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1.
Volunteers are behind much of the ecological restoration work done in Australia. Private landholders, environmental nongovernment organisations (ENGOs) and community groups all donate time and money to much‐needed restoration and revegetation efforts. Biodiversity offsetting has emerged as a potential source of financial support for such work. We consider the question: should it matter to practitioners of restoration, particularly landholders and volunteers, how it is financed? We argue it should, because when offsets fund restoration work, the net environmental outcome is usually intended to be neutral – not an environmental gain. This is often not clear, because only the localised environmental gain is seen by the restoration practitioner, not the associated loss. For mandated offsets, the restoration work is required to occur regardless of whether the volunteer contributes to it or not, so their contribution only replaces work that would otherwise be done by a commercial provider. We contend that informed involvement in offset provision requires full disclosure, particularly to volunteers and landholders. Unfortunately, however, such transparency does not always occur. We acknowledge that there are valid reasons why well‐informed practitioners might willingly subsidise offset provision, but they might equally choose not to. Furthermore, offsets are intended to cover the full cost of biodiversity damage, creating a disincentive for damage by developers. Yet, subsidies from offset providers work against sending market signals that reflect the true replacement cost of biodiversity. We recommend that all ENGOs, developers, offset funders and brokers commit to transparency, particularly to landholders, donors and volunteers, about the environmental impact that is to be offset and the fact that their involvement generates no additional environmental benefit, as the offset is a condition of approval for a permitted loss, much like the rehabilitation of a mine site. Providing restoration services in partnership with industry may be something that landholders, volunteers and ENGOs are happy to support. But this must be decided consciously, not through unnoticed incremental changes that contradict some volunteers’ values or donors’ understanding of an organisation's mission.  相似文献   

2.
Offsets for land clearing: No net loss or the tail wagging the dog?   总被引:3,自引:0,他引:3  
Summary   Offsets (also known as mitigation banks, compensatory habitat, set-asides) is a policy instrument recently introduced in several States in Australia to permit some land clearing while striving for no net loss in the extent and condition of native vegetation overall. Offsetting is criticized with respect to the amount of gain required to compensate for losses from clearing, the equivalence of losses and gains, the time lag between losses and gains and a poor record of compliance. Despite these criticisms, we conclude that offsetting is a useful policy instrument while governments continue to permit some clearing of native vegetation. However, offsets will only contribute to no net loss if (i) clearing is restricted to vegetation that is simplified enough so that its functions can be restored elsewhere with confidence or clearing is restricted to vegetation that is unlikely to persist and is not practicable to restore irrespective of clearing; (ii) any temporary loss in habitat between clearing and the maturation of an offset, or differences between the habitat lost from clearing and gained through an offset, does not represent significant risk to a species, population or ecosystem process; (iii) there will be gains of sufficient magnitude on the offset site to compensate for losses from clearing; (iv) best practice adaptive management is applied to offsets; (v) offsets are in place for at least the same duration as the impacts from clearing; and (vi) there is adequate compliance. Land clearing with offsets outside these parameters is inconsistent with 'no net loss'.  相似文献   

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Most climate mitigation scenarios involve negative emissions, especially those that aim to limit global temperature increase to 2°C or less. However, the carbon uptake potential in land‐based climate change mitigation efforts is highly uncertain. Here, we address this uncertainty by using two land‐based mitigation scenarios from two land‐use models (IMAGE and MAgPIE) as input to four dynamic global vegetation models (DGVMs; LPJ‐GUESS, ORCHIDEE, JULES, LPJmL). Each of the four combinations of land‐use models and mitigation scenarios aimed for a cumulative carbon uptake of ~130 GtC by the end of the century, achieved either via the cultivation of bioenergy crops combined with carbon capture and storage (BECCS) or avoided deforestation and afforestation (ADAFF). Results suggest large uncertainty in simulated future land demand and carbon uptake rates, depending on the assumptions related to land use and land management in the models. Total cumulative carbon uptake in the DGVMs is highly variable across mitigation scenarios, ranging between 19 and 130 GtC by year 2099. Only one out of the 16 combinations of mitigation scenarios and DGVMs achieves an equivalent or higher carbon uptake than achieved in the land‐use models. The large differences in carbon uptake between the DGVMs and their discrepancy against the carbon uptake in IMAGE and MAgPIE are mainly due to different model assumptions regarding bioenergy crop yields and due to the simulation of soil carbon response to land‐use change. Differences between land‐use models and DGVMs regarding forest biomass and the rate of forest regrowth also have an impact, albeit smaller, on the results. Given the low confidence in simulated carbon uptake for a given land‐based mitigation scenario, and that negative emissions simulated by the DGVMs are typically lower than assumed in scenarios consistent with the 2°C target, relying on negative emissions to mitigate climate change is a highly uncertain strategy.  相似文献   

4.
  总被引:1,自引:0,他引:1  
Edge effect is the modification of ecological patterns and processes that occur around the edge of two adjacent ecosystems. Depending on their aim, edge effect studies have adopted one of the following methodological approaches: (1) the one‐sided approach—which studies ecological patterns and processes from an edge to the interior of just one of the habitats and (2) the two‐sided approach—which studies ecological patterns and processes across the whole gradient from the interior of one habitat to the interior of the other habitat, passing through the edge zone. A database containing information on 317 published papers revealed that both methodological approaches were equally used until the end of the 1980s. During the 1990s, the question of how organisms respond to habitat destruction and fragmentation led to an abrupt increase in the number of one‐sided studies. Recently, however, two‐sided studies have become more frequent. In this review, we put forth theoretical arguments of why the two‐sided edge effect approach can produce a broader understanding of the ecological processes associated with edges. We highlight that two‐sided edge effect studies must become more experimental and predictive, focusing on the factors controlling edge dynamics. Finally, we point out that two‐sided edge effect studies have the potential to create a positive research agenda for the restoration and expansion of endangered ecosystems.  相似文献   

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This article examines four periods of environmental policy-making in the Amazon region of Brazil. It specifically analyses the role of pro-environment and pro-development policy networks in affecting policy design and implementation. It argues that the efforts of environmentalist networks trying to advocate or block relative developmentalist policies in the Amazon depend on three critical factors-whether they are able to attract the support of elites (or at least block their developmentalist policy initiatives); the type and level of international support they have; and the organizational and financial resources that they are able to mobilize. In analysing the four periods, this article finds that while international influences and resources have been substantial in enabling environmentalist networks to flourish and influence the policy, their effectiveness has been nearly always outweighed by Brazilian developmentalist interests. The outcome in each phase has been a different form of stalemate on environmental protection, and the deforestation continued each time, albeit at slower rates. These findings suggest that the key for significantly lower rates of deforestation on the Amazon may be in the ability of pro-environment networks to neutralize opposition by creating an incentive structure that 'compensates' potential losers of policies that promote conservation.  相似文献   

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Given high‐level commitments to reducing the rate of biodiversity loss by 2010, there is a pressing need to develop simple and practical indicators to monitor progress. In this context, a biodiversity intactness index (BII) was recently proposed, which provides an overall indicator suitable for policy makers. The index links data on land use with expert assessments of how this impacts the population densities of well‐understood taxonomic groups to estimate current population sizes relative to premodern times. However, when calculated for southern Africa, the resulting BII of 84% suggests a far more positive picture of the state of wild nature than do other large‐scale estimates. Here, we argue that this discrepancy is in part an artefact of the coarseness of the land degradation data used to calculate the BII, and that the overall BII for southern Africa is probably much lower than 84%. In particular, based on two relatively inexpensive, ground‐truthed studies of areas not generally regarded as exceptional in terms of their degradation status, we demonstrate that Scholes and Biggs might have seriously underestimated the extent of land degradation. These differences have substantial bearing on BII scores. Urgent attention should be given to the further development of cost‐effective ground‐truthing methods for quantifying the extent of land degradation in order to provide reliable estimates of biodiversity loss, both in southern Africa and more widely.  相似文献   

10.
    
Habitat restoration is vital to ameliorate the effects of anthropogenic disturbances on animal habitats. We reviewed the peer‐reviewed literature to examine where and how habitat restoration is undertaken. Our aim was to identify key knowledge gaps as well as research and monitoring needs that can inform future restoration actions. We found: (1) marine and terrestrial actions focus most commonly on restoring vegetation, and freshwater actions focus on restoring the in‐channel habitat; (2) arthropods are the most common focal group; (3) there is often no collection of pre‐restoration data, so certainty in attributing environmental changes to restoration actions is limited; and (4) population and community measures are most commonly used in monitoring programs, which only show if animals are present at restored sites and not whether they are able to grow, survive, and reproduce. We highlight three important considerations for future restoration actions. First, more integration of knowledge among freshwater, marine, and terrestrial systems will help us to understand how, and why, restoration outcomes might vary in different contexts. Second, where possible, restoration projects should be assessed using before‐after‐control‐impact designs, which will provide the strongest evidence if desired restoration responses occur. Third, if the goal of restoration is to develop self‐sustaining breeding populations of target animals, then measures of fitness (i.e. breeding, survival) should be collected. These recommendations will hopefully help guide more effective restoration practices and monitoring in the future.  相似文献   

11.
选取黄土高原区黑岱沟露天煤矿不同复垦阶段(1995~2010年)样地4块,以原地貌样地为对照,以时空替代的方法,对煤矿复垦地的植物群落的功能群结构及生物多样性进行研究.结果表明:(1)随着复垦时间的延长,植物群落功能群组成以多年生禾草和多年生杂类草为主,其累积优势度均呈现增加的趋势,而一、二年生草本的累积优势度减小;复垦初期,群落功能群单一、组成种类贫乏,多为一、二年生植物;复垦后期,羊草及冰草逐步出现,复垦地最终形成以克氏针茅、本氏针茅、赖草及糙隐子草为主的植物群落.(2)复垦过程中,中生植物及中旱生植物所占比例逐步增加,而旱生植物比例逐步减少;多年生禾草及多年生杂类草生物量随着复垦时间的增加而递增,而一、二年生草本植物生物量递减;群落总生物量呈先急剧增加、又急剧减少、后缓慢增加的规律.(3)群落的Shan-non-Wiener多样性指数(H)、Patrick丰富度指数(Pa)及Pielou均匀度指数(JP)随着复垦时间延长而增加.  相似文献   

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In 2017, Sri Lanka set a goal to increase its forest cover to 32% by 2030 (Sri Lanka UN-REDD, 2017). However, on November 4th 2020, the government published circular MWFC/1/2020 revoking the circular 5/2001 of August 10th 2001, one of the country's most crucial forest protection directives. The revocation of the 5/2001 circular could severely hamper this target, posing a threat of deforestation to a variety of ecosystems which are not part of any formally designated protected areas (PA) in Sri Lanka, also known as Other State Forests. This includes forested areas adjoining PAs which are crucial for habitat connectivity and standalone state forest lands. Such a retrograde step could have potentially catastrophic ramifications on Sri Lanka's declining forest cover. It would also severely weaken the country's commitments to inter alia, the UNREDD Programme, Kyoto protocol and CBD. We therefore call on the Government of Sri Lanka to urgently reconsider and reverse this decision.  相似文献   

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Regular contact with nature provides multiple health benefits for people, but biodiversity is declining fast in an urbanizing world. Biodiversity offsets are implemented to compensate for the negative residual impacts of economic development projects on biodiversity, but the impacts on people who stand to lose biodiversity from their local environment are rarely considered. Offsetting typically involves creating, restoring or protecting biodiversity values at a specified site that can be located some distance away from the development site. In this article, we explore whether any relocation of nature is occurring due to development and offsets in Western Australia (WA); a jurisdiction with one of the world's few spatially referenced and comprehensive public offset registers. We analyzed data from 158 projects within the WA Environmental Offsets Register. We compared the location of development sites within 50 km (the urban and peri urban zone) and 500 km (~one day's drive) of the central business district (CBD) of Perth with the associated offset sites. The development and offset process together can be considered to contribute to a loss of urban nature as the offset sites tended to be further away from urban areas than the associated development sites. The offset sites were also located in significantly lower population density areas. However, offsets increased the publicly accessible land area by changing land ownership and creating amenity benefit by improving nature values on public land. Nevertheless, it is unclear to what extent relocation of nature further from people is balanced by increased public access to nature. In order to maintain nature connectedness, ecosystem service delivery and environmental justice in cities, we argue offset policies should require spatial proximity between impact and offset sites.  相似文献   

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In the USA, Species Conservation Banking is a prominent example of compensatory biodiversity impact mitigation, with an annual market value estimated at US$354.2 million. Species Conservation Banking represents a useful case study of a well-established program that can provide empirical insights into the practicalities of implementing quantitative compensatory biodiversity mitigation on-the-ground. Using semi-structured key-informant interviews structured around well-established technical challenges to compensatory mitigation, this study aimed to understand (i) how and why these challenges are or are not addressed in practice; and (ii) how these challenges relate to practical challenges faced by conservation banking stakeholders on-the-ground. Challenges identified included: (i) defining trading currencies and equivalence, (ii) regulatory and political uncertainty, (iii) regulatory agency capacity, will and knowledge, (iv) lack of policies, standards, and competition with other mitigation mechanisms, (v) long-term uncertainty/longevity, and (vi) lack of species knowledge and data transparency. These challenges are numerous, diverse, interlinked and transdisciplinary, and collectively inhibit the ability of practitioners to resolve underlying technical challenges—a finding likely applicable to related biodiversity offset programs. To help address challenges and navigate this complexity, we formulate several recommendations for conservation banking stakeholders to improve the chances of beneficial biodiversity outcomes being achieved.  相似文献   

15.
    
Aims Australia is among one of the world's wealthiest nations; yet, its relatively small human population (22.5 million) has been responsible for extensive deforestation and forest degradation since European settlement in the late 18th century. Despite most (~75%) of Australia's 7.6 million-km 2 area being covered in inhospitable deserts or arid lands generally unsuitable to forest growth, the coastal periphery has witnessed a rapid decline in forest cover and quality, especially over the last 60 years. Here I document the rates of forest loss and degradation in Australia based on a thorough review of existing literature and unpublished data.Important findings Overall, Australia has lost nearly 40% of its forests, but much of the remaining native vegetation is highly fragmented. As European colonists expanded in the late 18th and the early 19th centuries, deforestation occurred mainly on the most fertile soils nearest to the coast. In the 1950s, southwestern Western Australia was largely cleared for wheat production, subsequently leading to its designation as a Global Biodiversity Hotspot given its high number of endemic plant species and rapid clearing rates. Since the 1970s, the greatest rates of forest clearance have been in southeastern Queensland and northern New South Wales, although Victoria is the most cleared state. Today, degradation is occurring in the largely forested tropical north due to rapidly expanding invasive weed species and altered fire regimes. Without clear policies to regenerate degraded forests and protect existing tracts at a massive scale, Australia stands to lose a large proportion of its remaining endemic biodiversity. The most important implications of the degree to which Australian forests have disappeared or been degraded are that management must emphasize the maintenance of existing primary forest patches, as well as focus on the regeneration of matrix areas between fragments to increase native habitat area, connectivity and ecosystem functions.  相似文献   

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Anthropogenic activities have altered approximately two-thirds of the Earth's land surface. Urbanization, industrialization, agricultural expansion, and deforestation are increasingly impacting the terrestrial landscapes, leading to shifts of areas in artificial surface (i.e., humanmade), cropland, pasture, forest, and barren land. Land use patterns and associated greenhouse gas (GHG) emissions play a critical role in global climate change. Here we synthesized 29 years of global historical data and demonstrated how land use impacts global GHG emissions using structural equation modeling. We then obtained predictive estimates of future global GHG emissions using a deep learning model. Our results show that, from 1992 to 2020, the global terrestrial areas covered by artificial surface and cropland have expanded by 133% and 6% because of population growth and socioeconomic development, resulting in 4.0% and 3.8% of declines in pasture and forest areas, respectively. Land use was significantly associated with GHG emissions (p < 0.05). Artificial surface dominates global GHG emissions, followed by cropland, pasture, and barren land. The increase in artificial surfaces has driven up global GHG emissions through the increase in energy consumption. Conversely, improved agricultural management practices have contributed to mitigating agricultural GHG emissions. Forest, on the other hand, serves as a sink of GHG. In total, global GHG emissions increased from 31 to 46 GtCO2eq from 1992 to 2020. Looking ahead, if current trends in global land use continue at the same rates, our model projects that global GHG emissions will reach 76 ± 8 GtCO2eq in 2050. In contrast, reducing the rates of land use change by half could limit global GHG emissions to 60 ± 3 GtCO2eq in 2050. Monitoring and analyzing these projections allow a better understanding of the potential impacts of various land use scenarios on global climate and planning for a sustainable future.  相似文献   

17.
Effects of soil and wood depletion on biodiversity   总被引:1,自引:0,他引:1  
Human depletion of soil and wood resources is dramatically altering the biodiversity of both terrestrial and aquatic ecosystems. This paper provides an overview of the numerous linkages between the depletion of soil and wood resources and the loss of biodiversity. While some of these linkages are well documented, others remain speculative or unexplored. In order to understand the full ramifications of resource depletion on biodiversity, additional research is required.  相似文献   

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Despite high deforestation rates in dry forests there are few assessments of the impacts of this transformation on biodiversity. This study addresses the impact of clearing on plant species composition and diversity in mulga (Acacia aneura) forests of Queensland, Australia using data collected from either side of 58 clearing boundaries, incorporating data on site and management conditions. The physical and climatic conditions of the study sites were narrowly constrained but had greater influence on plant composition and richness than clearing per se. In general, the abundance of perennial forbs and shrubs was higher in cleared forest compared with adjacent intact forest and there was no significant difference in abundance of other plant life forms. Perennial forb richness diminished with the age of clearings, particularly where acid sub‐soils had been exposed and shrubs proliferated. Where deforestation in the mulga dry forests is not accompanied by the establishment of exotic pasture it has a relatively benign effect on plant diversity, mulga itself remains in high density as small trees and the integrity of the forest could be maintained with restoration.  相似文献   

20.
To assess the conservation status of Lacandonia, a megadiversity area in Mexico, rates of deforestation were calculated for the periods 1974–1981 and 1981–1991, using a random sample of 38 5 × 5km sites. We evaluated: (i) the overall magnitude of, and spatial and temporal variation in deforestation; (ii) how spatial variation relates to human population density, terrain slope and the presence of the Montes Azules Biosphere Reserve; (iii) the magnitude of potential plant species loss associated with deforestation. Overall deforestation was greater in the former than in the second period (1412 vs. 744ha/year), although mean rates (2.1 and 1.6%/year) were statistically indistinguishable due to a considerable spatial variation. The greatest spatial variation was related to the presence of the Montes Azules Reserve: deforestation outside the reserve was 20 and 6 times greater in the first and second period, respectively. Population density and terrain slope were related to deforestation but the relationship was considerably poor. Estimates of plant species committed to extinction (out of the expected total flora of 4314 species) were as high as 22% by year 2035, and 55% by year 2135. Such levels of potential species extinction associated to deforestation, and the great biological diversity of Lacandonia provide evidence to declare it as the northernmost tropical hot-spot and a priority goal in conservation efforts.  相似文献   

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