A framework to evaluate land degradation and restoration responses for improved planning and decision-making

Avoiding, reducing or reversing land degradation will require increased restoration investments, carefully targeted and implemented to maximize environmental, economic and social benefits. Our objective was to develop a multi-criteria framework to assess effectiveness of land degradation responses for enhanced land use planning and restoration by evaluating both direct biophysical and socio-economic responses and indirect effects of various restoration strategies. The effectiveness of restoration responses is demonstrated for degraded forestland using a comprehensive literature review and case study in Nepal. The results show that most forestland restoration responses have an ecological focus with tree planting being the dominant direct response and economic and financial instruments the indirect responses. The results confirmed that environmental desirability was the dominant factor and economic feasibility was secondary for assessing restoration responses. Cultural acceptability was given the least consideration. Among sub-criteria, improved vegetative structure was the dominant restoration response. This study, originating from the Land Degradation and Restoration Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, supports the view that the scientific community and decision-makers must give greater attention to cultural, social, technical, and political dimensions that influence the outcomes of restoration responses to solve the pervasive problem of land degradation

Effects of plant diversity on productivity strengthen over time due to trait-dependent shifts in species overyielding

Plant diversity effects on community productivity often increase over time. Whether the strengthening of diversity effects is caused by temporal shifts in species-level overyielding (i.e., higher species-level productivity in diverse communities compared with monocultures) remains unclear. Here, using data from 65 grassland and forest biodiversity experiments, we show that the temporal strength of diversity effects at the community scale is underpinned by temporal changes in the species that yield. These temporal trends of species-level overyielding are shaped by plant ecological strategies, which can be quantitatively delimited by functional traits. In grasslands, the temporal strengthening of biodiversity effects on community productivity was associated with increasing biomass overyielding of resource-conservative species increasing over time, and with overyielding of species characterized by fast resource acquisition either decreasing or increasing. In forests, temporal trends in species overyielding differ when considering above- versus belowground resource acquisition strategies. Overyielding in stem growth decreased for species with high light capture capacity but increased for those with high soil resource acquisition capacity. Our results imply that a diversity of species with different, and potentially complementary, ecological strategies is beneficial for maintaining community productivity over time in both grassland and forest ecosystems.This article is published as Zheng, L., Barry, K.E., Guerrero-Ramírez, N.R. et al. Effects of plant diversity on productivity strengthen over time due to trait-dependent shifts in species overyielding. Nat Commun 15, 2078 (2024). https://doi.org/10.1038/s41467-024-46355-z. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted

Effects of plant diversity on productivity strengthen over time due to trait-dependent shifts in species overyielding

Plant diversity effects on community productivity often increase over time. Whether the strengthening of diversity effects is caused by temporal shifts in species-level overyielding (i.e., higher species-level productivity in diverse communities compared with monocultures) remains unclear. Here, using data from 65 grassland and forest biodiversity experiments, we show that the temporal strength of diversity effects at the community scale is underpinned by temporal changes in the species that yield. These temporal trends of species-level overyielding are shaped by plant ecological strategies, which can be quantitatively delimited by functional traits. In grasslands, the temporal strengthening of biodiversity effects on community productivity was associated with increasing biomass overyielding of resource-conservative species increasing over time, and with overyielding of species characterized by fast resource acquisition either decreasing or increasing. In forests, temporal trends in species overyielding differ when considering above- versus belowground resource acquisition strategies. Overyielding in stem growth decreased for species with high light capture capacity but increased for those with high soil resource acquisition capacity. Our results imply that a diversity of species with different, and potentially complementary, ecological strategies is beneficial for maintaining community productivity over time in both grassland and forest ecosystems

Forest Structure, Wood Standing Stock, and Tree Biomass in Different Restoration Systems in the Brazilian Atlantic Forest

Reliable estimates of tree growth and wood yield are fundamental to support the management of restored forests and better reconcile the objectives of recovering biodiversity with the provision of ecosystem services. In this study, wood standing volumes and tree biomass stocks were estimated in different ecological restoration systems and at two sites with contrasting soil fertility, in order to evaluate the potential trade-offs between biodiversity and forest production. At each site, a complete randomized block design, with three replications of six treatments, was established in 1997–1998: direct seeding (DIRS), high-diversity tree plantation (HDIV), modified “Taungya” agroforestry system (AFS), mixed plantation with timber and firewood species (MIX), managed agroforestry system (AFSm) and managed mixed plantation (MIXm). We inventoried all trees with diameter at breast height (DBH) ≥ 5 cm in 450 m2 per treatment per plot, 19–20 years after establishment, using site-specific allometric models. Significant site effects were found for tree height, tree density and wood volume. Restoration systems (treatments) affected forest structure and forest productivity. Higher wood stock and biomass tree were observed in the less complex system (DIRS), while AFSm and HDIV reconciled higher species richness and diversity with good wood volume yields and tree biomass