14 research outputs found

    Limited carbon and biodiversity co-benefits for tropical forest mammals and birds

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    The conservation of tropical forest carbon stocks offers the opportunity to curb climate change by reducing greenhouse gas emissions from deforestation and simultaneously conserve biodiversity. However, there has been considerable debate about the extent to which carbon stock conservation will provide benefits to biodiversity in part because whether forests that contain high carbon density in their aboveground biomass also contain high animal diversity is unknown. Here, we empirically examined medium to large bodied ground-dwelling mammal and bird (hereafter "wildlife") diversity and carbon stock levels within the tropics using camera trap and vegetation data from a pantropical network of sites. Specifically, we tested whether tropical forests that stored more carbon contained higher wildlife species richness, taxonomic diversity, and trait diversity. We found that carbon stocks were not a significant predictor for any of these three measures of diversity, which suggests that benefits for wildlife diversity will not be maximized unless wildlife diversity is explicitly taken into account; prioritizing carbon stocks alone will not necessarily meet biodiversity conservation goals. We recommend conservation planning that considers both objectives because there is the potential for more wildlife diversity and carbon stock conservation to be achieved for the same total budget if both objectives are pursued in tandem rather than independently. Tropical forests with low elevation variability and low tree density supported significantly higher wildlife diversity. These tropical forest characteristics may provide more affordable proxies of wildlife diversity for future multi-objective conservation planning when fine scale data on wildlife are lacking

    Standardized Assessment of Biodiversity Trends in Tropical Forest Protected Areas: The End Is Not in Sight

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    Extinction rates in the Anthropocene are three orders of magnitude higher than background and disproportionately occur in the tropics, home of half the world’s species. Despite global efforts to combat tropical species extinctions, lack of high-quality, objective information on tropical biodiversity has hampered quantitative evaluation of conservation strategies. In particular, the scarcity of population-level monitoring in tropical forests has stymied assessment of biodiversity outcomes, such as the status and trends of animal populations in protected areas. Here, we evaluate occupancy trends for 511 populations of terrestrial mammals and birds, representing 244 species from 15 tropical forest protected areas on three continents. For the first time to our knowledge, we use annual surveys from tropical forests worldwide that employ a standardized camera trapping protocol, and we compute data analytics that correct for imperfect detection. We found that occupancy declined in 22%, increased in 17%, and exhibited no change in 22% of populations during the last 3–8 years, while 39% of populations were detected too infrequently to assess occupancy changes. Despite extensive variability in occupancy trends, these 15 tropical protected areas have not exhibited systematic declines in biodiversity (i.e., occupancy, richness, or evenness) at the community level. Our results differ from reports of widespread biodiversity declines based on aggregated secondary data and expert opinion and suggest less extreme deterioration in tropical forest protected areas. We simultaneously fill an important conservation data gap and demonstrate the value of large-scale monitoring infrastructure and powerful analytics, which can be scaled to incorporate additional sites, ecosystems, and monitoring methods. In an era of catastrophic biodiversity loss, robust indicators produced from standardized monitoring infrastructure are critical to accurately assess population outcomes and identify conservation strategies that can avert biodiversity collapse. © 2016 Beaudrot et al

    What If Neighbors’ Neighborhoods Differ? The Influence of Neighborhood Definitions of Health Outcomes in Accra

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    Neighborhood context is recognized as an important predictor of individual-level behaviors and health outcomes (Pickett and Pearl 2001; Lee and Cubbin 2002; Sampson 2003). Neighborhoods, however, are difficult to define both in theory and in practice, and are often drawn to follow existing administrative boundaries or sampling schemes, or must be set arbitrarily due to a lack of sufficient data. Given the role of neighborhood context in influencing health outcomes, it is crucial that the area of influence surrounding the unit of analysis (be it a person, household, etc.) be properly defined. As already discussed in previous chapters, if we do not identify neighborhoods correctly, we cannot properly evaluate neighborhood effects. Defining neighborhoods is a challenge across the social sciences; investigations of the role of neighborhood context in decision making and shaping of individual-level outcomes are seen in public health, geography, demography, and sociology with no consistent approach to identifying and evaluating neighborhood effects. In this chapter, we outline several types of neighborhood definitions from the literature, and then, using data from the Women’s Health Study of Accra, implement a spatial model together with a simulation approach to examine how two alternative neighborhood definitions affect modeling of individual-level health outcomes

    Fertility in Context: Exploring Egocentric Neighborhoods in Accra

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    As recently as 1988 the total fertility rate (TFR) in the Greater Accra Region of Ghana was 4.7 children per woman (compared to the national average of 6.4). The most recent (2008) Ghana Demographic and Health Survey estimates the TFR in the Greater Accra Region to be down to 2.5 (compared to 4.0 for the country as a whole). Within the core metropolis of the Greater Accra Region—the Accra Metropolitan Assembly or Accra Metropolis, our data (described below) suggest that fertility has dropped to near replacement level as of 2008–2009. Within Accra, as throughout the nation, this has been accomplished especially through a delay in marriage and reductions in exposure within marriage, accompanied by an increase in the use of abortion and modern contraceptives. At the same time, reported levels of abortion and contraceptive utilization remain substantially below what would be expected in order to achieve Accra’s low fertility. Thus, the exact proximate determinants of the decline remain a bit murky

    Agent-Based Modeling in Coupled Human and Natural Systems (CHANS): Lessons from a Comparative Analysis

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    <div><p>Coupled human and natural systems (CHANS) are characterized by many complex features, including feedback loops, nonlinearity and thresholds, surprises, legacy effects and time lags, and resilience. Agent-based models (ABMs) are powerful for handling such complexity in CHANS models, facilitating in-depth understanding of CHANS dynamics. ABMs have been employed mostly on a site-specific basis, however. Little of this work provides a common infrastructure with which CHANS researchers (especially nonmodeling experts) can comprehend, compare, and envision CHANS processes and dynamics. We advance the science of CHANS by developing a CHANS-oriented protocol based on the overview, design concepts, and details (ODD) framework to help CHANS modelers and other researchers build, document, and compare CHANS-oriented ABMs. Using this approach, we show how complex demographic decisions, environmental processes, and human–environment interaction in CHANS can be represented and simulated in a relatively straightforward, standard way with ABMs by focusing on a comparison of two world-renowned CHANS: the Wolong Nature Reserve in China and the Chitwan National Park in Nepal. The four key lessons we learn from this cross-site comparison in relation to CHANS models include how to represent agents and the landscape, the need for standardized modules for CHANS ABMs, the impacts of scheduling on model outcomes, and precautions in interpreting “surprises” in CHANS model outcomes. We conclude with a CHANS protocol in the hope of advancing the science of CHANS.</p></div

    The impact of geography on energy infrastructure costs

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    Infrastructure planning for networked infrastructure such as grid electrification (or piped supply of water) has historically been a process of outward network expansion, either by utilities in response to immediate economic opportunity, or in response to a government mandate or subsidy intended to catalyze economic growth. While significant progress has been made in access to grid electricity in Asia, where population densities are greater and rural areas tend to have nucleated settlements, access to grid electricity in Sub-Saharan Africa remains low; a problem generally ascribed to differences in settlement patterns. The discussion, however, has remained qualitative, and hence it has been difficult for planners to understand the differing costs of carrying out grid expansion in one region as opposed to another. This paper describes a methodology to estimate the cost of local-level distribution systems for a least-cost network, and to compute additional information of interest to policymakers, such as the marginal cost of connecting additional households to a grid as a function of the penetration rate. We present several large datasets of household locations developed from satellite imagery, and examine them with our methodology, providing insight into the relationship between settlement pattern and the cost of rural electrification.Energy planning Energy economics Electrification

    A Conceptual Approach towards Improving Monitoring of Living Conditions for Populations Affected by Desertification, Land Degradation, and Drought

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    Addressing the global challenges of desertification, land degradation, and drought (DLDD), and their impacts on achieving sustainable development goals for coupled human-environmental systems is a key component of the 2030 Agenda for Sustainable Development. In particular, Sustainable Development Goal (SDG) 15.3 aims to, “by 2030, combat desertification, restore degraded land and soil, including land affected by desertification, drought and floods, and strive to achieve a land degradation-neutral world”. Addressing this challenge is essential for improving the livelihoods of those most affected by DLDD and for safeguarding against the most extreme effects of climate change. This paper introduces a conceptual framework for improved monitoring of DLDD in the context of United Nations Convention to Combat Desertification (UNCCD) Strategic Objective 2 (SO2) and its expected impacts: food security and adequate access to water for people in affected areas are improved; the livelihoods of people in affected areas are improved and diversified; local people, especially women and youth, are empowered and participate in decision-making processes in combating DLDD; and migration forced by desertification and land degradation is substantially reduced. While it is critical to develop methods and tools for assessing DLDD, work is needed first to provide a conceptual roadmap of the human dimensions of vulnerability in relation to DLDD, especially when attempting to create a globally standardized monitoring approach

    Synergizing global tools to monitor progress towards land degradation neutrality: Trends.Earth and the World Overview of Conservation Approaches and Technologies sustainable land management database

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    As part of the Sustainable Development Goals, countries are striving to achieve by 2030 a land degradation neutral world. Land degradation neutrality (LDN) is the state whereby the amount and quality of land resources remains stable or increases within specified temporal and spatial scales. Achieving this will require the uptake of sustainable land management (SLM) practices to increase the sustainable provision of ecosystem goods and services the human population will require. It will also require the development of systematic, robust, and validated methods for tracking progress at project, subnational and national scales. However, to date, no systematic comparison between the SLM practices and the indicators proposed for monitoring LDN has been performed. In this article, we used the United Nations Convention to Combat Desertification primary recommended global sustainable land management database of World Overview of Conservation Approaches and Technologies (WOCAT), and an innovative tool designed to assess and monitor land condition via changes in land productivity, Trends.Earth, to evaluate the agreement between self-reported sustainable land management technologies and indicators derived from satellite-based earth observations. We found that a combination of two primary productivity indicators derived from annual integrals of normalized difference vegetation indices (NDVI), trajectory and state, were able to identify increases in primary productivity in the locations where the SLM practices are implemented in comparison to control sites where SLM practices are not known to have occurred. Moreover, different SLM practices showed unique responses in terms of proportional area which experienced increase, decrease, or remained stable terms of primary productivity. We also found that the time since establishment of the SLM technology was critical for identifying improvements in the SLM sites, as only technologies with more than 10 years since implementation show statistically significant improvements. Our results show that satellite-derived land productivity indicators are successful at detecting the impacts of SLM practices on primary productivity, positioning them as essential elements of the monitoring and assessment tools needed to track land condition to assure the achievement of a land degradation neutral world

    Sex-Specific Habitat Suitability Modeling for <i>Panthera tigris</i> in Chitwan National Park, Nepal: Broader Conservation Implications

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    Although research on wildlife species across taxa has shown that males and females may differentially select habitat, sex-specific habitat suitability models for endangered species are uncommon. We developed sex-specific models for Bengal tigers (Panthera tigris) based on camera trapping data collected from 20 January to 22 March 2010 within Chitwan National Park, Nepal, and its buffer zone. We compared these to a sex-indiscriminate habitat suitability model to assess the benefits of a sex-specific approach to habitat suitability modeling. Our sex-specific models produced more informative and detailed habitat suitability maps and highlighted vital differences in the spatial distribution of suitable habitats for males and females, specific associations with different vegetation types, and habitat use near human settlements. Improving and refining habitat models for this and other critically endangered species provides the necessary information to meet established conservation goals and population recovery targets
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