level rise coupled with rainfall deficits that triggered a threshold event with a switch from two types of littoral forest (an open Uapaca forest and a closed littoral forest fragment) to an Erica-Myrica heath/grassland occurring in approximately less than 100 years. Resilience to sea-level rise differed in the two adjacent habitats, suggesting that the littoral forest fragment was more resilient to the impacts of sea-level change and aridity than the open Uapaca woodland. Conclusions: We demonstrated that the littoral ecosystem was influenced by late Holocene sea-level rise and climatic desiccation. While climate change-integrated conservation strategies address the effects of climate change on species distribution and dispersal, our work suggests that more attention should be paid to the impacts of interactive climatic variables that affect ecosystem thresholds

Appendix A. Radiocarbon dates for the sedimentary sequences.

Radiocarbon dates for the sedimentary sequences

What influences and inhibits reduction of deforestation in the soy supply chain? A mental model perspective

Multiple sustainability initiatives have emerged in response to the environmental impacts of soy production, especially deforestation and climate change. But company commitments to reduce deforestation in their supply chains are not leading to outcomes on the ground. Achieving concerted action by supply chain actors requires consideration of their diverse perspectives. We investigate the mental models of Producer Associations, Traders, Fast Moving Consumer Goods Companies (FMCGs), NGOs, and financial institutions to identify the key similarities and differences in the factors perceived to promote or inhibit a reduction of deforestation from soy production in Brazil. Our results show general agreement across participants that NGO pressure and reputational risk are external motivators for companies to move towards sustainability, but only certain actor groups recognised that internal motivators are additionally needed for alignment between a sustainability agenda and a company's corporate strategy—highlighting the importance of internal motivators to stimulate companies to translate commitments into actionable policies. Our results suggest that implementation of commitments to reduce deforestation is hampered by different perceived financial risks, differences in the levels of influence and power held by different actors, and a perceived entitlement to deforest that prevails over a sense of urgency for environmental sustainability. We highlight that any policy that threatens this “right to deforest” mindset can lead to the erosion of producers’ conservation behaviour through unnecessary clearing of land before such policy is implemented. Our findings highlight an opportunity for the organisations driving sustainability initiatives to consider and explore these differences as they seek transnational corporations to transition to a more sustainable soy industry and supply chain. Moreover, our study provides an example of how mental models can provide valuable insights for the achievement of sustainability in agricultural supply chains more broadly.</p

A landscape vulnerability framework for identifying integrated conservation and adaptation pathways to climate change: the case of Madagascar’s spiny forest

Context Integrated conservation decision-making frameworks that help to design or adjust practices that are cognisant of environmental change and adaptation are urgently needed. Objective We demonstrate how a landscape vulnerability framework combining sensitivity, adaptive capacity, and exposure to climate change framed along two main axes of concern can help to identify potential strategies for conservation and adaptation decision-making, using a landscape in Madagascar’s spiny forest as a case-study. Methods To apply such a vulnerability landscape assessment, we inferred the sensitivity of habitats using temporal and spatial botanical data-sets, including the use of fossil pollen data and vegetation surveys. For understanding adaptive capacity, we analysed existing spatial maps (reflecting anthropogenic stressors) showing the degree of habitat connectivity, matrix quality and protected area coverage for the different habitats in the landscape. Lastly, for understanding exposures, we used climate change predictions in Madagascar, together with a digital elevation model. Results The fossil pollen data showed how sensitive arid-adapted species were to past climate changes, especially the conditions between 1000 and 500 cal yr BP. The spatial analysis then helped locate habitats on the two-dimensional axes of concern integrating sensitivity, adaptive capacity and climate change exposure. By identifying resistant, resilient, susceptible, and sensitive habitats to climate change in the landscape under study, we identify very different approaches to integrate conservation and adaptation strategies in contrasting habitats. Conclusion This framework, illustrated through a case study, provides easy guidance for identifying potential integrated conservation and adaptation strategies, taking into account aspects of climate vulnerability and conservation capacity