205 research outputs found
Built-up areas within and around protected areas: Global patterns and 40-year trends
Protected areas (PAs) are a key strategy in global efforts to conserve biodiversity and ecosystem services that are critical for human well-being. Most PAs have some built-up structures within their boundaries or in surrounding areas, ranging from individual buildings to villages, towns and cities. These structures, and the associated human activities, can exert direct and indirect pressures on PAs. Here we present the first global analysis of current patterns and observed long-term trends in built-up areas within terrestrial PAs and their immediate surroundings. We calculate for each PA larger than 5 km2 and for its 10-km unprotected buffer zone the percentage of land area covered by built-up areas in 1975, 1990, 2000 and 2014. We find that globally built-up areas cover only 0.12% of PA extent and a much higher 2.71% of the unprotected buffers as of 2014, compared to 0.6% of all land (protected or unprotected). Built-up extent in and around PAs is highest in Europe and Asia, and lowest in Africa and Oceania. Built-up area percentage is higher in coastal and small PAs, and lower in older PAs and in PAs with stricter management categories. From 1975 to 2014, the increase in built-up area was 23 times larger in the 10-km unprotected buffers than within PAs. Our findings show that the development of built-up structures remains limited within the boundaries of PAs but highlight the need to carefully manage the considerable pressure that PAs face from their immediate surroundings
Mapping Status and Conservation of Global At-Risk Marine Biodiversity
To conserve marine biodiversity, we must first understand the spatial distribution and status of atârisk biodiversity. We combined range maps and conservation status for 5,291 marine species to map the global distribution of extinction risk of marine biodiversity. We find that for 83% of the ocean, \u3e25% of assessed species are considered threatened, and 15% of the ocean shows \u3e50% of assessed species threatened when weighting for rangeâlimited species. By comparing mean extinction risk of marine biodiversity to noâtake marine reserve placement, we identify regions where reserves preferentially afford proactive protection (i.e., preserving lowârisk areas) or reactive protection (i.e., mitigating highârisk areas), indicating opportunities and needs for effective future protection at national and regional scales. In addition, elevated risk to high seas biodiversity highlights the need for credible protection and minimization of threatening activities in international waters
Conservation Performance of Tropical Protected Areas: How Important is Management?
Increasing the coverage of effectively managed protected areas (PAs) is a key focus of the 2020 Aichi biodiversity targets. PA management has received considerable attention, often based on the widely-held, but rarely examined, assumption that positive conservation outcomes will result from increased PA management inputs. To shed light on this assumption, we integrated data on PA management factors with 2006-2011 avoided forest degradation and deforestation across the Peruvian Amazon, using a counterfactual approach, combined with interviews and ranking exercises. We show that while increasing PA management input to Amazonian PAs tended to reduce likelihoods of forest degradation and deforestation, the associations were weak. Key challenges facing PAs ranked by PA managers included wider law enforcement, corruption and land title issues, rather than local management factors. We therefore encourage the post-2020 conservation targets to adopt holistic approaches beyond PA management, incorporating political, institutional and governance contexts across scales.This work was supported by the Economic and Social Research Council (grant number ES/I019650/1); Cambridge Political Economy Society; Cambridge Philosophical Society; St Johnâs College; and the Department of Geography, University of Cambridge
Invasion of freshwater ecosystems is promoted by network connectivity to hotspots of human activity
Aim: Hotspots of human activity are focal points for ecosystem disturbance and nonânative introduction, from which invading populations disperse and spread. As such, connectivity to locations used by humans may influence the likelihood of invasion. Moreover, connectivity in freshwater ecosystems may follow the hydrological network. Here we tested whether multiple forms of connectivity to human recreational activities promotes biological invasion of freshwater ecosystems.
Location: England, UK.
Time period: 1990â2018.
Major taxa studied: One hundred and twentyâsix nonânative freshwater birds, crustaceans, fish, molluscs and plants.
Methods: Machine learning was used to predict spatial gradients in human recreation and two high risk activities for invasion (fishing and water sports). Connectivity indices were developed for each activity, in which human influence decayed from activity hotspots according to Euclidean distance (spatial connectivity) or hydrological network distance (downstream, upstream and alongâchannel connectivity). Generalized linear mixed models identified the connectivity type most associated to invasive species richness of each group, while controlling for other anthropogenic and environmental drivers.
Results: Connectivity to humans generally had stronger positive effects on invasion than all other drivers except recording effort. Recreation had stronger influence than urban land cover, and for most groups high risk activities had stronger effects than general recreation. Downstream human connectivity was most important for invasion by most of the groups, potentially reflecting predominantly hydrological dispersal. An exception was birds, for which spatial connectivity was most important, possibly because of overland dispersal capacity.
Main conclusions: These findings support the hypothesis that freshwater invasion is partly determined by an interaction between human activity and species dispersal in the hydrological network. By comparing alternative connectivity types for different human activities, our approach could enable robust inference of specific pathways and spread mechanisms associated with particular taxa. This would provide evidence to support better prioritization of surveillance and management for invasive nonânative species
Benthic habitat modelling and mapping as a conservation tool for marine protected areas: A seamount in the western Mediterranean
1. An ecologically representative, wellâconnected, and effectively managed system of
marine protected areas (MPAs) has positive ecological and environmental effects
as well as social and economic benefits. Although progress in expanding the coverage of MPAs has been made, the application of management tools has not yet
been implemented in most of these areas.
2. In this work, distribution models were applied to nine benthic habitats on a Mediterranean seamount within an MPA for conservation purposes. Benthic habitat
occurrences were identified from 55 remotely operated vehicle (ROV) transects,
at depths from 76 to 700 m, and data derived from multibeam bathymetry. Generalized additive models (GAMs) were applied to link the presence of each benthic
habitat to local environmental proxies (depth, slope, backscatter, aspect, and
bathymetric position index, BPI).
3. The main environmental drivers of habitat distribution were depth, slope, and BPI.
Based on this result, five different geomorphological areas were distinguished. A
full coverage map indicating the potential benthic habitat distribution on the seamount was obtained to inform spatial management.
4. The distribution of those habitats identified as vulnerable marine ecosystems (VMEs)
was used to make recommendations on zonation for developing the management
plan of the MPA. This process reveals itself as an appropriate methodological
approach that can be developed in other areas of the Natura 2000 marine networkEn prensa1,92
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Putting susceptibility on the map to improve conservation planning, an example with terrestrial mammals
Aim
To propose a general approach to spatially synthesize known predictors of vulnerability at the species level in order to identify areas directly associated with specific conservation problems. Under this problem-detection framework, the coincidence or divergence of main strengths and weaknesses can be used to propose tailor-made conservation strategies. This approach is illustrated for terrestrial mammal species evaluating two of their main components of vulnerability: life-history traits and land use pressure.
Location
Global.
Methods
We determine, at the species level, the relationships between extinction risk and two well-known predictors of vulnerability: life-history traits (intrinsic) and land use (extrinsic). Transferring these findings into the spatial domain, we identify the areas of the world where one of these two facets is predominant and those areas where both coincide.
Results
The proposed approach allows us to recognize four types of areas: 1) double-susceptibility areas: where both the characteristics of the species and the existing human activities pose a threat, therefore the simultaneous management of both species/habitats and human activities are needed; 2) intrinsic-susceptibility areas: where species are naturally fragile and human presence is scarce, thus species-specific management plans would be particularly efficient; 3) extrinsic-susceptibility areas: where human pressure is high but species are not intrinsically vulnerable; which requires special attention to human activities; and 4) low-susceptibility areas: where there are not remarkable threats for existing terrestrial mammals, which additionally are not particularly fragile.
Main conclusions
Our approach can spatially synthesize known predictors of vulnerability identifying areas where different factors predispose species to become extinct. This method builds on conservation planning approaches by targeting actions based on known strengths and weaknesses of a given area, and offering a new implementation of comparative studies of extinction risk. This approach may be applied to different species and to particular regions, focusing on different drivers, and complemented by incorporating social and economic trade-offs
Effects of logging on roadless space in intact forest landscapes of the Congo Basin
Forest degradation in the tropics is often associated with roads built for selective logging. The protection of intact forest landscapes (IFL) that are not accessible by roads is high on the biodiversity conservation agenda and a challenge for logging concessions certified by the Forest Stewardship Council (FSC). A frequently advocated conservation objective is to maximize the retention of roadless space, a concept that is based on distance to the nearest road from any point. We developed a novel use of the empty-space function â a general statistical tool based on stochastic geometry and random sets theory â to calculate roadless space in a part of the Congo Basin where road networks have been expanding rapidly. We compared the temporal development of roadless space in certified and uncertified logging concessions inside and outside areas declared IFL in 2000. Inside IFLs, road-network expansion led to a decrease in roadless space by more than half from 1999 to 2007. After 2007, loss leveled out in most areas to close to 0 due to an equilibrium between newly built roads and abandoned roads that became revegetated. However, concessions in IFL certified by FSC since around 2007 continuously lost roadless space and reached a level comparable to all other concessions. Only national parks remained mostly roadless. We recommend that forest-management policies make the preservation of large connected forest areas a top priority by effectively monitoring â and limiting â the occupation of space by roads that are permanently accessible. (RĂ©sumĂ© d'auteur
A spatial overview of the global importance of Indigenous lands for conservation
Understanding the scale, location and nature conservation values of the lands over which Indigenous Peoples exercise tradi- tional rights is central to implementation of several global conservation and climate agreements. However, spatial information on Indigenous lands has never been aggregated globally. Here, using publicly available geospatial resources, we show that Indigenous Peoples manage or have tenure rights over at least ~38 million km2 in 87 countries or politically distinct areas on all inhabited continents. This represents over a quarter of the worldâs land surface, and intersects about 40% of all terrestrial protected areas and ecologically intact landscapes (for example, boreal and tropical primary forests, savannas and marshes). Our results add to growing evidence that recognizing Indigenous Peoplesâ rights to land, benefit sharing and institutions is essential to meeting local and global conservation goals. The geospatial analysis presented here indicates that collaborative partnerships involving conservation practitioners, Indigenous Peoples and governments would yield significant benefits for conservation of ecologically valuable landscapes, ecosystems and genes for future generations
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