Humans have altered terrestrial ecosystems for millennia 1, yet wilderness areas still remain as vital refugia where natural ecological and evolutionary processes operate with minimal human ...disturbance 2–4, underpinning key regional- and planetary-scale functions 5, 6. Despite the myriad values of wilderness areas—as critical strongholds for endangered biodiversity 7, for carbon storage and sequestration 8, for buffering and regulating local climates 9, and for supporting many of the world’s most politically and economically marginalized communities 10—they are almost entirely ignored in multilateral environmental agreements. This is because they are assumed to be relatively free from threatening processes and therefore are not a priority for conservation efforts 11, 12. Here we challenge this assertion using new comparable maps of global wilderness following methods established in the original “last of the wild” analysis 13 to examine the change in extent since the early 1990s. We demonstrate alarming losses comprising one-tenth (3.3 million km2) of global wilderness areas over the last two decades, particularly in the Amazon (30%) and central Africa (14%). We assess increases in the protection of wilderness over the same time frame and show that these efforts are failing to keep pace with the rate of wilderness loss, which is nearly double the rate of protection. Our findings underscore an immediate need for international policies to recognize the vital values of wilderness and the unprecedented threats they face and to underscore urgent large-scale, multifaceted actions needed to maintain them.
•Globally important wilderness areas are ignored in conservation policy•We reveal that extensive losses of wilderness have occurred in the last two decades•Efforts aimed at protecting wilderness areas are failing to keep pace with its loss•International policy must recognize the actions needed to maintain wilderness areas
Watson et al. discover that the Earth’s wilderness areas are disappearing at a rate that has significantly outpaced their protection over the past two decades. Despite their ecological, climatological, and cultural importance, wilderness areas are ignored in multilateral environmental agreements, highlighting the need for urgent global policy attention.
Human pressures on the environment are changing spatially and temporally, with profound implications for the planet's biodiversity and human economies. Here we use recently available data on ...infrastructure, land cover and human access into natural areas to construct a globally standardized measure of the cumulative human footprint on the terrestrial environment at 1 km(2) resolution from 1993 to 2009. We note that while the human population has increased by 23% and the world economy has grown 153%, the human footprint has increased by just 9%. Still, 75% the planet's land surface is experiencing measurable human pressures. Moreover, pressures are perversely intense, widespread and rapidly intensifying in places with high biodiversity. Encouragingly, we discover decreases in environmental pressures in the wealthiest countries and those with strong control of corruption. Clearly the human footprint on Earth is changing, yet there are still opportunities for conservation gains.
From Bottleneck to Breakthrough SANDERSON, ERIC W.; WALSTON, JOSEPH; ROBINSON, JOHN G.
Bioscience,
06/2018, Letnik:
68, Številka:
6
Journal Article
Recenzirano
Odprti dostop
For the first time in the Anthropocene, the global demographic and economic trends that have resulted in unprecedented destruction of the environment are now creating the necessary conditions for a ...possible renaissance of nature. Drawing reasonable inferences from current patterns, we can predict that 100 years from now, the Earth could be inhabited by between 6 and 8 billion people, with very few remaining in extreme poverty, most living in towns and cities, and nearly all participating in a technologically driven, interconnected market economy. Building on the scholarship of others in demography, economics, sociology, and conservation biology, here, we articulate a theory of social– environmental change that describes the simultaneous and interacting effects of urban lifestyles on fertility, poverty alleviation, and ideation. By recognizing the shifting dynamics of these macrodrivers, conservation practice has the potential to transform itself from a discipline managing declines (“bottleneck”) to a transformative movement of recovery (“breakthrough”).
Remotely-sensed and bottom-up survey information were compiled on eight variables measuring the direct and indirect human pressures on the environment globally in 1993 and 2009. This represents not ...only the most current information of its type, but also the first temporally-consistent set of Human Footprint maps. Data on human pressures were acquired or developed for: 1) built environments, 2) population density, 3) electric infrastructure, 4) crop lands, 5) pasture lands, 6) roads, 7) railways, and 8) navigable waterways. Pressures were then overlaid to create the standardized Human Footprint maps for all non-Antarctic land areas. A validation analysis using scored pressures from 3114×1 km(2) random sample plots revealed strong agreement with the Human Footprint maps. We anticipate that the Human Footprint maps will find a range of uses as proxies for human disturbance of natural systems. The updated maps should provide an increased understanding of the human pressures that drive macro-ecological patterns, as well as for tracking environmental change and informing conservation science and application.
Most conservation planning to date has focused on protecting today's biodiversity with the assumption that it will be tomorrow's biodiversity. However, modern climate change has already resulted in ...distributional shifts of some species and is projected to result in many more shifts in the coming decades. As species redistribute and biotic communities reorganize, conservation plans based on current patterns of biodiversity may fail to adequately protect species in the future. One approach for addressing this issue is to focus on conserving a range of abiotic conditions in the conservation‐planning process. By doing so, it may be possible to conserve an abiotically diverse “stage” upon which evolution will play out and support many actors (biodiversity). We reviewed the fundamental underpinnings of the concept of conserving the abiotic stage, starting with the early observations of von Humboldt, who mapped the concordance of abiotic conditions and vegetation, and progressing to the concept of the ecological niche. We discuss challenges posed by issues of spatial and temporal scale, the role of biotic drivers of species distributions, and latitudinal and topographic variation in relationships between climate and landform. For example, abiotic conditions are not static, but change through time—albeit at different and often relatively slow rates. In some places, biotic interactions play a substantial role in structuring patterns of biodiversity, meaning that patterns of biodiversity may be less tightly linked to the abiotic stage. Furthermore, abiotic drivers of biodiversity can change with latitude and topographic position, meaning that the abiotic stage may need to be defined differently in different places. We conclude that protecting a diversity of abiotic conditions will likely best conserve biodiversity into the future in places where abiotic drivers of species distributions are strong relative to biotic drivers, where the diversity of abiotic settings will be conserved through time, and where connectivity allows for movement among areas providing different abiotic conditions.
The extinction of a species is inevitably preceded by the extirpation of a series of local populations. Ecological theory predicts that vulnerability to extirpation varies between populations and is ...ultimately linked to environmental heterogeneity. If populations of a species are present in multiple regions separated by abrupt changes in environmental conditions (e.g., biomes), spatial variation in vulnerability to extirpation may be closely linked to the distribution of these regions. In the absence of abrupt shifts in environmental conditions, populations at the edge of a species' range should have low growth rates and be more vulnerable to extirpation, whereas populations located in the core of the species' range should be exposed to more favorable environmental conditions, have higher growth rates, and be less vulnerable. Here, we ask whether the distribution of biomes or range position better reflects spatial variation in vulnerability for 43 mammal species distributed through four continents. We control for the distribution of human threats and quantify the importance of protected areas in population persistence. We conclude that the distribution of biomes is a better predictor of vulnerability than position in the geographic range. We also find that core populations are less vulnerable than edge populations (after controlling for threats levels and protected areas). Protected areas are important for the persistence of most species we studied. By providing a measure of vulnerability linked directly to the distribution of threats, our results offer insights for scaling up from species vulnerability to extinction risk.
The human footprint is a global map of human influence on the land surface, which suggests that human beings are stewards of nature, whether people acknowledge it or not. The technique for mapping ...the human footprint grows out of a recent tradition of wilderness mapping.
We explore the issues relevant to those types of ecosystems containing new combinations of species that arise through human action, environmental change, and the impacts of the deliberate and ...inadvertent introduction of species from other regions. Novel ecosystems (also termed 'emerging ecosystems) result when species occur in combinations and relative abundances that have not occurred previously within a given biome. Key characteristics are novelty, in the form of new species combinations and the potential for changes in ecosystem functioning, and human agency, in that these ecosystems are the result of deliberate or inadvertent human action. As more of the Earth becomes transformed by human actions, novel ecosystems increase in importance, but are relatively little studied. Either the degradation or invasion of native or 'wild' ecosystems or the abandonment of intensively managed systems can result in the formation of these novel systems. Important considerations are whether these new systems are persistent and what values they may have. It is likely that it may be very difficult or costly to return such systems to their previous state, and hence consideration needs to be given to developing appropriate management goals and approaches.
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