首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Large‐scale and long‐term restoration efforts are urgently needed to reverse historical global trends of deforestation and forest degradation in the tropics. Restoration of forests within landscapes offers multiple social, economic, and environmental benefits that enhance lives of local people, mitigate effects of climate change, increase food security, and safeguard soil and water resources. Despite rapidly growing knowledge regarding the extent and feasibility of natural regeneration and the environmental and economic benefits of naturally regenerating forests in the tropics, tree planting remains the major focus of restoration programs. Natural regeneration is often ignored as a viable land‐use option. Here, we assemble a set of 16 original papers that provide an overview of the ecological, economic, and social dimensions of forest and landscape restoration (FLR), a relatively new approach to forest restoration that aims to regain ecological integrity and enhance human well‐being in deforested or degraded forest landscapes. The papers describe how spontaneous (passive) and assisted natural regeneration can contribute to achieving multiple social and ecological benefits. Forest and landscape restoration is centered on the people who live and work in the landscape and whose livelihoods will benefit and diversify through restoration activities inside and outside of farms. Given the scale of degraded forestland and the need to mitigate climate change and meet human development needs in the tropics, harnessing the potential of natural regeneration will play an essential role in achieving the ambitious goals that motivate global restoration initiatives.  相似文献   

2.
A major global effort to enable cost‐effective natural regeneration is needed to achieve ambitious forest and landscape restoration goals. Natural forest regeneration can potentially play a major role in large‐scale landscape restoration in tropical regions. Here, we focus on the conditions that favor natural regeneration within tropical forest landscapes. We illustrate cases where large‐scale natural regeneration followed forest clearing and non‐forest land use, and describe the social and ecological factors that drove these local forest transitions. The self‐organizing processes that create naturally regenerating forests and natural regeneration in planted forests promote local genetic adaptation, foster native species with known traditional uses, create spatial and temporal heterogeneity, and sustain local biodiversity and biotic interactions. These features confer greater ecosystem resilience in the face of future shocks and disturbances. We discuss economic, social, and legal issues that challenge natural regeneration in tropical landscapes. We conclude by suggesting ways to enable natural regeneration to become an effective tool for implementing large‐scale forest and landscape restoration. Major research and policy priorities include: identifying and modeling the ecological and economic conditions where natural regeneration is a viable and favorable land‐use option, developing monitoring protocols for natural regeneration that can be carried out by local communities, and developing enabling incentives, governance structures, and regulatory conditions that promote the stewardship of naturally regenerating forests. Aligning restoration goals and practices with natural regeneration can achieve the best possible outcome for achieving multiple social and environmental benefits at minimal cost.  相似文献   

3.
Forests are sources of wood, non‐timber forest products and ecosystems services and goods that benefit society as a whole, and are especially important to rural livelihoods. Forest landscape restoration (FLR) has been proposed as a way to counteract deforestation and reconcile the production of ecosystem services and goods with conservation and development goals. But limited evidence indicates how large‐scale forest restoration could contribute to improving local livelihoods. Here, we present a conceptual framework to analyze the effects of large‐scale restoration on local livelihoods, and use it to review the scientific literature and reduce this knowledge gap. Most of the literature referred to case studies (89%), largely concentrated in China (49%). The main theme explored was income, followed by livelihoods diversification, off‐farm employment opportunities, poverty reduction, equity and the provision of timber and energy as ecosystem services. Nearly 60 percent of the papers discussed the importance of governance systems to socioeconomic outcomes. The reforestation/restoration programs and policies investigated in the studies had mixed socioeconomic effects on local livelihoods depending on other variables, such as availability of off‐farm jobs, household characteristics, land productivity, land tenure, and markets for forest products and ecosystem services. We conclude that the effects of large‐scale restoration initiatives on local livelihoods may vary due to several factors and is still not clear for many situations; therefore, monitoring over time with clear indicators is needed.  相似文献   

4.
Natural regeneration offers a cheaper alternative to active reforestation and has the potential to become the predominant way of restoring degraded tropical landscapes at large‐scale. We conducted a meta‐analysis for tropical regions and quantified the relationships between both ecological and socioeconomic factors and biodiversity responses in naturally regenerating areas. Biogeographic realms, past disturbance, and the human development index (HDI) were used as explanatory variables for biodiversity responses. In addition, we present a case study of large‐scale natural regeneration in the Brazilian Atlantic Forest and identify areas where different forms of restoration would be most suitable. Using our dataset for tropical regions, we showed that natural regeneration was predominantly reported within: the Neotropical realm; areas that were intensively disturbed; and countries with medium HDI. We also found that biodiversity in regenerating forests was more similar to the values found in old growth forests in: countries with either low, high, or very high HDI; less biodiverse realms; and areas of less intensive past disturbance. Our case study from Brazil showed that the level of forest gain resulting from environmental legislation, in particular the Brazilian Forest Code, has been reduced, but remains substantial. Complementary market incentives and financial mechanisms to promote large‐scale natural regeneration in human‐modified agricultural landscapes are also needed. Our analysis provides insights into the factors that promote or limit the recovery of biodiversity in naturally regenerating areas, and aids to identify areas with higher potential for natural regeneration.  相似文献   

5.
The Forest and Landscape Restoration movement has emerged as an approach to reconcile biodiversity conservation, ecosystem services provisioning and human well‐being in degraded landscapes, but little is known so far about the potential of different reforestation methods to achieve these objectives. Based on this gap, we assessed the ecological outcomes and local livelihood benefits of community‐managed agroforests and second growth forests to assist natural regeneration in the coastal Atlantic Forest of Brazil. We investigated and compared agroforests and secondary forests according to their structure and floristic composition in 51 circular plots of 314 m², their role in supporting local livelihoods (45 semi‐structured interviews) and the use and cultural importance of plant species (61 interviews). Agroforests and, more remarkably, managed secondary forests (1) re‐established a well‐developed forest structure, with a higher density of tree‐sized individuals and similar basal area compared to nearby old growth forests; (2) were composed by a rich array of native species, including five threatened species, but had lower species richness than old growth remnants; and (3) improved local livelihoods by supplying market valuable and culturally important plants, including 231 native ethnospecies. Overall, local production systems showed remarkable potential to engage smallholders of developing tropical countries in Forest and Landscape Restoration and contribute to achieve its overall goals. We advocate the promotion of these systems as effective Forest and Landscape Restoration approaches in multi‐scale programs and policies.  相似文献   

6.
Forest restoration requires strategies such as passive restoration to balance financial investments and ecological outcomes. However, the ecological outcomes of passive restoration are traditionally regarded as uncertain. We evaluated technical and legal strategies for balancing economic costs and ecological outcomes of passive versus active restoration in agricultural landscapes. We focused in the case of Brazil, where we assessed the factors driving the proportion of land allocated to passive and active restoration in 42 programs covering 698,398 hectares of farms in the Atlantic Forest, Atlantic Forest/cerrado ecotone and Amazon; the ecological outcomes of passive and active restoration in 2955 monitoring plots placed in six restoration programs; and the legal framework developed by some Brazilian states to balance the different restoration approaches and comply with legal commitments. Active restoration had the highest proportion of land allocated to it (78.4%), followed by passive (14.2%) and mixed restoration (7.4%). Passive restoration was higher in the Amazon, in silviculture, and when remaining forest cover was over 50 percent. Overall, both restoration approaches showed high levels of variation in the ecological outcomes; nevertheless, passively restored areas had a smaller percentage canopy cover, lower species density, and less shrubs and trees (dbh > 5 cm). The studied legal frameworks considered land abandonment for up to 4 years before deciding on a restoration approach, to favor the use of passive restoration. A better understanding of the biophysical and socioeconomic features of areas targeted for restoration is needed to take a better advantage of their natural regeneration potential.  相似文献   

7.
Large‐scale forest restoration relies on approaches that are cost‐effective and economically attractive to farmers, and in this context agroforestry systems may be a valuable option. Here, we compared ecological outcomes among (1) 12–15‐year‐old coffee agroforests established with several native shade trees, (2) 12–15‐year‐old high‐diversity restoration plantations, and (3) reference old‐growth forests, within a landscape restoration project in the Pontal do Paranapanema region, in the Atlantic Forest of southeastern Brazil. We compared the aboveground biomass, canopy cover, and abundance, richness, and composition of trees, and the regenerating saplings in the three forest types. In addition, we investigated the landscape drivers of natural regeneration in the restoration plantations and coffee agroforests. Reference forests had a higher abundance of trees and regenerating saplings, but had similar levels of species richness compared to coffee agroforests. High‐diversity agroforests and restoration plantations did not differ in tree abundance. However, compared to restoration plantations, agroforests showed higher abundance and species richness of regenerating saplings, a higher proportion of animal‐dispersed species, and higher canopy cover. The abundance of regenerating saplings declined with increasing density of coffee plants, thus indicating a potential trade‐off between productivity and ecological benefits. High‐diversity coffee agroforests provide a cost‐effective and ecologically viable alternative to high‐diversity native tree plantations for large‐scale forest restoration within agricultural landscapes managed by local communities, and should be included as part of the portfolio of reforestation options used to promote the global agenda on forest and landscape restoration.  相似文献   

8.
Stephen Elliott 《Biotropica》2016,48(6):825-833
Assisted (or accelerated) natural regeneration (ANR) will play an important role in meeting the UN target to restore forest to 350 million hectares of degraded land, by 2030. However, since most accessible land is already used for agriculture, most of the sites, available for ANR, are far from roads and/or on difficult terrain, where implementing ANR with human labour is not practical. Therefore, this paper explores the potential of emerging technologies, such as low‐cost UAVs (drones) and new imaging devices, to automate ANR tasks, including site monitoring (to assess site potential for natural regeneration, plan interventions and assess progress), maintenance of natural regeneration (particularly weeding) and species enrichment through aerial seeding. The usefulness of existing technologies is reviewed and future innovations needed, to provide practicable support for ANR, are discussed. Intensive collaboration, among technologists and forest ecologists, will be essential to ensure that technological innovations are based firmly on sound restoration science.  相似文献   

9.
Large areas of rainforests in Australia and other tropical regions have been extensively cleared since the mid‐19th century. As abandoned agro‐pastoral land becomes increasingly prominent, there is an ongoing need to identify cost‐effective approaches to reinstate forest on these landscapes. Assisted regeneration is a potentially lower cost restoration approach which aims to accelerate forest recovery by removing barriers to natural regeneration. However, despite being widely used its ecological benefits are poorly quantified, particularly on long cleared and grazed land. This study quantified the benefits of assisted regeneration on previously cleared land in a subtropical rainforest ecosystem within eastern Australia. Three different site types were used (grazed, grazing excluded and grazing excluded plus assisted regeneration, each with a maximum distance of 120 m to remnant forest) to compare forest recovery up to 10 years after grazing was relieved with and without 4–6 years of assisted regeneration. Assisted regeneration sites showed a threefold increase in canopy cover, fourfold increase in native tree and shrub species richness and over 40 times greater native stem density compared to nonassisted regeneration sites. Stimulation of native recruitment appears dependent on the simultaneous removal of multiple barriers to regeneration, with the exclusion of grazing alone insufficient. This demonstrates the additional ecological benefits arising from investment in assisted regeneration. It offers considerable promise as a cost‐effective tool for accelerating and improving reinstatement of forest on retired agro‐pastoral land in the humid subtropics.  相似文献   

10.
Natural regeneration provides multiple benefits to nature and human societies, and can play a major role in global and national restoration targets. However, these benefits are context specific and impacted by both biophysical and socioeconomic heterogeneity across landscapes. Here, we investigate the benefits of natural regeneration for climate change mitigation, sediment retention and biodiversity conservation in a spatially explicit way at very high resolution for a region within the global biodiversity hotspot of the Atlantic Forest. We classified current land‐use cover in the region and simulated a natural regeneration scenario in abandoned pasturelands, areas where potential conflicts with agricultural production would be minimized and where some early stage regeneration is already occurring. We then modeled changes in biophysical functions for climate change mitigation and sediment retention, and performed an economic valuation of both ecosystem services. We also modeled how land‐use changes affect habitat availability for species. We found that natural regeneration can provide significant ecological and social benefits. Economic values of climate change mitigation and sediment retention alone could completely compensate for the opportunity costs of agricultural production over 20 yr. Habitat availability is improved for three species with different dispersal abilities, although by different magnitudes. Improving the understanding of how costs and benefits of natural regeneration are distributed can be useful to design incentive structures that bring farmers’ decision making more in line with societal benefits. This alignment is crucial for natural regeneration to fulfill its potential as a large‐scale solution for pressing local and global environmental challenges.  相似文献   

11.
Ecological restoration is a globally important and well‐financed management intervention used to combat biodiversity declines and land degradation. Most restoration aims to increase biodiversity towards a reference state, but there are concerns that intended outcomes are not reached due to unsuccessful interventions and land‐use legacy issues. Monitoring biodiversity recovery is essential to measure success; however, most projects remain insufficiently monitored. Current field‐based methods are hard to standardize and are limited in their ability to assess important components of ecosystems, such as bacteria. High‐throughput amplicon sequencing of environmental DNA (metabarcoding of eDNA) has been proposed as a cost‐effective, scalable and uniform ecological monitoring solution, but its application in restoration remains largely untested. Here we show that metabarcoding of soil eDNA is effective at demonstrating the return of the native bacterial community in an old field following native plant revegetation. Bacterial composition shifted significantly after 8 years of revegetation, where younger sites were more similar to cleared sites and older sites were more similar to remnant stands. Revegetation of the native plant community strongly impacted on the belowground bacterial community, despite the revegetated sites having a long and dramatically altered land‐use history (i.e. >100 years grazing). We demonstrate that metabarcoding of eDNA provides an effective way of monitoring changes in bacterial communities that would otherwise go unchecked with conventional monitoring of restoration projects. With further development, awareness of microbial diversity in restoration has significant scope for improving the efficacy of restoration interventions more broadly.  相似文献   

12.
Tree species that produce resources for fauna are recommended for forest restoration plantings to attract pollinators and seed dispersers; however, information regarding the flowering and fruiting of these species during early growth stages is scarce. We evaluated the reproductive phenology of animal‐dispersed tree species widely used in Atlantic Forest restoration. We marked 16 animal‐dispersed tree species in 3‐ to 8‐year‐old forest restoration plantings in Itu‐São Paulo, southeast Brazil. We noted the age of the first reproductive event, flowering and fruiting seasonality, percentage of trees that reached reproductive stages, and intensity of bud, flower, and fruit production for each species. Flowering and fruiting are seasonal for most species; only two, Cecropia pachystachya and Ficus guaranitica, exhibited continuous flowering and fruiting throughout the year; we also identified Schinus terebinthifolia and Dendropanax cuneatus fruiting in the dry season during resource scarcity. Therefore, we recommend all as framework species, that is, species that are animal‐dispersed with early flowering and fruiting potential, for forest restoration. Further, we recommend identifying and planting similar animal‐dispersed tree species that produce fruits constantly or in the dry season to maximize fauna resource availability throughout the year in tropical forest restoration plantings. Abstract in Portuguese is available with online material  相似文献   

13.
Two processes globally threatening natural ecosystems are changes in land use and deforestation. Two methods used to restore threatened ecosystems are: (1) unassisted forest regeneration, which promotes the establishment of plants and fauna arriving from surrounding habitats and (2) assisted restoration, which involves the reconstruction of forests by planting native or exotic trees. Functional attributes, such as plant–pollinator interactions, are essential for ecosystem recovery. Unfortunately, information regarding the effect of restoration on pollination systems is limited. Forty years ago, a tropical cloud forest in Colombia was restored through unassisted forest regeneration, as well as by establishing monospecific plantations of the exotic Chinese ash Fraxinus chinensis. The understories of both restoration strategies were colonized by the beetle‐pollinated aroid Xanthosoma daguense. Using isolation‐by‐distance and multi‐strata mark‐recapture models, I estimated in each restoration strategy two fundamental pollination processes: (1) the magnitude of X. daguense pollination neighborhood and (2) the directionality of pollen flow among plants colonizing both restoration strategies. In addition, I recorded pollinator visits and fruit production for X. daguense in each restored habitats. The pollination neighborhood of X. daguense in the ash plantation is two times larger than its pollination neighborhood in natural regeneration. Inflorescences in the ash plantation donated 10 times more pollen to inflorescences in natural regeneration. Plants in natural regeneration produced two times more infructescences and more fruits than plants in ash plantation. Results show that the selection of different restoration strategies can alter two major components of plant–pollinator interactions in plants colonizing restored habitats, pollination neighborhoods, and pollen flow within the population.  相似文献   

14.
Lower‐cost tropical forest restoration methods, particularly those framed as win–win business‐protected area partnerships, could dramatically increase the scale of tropical forest restoration activities, thereby providing a variety of societal and ecosystem benefits, including slowing both global biodiversity loss and climate change. Here we describe the long‐term regenerative effects of a direct application of agricultural waste on tropical dry forest. In 1998, as part of an innovative agricultural waste disposal service contract, an estimated 12,000 Mg of processed orange peels and pulp were applied to a 3 ha portion of a former cattle pasture with compacted, rocky, nutrient‐poor soils characteristic of prolonged fire‐based land management and overgrazing in Área de Conservación Guanacaste, northwestern Costa Rica. After 16 years, the experimental plot showed a threefold increase in woody plant species richness, a tripling of tree species evenness (Shannon Index), and a 176% increase in aboveground woody biomass over an adjacent control plot. Hemispheric photography showed significant increases in canopy closure in the area where orange waste was applied relative to control. Orange waste deposition significantly elevated levels of soil macronutrients and important micronutrients in samples taken 2 and 16 years after initial orange waste application. Our results point to promising opportunities for valuable synergisms between agricultural waste disposal and tropical forest restoration and carbon sequestration.  相似文献   

15.
16.
Governance challenges are frequently underestimated in forest landscape restoration. Forest restoration practitioners are generally foresters or ecologists and their focus tends to be limited to the specific restoration interventions themselves, such as removing exotic species, protecting sites for natural regeneration and re-planting indigenous trees. Indeed there are many technical challenges, unknowns in technical aspects of forest landscape restoration and knowledge gaps. However, and even more so when dealing with large scales, additional challenges that fall under the governance umbrella such as tenure, policy measures and institutions have a significant impact on restoration, influencing it either positively or negatively. Conversely, the landscape-scale restoration work itself can influence and shape governance arrangements. This paper attempts to explore this wider relationship between large scale forest restoration − and specifically forest landscape restoration (FLR) − and governance. It is intended to assist and provide guidance to forest landscape restoration practitioners, researchers and policymakers on the consideration and importance of governance, and alternative ways in which the two-way relationship (between governance and FLR) plays out. A framework is proposed to support practitioners, researchers and decision-makers to address governance in forest landscape restoration.  相似文献   

17.
Extensive land clearing in many parts of the global tropics is a major threat to biodiversity, and strategies are urgently needed to reinstate forest. Tree planting is a commonly used strategy to rapidly restore forest to degraded landscapes. However, tree planting is expensive, and in most cases financial constraints prevent its use at a scale needed to address the ongoing legacy of land clearing. Here, we conduct a quantitative review of literature from the global tropics and evaluate outcomes of less intensive interventions (i.e. non‐planting) aimed at stimulating natural regeneration of forest. We focus specifically on overcoming barriers to native plant regeneration that predominate in the earliest stages of succession. Common interventions include varied strategies to suppress herbaceous vegetation (e.g. cutting or herbicide treatment), and measures to bolster propagule supply (e.g. direct seeding and artificial bird perches). There was an apparent trend among pair‐wise comparisons of effect sizes to suggest that combined interventions to simultaneously suppress herbaceous vegetation and increase propagule supply resulted in the most consistent outcomes in terms of promoting progress toward restoring forest structure. Despite an obvious demand for lower cost interventions, a paucity of information means that it is still premature to generalize outcomes of specific interventions and their overall cost relative to active tree planting. Nevertheless, we report an increase in research effort in this area, and suggest promising directions to accelerate progress that will improve capacity to select optimal, cost effective strategies that achieve long‐term restoration objectives with a particular level of certainty .  相似文献   

18.
While overall numbers of African elephant have declined dramatically in recent times, some populations are now confined to protected areas and are locally overabundant—an undesirable situation for both biodiversity conservation and elephants. In forested protected areas, options to manage elephants are limited because it is difficult to safely approach animals, yet it is vital that these populations are managed because browsing by elephants can dramatically alter forest ecosystems. Using data collected over 50 yr in Kibale National Park, Uganda, we examine the prediction that increasing elephant numbers and associated changes in their foraging behavior have caused a shift in tree community composition. Although the relative abundance of elephants increased significantly between 1996 and 2010, the population structure of their preferred tree food species did not change, nor did tree community composition change in favor of species able to re‐sprout after elephant damage. Furthermore, over the last 50 yr Kibale elephants have not become more selective foragers, as would be expected if more nutritious tree species were declining. However, elephants are more abundant in disturbed areas dominated by shrubs and grasses and appear to have arrested forest succession in these areas. At their current abundance, elephants have not selectively altered the composition of intact old growth forest, but they do inhibit the regeneration of disturbed areas.  相似文献   

19.
With the rapidly expanding ecological footprint of agriculture, the design of farmed landscapes will play an increasingly important role for both carbon storage and biodiversity protection. Carbon and biodiversity can be enhanced by integrating natural habitats into agricultural lands, but a key question is whether benefits are maximized by including many small features throughout the landscape (‘land‐sharing’ agriculture) or a few large contiguous blocks alongside intensive farmland (‘land‐sparing’ agriculture). In this study, we are the first to integrate carbon storage alongside multi‐taxa biodiversity assessments to compare land‐sparing and land‐sharing frameworks. We do so by sampling carbon stocks and biodiversity (birds and dung beetles) in landscapes containing agriculture and forest within the Colombian Chocó‐Andes, a zone of high global conservation priority. We show that woodland fragments embedded within a matrix of cattle pasture hold less carbon per unit area than contiguous primary or advanced secondary forests (>15 years). Farmland sites also support less diverse bird and dung beetle communities than contiguous forests, even when farmland retains high levels of woodland habitat cover. Landscape simulations based on these data suggest that land‐sparing strategies would be more beneficial for both carbon storage and biodiversity than land‐sharing strategies across a range of production levels. Biodiversity benefits of land‐sparing are predicted to be similar whether spared lands protect primary or advanced secondary forests, owing to the close similarity of bird and dung beetle communities between the two forest classes. Land‐sparing schemes that encourage the protection and regeneration of natural forest blocks thus provide a synergy between carbon and biodiversity conservation, and represent a promising strategy for reducing the negative impacts of agriculture on tropical ecosystems. However, further studies examining a wider range of ecosystem services will be necessary to fully understand the links between land‐allocation strategies and long‐term ecosystem service provision.  相似文献   

20.
The forests of southeastern Amazonia are highly threatened by disturbances such as fragmentation, understory fires, and extreme climatic events. Large‐bodied frugivores such as the lowland tapir (Tapirus terrestris) have the potential to offset this process, supporting natural forest regeneration by dispersing a variety of seeds over long distances to disturbed forests. However, we know little about their effectiveness as seed dispersers in degraded forest landscapes. Here, we investigate the seed dispersal function of lowland tapirs in Amazonian forests subject to a range of human (fire and fragmentation) and natural (extreme droughts and windstorms) disturbances, using a combination of field observations, camera traps, and light detection and ranging (LiDAR) data. Tapirs travel and defecate more often in degraded forests, dispersing much more seeds in these areas [9,822 seeds per ha/year (CI95% = 9,106; 11,838)] than in undisturbed forests [2,950 seeds per ha/year (CI95% = 2,961; 3,771)]. By effectively dispersing seeds across disturbed forests, tapirs may contribute to natural forest regeneration—the cheapest and usually the most feasible way to achieve large‐scale restoration of tropical forests. Through the dispersal of large‐seeded species that eventually become large trees, such frugivores also contribute indirectly to maintaining forest carbon stocks. These functions may be critical in helping tropical countries to achieve their goals to maintain and restore biodiversity and its ecosystem services. Ultimately, preserving these animals along with their habitats may help in the process of natural recovery of degraded forests throughout the tropics. Abstract in Portuguese is available with online material.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号