Ecological restoration of fragile Eastern Himalayan landscapes through bamboo bioengineering

EXECUTIVE SUMMARY Ecological restoration, when implemented effectively and sustainably, contributes to protecting biodiversity; improving human health and wellbeing; increasing food and water security; delivering goods, services, and economic prosperity; and supporting climate change mitigation, resilience, and adaptation. It is a solutions-based approach that engages communities, scientists, policymakers, and land managers to repair ecological damage and rebuild a healthier relationship between people and the rest of nature. When combined with conservation and sustainable use, ecological restoration is the link needed to move local, regional, and global environmental conditions from a state of continued degradation, to one of net positive improvement. The second edition of the International Principles and Standards for the Practice of Ecological Restoration (the Standards) presents a robust framework for restoration projects to achieve intended goals, while addressing challenges including effective design and implementation, accounting for complex ecosystem dynamics (especially in the context of climate change), and navigating trade-offs associated with land management priorities and decisions. The Standards establish eight principles that underpin ecological restoration. Principles 1 and 2 articulate important foundations that guide ecological restoration: effectively engaging a wide range of stakeholders, and fully utilizing available scientific, traditional, and local knowledge, respectively. Principles 3 and 4 summarize the central approach to ecological restoration, by highlighting ecologically appropriate reference ecosystems as the target of restoration and clarifying the imperative for restoration activities to support ecosystem recovery processes. Principle 5 underscores the use of measurable indicators to assess progress toward restoration objectives. Principle 6 lays out the mandate for ecological restoration to seek the highest attainable recovery. Tools are provided to identify the levels of recovery aspired to and to track progress. Principle 7 highlights the importance of restoration at large spatial scales for cumulative gains. Finally, ecological restoration is one of several approaches that address damage to ecosystems and Principle 8 clarifies its relationships to allied approaches on a “Restorative Continuum”. The Standards highlight the role of ecological restoration in connecting social, community, productivity, and sustainability goals. The Standards also provide recommended performance measures for restorative activities for industries, communities, and governments to consider. In addition, the Standards enhance the list of practices and actions that guide practitioners in planning, implementation, and monitoring activities. The leading practices and guidance include discussion on appropriate approaches to site assessment and identification of reference ecosystems, different restoration approaches including natural regeneration, consideration of genetic diversity under climate change, and the role of ecological restoration in global restoration initiatives. This edition also includes an expanded glossary of restoration terminology. SER and its international partners produced the Standards for adoption by communities, industries, governments, educators, and land managers to improve ecological restoration practice across all sectors and in all ecosystems, terrestrial and aquatic. The Standards support development of ecological restoration plans, contracts, consent conditions, and monitoring and auditing criteria. Generic in nature, the Standards framework can be adapted to particular ecosystems, biomes, or landscapes; individual countries; or traditional cultures. The Standards are aspirational and provide tools that are intended to improve outcomes, promote best practices, and deliver net global environmental and social benefits. As the world enters the UN Decade on Ecosystem Restoration (2021–2030), the Standards provide a blueprint for ensuring ecological restoration achieves its full potential in delivering social and environmental equity and, ultimately, economic benefits and outcomes.

The UN Decade of Ecosystem Restoration (2021–2030) provides a new momentum for scaling up ecosystem restoration efforts to landscape restoration. China’s recent experience with transformative investment in landscape restoration provides invaluable guidance for the world. We retrospectively reviewed the scientific evidence on the responses of physical, ecological, and social processes to China’s landscape restoration under geographic heterogeneity and obtained four experiences and lessons. First, China’s forest landscape restoration has successfully promoted vegetation growth and enlarged the carbon sink. Second, landscape restoration has reduced the local water yield, while the regional responses of rainfall are still not clear. Third, the local conditions of soil erosion and habitat quality were largely improved by landscape restoration, while the decreases in soil moisture and streamflow demonstrated significant trade-offs among ecosystem services. Last, geographical differentiation existed in the local responses of livelihoods to landscape restoration strategies, and the win‒win solutions between human development and nature improvement under different landscape contexts were still uncertain. We summarize three additional questions as future prospects: what is the scale of the thresholds to prevent overshoot and cascading negative ecological effects? what are people’s prior needs from nature? considering that there may be no universal win‒win pathways, how to promote co-benefits based on regional human–nature relationships?

Effective restoration planning tools are needed to mitigate global carbon and biodiversity crises. Published spatial assessments of restoration potential are often at large scales or coarse resolutions inappropriate for local action. Using a Tanzanian case study, we introduce a systematic approach to inform landscape restoration planning, estimating spatial variation in cost-effectiveness, based on restoration method, logistics, biomass modelling and uncertainty mapping. We found potential for biomass recovery across 77.7% of a 53 000 km2 region, but with some natural spatial discontinuity in moist forest biomass, that was previously assigned to human causes. Most areas with biomass deficit (80.5%) were restorable through passive or assisted natural regeneration. However, cumulative biomass gains from planting outweighed initially high implementation costs meaning that, where applicable, this method yielded greater long-term returns on investment. Accounting for ecological, funding and other uncertainty, the top 25% consistently cost-effective sites were within protected areas and/or moderately degraded moist forest and savanna. Agro-ecological mosaics had high biomass deficit but little cost-effective restoration potential. Socio-economic research will be needed to inform action towards environmental and human development goals in these areas. Our results highlight value in long-term landscape restoration investments and separate treatment of savannas and forests. Furthermore, they contradict previously asserted low restoration potential in East Africa, emphasizing the importance of our regional approach for identifying restoration opportunities across the tropics.This article is part of the theme issue ‘Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration’.

An important issue in the United Nations plan for the Decade on Ecosystem Restoration is how to enhance the overall social–ecological benefits by optimizing the spatial and temporal arrangements of ecological restoration. However, there was a lack of a benefit assessment system combining ecological, social, and economic indicators, and the methodology for identifying directions for ecological restoration remains controversial, especially in mining landscapes. By integrating the aesthetic viewing service into assessments of ecological restoration benefits on mining landscapes, four benefit objectives were evaluated, including habitat conservation, climate regulation, residential viewsheds, and conservation cost, and a multi‐objective optimization for ecological restoration of mining landscapes was performed. The results demonstrated that multiobjective ecological restoration could provide comprehensive ecological–social–economic benefits compared with a single‐objective restoration, since selecting the top 50% of the multiobjective restoration areas would achieve 80% climate regulation, 63% habitat protection, and 54% residential viewshed benefits and would result in 295%, 200%, and 114% higher benefits, respectively, than the minimization cost objective. The restoration priority map showed that only 17% of the landscape needed to be restored to forest among the top 30% of degraded areas that need to be restored. In conclusion, ecological restoration of mining landscapes required attention to win–win situations with multiobjectives. Coordinated arrangement of restoration of different ecosystems in different ages was the key to obtaining maximum socioecological benefits.

Healing country and healing relationships

As a fairly new approach, the ecohydrology-based landscape restoration (EcoLaR) needs to have its guiding principles that denote the important values of the approach. This chapter synthesizes those principles that are emanated from the basic principles of ecohydrology amalgamated with related approaches such as: Ecosystem Restoration, Forest Landscape Restoration, and Landscape Restoration. Accordingly, the first two principles guide the planning phase of landscape restoration by signifying the consideration of both hydrological and ecological management units (principle 1) and building local stewardship – human dimension (principle 2). Principle 3 guides target-setting by indicating the multidimensional goals of the restoration efforts toward sustainability through parallel improvement of Water, Biodiversity, and Services from ecosystems for society, Resilience to climate and various anthropogenic impacts and Culture and Education – WBSRCE. The fourth principle operationalizes the first and second principles of ecohydrology by proposing regulation of the hydrology followed by place-based and use-inspired biota establishment. The fifth principle signifies the importance of adopting the indigenous ways of doing ecological engineering: Ethno-engineering while the sixth principle recommends establishment of green- (semi-) gray infrastructure as ecohydrological systemic solution (EHSS) and the seventh principle justifies the necessity of managing the landscape adaptively for emerging issues.

To support implementation of the UN Decade on Ecosystem Restoration, this report focuses on finance flows and investment needs for restoration. Ecosystem restoration is based on “the process of halting and reversing degradation, resulting in improved ecosystem services and recovered biodiversity” (FAO 2021). Active restoration includes different restoration approaches (World Bank 2022): • Regenerative agriculture: cover cropping, To support implementation of the UN Decade on Ecosystem Restoration, this report focuses on finance flows and investment needs for restoration. Ecosystem restoration is based on “the process of halting and reversing degradation, resulting in improved ecosystem services and recovered biodiversity” (FAO 2021). Active restoration includes different restoration approaches (World Bank 2022): • Regenerative agriculture: cover cropping, agroforestry, no-till farming • Forest and landscape restoration: agroforestry, planting of native species • Restoration of aquatic production systems: stream restoration, reintroduction of native species, coral rehabilitation • Ecological restoration: reintroduction of key native animal and plant species, invasive species eradication • Rewilding: reintroduction of key native animal and plant species This report focuses on nature-based solutions (NbS) that can reverse degradation across ecosystems by restoring and sustainably managing land and seascapes. This analysis covers activities that directly contribute to ecosystem restoration as depicted in the boxed area of Figure 1.1, from repairing ecosystem function through regenerative agriculture to full recovery of natural ecosystems. agroforestry, no-till farming • Forest and landscape restoration: agroforestry, planting of native species • Restoration of aquatic production systems: stream restoration, reintroduction of native species, coral rehabilitation • Ecological restoration: reintroduction of key native animal and plant species, invasive species eradication • Rewilding: reintroduction of key native animal and plant species This report focuses on nature-based solutions (NbS) that can reverse degradation across ecosystems by restoring and sustainably managing land and seascapes. This analysis covers activities that directly contribute to ecosystem restoration as depicted in the boxed area of Figure 1.1, from repairing ecosystem function through regenerative agriculture to full recovery of natural ecosystems.

With the continuous development of landscape restoration technology, how to use modern technology to efficiently reconstruct degraded and damaged historical gardens to help them restore and protect has become an important topic. Traditional 3D reconstruction methods often face challenges in accuracy and efficiency when facing complex garden geometry and ecological environment. To this end, this paper proposes a hybrid model DGA-Net that combines deep convolutional network (DCN), graph convolutional network (GCN) and attention mechanism to improve the 3D reconstruction accuracy and detail recovery in historical garden landscape restoration. DGA-Net extracts spatial features through DCN, uses GCN to model the topological relationship of point clouds, and optimizes the recovery of key geometric details by combining attention mechanism. Compared with traditional methods, this hybrid method shows better performance in the reconstruction of complex structures and ecological characteristics of historical gardens, especially in the accuracy of point cloud generation and detail recovery. Experimental results show that DGA-Net can reconstruct the structure and ecological characteristics of historical gardens more finely, providing higher reconstruction accuracy and efficiency. This study provides innovative technical support for digital modeling and monitoring in landscape restoration, especially in the fields of ecological environment restoration and cultural heritage protection.

Although ecosystem restoration is based on the concepts, approaches, and applied aspects of restoration ecology, science and practice of restoration must go far beyond that in a multidimensional perspective. This is shown by deepening certain topics related to ecosystem and landscape restoration. Hereby, terra preta as an ancient soil management, multipurpose plant species, and Cultural Keystone Species are introduced. Since the restoration and revitalization of cultural landscapes encompasses also socio-economic aspects and approaches, the village as an engine for cultural landscape maintenance and rural development, traditional cultural landscapes as tourist destinations, health care on the countryside, rural-urban partnerships, infrastructure and energy in rural areas, and the design of new cultural landscapes based on land-use traditions are discussed. Also, Higher Education should contribute to ecosystem and landscape restoration by preparing a new generation of well-skilled actors, stakeholders, and scholars who can apply their knowledge in an interdisciplinary and intercultural environment.KeywordsCultural keystone speciesInfrastructureMultipurpose speciesRenewable energyRural-urban partnershipsTerra pretaVillage

ContextIntegrating the spatial flow perspective, temporal trade-off perspective, and future tendency perspective enables a comprehensive assessment of nature’s contributions to people (NCPs). However, assessments that integrate these perspectives and combine them with regional ecological restoration policy remain limited.ObjectivesBased on the perspective of spatial flow and considering the two dimensions of nature’s contributions and people’s needs, we assessed and forecasted water-related NCPs, including water yield (NCP6), water purification (NCP7), and soil conservation (NCP8), from the Loess Plateau to downstream regions of the Yellow River in China.MethodsTo forecast the future tendencies of the NCPs and their temporal trade-offs, we simulate land use changes based on rapid landscape restoration and slow landscape restoration under five shared socioeconomic pathways (SSPs) from 2020 to 2100.ResultsThe results showed that the spatial distributions of the values of the three NCPs differ greatly from the corresponding values of nature’s contributions. The soil conservation NCP and water purification NCP will decrease under all scenarios, while the water yield NCP will be stable in most of the scenarios except SSP3. The soil conservation NCP showed a faster decrease under R2 compared to R1, with the highest rate observed at 2.11%. Conversely, the water purification NCP and water yield NCP experienced a faster decrease under R1 than under R2, with rates of 8.61% and 14.30% respectively. The rapid landscape restoration will have a more positive impact on the soil conservation NCP, and a more negative impact on the other two water-related NCPs than the slow landscape restoration.ConclusionsThis assessment provides a forecast of the future benefits of landscape restoration from dual dimensions of nature’s contributions and people’s needs, indicating the importance of integrating the future changes in both dimensions when making regional landscape restoration policy.

Summary Agriculture now constitutes 40–50% of terrestrial land use globally. By enhancing habitat suitability and connectivity, restoration within agricultural landscapes could have a major influence on biodiversity conservation. However, habitat management within intensive agricultural landscapes may primarily boost abundances of common, highly mobile generalists, rather than vulnerable or endangered species. We studied pollinator community response to small‐scale habitat restoration in the intensively farmed Central Valley of California to determine whether restoration could also promote more specialized, less common and/or less mobile species. Composition of pollinator communities was assessed in five experimental and 10 control (unrestored) sites before and after restoration of native plant hedgerows over an 8‐year period, using a before‐after control‐impact design. We characterized bee and fly species based on functional response traits [floral specialization, habitat specialization, abundance, body size and sociality (bees only)] known to influence the response to habitat change. We modelled how species occurrences changed with habitat restoration over time as modulated by their response traits. We found that hedgerows not only significantly enhanced occurrences of native bee and syrphid fly species, but that as hedgerows matured, they had a greater positive effect on species that were more specialized in floral and nesting resources and smaller (less mobile). Synthesis and applications. Unlike previous studies that suggest habitat restoration in agricultural landscapes only benefits mobile, generalist species, our results suggest that small‐scale habitat restoration can promote species whose traits likely render them particularly vulnerable to habitat degradation. Thus, even within highly intensive agricultural landscapes, small‐scale habitat restoration can be a conservation management tool. However, tailoring habitat enhancements to promote certain species or guilds may be critical for their success as a conservation intervention in agricultural landscapes.

Assisted Natural Regeneration (ANR) is a set of restoration strategies and interventions primarily based on natural regeneration, aimed at accelerating succession and providing multiple benefits in degraded ecosystems and landscapes. These strategies have the potential to significantly contribute to global Forest and Landscape Restoration efforts. However, ANR faces challenges due to limited recognition, support, and formal integration into relevant sectors and restoration policies, particularly in tropical regions. The dearth of evidence-based syntheses further compounds these challenges. To address this gap, a bibliometric analysis of selected scientific publications on ANR (n = 208) from 1987 to 2023 was conducted, using Web of Science and Google Scholar databases. A systematic review was undertaken, using a subset of original research articles (n = 44), to synthesize published data on interventions, contexts, costs, and benefits of ANR and to identify major knowledge gaps. Analysis of bibliometric metadata revealed an increasing annual output of ANR publications in over 80 journals, encompassing various document types and authors from over 40 countries. Despite ANR’s formal emergence in the Philippines, Brazil has taken the lead in both its research and implementation, and international collaboration in ANR research has grown. While ANR research focused mostly on ecosystem services and ecological outcomes, social aspects have been poorly studied. Diverse ANR interventions align not only with ecological restoration but also with integrated land management, biodiversity conservation, forest and landscape restoration, and forest management. The cost-effectiveness of ANR implementation, especially in restoration for carbon storage, exhibited considerable variability when compared to active tree planting, and varied with intervention types, time, land use history, and long-term costs. This synthesis provides critical insights and evidence to enhance the effective integration of ANR into restoration and reforestation programs and policies.

There is an urgent need for restoration of degraded habitats worldwide to secure the sustainable provision of ecosystem services and support resilient societies. Healthy and biodiverse ecosystems can only thrive in ecologically well-functioning and well-connected landscapes. Habitat restoration, although often still focusing on individual habitat patches, needs to take into account the crucial role of landscape-scale processes. This chapter outlines why restoration needs to focus on landscapes and summarizes the landscape ecological aspects that are relevant for successful restoration. I give an overview of landscape restoration, discuss the role of landscape structure and composition and the importance of species pools and small landscape elements, and provide ecological background on the restoration of landscape-scale dispersal and ecological interactions. In the coming years, the relevance of landscape-scale restoration will increase, and the focus will be put on restoration activities that help achieve global goals. However, it is necessary to stress that objectives and means for successful restoration cannot be set globally. First and foremost, landscape restoration is a local action that needs to be designed and applied in full recognition and appreciation of natural and socio-economic conditions in any given landscape.

Building on different bodies of the governance literature, we propose a conceptual framework specifying nine scale-sensitive governance arrangements that aim to (1) create cross-scale fit between the governance and ecological scales, and/or (2) foster cross-level alignment between different governance levels. To understand how scale-sensitive governance has played out in practice, our systematic review builds on 84 peer-reviewed empirical journal articles, which represent 84 cases of forest and landscape restoration governance. In the case studies, we identified eight out of nine scale-sensitive governance arrangements: moving tasks to other governance levels; task-specific organisations; polycentric governance; multilevel coordination; multilevel collaboration; multilevel learning; bridging organisations; and multilevel networks. These arrangements constitute important elements of the multilevel environmental governance landscape, and we analysed their role in promoting forest and landscape restoration. By using the proposed conceptual framework, a better understanding is created of how different scale-sensitive governance arrangements can support existing and future restoration efforts that are implemented as part of the UN Decade on Ecosystem Restoration.

This concluding chapter summarizes the core messages of the proposed ecohydrology-based landscape restoration (EcoLaR) approach. Accordingly, the approach is found to improve most of the limitations exhibited by the conventional practices in the sector. Another core lesson from the approach is related to its potential to reshape the underlying theory of change of the initiatives in the restoration sector where huge amount of finance and technical assistances have been pledged around the globe. The value in this fairly new approach is heightened due to the contemporary fact that none of the 17 Sustainable Development Goals can be achieved unless a significant effort in ecosystem restoration is implemented. Another lesson to be taken from this book is that it is not a stand-alone manuscript for landscape restoration, but rather the book significantly contributes to the sustainable future if combined with the existing scientific resources. Furthermore, this book is expected to ignite professional dialogue on both theory and practices of adopting the principles of ecohydrology for effective landscape restoration and sustainability which will pave the way for additional scientific fervor.