47 research outputs found

    A framework for considering ecological interactions for common non-timber forest product species: a case study of mountain date palm (Phoenix loureiroi Kunth) leaf harvest in South India

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    Introduction: Many economically important non-timber forest products (NTFPs) come from widespread and common plant species. Harvest of these species often is assumed to be sustainable due to their commonness. However, because of the ecological roles of common species, harvest may affect and be affected by ecological interactions at broader scales, which are rarely considered when evaluating the sustainability of harvest. We use a case study of the mountain date palm (Phoenix loureiroi Kunth), harvested in South India to produce brooms, to present a conceptual framework illustrating how intensive harvest of a common species interacts with other anthropogenic management practices, plant-animal interactions and surrounding environmental conditions. Methods: We apply this framework to understanding the impacts of mountain date palm harvest in the southern Western Ghats regions of the Indian states of Tamil Nadu and Karnataka. We integrate data on the extent and levels of commercial harvest, local management practices, the ecological context in which harvest occurs, and research on harvest effects. We use this information to document the intensity and extent of mountain date palm harvest in the study area, identify the ecological implications of harvest, and demonstrate how a framework that considers harvest in the context of ecological communities and ecosystems is important for assessing the impacts of harvest of common NTFP species.Results: We show that mountain date palm leaves are heavily harvested from natural areas in the southern Western Ghats but that harvest levels have declined in recent years. Mountain date palm management and harvest occur within a network of ecological interactions, linking human activities to population-, community-, and ecosystem-level processes. We demonstrate that understanding the effects of return interval of anthropogenic fire, herbivory by wild animals and livestock, as well as the light environment in which harvest occurs are critical to assessing the sustainability of mountain date palm harvest. Conclusions: By considering mountain date palm leaf harvest in the context of ecological interactions at multiple scales, our findings show that sustainability cannot be assessed only from a population-level perspective. This general framework highlights the need to incorporate ecosystem- and community-level properties and processes more frequently into assessments of the sustainability of NTFP harvest—especially for widespread and common species—to ensure that their important economic and ecological roles are maintained

    Conclusions about Niche Expansion in Introduced Impatiens walleriana Populations Depend on Method of Analysis

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    Determining the degree to which climate niches are conserved across plant species' native and introduced ranges is valuable to developing successful strategies to limit the introduction and spread of invasive plants, and also has important ecological and evolutionary implications. Here, we test whether climate niches differ between native and introduced populations of Impatiens walleriana, globally one of the most popular horticultural species. We use approaches based on both raw climate data associated with occurrence points and ecological niche models (ENMs) developed with Maxent. We include comparisons of climate niche breadth in both geographic and environmental spaces, taking into account differences in available habitats between the distributional areas. We find significant differences in climate envelopes between native and introduced populations when comparing raw climate variables, with introduced populations appearing to expand into wetter and cooler climates. However, analyses controlling for differences in available habitat in each region do not indicate expansion of climate niches. We therefore cannot reject the hypothesis that observed differences in climate envelopes reflect only the limited environments available within the species' native range in East Africa. Our results suggest that models built from only native range occurrence data will not provide an accurate prediction of the potential for invasiveness if applied to areas containing a greater range of environmental combinations, and that tests of niche expansion may overestimate shifts in climate niches if they do not control carefully for environmental differences between distributional areas

    Global Dam Watch: curated data and tools for management and decision making

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    Dams, reservoirs, and other water management infrastructure provide benefits, but can also have negative impacts. Dam construction and removal affects progress toward the UN sustainable development goals at local to global scales. Yet, globally-consistent information on the location and characteristics of these structures are lacking, with information often highly localised, fragmented, or inaccessible. A freely available, curated, consistent, and regularly updated global database of existing dams and other instream infrastructure is needed along with open access tools to support research, decision-making and management needs. Here we introduce the Global Dam Watch (GDW) initiative (www.globaldamwatch.org ) whose objectives are: (a) advancing recent efforts to develop a single, globally consistent dam and instream barrier data product for global-scale analyses (the GDW database); (b) bringing together the increasingly numerous global, regional and local dam and instream barrier datasets in a directory of databases (the GDW directory); (c) building tools for the visualisation of dam and instream barrier data and for analyses in support of policy and decision making (the GDW knowledge-base) and (d) advancing earth observation and geographical information system techniques to map a wider range of instream structures and their properties. Our focus is on all types of anthropogenic instream barriers, though we have started by prioritizing major reservoir dams and run-of-river barriers, for which more information is available. Our goal is to facilitate national-scale, basin-scale and global-scale mapping, analyses and understanding of all instream barriers, their impacts and their role in sustainable development through the provision of publicly accessible information and tools. We invite input and partnerships across sectors to strengthen GDW’s utility and relevance for all, help define database content and knowledge-base tools, and generally expand the reach of GDW as a global hub of impartial academic expertise and policy information regarding dams and other instream barriers

    Distilling the role of ecosystem services in the Sustainable Development Goals

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    Achieving well-being for all, while protecting the environment, is one of the most pressing global challenges of our time, and a central idea in the UN Sustainable Development Goals (SDGs). We believe that integrating ecosystem services, the benefits nature provides to people, into strategies for meeting the SDGs can help achieve this. Many development goals are likely underpinned by the delivery of one or more ecosystem services. Understanding how these services could support multiple development targets will be essential for planning synergistic and cost-effective interventions. Here we present the results of an expert survey on the contributions of 16 ecosystem services to achieving SDG targets linked to environment and human well-being, and review the capacity of modelling tools to evaluate SDG-relevant ecosystem services interactions. Survey respondents judged that individual ecosystem services could make important contributions to achieving 41 targets across 12 SDGs. The provision of food and water, habitat & biodiversity maintenance, and carbon storage & sequestration were perceived to each make contributions to >14 SDG targets, suggesting cross-target interactions are likely, and may present opportunities for synergistic outcomes across multiple SDGs. Existing modelling tools are well-aligned to support SDG-relevant ecosystem service planning. Together, this work identifies entry points and tools to further analyze the role of ecosystem services to support the SDGs

    Model development for the assessment of terrestrial and aquatic habitat quality in conservation planning

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    There is a growing pressure of human activities on natural habitats, which leads to biodiversity losses. To mitigate the impact of human activities, environmental policies are developed and implemented, but their effects are commonly not well understood because of the lack of tools to predict the effects of conservation policies on habitat quality and/or diversity. We present a straightforward model for the simultaneous assessment of terrestrial and aquatic habitat quality in river basins as a function of land use and anthropogenic threats to habitat that could be applied under different management scenarios to help understand the trade-offs of conservation actions. We modify the InVEST model for the assessment of terrestrial habitat quality and extend it to freshwater habitats. We assess the reliability of the model in a severely impaired basin by comparing modeled results to observed terrestrial and aquatic biodiversity data. Estimated habitat quality is significantly correlated with observed terrestrial vascular plant richness (R 2 =0.76) and diversity of aquatic macroinvertebrates (R 2 =0.34), as well as with ecosystem functions such as in-stream phosphorus retention (R 2 =0.45). After that, we analyze different scenarios to assess the suitability of the model to inform changes in habitat quality under different conservation strategies. We believe that the developed model can be useful to assess potential levels of biodiversity, and to support conservation planning given its capacity to forecast the effects of management actions in river basins

    Balancing biodiversity and human land use : effects of fire, grazing and harvest on plant individuals, populations and communities in the Western Ghats, India

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    Ph.D. University of Hawaii at Manoa 2012.Includes bibliographical references.Effective conservation of the world's remaining diversity requires determining to what degree preservation of biodiversity is compatible with meeting human needs. However, there is still a limited scientific understanding of the compatibility and tradeoffs between biodiversity conservation and human land use. I used the case study of wild mountain date palm (Phoenix loureiri Kunth) in savanna woodland ecosystems of India's Western Ghats biodiversity hotspot to investigate the ecological effects and conservation implications of fire, grazing and palm leaf harvest--three widespread and commonly cooccurring forms of land management activities in the tropics. I integrated results from a manipulative experiment, a regional observational study and mathematical models to determine how the effects of and interactions among these activities scale from palm individuals to populations to plant communities. I found that mountain date palm populations exhibited resilience to fire and low intensities of harvest and grazing, indicating a high potential for sustainable harvest. Individual-level compensatory growth, vegetative reproduction and density-dependent survival contributed to palm population resilience to disturbance. At the community level, areas managed for palm leaf harvest and livestock grazing retained similar levels of plant species and functional diversity to areas protected from these activities. However, the combined effects of fire, wild plant harvest and livestock grazing were associated with reduced tree cover and diversity and increased understory diversity. I also found evidence for a trade-off between maximizing the growth of mountain date palm populations and maximizing tree species diversity, mediated by the relationship between fire and canopy openness. Overall, my results suggest that human-managed savanna woodlands can both support mountain date palm leaf harvest and contribute to conservation objectives. Promoting a mosaic of land management practices would be an effective way to balance the need to preserve plant diversity with the potential for these ecosystems to contribute to the livelihoods of local people. Protected areas with reduced human land use may more effectively conserve tree cover and tree diversity, while areas managed for plant harvest and livestock grazing could still maintain substantial overall plant diversity and provide connectivity between protected areas, while additionally providing benefits to local people

    Data from: Moderate land use changes plant functional composition without loss of functional diversity in India's Western Ghats. Ecological Applications. http://dx.doi.org/10.1890/15-0068.1

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    Data on plot characteristics, plant community composition (overstory, understory and seedlings) and functional traits from study sites in the Western Ghats region of India. See file Mandle_readme_2015-02-22.txt for details

    Data from: Resilience of palm populations to disturbance is determined by interactive effects of fire, herbivory and harvest. Journal of Ecology

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    Data on mountain date palm ramets and code for an intregral project model of population dynamics. See file Mandle_readme_2015-04-17.txt for details

    Appendix A. Bioclimatic conditions across study plots.

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    Bioclimatic conditions across study plots

    Appendix B. Ranking of candidate models for changes in functional composition with land use.

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    Ranking of candidate models for changes in functional composition with land use
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