Reserves Protect against Deforestation Fires in the Amazon

BACKGROUND: Reserves are the principal means to conserve forests and biodiversity, but the question of whether reserves work is still debated. In the Amazon, fires are closely linked to deforestation, and thus can be used as a proxy for reserve effectiveness in protecting forest cover. We ask whether reserves in the Brazilian Amazon provide effective protection against deforestation and consequently fires, whether that protection is because of their location or their legal status, and whether some reserve types are more effective than others. METHODOLOGY/PRINCIPAL FINDINGS: Previous work has shown that most Amazonian fires occur close to roads and are more frequent in El Niño years. We quantified these relationships for reserves and unprotected areas by examining satellite-detected hot pixels regressed against road distance across the entire Brazilian Amazon and for a decade with 2 El Niño-related droughts. Deforestation fires, as measured by hot pixels, declined exponentially with increasing distance from roads in all areas. Fewer deforestation fires occurred within protected areas than outside and the difference between protected and unprotected areas was greatest near roads. Thus, reserves were especially effective at preventing these fires where they are known to be most likely to burn; but they did not provide absolute protection. Even within reserves, at a given distance from roads, there were more deforestation fires in regions with high human impact than in those with low impact. The effect of El Niño on deforestation fires was greatest outside of reserves and near roads. Indigenous reserves, limited-use reserves, and fully protected reserves all had fewer fires than outside areas and did not appear to differ in their effectiveness. CONCLUSIONS/SIGNIFICANCE: Taking time, regional factors, and climate into account, our results show that reserves are an effective tool for curbing destructive burning in the Amazon

How to protect half of Earth to ensure it protects sufficient biodiversity

It is theoretically possible to protect large fractions of species in relatively small regions. For plants, 85% of species occur entirely within just over a third of the Earth’s land surface, carefully optimized to maximize the species captured. Well-known vertebrate taxa show similar patterns. Protecting half of Earth might not be necessary, but would it be sufficient given the current trends of protection? The predilection of national governments is to protect areas that are “wild,” that is, typically remote, cold, or arid. Unfortunately, those areas often hold relatively few species. Wild places likely afford the easier opportunities for the future expansion of protected areas, with the expansion into human-dominated landscapes the greater challenge. We identify regions that are not currently protected, but that are wild, and consider which of them hold substantial numbers of especially small-ranged vertebrate species. We assess how successful the strategy of protecting the wilder half of Earth might be in conserving biodiversity. It is far from sufficient. (Protecting large wild places for reasons other than biodiversity protection, such as carbon sequestration and other ecosystem services, might still have importance.) Unexpectedly, we also show that, despite the bias in establishing large protected areas in wild places to date, numerous small protected areas are in biodiverse places. They at least partially protect significant fractions of especially small-ranged species. So, while a preoccupation with protecting large areas for the sake of getting half of Earth might achieve little for biodiversity, there is more progress in protecting high-biodiversity areas than currently appreciated. Continuing to prioritize the right parts of Earth, not just the total area protected, is what matters for biodiversity

How many species of flowering plants are there?

We estimate the probable number of flowering plants. First, we apply a model that explicitly incorporates taxonomic effort over time to estimate the number of as-yet-unknown species. Second, we ask taxonomic experts their opinions on how many species are likely to be missing, on a family-by-family basis. The results are broadly comparable. We show that the current number of species should grow by between 10 and 20 per cent. There are, however, interesting discrepancies between expert and model estimates for some families, suggesting that our model does not always completely capture patterns of taxonomic activity. The as-yet-unknown species are probably similar to those taxonomists have described recently—overwhelmingly rare and local, and disproportionately in biodiversity hotspots, where there are high levels of habitat destruction

Metapopulation capacity with self-colonization: Finding the best patches in fragmented habitats

Habitat fragmentation continues to be a leading threat for our global future. Methods to quantify fragmentation of habitat landscapes, particularly for endangered species, would be especially useful in conservation planning. Using the principles of metapopulation theory, we updated and devised two methods for analyzing fragmented landscapes: metapopulation capacity and abandonment rate. Our version of metapopulation capacity includes a self-colonization component to counteract the issue metapopulation theory experiences with single large patches. We then tested these methods on satellite image range maps of endemic birds in the highland forests of northern Central America.

The metapopulation capacity method proved to be a better measure in that it highlighted which patches would be the most successful habitat in the landscape, based on size and connectivity to surrounding patches, thus allowing for species persistence. Unexpectedly, the abandonment rate method proved useful in providing a way of measuring each individual patch’s support to the rest of the landscape system. This could then be used to rank the remaining patches in order of their greatest contribution. Finally, by using a historical satellite map that showed previously forested habitat in the now deforested landscape, we were able to generate optimal restoration sequences by ranking each 1 km squares’ potential contribution

The impacts of oil palm on recent deforestation and biodiversity loss

Palm oil is the most widely traded vegetable oil globally, with demand projected to increase substantially in the future. Almost all oil palm grows in areas that were once tropical moist forests, some of them quite recently. The conversion to date, and future expansion, threatens biodiversity and increases greenhouse gas emissions. Today, consumer pressure is pushing companies toward deforestation-free sources of palm oil. To guide interventions aimed at reducing tropical deforestation due to oil palm, we analysed recent expansions and modelled likely future ones. We assessed sample areas to find where oil palm plantations have recently replaced forests in 20 countries, using a combination of high-resolution imagery from Google Earth and Landsat. We then compared these trends to countrywide trends in FAO data for oil palm planted area. Finally, we assessed which forests have high agricultural suitability for future oil palm development, which we refer to as vulnerable forests, and identified critical areas for biodiversity that oil palm expansion threatens. Our analysis reveals regional trends in deforestation associated with oil palm agriculture. In Southeast Asia, 45% of sampled oil palm plantations came from areas that were forests in 1989. For South America, the percentage was 31%. By contrast, in Mesoamerica and Africa, we observed only 2% and 7% of oil palm plantations coming from areas that were forest in 1989. The largest areas of vulnerable forest are in Africa and South America. Vulnerable forests in all four regions of production contain globally high concentrations of mammal and bird species at risk of extinction. However, priority areas for biodiversity conservation differ based on taxa and criteria used. Government regulation and voluntary market interventions can help incentivize the expansion of oil palm plantations in ways that protect biodiversity-rich ecosystems

Ambient temperature as a determinant of landscape use in the savanna elephant, Loxodonta africana

Elephants occur in landscapes where temperatures can reach 50 °C. Due to their large size they may face physiological problems of dissipating heat during such high temperatures. In spite of this, no one seems to have considered ambient temperature as limiting landscape choices in elephants. We recorded hourly landscape use in free-ranging elephants using GPS collars. We also placed temperature data loggers in each of the landscapes, to obtain corresponding ambient temperatures for each hour. Our results suggest that elephants may select landscapes based on the rate at which temperatures changed and also for shade. We suggest that these selected variables provide a thermal benefit to individuals. As such, we propose that landscape use in elephants may be constrained by their thermal physiological requirements as well as other resources such as food and water.We would like to thank the International Fund for Animal Welfare for financing this project and the Zambian Wildlife Authority for allowing this study to occur. We would particularly like to thank the Ngoma and Lower Zambezi Area Management Units, Conservation Lower Zambezi, J. Hanks, J. Fourie, T. Simpamba, B. Kabungo, N. Fairall, S. Ferreira and R. Guldemond for their assistance and support. AK received a post-doctoral fellowship from the University of Pretoria. This study complied with the current laws in Zambia and was sanctioned by the ethics committee of the University of Pretoria (clearance code: AUCC 040611-013). The comments from two anonymous referees contributed to improving the manuscript

Measuring resilience is essential to understand it

The terms sustainability, resilience and others group under the heading of ‘stability’. Their ubiquity speaks to a vital need to characterize changes in complex social and environmental systems. In a bewildering array of terms, practical measurements are essential to permit comparisons and so untangle underlying relationships

Functional Integration of Ecological Networks through Pathway Proliferation

Large-scale structural patterns commonly occur in network models of complex systems including a skewed node degree distribution and small-world topology. These patterns suggest common organizational constraints and similar functional consequences. Here, we investigate a structural pattern termed pathway proliferation. Previous research enumerating pathways that link species determined that as pathway length increases, the number of pathways tends to increase without bound. We hypothesize that this pathway proliferation influences the flow of energy, matter, and information in ecosystems. In this paper, we clarify the pathway proliferation concept, introduce a measure of the node--node proliferation rate, describe factors influencing the rate, and characterize it in 17 large empirical food-webs. During this investigation, we uncovered a modular organization within these systems. Over half of the food-webs were composed of one or more subgroups that were strongly connected internally, but weakly connected to the rest of the system. Further, these modules had distinct proliferation rates. We conclude that pathway proliferation in ecological networks reveals subgroups of species that will be functionally integrated through cyclic indirect effects.Comment: 29 pages, 2 figures, 3 tables, Submitted to Journal of Theoretical Biolog