Carbon stock quantification in a floodplain restoration chronosequence along a Mediterranean-montane riparian corridor

Uncertainty in the global carbon (C) budget has been reduced for most stocks, though it remains incomplete by not considering aquatic and transitional zone carbon stocks. A key issue preventing such complete accounting is a lack of available C data within these aquatic and aquatic-terrestrial transitional ecosystems. Concurrently, quantifiable results produced by restoration practices that explicitly target C stock accumulation and sequestration remain inconsistent or undocumented. To support a more complete carbon budget and identify impacts on C stock accumulation from restoration treatment actions, we investigated C stock values in a Mediterranean-montane riparian floodplain system in California, USA. We quantified the C stock in aboveground biomass, large wood, and litter in addition to the C and total nitrogen in the upper soil profile (5 cm) across 23 unique restoration treatments and remnant old-growth forests. Treatments span 40 years of restoration actions along seven river kilometers of the Cosumnes River, and include process-based (limited intervention), assisted (horticultural planting and other intensive restoration activities), hybrid (a combination of process and assisted actions), and remnant (old-growth forests that were not created with restoration actions) sites. Total C values measured up to 1100 Mg ha-1 and averaged 129 Mg ha-1 with biomass contributing the most to individual plot measurements. From 2012 to 2020, biomass C stock measurements showed an average 32 Mg ha-1 increase across all treatments, though treatment specific values varied. While remnant forest plots held the highest average C values across all stocks (336 Mg ha-1), C values of different stocks varied across treatment type. Process-based restoration treatments held more average biomass C (120 Mg ha-1) than hybrid (23 Mg ha-1) or assisted restoration treatments (50 Mg ha-1), while assisted restoration treatments held more average total C in soil and litter (58 Mg ha-1) than hybrid (35 Mg ha-1) and process-based restoration treatments (37 Mg ha-1). Regardless of treatment type, time was a significant factor for all C stock values. These findings support a more inclusive global carbon budget and provide valuable insight into restoration treatment actions that support C stock accumulation.

Future-proofing ecosystem restoration through enhancing adaptive capacity

Social-ecological ecosystem restoration involves interacting challenges, including climate change, resource overexploitation and political instability. To prepare for these and other emerging threats, we synthesized key restoration and social-ecological systems literature and derived three guiding themes that can help to enhance the adaptive capacity of restoration sites: (i) work with the existing system, (ii) create self-sustaining, adaptive systems, and (iii) foster diversity and participation. We propose a two-step approach and provide an example from Rwanda detailing the application of these principles. While site-specific activities have to be designed and implemented by local practitioners, our synthesis can guide forward-thinking restoration practice.

Ecological restoration can enhance the radiation benefit of sand fixation service: A simulated evidence of Xilingol League, China

Large-scale ecological restoration programs have been initiated globally with the aim of combating desertification and improving ecosystem services, especially for sand fixation service (SF) in arid and semi-arid regions. However, the effectiveness of ecological restoration in the radiation benefit of SF, such as improving air quality, remains not well known. In this study, we selected Xilingol as the study area, investigated the dynamics of SF, and quantified the radiation benefit of SF in downwind areas by employing PM10 concentration as the proxy. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was applied to assess the response of radiation benefit to ecological restoration by designing land use scenarios. Results showed that the SF in Xilingol increased with fluctuation at an average rate of 0.27%/year from 2000 to 2018. Under the effect of ecological restoration, the radiation benefit in the downwind regions was substantially improved, as manifested by a 104.22 μg/m³ reduction in PM10 concentration. The changes in radiation benefit varied greatly across space, and northern and southern Xilingol were hot spots for increased radiation benefit. Based on regional disparity in benefit level, this work could provide a reference to make differentiated cross-regional ecological compensation schemes at the national level.

Fifteen essential science advances needed for effective restoration of the world's forest landscapes

There has never been a more pressing and opportune time for science and practice to collaborate towards restoration of the world's forests. Multiple uncertainties remain for achieving successful, long-term forest landscape restoration (FLR). In this article, we use expert knowledge and literature review to identify knowledge gaps that need closing to advance restoration practice, as an introduction to a landmark theme issue on FLR and the UN Decade on Ecosystem Restoration. Aligned with an Adaptive Management Cycle for FLR, we identify 15 essential science advances required to facilitate FLR success for nature and people. They highlight that the greatest science challenges lie in the conceptualization, planning and assessment stages of restoration, which require an evidence base for why, where and how to restore, at realistic scales. FLR and underlying sciences are complex, requiring spatially explicit approaches across disciplines and sectors, considering multiple objectives, drivers and trade-offs critical for decision-making and financing. The developing tropics are a priority region, where scientists must work with stakeholders across the Adaptive Management Cycle. Clearly communicated scientific evidence for action at the outset of restoration planning will enable donors, decision makers and implementers to develop informed objectives, realistic targets and processes for accountability. This article paves the way for 19 further articles in this theme issue, with author contributions from across the world. This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'.

Digitalizing forest landscape restoration: a social and political analysis of emerging technological practices

Digital technologies are increasingly influencing forest landscape restoration practices worldwide. We investigate how digital platforms specifically reconfigure restoration practices, resources, and policy across scales. By analyzing digital restoration platforms, we identify four drivers of technological developments, including: scientific expertise to optimize decisions; capacity building through digital networks; digital tree-planting markets to operate supply chains; and community participation to foster co-creation. Our analysis shows how digital developments transform restoration practices by producing techniques, remaking networks, creating markets, and reorganizing participation. These transformations often involve power imbalances regarding expertise, finance, and politics across the Global North and Global South. However, the distributed qualities of digital systems can also create alternative ways of undertaking restoration actions. We propose that digital developments for restoration should not be understood as neutral tools but rather as power-laden processes that can create, perpetuate, or counteract social and environmental inequalities.