149 research outputs found
BIOFRAG – a new database for analyzing BIOdiversity responses to forest FRAGmentation
Habitat fragmentation studies have produced complex results that are challenging to synthesize. Inconsistencies among studies may result from variation in the choice of landscape metrics and response variables, which is often compounded by a lack of key statistical or methodological information. Collating primary datasets on biodiversity responses to fragmentation in a consistent and flexible database permits simple data retrieval for subsequent analyses. We present a relational database that links such field data to taxonomic nomenclature, spatial and temporal plot attributes, and environmental characteristics. Field assessments include measurements of the response(s) (e.g., presence, abundance, ground cover) of one or more species linked to plots in fragments within a partially forested landscape. The database currently holds 9830 unique species recorded in plots of 58 unique landscapes in six of eight realms: mammals 315, birds 1286, herptiles 460, insects 4521, spiders 204, other arthropods 85, gastropods 70, annelids 8, platyhelminthes 4, Onychophora 2, vascular plants 2112, nonvascular plants and lichens 320, and fungi 449. Three landscapes were sampled as long-term time series (\u3e10 years). Seven hundred and eleven species are found in two or more landscapes. Consolidating the substantial amount of primary data available on biodiversity responses to fragmentation in the context of land-use change and natural disturbances is an essential part of understanding the effects of increasing anthropogenic pressures on land. The consistent format of this database facilitates testing of generalizations concerning biologic responses to fragmentation across diverse systems and taxa. It also allows the re-examination of existing datasets with alternative landscape metrics and robust statistical methods, for example, helping to address pseudoreplication problems. The database can thus help researchers in producing broad syntheses of the effects of land use. The database is dynamic and inclusive, and contributions from individual and large-scale data-collection efforts are welcome
Variation of life history characteristics, long-term population dynamics and genetics differentiation of Himantoglossum hircinum (Orchidaceae): implications for conservation and general questions im plant ecology
The dissertation is a comprehensive approach to explain the long-term dynamics of a plant population in its environment, based on a long-term data set covering 26 years. One part of the thesis deals with life-history traits and population dynamics that are analysed in detail and related to weather conditions, another part deals with the spatial pattern and spatial variability of plant and population performance. Finally, genetic pattern of three populations of the species growing within central Germany were analysed to evaluate genetic diversity and genetic differentiation of the populations.
Die Dissertation ist ein umfassender Ansatz, um die Langzeitdynamik einer Pflanzenpopulation in ihrer Umwelt zu erklären. Die Arbeit basiert auf Langzeitdaten zur Populationsdynamik, die über 26 Jahre aufgenommen wurden. Ein Teil der Doktorarbeit beschäftigt sich mit den Lebenszykluseigenschaften und der Populationsdynamik, die im Detail analysiert und zu Wetterbedingungen in Beziehung gesetzt werden. Ein weiterer Abschnitt untersucht das räumliche Muster auf verschiedenen räumlichen Skalen und die räumliche Heterogenität der Performanz von Pflanzen und Population. Weiterhin wurden drei sich in Zentraldeutschland befindliche Populationen genetisch analysiert und verglichen, um deren genetische Diversität und genetische Differenzierung bewerten zu können
Land-use change alters the mechanisms assembling rainforest mammal communities in Borneo
1. The assembly of species communities at local scales is thought to be driven by environmental filtering, species interactions and spatial processes such as dispersal limitation. Little is known about how the relative balance of these drivers of community assembly changes along environmental gradients, especially manmade environmental gradients associated with land-use change. 2. Using concurrent camera- and live-trapping, we investigated the local-scale assembly of mammal communities along a gradient of land-use intensity (old-growth forest, logged forest and oil palm plantations) in Borneo. We hypothesised that increasing land-use intensity would lead to an increasing dominance of environmental control over spatial processes in community assembly. Additionally, we hypothesised that competitive interactions among species might reduce in concert with declines in α-diversity (previously documented) along the land-use gradient. 3. To test our first hypothesis, we partitioned community variance into the fractions explained by environmental and spatial variables. To test our second hypothesis, we used probabilistic models of expected species co-occurrence patterns, in particular focussing on the prevalence of spatial avoidance between species. Spatial avoidance might indicate competition, but might also be due to divergent habitat preferences. 4. We found patterns that are consistent with a shift in the fundamental mechanics governing local community assembly. In support of our first hypothesis, the importance of spatial processes (dispersal limitation and fine-scale patterns of home-ranging) appeared to decrease from low to high intensity land-uses, whilst environmental control increased in importance (in particular due to fine-scale habitat structure). Support for our second hypothesis was weak: whilst we found that the prevalence of spatial avoidance decreased along the land-use gradient, in particular between congeneric species pairs most likely to be in competition, few instances of spatial avoidance were detected in any land-use, and most were likely due to divergent habitat preferences. 5. The widespread changes in land-use occurring in the tropics might be altering not just the biodiversity found in landscapes, but also the fundamental mechanics governing the local assembly of communities. A better understanding of these mechanics, for a range of taxa, could underpin more effective conservation and management of threatened tropical landscapes
Leaf area index for biomes of the Eastern Arc Mountains : Landsat and SPOT observations along precipitation and altitude gradients
Peer reviewe
Forest floor temperature and greenness link significantly to canopy attributes in South Africa’s fragmented coastal forests
Tropical landscapes are changing rapidly due to changes in land use and land management. Being able to predict and monitor land use change impacts on species for conservation or food security concerns requires the use of habitat quality metrics, that are consistent, can be mapped using above-ground sensor data and are relevant for species performance. Here, we focus on ground surface temperature (Thermalground) and ground vegetation greenness (NDVIdown) as potentially suitable metrics of habitat quality. Both have been linked to species demography and community structure in the literature. We test whether they can be measured consistently from the ground and whether they can be up-scaled indirectly using canopy structure maps (Leaf Area Index, LAI, and Fractional vegetation cover, FCover) developed from Landsat remote sensing data. We measured Thermalground and NDVIdown across habitats differing in tree cover (natural grassland to forest edges to forests and tree plantations) in the human-modified coastal forested landscapes of Kwa-Zulua Natal, South Africa. We show that both metrics decline significantly with increasing canopy closure and leaf area, implying a potential pathway for upscaling both metrics using canopy structure maps derived using earth observation. Specifically, our findings suggest that opening forest canopies by 20% or decreasing forest canopy LAI by one unit would result in increases of Thermalground by 1.2 °C across the range of observations studied. NDVIdown appears to decline by 0.1 in response to an increase in canopy LAI by 1 unit and declines nonlinearly with canopy closure. Accounting for micro-scale variation in temperature and resources is seen as essential to improve biodiversity impact predictions. Our study suggests that mapping ground surface temperature and ground vegetation greenness utilising remotely sensed canopy cover maps could provide a useful tool for mapping habitat quality metrics that matter to species. However, this approach will be constrained by the predictive capacity of models used to map field-derived forest canopy attributes. Furthermore, sampling efforts are needed to capture spatial and temporal variation in Thermalground within and across days and seasons to validate the transferability of our findings. Finally, whilst our approach shows that surface temperature and ground vegetation greenness might be suitable habitat quality metric used in biodiversity monitoring, the next step requires that we map demographic traits of species of different threat status onto maps of these metrics in landscapes differing in disturbance and management histories. The derived understanding could then be exploited for targeted landscape restoration that benefits biodiversity conservation at the landscape scale
Functional diversity mediates contrasting direct and indirect effects of fragmentation on below- and above-ground carbon stocks of coastal dune forests
Changes in structure and functioning of tree communities in response to forest fragmentation may alter tropical forest’s capacity to store carbon and regulate climate. However, evidence for indirect effects of forest fragmentation on above – and belowground carbon pools through changes in forest biodiversity is scarce. Here we focus on understanding the relative importance of taxonomic and functional diversity and tree cover to explain above- and below-ground carbon stocks in coastal dune forest fragments. We surveyed tree species composition and structure in six coastal forest patches varying in size from 215 to 13350 ha, in Kwa-Zulu Natal, South Africa. For each fragment, we estimated carbon stocks of two pools, aboveground biomass (AGC) and soil organic carbon (SOC). We used structural equation models to test if and to what extent the effects of forest fragmentation on AGC and SOC were mediated by tree cover and taxonomic and functional diversity. Our results showed that forest fragmentation directly reduced AGC, but increased SOC. In contrast, forest fragmentation indirectly, through decreasing functional diversity, increased AGC, but decreased SOC. Small patches therefore had few tree species that were functional similar and had high AGC, but low SOC, which led to a negative relationship between species richness and AGC. Tree cover was not affected by fragmentation, and had a direct positive effect on AGC but not on SOC. Our results suggest that forest fragmentation simultaneously affect multiple processes which directly and indirectly affects carbon stocks of different pools. Fragmentation may trigger a process of biotic homogenization, in which a few species are positively related with carbon storage above-, but not below-ground.V. Rolo and P.I. Olivier are supported by post-doctoral grants from the National Research Foundation (NRF) of South Africa. This work was also partly funded by an Ecologists in Africa grant by the British Ecological Society to P.I. Olivier. R.J. van Aarde is supported by Richards Bay Minerals, NRF and the Technology and Human Resources for Industry Programme (THRIP). M. Pfeifer was supported by European Research Council Project number 281986.http://www.elsevier.com/locate/foreco2019-01-01hj2017Zoology and Entomolog
Recognizing the equity implications of restoration priority maps
A growing number of studies seek to identify global priority areas for conservation and restoration. These studies often produce maps that highlight the benefits of concentrating such activity in the tropics. However, the potential equity implications of using these prioritization exercises to guide global policy are less often explored and articulated. We highlight those equity issues by examining a widely publicized restoration priority map as an illustrative case. This map is based on a prioritization analysis that sought to identify places where restoration of agricultural land might provide the greatest biodiversity and carbon sequestration benefits at the lowest cost. First, we calculate the proportion of agricultural land in countries around the world that the map classifies as a top 15% restoration priority. A regression analysis shows that this map prioritizes restoration in countries where displacing agriculture may be most detrimental to livelihoods: countries that are poorer, more populated, more economically unequal, less food secure, and that employ more people in agriculture. Second, we show through another regression analysis that a similar pattern appears sub-nationally within the tropics: 5 km x 5 km parcels of land in the tropics that are less economically developed or more populated are more likely to be top 15% restoration priorities. In other words, equity concerns persist at a subnational scale even after putting aside comparisons between the tropics and the Global North. Restorative activity may be beneficial or harmful to local livelihoods depending on its conceptualization, implementation, and management. Our findings underline a need for prioritization exercises to better attend to the risks of concentrating potentially negative livelihood impacts in vulnerable regions. We join other scholars calling for greater integration of social data into restoration science
Recognizing the equity implications of restoration priority maps
A growing number of studies seek to identify global priority areas for conservation and restoration. These studies often produce maps that highlight the benefits of concentrating such activity in the tropics. However, the potential equity implications of using these prioritization exercises to guide global policy are less often explored and articulated. We highlight those equity issues by examining a widely publicized restoration priority map as an illustrative case. This map is based on a prioritization analysis that sought to identify places where restoration of agricultural land might provide the greatest biodiversity and carbon sequestration benefits at the lowest cost. First, we calculate the proportion of agricultural land in countries around the world that the map classifies as a top 15% restoration priority. A regression analysis shows that this map prioritizes restoration in countries where displacing agriculture may be most detrimental to livelihoods: countries that are poorer, more populated, more economically unequal, less food secure, and that employ more people in agriculture. Second, we show through another regression analysis that a similar pattern appears sub-nationally within the tropics: 5 km Ă— 5 km parcels of land in the tropics that are less economically developed or more populated are more likely to be top 15% restoration priorities. In other words, equity concerns persist at a subnational scale even after putting aside comparisons between the tropics and the Global North. Restorative activity may be beneficial or harmful to local livelihoods depending on its conceptualization, implementation, and management. Our findings underline a need for prioritization exercises to better attend to the risks of concentrating potentially negative livelihood impacts in vulnerable regions. We join other scholars calling for greater integration of social data into restoration science
Room to roam for African lions Panthera leo: a review of the key drivers of lion habitat use and implications for conservation
1. Globally, large terrestrial carnivores (Carnivora) have suffered precipitous declines in population and range. Today, they must persist in increasingly isolated natural habitat patches within a human-dominated matrix. Effective conservation aimed at supporting carnivores in such landscapes requires species-specific understanding of habitat requirements. 2. We present results from a review of the published literature to assess the current state of knowledge regarding habitat preferences of the African lion Panthera leo, with the aim of identifying common drivers of habitat use across contexts. 3. Using the Web of Science, we identified 154 usable articles and extracted information relating to study topic, location, habitats described, land-use type, and any documented habitat preferences. 4. Only 31 studies documented evidence of habitat use, and collectively, they suggested that preferences for specific habitat types were varied and context-specific. The importance of prey abundance and proximity to water was highlighted in multiple studies. Anthropogenic factors interfered with expected patterns of habitat use. There was evident bias in study locations: 83% of the habitat-use studies were based in only three countries, and 70% were focussed on protected or managed areas. 5. Our synthesis suggests that lions demonstrate behavioural plasticity in habitat use in response to anthropogenic pressures. To understand the limits of this plasticity and to manage Africa’s changing landscapes effectively for roaming lions, future research should be focussed on analysis of habitat use outside protected areas, taking into account gradients of distance to water, prey abundance, and anthropogenic risk
Existing evidence on the use of participatory scenarios in ecological restoration: a systematic map
Background and context The scale of land degradation worldwide has led to nearly one billion hectares committed to restoration globally. However, achieving such restoration targets will necessitate complex trade-offs against limited time, competing knowledge, costs, resources and varying stakeholder and societal preferences. Participatory scenarios allow a way to identify collaborative solutions for restoration planning and implementation best suited for the local cultures and societies they are tied to. They can be used to navigate uncertainties surrounding future trajectories of restored areas by evaluating trade-offs in outcomes. This research aims to systematically map the evidence on the use of participatory scenarios in restoration planning. We use the following research question: What evidence exists on the use of participatory scenarios in ecological restoration? This is answered by examining the characteristics of the evidence base, types of study design, types of outcomes, trade-offs in outcomes, and the role of participants. Methods A comprehensive and reproducible search strategy was followed using bibliographic databases, webbased searches, and targeted searching. Search results underwent a two-step screening process according to eligibility criteria. Metadata on key areas of interest were extracted from included texts and were narratively synthesised alongside data visualisations to answer the research questions. Review findings 18,612 records were initially identified, and 106 articles were included in the final map. Most studies were conducted in Europe and North America, focusing on restoring agricultural land or forests. Most texts used mixed methods and explored multiple outcome types, but environmental outcomes were the most assessed. Within environmental outcomes, indicators for ecological function were assessed more frequently than structural or compositional indicators. The most common reason for choosing outcomes and indicators was stakeholder interest. Tradeoffs in social, ecological, and economic outcomes were mainly examined across space using mapping techniques, while far fewer studies looked at trade-offs across stakeholders and time. Participants were mostly included in the scenario creation step and were usually chosen purposefully by the research team. Conclusions It is difficult to understand how useful scenarios are for restoration planning because few texts reported how scenarios fed into the process. Despite this, the range of outcomes used and different method types adopted suggests participatory scenarios allow for integrating different knowledge and approaches, alongside facilitating the use of qualitative or semi-quantitative data when this is more appropriate or quantitative data is not widely available. To better use participatory scenarios as a tool for ecological restoration planning, decision-makers can push for greater levels and definitions of participation from the offset of restoration projects with specified, regular, and structured communication and participation channels. We also recommend more systematic methods of participant selection, such as stakeholder analysis. Further research is needed to understand the effectiveness of participatory scenarios in restoration planning and whether the participation of stakeholders was successful in meeting objectives. To improve the evidence base, future studies should clearly evaluate their effectiveness in the restoration planning process and their success in meeting their participatory objectives. Evidence synthesis, Stakeholder engagement, Collaboration, Alternative futures, Socioecological systems, Co-productionpublishedVersio
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