Global Protected Area Research Articles

Impacts and mechanisms of biological invasions in global protected areas

Impacts and mechanisms of biological invasions in global protected areas

Mixed effectiveness of global protected areas in resisting habitat loss

Protected areas are the cornerstones of conservation efforts to mitigate the anthropogenic pressures driving biodiversity loss. Nations aim to protect 30% of Earth’s land and water by 2030, yet the effectiveness of protected areas remains unclear. Here we analyze the performance of over 160,000 protected areas in resisting habitat loss at different spatial and temporal scales, using high-resolution data. We find that 1.14 million km2 of habitat, equivalent to three times the size of Japan, across 73% of protected areas, had been altered between 2003 and 2019. These protected areas experienced habitat loss due to the expansion of built-up land, cropland, pastureland, or deforestation. Larger and stricter protected areas generally had lower rates of habitat loss. While most protected areas effectively halted the expansion of built-up areas, they were less successful in preventing deforestation and agricultural conversion. Protected areas were 33% more effective in reducing habitat loss compared to unprotected areas, though their ability to mitigate nearby human pressures was limited and varied spatially. Our findings indicate that, beyond establishing new protected areas, there is an urgent need to enhance the effectiveness of existing ones to better prevent habitat loss and achieve the post-2020 global biodiversity goals.

Trends in habitat quality and habitat degradation in terrestrial protected areas.

Protected areas are typically considered a cornerstone of conservation programs and play a fundamental role in protecting natural areas and biodiversity. Human-driven land-use and land-cover (LULC) changes lead to habitat loss and biodiversity loss inside protected areas, impairing their effectiveness. However, the global dynamics of habitat quality and habitat degradation in protected areas remain unclear. We used the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model based on global annual remotely sensed data to examine the spatial and temporal trends in habitat quality and degradation in global terrestrial protected areas. Habitat quality represented the ability of habitats to provide suitable conditions for the persistence of individuals and populations, and habitat degradation represented the impacts on habitats from human-driven LULC changes in the surrounding landscape. Based on a linear mixed-effects modeling method, we also explored the relationship between habitat degradation trends and protected area characteristics, biophysical factors, and socioeconomic factors. Habitat quality declined by 0.005 (0.6%) and habitat degradation increased by 0.002 (11%) from 1992 to 2020 globally, and similar trends occurred even in remote or restrictively managed protected areas. Habitat degradation was attributed primarily to nonirrigated cropland (62%) and urbanization (27%) in 2020. Increases in elevation, gross domestic production per capita, and human population density and decreases in agricultural suitability were associated with accelerated habitat degradation. Our results suggest that human-induced LULC changes have expanded from already-exploited areas into relatively undisturbed areas, and that in wealthy countries in particular, degradation is related to rapid urbanization and increasing demand for agricultural products.

Comparing expedient and proactive approaches to the planning of protected area networks on Borneo

Protected areas are an important tool for wildlife conservation; however, research is increasingly revealing both biases and inadequacies in the global protected area network. One common criticism is that protected areas are frequently located in remote, high-elevation regions, which may face fewer threats compared to more accessible locations. To explore the conservation implications of this issue, we consider a thought experiment with seven different counterfactual scenarios for the Sunda clouded leopard’s conservation on Borneo. This allows us to examine two contrasting paradigms for conservation: “proactive conservation” which prioritises areas with high biodiversity and high risk of development, and “expedient conservation” which focusses on areas with the lowest development risk. We select clouded leopards as our focal species not only because of their emerging conservation importance, but also because, as top predators, they represent both keystone species and ambassadors for wider forest biodiversity. Furthermore, a published analysis of the likely impacts of forest loss in their habitat provides a benchmark for evaluating the modelled outcomes of alternative hypothetical conservation scenarios. We find that, across all metrics, expedient reserve design offered few benefits over the business-as-usual scenario, in contrast to the much greater conservation effectiveness of proactive protected area design. This paper sheds light on the challenging trade-offs between conservation goals and the competing land uses essential for the economic development and well-being of local communities.

Conservation Imperatives: securing the last unprotected terrestrial sites harboring irreplaceable biodiversity

Ambitious biodiversity goals to protect 30% or more of the Earth’s surface by 2030 (30x30) require strategic near-term targets. To define areas that must be protected to prevent the most likely and imminent extinctions, we propose Conservation Imperatives—16,825 unprotected sites spanning ~164 Mha of the terrestrial realm that harbor rare and threatened species. We estimate that protecting the Conservation Imperatives would cost approximately US$169 billion (90% probability: US$146—US$228 billion). Globally, 38% of the 16,825 sites are either adjacent to or within 2.5 km of an existing protected area, potentially reducing land acquisition and management costs. These sites should be prioritized for conservation action over the next 5 years as part of a broader strategy to expand the global protected area network. The expansion of global protected areas between 2018 and 2023 incorporated only 7% of sites harboring range-limited and threatened species, highlighting a renewed urgency to conserve these habitats. Permanently protecting only 0.74% of land found in the tropics, where Conservation Imperatives are concentrated, could prevent the majority of predicted near-term extinctions once adequately resourced. We estimate this cost to be from US$29 billion to US$46 billion per year over the next 5 years. Multiple approaches will be required to meet long-term protection goals: providing rights and titles to Indigenous Peoples and Local Communities (IPLCs) conserving traditional lands, government designation of new protected areas on federal and state lands, and land purchase or long-term leasing of privately held lands.

Current national nature reserves are insufficient to safeguard the long-term survival of birds and mammals in China

Enhancing the connectivity of protected areas is a global consensus for conserving biodiversity. Yet, it is unclear whether habitats are sufficiently connected within protected areas to efficiently protect wildlife populations for long-term survival. Here we show that, in general, China’s national nature reserves can effectively protect about one-half of the bird and mammal populations within protected areas for long-term survival. However, they can only protect 25% of birds and 13% of terrestrial mammals with high motility. Areas of low conservation effectiveness are highly overlapped with protected areas of small size and high intensity of human activity. Artificial landscapes (arable land and built-up land), which account for less than 2% area of the protected areas, disproportionately cause nearly 40% of the connectivity loss. The results suggest that maintaining high levels of functional connectivity within protected areas is as important as maintaining high connectivity in the national or global protected area networks. Our findings have important implications for improving the management of protected areas in China and beyond.

The impact of habitat loss and fragmentation on biodiversity in global protected areas

Protected areas (PAs) serve as effective means for biodiversity conservation but face threats from habitat loss and fragmentation. Current research on the impact of habitat loss or habitat fragmentation on biodiversity in PAs mostly focuses on individual PA or regional scales. At the global scale, the extent of habitat loss and fragmentation in PAs and their effects on biodiversity remains unclear. Therefore, we investigated the degree of habitat loss and fragmentation in global PAs from 2000 to 2020, analyzed the impact of habitat loss and fragmentation on biodiversity in PAs, identified hotspot PAs of severe habitat loss or fragmentation, and highlighted critically endangered species within these PAs. Our study reveals that, between 2000 and 2020, 19 % of global PAs experienced habitat loss, and 34 % experienced habitat fragmentation, with large PAs and South American tropical PAs exhibiting the most severe levels of habitat loss and fragmentation. The impact of habitat loss and fragmentation on biodiversity was most significant in small PAs and African tropical PAs. There are 10 global hotspot PAs of habitat loss or fragmentation, posing a serious threat to the survival of endangered species within PAs. Biodiversity conservation remains a prominent research focus globally, and the issues of habitat loss and fragmentation in PAs may impact the achievement of the COP15 biodiversity conservation goals. Therefore, this study aims to provide data support and scientific guidance for the management and development of global PAs.

Small Felids Coexist in Mixed-Use Landscape in the Bolivian Amazon.

In the face of global species loss, it is paramount to understand the effects of human activity on vulnerable species, particularly in highly diverse, complex systems. The Greater Madidi Landscape in the Bolivian Amazon includes several biodiverse protected areas that were created with the goal of sustaining healthy and diverse ecosystems while not impeding the livelihoods of local indigenous peoples. In this study, we sought to use camera trap data and single-species occupancy analysis to assess the impacts of different forms of human activity on four species of small felids: ocelots (Leopardus pardalis), margays (Leopardus wiedii), jaguarundi (Herpailurus yagouaroundi), and oncilla (Leopardus tigrinus). We modeled both human variables (proximity to indigenous communities, roads, and tourist camps) and non-human variables (terrain ruggedness, proximity to rivers, canopy height, prey availability, and large cat abundance). Margay occupancy was unaffected by any of these human variables and ocelots showed only weak evidence of being affected by tourism. Ocelots were particularly pervasive throughout the study area and were consistently estimated to have high occupancy probability. We did not obtain sufficient data on jaguarundi or oncilla to reliably model these effects. Our results indicate that small cats successfully coexist both with each other and with the surrounding human activity in this unique landscape, which serves as a model for global protected area management.

Global patterns and drivers of spatial autocorrelation in plant communities in protected areas

AbstractAimStochastic and deterministic (biotic factors such as intraspecies competition or abiotic factors) processes affect the spatial patterns of ecological communities. These processes can be quantitatively assessed based on spatial autocorrelation (SAC) parameters. However, the global patterns of SAC and their differences across vegetation types remain unknown. We aimed to (1) quantitatively assess the SAC global pattern in plant communities and their variation from 1990 to 2020 and (2) identify the key drivers of SAC in plant communities in protected areas (PAs).LocationGlobal.Time Period1990–2020.Major Taxa StudiedTerrestrial plants.MethodsUsing normalized difference vegetation index data extracted from remote sensing datasets, we calculated the SAC parameters, including the Nugget, Partial Sill (PSill), and Sill, in 147 samples from 49 PAs in 1990, 2000, 2010, and 2020. The random forest model was employed to identify the drivers among 10 annual and 120 monthly climatic variables.ResultsThe SAC patterns of plant communities in global PAs differed across vegetation types. It reached the highest in grasslands and evergreen needleleaved forests, mainly explained by annual energy metrics, and the lowest in tropical evergreen rain forests around equator and boreal coniferous forests near the Arctic Circle. From 1990 to 2020, the Nugget, PSill, and Sill decreased by 92.36%, 58.36%, and 60.61%, respectively, indicating biological homogeneity. Monthly climatic variables explain SAC variations better than annual ones.Main ConclusionsFrom 1990 to 2020, the SAC parameters decreased sharply across vegetation types, indicating an obvious biologically homogenous trend that was mainly driven by monthly climatic variation, vary across sites and vegetation types. Our results highlight the need to assess the SAC in different vegetation types separately to understand the shifts of global plant communities under climate change.

Expanding protected areas: a case for repairing intergenerational social capital rather than taking the path of least resistance

With many international entities pushing for the protection of 30% of terrestrial and marine habitat by 2030 through the 30x30 global initiative, the expansion of protected areas (PA) will inevitably interface with populations carrying lived experiences of PA management as well as their community’s collective memory of how the promises and outcomes of previous PA establishments materialized. One community recently experiencing a government’s desire to expand a PA is the Ngöbe Indigenous community of Salt Creek, located in and around the Bastimentos Island National Marine Park in Bocas del Toro, Panama. This qualitative case study applies an intergenerational social capital lens to demonstrate that time does not heal past grievances with park administration as broken social capital is a type of intergenerational trauma. It is suggested that repairing social capital is vital to achieving future sustainable tourism and global PA targets but will be a long and intentional process to overcome the collective memory of broken promises. While governments may find it expedient to expand PAs in areas with less resistance, we suggest the investment in repairing social capital will likely lead to better social and environmental outcomes and better align with the ethos of sustainable tourism and collaborative governance.

Prioritizing global tall forests toward the 30 × 30 goals.

The Global Deal for Nature sets an ambitious goal to protect 30% of Earth's land and ocean by 2030. The 30 × 30 initiative is a way to allocate conservation resources and extend protection to conserve vulnerable and underprotected ecosystems while reducing carbon emissions to combat climate change. However, most prioritization methods for identifying high-value conservation areas are based on thematic attributes and do not consider vertical habitat structure. Global tall forests represent a rare vertical habitat structure that harbors high species richness in various taxonomic groups and is associated with large amounts of aboveground biomass. Global tall forests should be prioritized when planning global protected areas toward reaching the 30 × 30 goals. We examined the spatial distribution of global tall forests based on the Global Canopy Height 2020 product. We defined global tall forests as areas with the average canopy height above 3 thresholds (20, 25, and 30m). We quantified the spatial distribution and protection level of global tall forests in high-protection zones, where the 30 × 30 goals are being met or are within reach, and low-protection zones, where there is a low chance of reaching 30 × 30 goals. We quantified the protection level by computing the percentage of global tall forest area protected based on the 2017 World Database on Protected Areas. We also determined the global extent and protection level of undisturbed, mature, tall forests based on the 2020 Global Intact Forest Landscapes mask. In most cases, the percentage of protection decreased as forest height reached the top strata. In the low-protection zones, <30% of forests were protected in almost all tall forest strata. In countries such as Brazil, tall forests had a higher percentage of protection (consistently >30%) compared to forests of lower height, presenting a more effective conservation model than in countries such as the United States, where forest protection was almost uniformly <30% across height strata. Our results show an urgent need to target forest conservation in the greatest height strata, particularly in high-protection areas, where most global tall forests are found. Vegetation vertical structure can inform the decision-making process toward the 30 × 30 goals because it can be used to identify areas of high conservation value for biodiversity protection which also contribute to carbon sequestration.

Landscape-scale benefits of protected areas for tropical biodiversity.

The United Nations recently agreed to major expansions of global protected areas (PAs) to slow biodiversity declines1. However, although reserves often reduce habitat loss, their efficacy at preserving animal diversity and their influence on biodiversity in surrounding unprotected areas remain unclear2-5. Unregulated hunting can empty PAs of large animals6, illegal tree felling can degrade habitat quality7, and parks can simply displace disturbances such as logging and hunting to unprotected areas of the landscape8 (a phenomenon called leakage). Alternatively, well-functioning PAs could enhance animal diversity within reserves as well as in nearby unprotected sites9 (an effect called spillover). Here we test whether PAs across mega-diverse Southeast Asia contribute to vertebrate conservation inside and outside their boundaries. Reserves increased all facets of bird diversity. Large reserves were also associated with substantially enhanced mammal diversity in the adjacent unprotected landscape. Rather than PAs generating leakage that deteriorated ecological conditions elsewhere, our results are consistent with PAs inducing spillover that benefits biodiversity in surrounding areas. These findings support the United Nations goal of achieving 30% PA coverage by 2030 by demonstrating that PAs are associated with higher vertebrate diversity both inside their boundaries and in the broader landscape.

Participatory monitoring drives biodiversity knowledge in global protected areas

Protected areas are central in strategies to conserve biodiversity. Effective area-based conservation relies on biodiversity data, but the current biodiversity knowledge base is insufficient and limited by geographic and taxonomic biases. Public participation in biodiversity monitoring such as via community-based monitoring or citizen science increases data collection but also contributes to replicating these biases or introducing new ones. Here we examine how participatory monitoring has changed the landscape of open biodiversity knowledge in protected areas using biodiversity data shared on the Global Biodiversity Information Facility. We highlight a growing dominance of participatory monitoring within protected areas. We find that patterns in geographic, taxonomic, and threatened species coverage differ from non-participatory monitoring, suggesting complementarity between the two approaches. The relative contribution of participatory monitoring varies with characteristics of both protected areas and monitoring programs. We synthesize these results to derive context-specific strategies for extending the conservation impact of participatory biodiversity monitoring.

Gaps and weaknesses in the global protected area network for safeguarding at-risk species.

Protected areas are essential to biodiversity conservation. Creating new parks can protect larger populations and more species, yet strengthening existing parks, particularly those vulnerable to harmful human activities, is a critical but underappreciated step for safeguarding at-risk species. Here, we model the area of habitat that terrestrial mammals, amphibians, and birds have within park networks and their vulnerability to current downgrading, downsizing, or degazettement events and future land-use change. We find that roughly 70% of species analyzed have scant representation in parks, or occur within parks that are affected by shifts in formal legal protections or are vulnerable to increased human pressures. Our results also show that expanding and strengthening park networks across just 1% of the world's land area could preserve irreplaceable habitats of 1191 species that are particularly vulnerable to extinction.

The effectiveness of global protected areas for climate change mitigation

Forests play a critical role in stabilizing Earth’s climate. Establishing protected areas (PAs) represents one approach to forest conservation, but PAs were rarely created to mitigate climate change. The global impact of PAs on the carbon cycle has not previously been quantified due to a lack of accurate global-scale carbon stock maps. Here we used ~412 million lidar samples from NASA’s GEDI mission to estimate a total PA aboveground carbon (C) stock of 61.43 Gt (+/− 0.31), 26% of all mapped terrestrial woody C. Of this total, 9.65 + /− 0.88 Gt of additional carbon was attributed to PA status. These higher C stocks are primarily from avoided emissions from deforestation and degradation in PAs compared to unprotected forests. This total is roughly equivalent to one year of annual global fossil fuel emissions. These results underscore the importance of conservation of high biomass forests for avoiding carbon emissions and preserving future sequestration.

Anthropogenic vulnerability assessment of global terrestrial protected areas with a new framework

Protected areas (PAs) are the major conservation tool for ecosystem conservation, but function unequally in mitigating human pressures in practice. Assessing PA vulnerability caused by human pressures and its association with socioeconomic and PA characteristic factors is vital for improving conservation effectiveness and the post-2020 PA expansion. Here, using a new framework integrating the intensity and temporal changes of human pressures in PAs and their matched unprotected areas, we categorize global terrestrial PAs into four anthropogenic vulnerability levels: high (11.7 %), moderate (18.6 %) and low (21.9 %) vulnerability and wilderness (47.8 %). We find significant variations in the anthropogenic vulnerability of PAs between countries, continents, and IUCN categories. Europe has the highest proportion of high-vulnerability PAs (ca. 19.7 % of protected areas in Europe), while South America and Oceania have the highest proportions of low-vulnerability PAs and wilderness PAs, respectively (33.2 % and 75.0 % respectively). The vulnerability of PAs is not significantly associated with socioeconomic factors at the country level, which might reflect the trade-offs between positive and negative outcomes of development. With a new framework that integrated four significant factors for anthropogenic vulnerability assessment, this study demonstrates that global PAs have different anthropogenic vulnerability levels and suggest that some PAs function effectively in mitigating human pressures despite currently intense human pressures within them. Our results also suggest that future evaluations on the conservation status should pay attention not only to PA coverage but also to the anthropogenic vulnerability levels within PAs to achieve higher conservation effectiveness.

Protected area planning to conserve biodiversity in an uncertain future.

Protected areas are a key instrument for conservation. Despite this, they are vulnerable to risks associated with weak governance, land-use intensification, and climate change. We used a novel hierarchical optimization approach to identify priority areas for expanding the global protected area system that explicitly accounted for such risks while maximizing protection of all known terrestrial vertebrate species. To incorporate risk categories, we built on the minimum set problem, where the objective is to reach species distribution protection targets while accounting for 1 constraint, such as land cost or area. We expanded this approach to include multiple objectives accounting for risk in the problem formulation by treating each risk layer as a separate objective in the problem formulation. Reducing exposure to these risks required expanding the area of the global protected area system by 1.6% while still meeting conservation targets. Incorporating risks from weak governance drove the greatest changes in spatial priorities for protection, and incorporating risks from climate change required the largest increase (2.52%) in global protected area. Conserving wide-ranging species required countries with relatively strong governance to protect more land when they bordered nations with comparatively weak governance. Our results underscore the need for cross-jurisdictional coordination and demonstrate how risk can be efficiently incorporated into conservation planning. Planeación de las áreas protegidas para conservar la biodiversidad en un futuro incierto.

Protected areas not likely to serve as steppingstones for species undergoing climate-induced range shifts.

Species across the planet are shifting their ranges to track suitable climate conditions in response to climate change. Given that protected areas have higher quality habitat and often harbor higher levels of biodiversity compared to unprotected lands, it is often assumed that protected areas can serve as steppingstones for species undergoing climate-induced range shifts. However, there are several factors that may impede successful range shifts among protected areas, including the distance that must be traveled, unfavorable human land uses and climate conditions along potential movement routes, and lack of analogous climates. Through a species-agnostic lens, we evaluate these factors across the global terrestrial protected area network as measures of climate connectivity, which is defined as the ability of a landscape to facilitate or impede climate-induced movement. We found that over half of protected land area and two-thirds of the number of protected units across the globe are at risk of climate connectivity failure, casting doubt on whether many species can successfully undergo climate-induced range shifts among protected areas. Consequently, protected areas are unlikely to serve as steppingstones for a large number of species under a warming climate. As species disappear from protected areas without commensurate immigration of species suited to the emerging climate (due to climate connectivity failure), many protected areas may be left with a depauperate suite of species under climate change. Our findings are highly relevant given recent pledges to conserve 30% of the planet by 2030 (30 × 30), underscore the need for innovative land management strategies that allow for species range shifts, and suggest that assisted colonization may be necessary to promote species that are adapted to the emerging climate.

Half-millennium evidence suggests that extinction debts of global vertebrates started in the Second Industrial Revolution

Extinction debt describes the time-lagged process of species extinction, which usually requires dozens to hundreds of years to be paid off. However, due to the lack of long-term habitat data, it is indeterminate how strong the signal of extinction debts is at the global scale and when the debts started. Here, by compiling the geographical distributions of 6120 reptiles, 6047 amphibians, and 4278 mammals and correlating them with annual forest cover data from 1500 to 1992, we show that the beginning of the Second Industrial Revolution (the mid-19th century) was the earliest signal of cumulative extinction debts for global forest-dwelling vertebrate groups. More importantly, the impact of global protected areas on mitigating accumulated vertebrate extinction debt is not as immediate as that of mitigating reduced forest cover but rather suffers from pronounced time-lag effects. As the disequilibrium of vertebrate richness and forested habitat is currently taking place, preventive actions should be taken to promote a well-balanced status among forest restoration, protected areas, and biodiversity conservation to slow the accumulating debts for global forest-dwelling vertebrates.

Conservation gaps for Neotropical vipers: Mismatches between protected areas, species richness and evolutionary distinctiveness

The continuous decline in biodiversity despite global efforts to create new protected areas calls into question the effectiveness of these areas in conserving biodiversity. Numerous habitats are absent from the global protected area network, and certain taxonomic groups are not being included in conservation planning. Here, we analyzed the level of protection that the current protected area system provides to viper species in the Neotropical region through a conservation gap analysis. We used distribution size and degree of threat to set species-specific conservation goals for 123 viper species in the form of minimum percentage of their distribution that should be covered by protected areas, and assessed the level of protection provided for each species by overlapping their distribution with protected areas of strict protection. Furthermore, using species richness and evolutionary distinctiveness as priority indicators, we conducted a spatial association analysis to detect areas of special concern. We found that most viper species have <1/4 of their distribution covered by protected areas, including 22 threatened species. Also, the large majority of cells containing high levels of species richness were significantly absent from protected areas, while evolutionary distinctiveness was particularly unprotected in regions with relatively low species richness, like northern Mexico and the Argentinian dry Chaco. Our results provide further evidence that vipers are largely being excluded from conservation planning, leaving them exposed to serious threats that can lead to population decline and ultimately extinction.