Ecological mechanisms linking protected areas to surrounding lands.

Land use is expanding and intensifying in the unprotected lands surrounding many of the world's protected areas. The influence of this land use change on ecological processes is poorly understood. The goal of this paper is to draw on ecological theory to provide a synthetic framework for understanding how land use change around protected areas may alter ecological processes and biodiversity within protected areas and to provide a basis for identifying scientifically based management alternatives. We first present a conceptual model of protected areas embedded within larger ecosystems that often include surrounding human land use. Drawing on case studies in this Invited Feature, we then explore a comprehensive set of ecological mechanisms by which land use on surrounding lands may influence ecological processes and biodiversity within reserves. These mechanisms involve changes in ecosystem size, with implications for minimum dynamic area, species-area effect, and trophic structure; altered flows of materials and disturbances into and out of reserves; effects on crucial habitats for seasonal and migration movements and population source/sink dynamics; and exposure to humans through hunting, poaching, exotics species, and disease. These ecological mechanisms provide a basis for assessing the vulnerability of protected areas to land use. They also suggest criteria for designing regional management to sustain protected areas in the context of surrounding human land use. These design criteria include maximizing the area of functional habitats, identifying and maintaining ecological process zones, maintaining key migration and source habitats, and managing human proximity and edge effects.     

Land-cover change within and around protected areas in a biodiversity hotspot

The landscape surrounding protected areas influences their ability to maintain ecosystem functions and achieve conservation goals. As anthropogenic intensification continues, it is important to monitor land-use and land-cover change in and around protected areas. We measure land-cover change surrounding protected areas in the Maputaland-Pondoland-Albany Biodiversity hotspot from the 1980s to present. Using Landsat imagery, we classified land cover within and around each protected area. Agricultural land uses were increasing and often directly border protected area boundaries. Human settlements increased around every protected area, potentially increasing human activity along the edges of protected areas and threatening their ecological integrity. Urban expansion around protected areas varied but increased as much as 10%. Woody vegetation cover varied both within and around protected areas with possible evidence of deforestation and shrub encroachment throughout the hotspot. We recommend monitoring land cover across southeastern Africa to better understand regional trends in land-use impacts to protected areas.     

Estimating the Effect of Protected Lands on the Development and Conservation of Their Surroundings

Abstract:  The fate of private lands is widely seen as key to the fate of biodiversity in much of the world. Organizations that work to protect biodiversity on private lands often hope that conservation actions on one piece of land will leverage the actions of surrounding landowners. Few researchers have, however, examined whether protected lands do in fact encourage land conservation nearby or how protected lands affect development in the surrounding landscape. Using spatiotemporal data sets on land cover and land protection for three sites (western North Carolina, central Massachusetts, and central Arizona), we examined whether the existence of a protected area correlates with an increased rate of nearby land conservation or a decreased rate of nearby land development. At all sites, newly protected conservation areas tended to cluster close to preexisting protected areas. This may imply that the geography of contemporary conservation actions is influenced by past decisions on land protection, often made for reasons far removed from concerns about biodiversity. On the other hand, we found no evidence that proximity to protected areas correlates with a reduced rate of nearby land development. Indeed, on two of our three sites the development rate was significantly greater in regions with more protected land. This suggests that each conservation action should be justified and valued largely for what is protected on the targeted land, without much hope of broader conservation leverage effects.     

Risk Assessment of Riparian Plant Invasions into Protected Areas

Abstract:  Protected areas are becoming increasingly isolated. River corridors represent crucial links to the surrounding landscape but are also major conduits for invasion of alien species. We developed a framework to assess the risk that alien plants in watersheds adjacent to a protected area will invade the protected area along rivers. The framework combines species- and landscape-level approaches and has five key components: (1) definition of the geographical area of interest, (2) delineation of the domain into ecologically meaningful zones, (3) identification of the appropriate landscape units, (4) categorization of alien species and mapping of their distribution and abundance, and (5) definition of management options. The framework guides the determination of species distribution and abundance through successive, easily followed steps, providing the means for the assessment of areas of concern. We applied the framework to Kruger National Park (KNP) in South Africa. We recorded 231 invasive alien plant species (of which 79 were major invaders) in the domain. The KNP is facing increasing pressure from alien species in the upper regions of the drainage areas of neighboring watersheds. On the basis of the climatic modeling, we showed that most major riparian invaders have the ability to spread across the KNP should they be transported down the rivers. With this information, KNP managers can identify areas for proactive intervention, monitoring, and resource allocation. Even for a very large protected area such as the KNP, sustainable management of biodiversity will depend heavily on the response of land managers upstream managing alien plants. We suggest that this framework is applicable to plants and other passively dispersed species that invade protected areas situated at the end of a drainage basin.     

How percentage-protected targets can support positive biodiversity outcomes

Global targets for the percentage area of land protected, such as 30% by 2030, have gained increasing prominence, but both their scientific basis and likely effectiveness have been questioned. As with emissions-reduction targets based on desired climate outcomes, percentage-protected targets combine values and science by estimating the area over which conservation actions are required to help achieve desired biodiversity outcomes. Protected areas are essential for achieving many biodiversity targets, in part because many species are highly sensitive to human-associated disturbance. However, because the contribution of protected areas to biodiversity outcomes is contingent on their location, management, governance, threats, and what occurs across the broader landscape matrix, global percentage-protected targets are unavoidably empirical generalizations of ecological patterns and processes across diverse geographies. Percentage-protected targets are insufficient in isolation but can complement other actions and contribute to biodiversity outcomes within a framework that balances accuracy and pragmatism in a global context characterized by imperfect biodiversity data. Ideally, percentage-protected targets serve as anchors that strengthen comprehensive national biodiversity strategies by communicating the level of ambition necessary to reverse current trends of biodiversity loss. If such targets are to fulfill this role within the complex societal process by which both values and science impel conservation actions, conservation scientists must clearly communicate the nature of the evidence base supporting percentage-protected targets and how protected areas can function within a broader landscape managed for sustainable coexistence between people and nature. A new paradigm for protected and conserved areas recognizes that national coordination, incentives, and monitoring should support rather than undermine diverse locally led conservation initiatives. However, the definition of a conserved area must retain a strong focus on biodiversity to remain consistent with the evidence base from which percentage-protected targets were originally derived.     

Conservation value of small reserves

The importance of large reserves has been long maintained in the scientific literature, often leading to dismissal of the conservation potential of small reserves. However, over half the global protected-area inventory is composed of protected areas that are <100 ha, and the median size of added protected area is decreasing. Studies of the conservation value of small reserves and fragments of natural area are relatively uncommon in the literature. We reviewed SCOPUS and WOK for studies on small reserve and fragment contributions to biodiversity conservation and ecosystem services, and fifty-eight taxon-specific studies were included in the review. Small reserves harbored substantial portions (upward of 50%) of regional species diversity for many taxa (birds, plants, amphibians, and small mammals) and even some endemic, specialist bird species. Unfortunately, small reserves and fragments almost always harbored more generalist and exotic species than large reserves. Community composition depended on habitat quality, surrounding land use (agricultural vs. urban), and reserve and fragment size, which presents opportunities for management and improvement. Small reserves also provided ecosystem services, such as pollination and biological pest control, and cultural services, such as recreation and improved human health. Limitations associated with small reserves, such as extinction debt and support of area-sensitive species, necessitate a complement of larger reserves. However, we argue that small reserves can make viable and significant contributions to conservation goals directly as habitat and indirectly by increasing landscape connectivity and quality to the benefit of large reserves. To effectively conserve biodiversity for future generations in landscapes fragmented by human development, small reserves and fragments must be included in conservation planning.     

Use of Inverse Spatial Conservation Prioritization to Avoid Biological Diversity Loss Outside Protected Areas

Globally expanding human land use sets constantly increasing pressure for maintenance of biological diversity and functioning ecosystems. To fight the decline of biological diversity, conservation science has broken ground with methods such as the operational model of systematic conservation planning (SCP), which focuses on design and on‐the‐ground implementation of conservation areas. The most commonly used method in SCP is reserve selection that focuses on the spatial design of reserve networks and their expansion. We expanded these methods by introducing another form of spatial allocation of conservation effort relevant for land‐use zoning at the landscape scale that avoids negative ecological effects of human land use outside protected areas. We call our method inverse spatial conservation prioritization. It can be used to identify areas suitable for economic development while simultaneously limiting total ecological and environmental effects of that development at the landscape level by identifying areas with highest economic but lowest ecological value. Our method is not based on a priori targets, and as such it is applicable to cases where the effects of land use on, for example, individual species or ecosystem types are relatively small and would not lead to violation of regional or national conservation targets. We applied our method to land‐use allocation to peat mining. Our method identified a combination of profitable production areas that provides the needed area for peat production while retaining most of the landscape‐level ecological value of the ecosystem. The results of this inverse spatial conservation prioritization are being used in land‐use zoning in the province of Central Finland.     

Value of protected areas to avian persistence across 20 years of climate and land-use change

Establishing protected areas, where human activities and land cover changes are restricted, is among the most widely used strategies for biodiversity conservation. This practice is based on the assumption that protected areas buffer species from processes that drive extinction. However, protected areas can maintain biodiversity in the face of climate change and subsequent shifts in distributions have been questioned. We evaluated the degree to which protected areas influenced colonization and extinction patterns of 97 avian species over 20 years in the northeastern United States. We fitted single-visit dynamic occupancy models to data from Breeding Bird Atlases to quantify the magnitude of the effect of drivers of local colonization and extinction (e.g., climate, land cover, and amount of protected area) in heterogeneous landscapes that varied in the amount of area under protection. Colonization and extinction probabilities improved as the amount of protected area increased, but these effects were conditional on landscape context and species characteristics. In this forest-dominated region, benefits of additional land protection were greatest when both forest cover in a grid square and amount of protected area in neighboring grid squares were low. Effects did not vary with species’ migratory habit or conservation status. Increasing the amounts of land protection benefitted the range margins species but not the core range species. The greatest improvements in colonization and extinction rates accrued for forest birds relative to open-habitat or generalist species. Overall, protected areas stemmed extinction more than they promoted colonization. Our results indicate that land protection remains a viable conservation strategy despite changing habitat and climate, as protected areas both reduce the risk of local extinction and facilitate movement into new areas. Our findings suggest conservation in the face of climate change favors creation of new protected areas over enlarging existing ones as the optimal strategy to reduce extinction and provide stepping stones for the greatest number of species.     

Conversion or conservation? Understanding wetland change in northwest Costa Rica.

Wetlands are more threatened than any other ecosystem type, with losses exceeding 50% of their original extent worldwide. Despite the small portion of the Earth's surface that they comprise, wetlands contribute significantly to global ecosystem services. In this study, we tested the hypothesis that the location and rate of change in wetland amount in the Tempisque Basin of northwest Costa Rica is predictable from landscape setting. Our results demonstrate that a strong potential exists for developing predictive models of wetland conversion based on an understanding of wetland location and surrounding trends of land use. We found that topography was the single most important predictor of wetland conversion in this area, entraining other conversion processes, and that spatial patterns of wetland loss could consistently be predicted from landscape-level variables. Areas with highest probabilities of conversion were found in the most accessible, non-protected regions of the landscape. While Palo Verde National Park made a substantial contribution to wetland conservation, our results highlight the dependence of lower-lying protected areas on upland processes, adding a little-addressed dimension of complexity to the dialogue about protected area management. Conservation strategies aimed at reducing wetland loss in tropical habitats will benefit from careful analysis of the dominant land use system(s) at a relatively broad scale, and the subsequent development of management and policy responses that take into account dynamic opportunities and constraints in the landscape.     

Land-use changes and implications for management of a small protected island off the coast of Bretagne

Over the 20th century, reduced land cultivation has caused an extension of fallow land in several European countries, which has led to a decrease in biodiversity. Knowledge of dynamic vegetation processes and of the impact of human activities on biodiversity provides the basis for land management recommendations, as well as for wildlife management programs. We analysed land-use changes on a small protected island (Ushant, Bretagne, France) using historical documentation (1844) and aerial photographs taken in 1952 and 1992. Over this period, especially during the last 40 yr, Ushant underwent a complete transformation from rural landscape to extensive shrubland. No cultivated area remains, grazed areas were moved from the coastal fringe to the core of the island, while over 40% of the island is fallow land. The relationship between current sheep grazing and vegetation suggests that grazed meadows used to be close to inhabited areas, i.e. 150 m outside the villages. These results allowed us to analyse landcover potential related to changes in the intensity of sheep grazing. The scenarios highlighted by our method provide an objective framework for further assessment of fallow land management.     

Capacity development in protected area management

Increasing land consumption and loss of biodiversity make it particularly important that protected areas fulfil their function. This, however, is often impaired by insufficient political and financial support. This study investigates how existing protected area management capacities can be used more effectively in a prompt and lasting manner. Therefore, data from protected area management effectiveness evaluations were analysed. Efficient workflows and teamwork were identified to be key capacities for effective management. Simultaneously, deficient financial and social security, lack of incentives and inflexible management structures prevent the productive use of existing capacities. In order to improve the situation, greater attention should be given to intangible assets. Additionally, protected area managers and employees must be enabled to be more self-reliant and self-responsible in order to foster a lasting learning process.     

南昌市生态空间和生态保护红线划定研究

生态保护红线作为生态空间的刚性约束区域,是保障和维护国家生态安全的底线和生命线。结合国土空间规划双评价技术,以南昌市为例,选取水源涵养功能、水土保持功能、水质保护功能、生物多样性保护功能4种重要性指标和土壤侵蚀、酸沉降、水污染3种敏感性指标,采用模型评估法和净初级生产力定量指标评估法,开展生态空间和生态保护红线划定研究。结果表明:南昌市生态保护红线面积为1648.43 km2,占总面积的22.27%,以水质保护与水污染敏感红线和生物多样性维护功能生态保护红线为主,面积分别为787.93 km2和628.96 km2,主要分布在南昌市梅岭森林公园及周边地区、中部赣江与瑶湖范围、东部军山湖与青岚湖地区、西部鄱阳湖湖域以及近鄱阳湖部分区域,以水域、农田、森林3种地类为主;生态空间面积为4271.43 km2,占总面积的57.70%,主要分布在南昌东部、南部以及西南方向,以农田、森林地类为主;其他空间面积为1482.67 km2,占总面积的20.03%,主要分布在南昌市中部以及市区周边部分地区,以建设用地为主。研究结果可为区域国土空间规划和生态安全提供参考。     

History and Importance of Land Use and Protection in the North Quabbin Region of Massachusetts (USA)

Evaluating the consequences and future of land protection requires broad temporal and spatial perspectives of ecological and cultural factors. We assessed the development of a system of protected areas comprising 37% of central Massachusetts in terms of changing rates and means of land protection. We compared protected areas to the surrounding matrix in terms of physical, biological, and historical features and used these results to raise issues concerning future planning. The rate, purpose, and means of land protection in the North Quabbin Region (168,312 ha) have been dynamic as a result of changes in cultural values and transformation of the landscape from predominantly agriculture to forest. Protected lands are managed by 25 federal and state agencies, private groups, and municipal departments and commissions and are physically and biologically typical of the regional landscape which results from (1) participation of diverse organizations with varied agendas; (2) predominance of large government acquisitions driven by landscape-scale criteria; and (3) absence of coordination among groups. The large area, relative homogeneity and largely undeveloped status of the North Quabbin Region suggest conservation goals distinct from those in the fragmented and extensively developed neighboring areas of the Connecticut River Valley and Cape Cod and Islands Region. Large tracts of forests, wetlands, and lakes in the North Quabbin Region provide (1) habitat for species requiring extensive, intact areas; (2) the opportunity to maintain broad-scale ecological processes; (3) connections to regional conservation areas; and (4) recreation. To realize the area's potential, a comprehensive plan must be based on a broad-scale perspective and historical understanding of the landscape.     

Assessing effects of land use on landscape connectivity: loss and fragmentation of western U.S. forests

Effects of land-use change on the conservation of biodiversity have become a concern to conservation scientists and land managers, who have identified loss and fragmentation of natural areas as a high-priority issue. Despite urgent calls to inform national, regional, and state planning efforts, there remains a critical need to develop practical approaches to identify where important lands are for landscape connectivity (i.e., linkages), where land use constrains connectivity, and which linkages are most important to maintain network-wide connectivity extents. Our overall goal in this paper was to develop an approach that provides comprehensive, quantitative estimates of the effects of land-use change on landscape connectivity and illustrate its use on a broad, regional expanse of the western United States. We quantified loss of habitat and landscape connectivity for western forested systems due to land uses associated with residential development, roads, and highway traffic. We examined how these land-use changes likely increase the resistance to movement of forest species in non-forested land cover types and, therefore, reduce the connectivity among forested habitat patches. To do so, we applied a graph-theoretic approach that incorporates ecological aspects within a geographic representation of a network. We found that roughly one-quarter of the forested lands in the western United States were integral to a network of forested patches, though the lands outside of patches remain critical for habitat and overall connectivity. Using remotely sensed land cover data (ca. 2000), we found 1.7 million km2 of forested lands. We estimate that land uses associated with residential development, roads, and highway traffic have caused roughly a 4.5% loss in area (20 000 km2) of these forested patches, and continued expansion of residential land will likely reduce forested patches by another 1.2% by 2030. We also identify linkages among forest patches that are critical for landscape connectivity. Our approach can be readily modified to examine connectivity for other habitats/ecological systems and for other geographic areas, as well as to address more specific requirements for particular conservation planning applications.     

A project for the integrated management of protected coastal areas in Malta

This paper examines a 3-yr EU LIFE-funded project for the management of two especially protected areas on the Maltese coast. Project partners are the Euro-Mediterranean Centre on Insular Coastal Dynamics (ICoD), the Gaia Foundation and the Ministry for the Environment of Malta. Project sites are the Ghajn Tuffieha area on the northwest coast of Malta, and the Ramla Bay area on the island of Gozo. While both sites are in a relatively pristine state and comprise a number of features of ecological and scientific importance, they are also prime recreational areas, hosting thousands of visitors especially during the summer months. The challenge is to manage these sites in a sustainable manner in order to protect their unique ecology while simultaneously controlling and managing the human activities taking place there. The following sequence of activities is being implemented at both sites: surveys of the resources present (biodiversity, habitats, geological and hydrological features, and archaeological heritage), implementation of first intervention measures, and the drawing up and implementation of site-specific management plans, including rehabilitation and protection of biodiversity and habitats, regulations for site use, and awareness raising and educational measures. The management structure of this project supports the concept of decentralization of management of protected areas, through the granting of responsibility for the direct management of these sites to a non-governmental organization, under joint government/EU funding. This paper thus presents the project as a model for similar initiatives for the management of protected sites in the Mediterranean.     

Conserving Connectivity: Some Lessons from Mountain Lions in Southern California

Abstract: Habitat corridors can be essential for persistence of wildlife populations in fragmented landscapes. Although much research has focused on identifying species and places critical for conservation action, the conservation literature contains surprisingly few examples of corridors that actually have been protected and so provides little guidance for moving from planning through implementation. We examined a case study from southern California that combines monitoring of radio‐collared mountain lions (Puma concolor) with an assessment of land‐protection efforts to illustrate lessons learned while attempting to maintain ecological connectivity in a rapidly urbanizing landscape. As in many places, conservation scientists have provided science‐based maps of where conservation efforts should focus. But implementing corridors is a business decision based not solely on ecological information but also on cost, opportunity cost, investment risk, and other feasibility considerations. Here, the type and pattern of development is such that key connections will be lost unless they are explicitly protected. Keeping pace with conversion, however, has been difficult, especially because conservation efforts have been limited to traditional parcel‐by‐parcel land‐protection techniques. The challenges of and trade‐offs in implementation make it clear that in southern California, connectivity cannot be bought one parcel at a time. Effective land‐use plans and policies that incorporate conservation principles, such as California's Natural Communities Conservation Planning program, are needed to support the retention of landscape permeability. Lessons from this study have broad application, especially as a precautionary tale for places where such extensive and intensive development has not yet occurred. Given how limiting resources are for biodiversity conservation, conservationists must be disciplined about where and how they attempt corridor protection: in rapidly fragmenting landscapes, the opportunity for success can be surprisingly fleeting.     

Analytical Solutions to Trade‐Offs between Size of Protected Areas and Land‐Use Intensity

Abstract: Land‐use change is affecting Earth's capacity to support both wild species and a growing human population. The question is how best to manage landscapes for both species conservation and economic output. If large areas are protected to conserve species richness, then the unprotected areas must be used more intensively. Likewise, low‐intensity use leaves less area protected but may allow wild species to persist in areas that are used for market purposes. This dilemma is present in policy debates on agriculture, housing, and forestry. Our goal was to develop a theoretical model to evaluate which land‐use strategy maximizes economic output while maintaining species richness. Our theoretical model extends previous analytical models by allowing land‐use intensity on unprotected land to influence species richness in protected areas. We devised general models in which species richness (with modified species‐area curves) and economic output (a Cobb–Douglas production function) are a function of land‐use intensity and the proportion of land protected. Economic output increased as land‐use intensity and extent increased, and species richness responded to increased intensity either negatively or following the intermediate disturbance hypothesis. We solved the model analytically to identify the combination of land‐use intensity and protected area that provided the maximum amount of economic output, given a target level of species richness. The land‐use strategy that maximized economic output while maintaining species richness depended jointly on the response of species richness to land‐use intensity and protection and the effect of land use outside protected areas on species richness within protected areas. Regardless of the land‐use strategy, species richness tended to respond to changing land‐use intensity and extent in a highly nonlinear fashion.     

Threats to intact tropical peatlands and opportunities for their conservation

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.     

Distinguishing stressors acting on land bird communities in an urbanizing environment

Urbanization has profound influences on ecological communities, but our understanding of causal mechanisms is limited by a lack of attention to its component stressors. Published research suggests that at landscape scales, habitat loss and fragmentation are the major drivers of community change, whereas at local scales, human activity and vegetation management are the primary stressors. Little research has focused on whether urbanization stressors may supplant natural factors as dominant forces structuring communities. We used model selection to determine the relative importance of urban development, human activity, local and landscape vegetation, topography, and geographical location in explaining land bird species richness, abundance, and dominance. We analyzed the entire community and groups of species based on ecological characteristics, using data collected in remnant forests along a gradient of urban development in the Lake Tahoe basin, California and Nevada, USA. Urbanization stressors were consistently among the principal forces structuring the land bird community. Strikingly, disturbance from human activity was the most important factor for richness in many cases, surpassing even habitat loss from development. Landscape-scale factors were consistently more important than local-scale factors for abundance. In demonstrating considerable changes in land bird community structure, our results suggest that ecosystem function in urban areas may be severely compromised. Such changes compel local- and landscape-scale management, focused research, and long-term monitoring to retain biodiversity in urban areas to the extent possible.