Evidence of forest restoration success and the conservation value of community-owned forests in Southwest China using dung beetles as indicators

Considering pollinators' ecosystem services in the remediation and restoration of contaminated lands: Overview of research and its gaps

The concept of ecosystem services provides a useful framework for understanding how people are affected by changes to the natural environment, such as when a contaminant is introduced (e.g., oil spills, hazardous substance releases) or, conversely, when contaminated lands are remediated and restored. Pollination is one example of an important ecosystem service; pollinators play a critical role in any functioning terrestrial ecosystem. Other studies have suggested that consideration of pollinators' ecosystem services could lead to better remediation and restoration outcomes. However, the associated relationships can be complex, and evaluation requires synthesis from numerous disciplines. In this article, we discuss the possibilities for considering pollinators and their ecosystem services when planning remediation and restoration of contaminated lands. To inform the discussion, we introduce a general conceptual model of how pollinators and the ecosystem services associated with them could be affected by contamination in the environment. We review the literature on the conceptual model components, including contaminant effects on pollinators and the direct and indirect ecosystem services provided by pollinators, and identify information gaps. Though increased public interest in pollinators likely reflects increasing recognition of their role in providing many important ecosystem services, our review indicates that many gaps in understanding-about relevant natural and social systems-currently impede the rigorous quantification and evaluation of pollinators' ecosystem services required for many applications, such as in the context of natural resource damage assessment. Notable gaps include information on non-honeybee pollinators and on ecosystem services beyond those benefitting the agricultural sector. We then discuss potential research priorities and implications for practitioners. Focused research attention on the areas highlighted in this review holds promise for increasing the possibilities for considering pollinators' ecosystem services in the remediation and restoration of contaminated lands. Integr Environ Assess Manag 2024;20:322-336. © 2023 SETAC.

Native ectomycorrhizal fungi from the endangered pine rocklands are superior symbionts to commercial inoculum for slash pine seedlings

The south Florida pine rocklands is a critically endangered, fire-dependent ecosystem dominated by the overstory tree Pinus densa (South Florida slash pine). Because pine recruitment in this ecosystem has proven problematic, restoration efforts need to include replanting slash pine trees. Even though ectomycorrhizal fungi are known to be critical symbionts of young pines and are necessary for the development of healthy pines, virtually nothing is known about these mutualists and their role in pine establishment and survival in the pine rocklands. One approach to improve pine establishment is to grow seedlings in a nursery before outplanting, facilitating early associations with ectomycorrhizae, and therefore improving seedling health. In this study, we compared health metrics (height, stem diameter, final needle length, root length, root colonization, needle greenness, root volume, and root:shoot ratio) of seedlings grown in soil amended with five commercially available mycorrhizal inocula versus field soil collected from three pine rockland fragments. Seedlings grown with native field soil from the pine rocklands generally performed better than those grown with commercial inoculum in all metrics except root length. According to their labels, each commercial inoculum contained between 4 and 10 ectomycorrhizal fungi species. However, no ectomycorrhizal fungi were recovered from two of the inoculum products and only three ectomycorrhizal fungi in total were recovered from the other three products. In contrast, seedlings grown with field soil are associated with ten ectomycorrhizal species. Our results highlight the importance of incorporating native ectomycorrhizal fungi into pine seedling replanting as part of restoration efforts in the pine rocklands.

Tropical forest dung beetle-mammal dung interaction networks remain similar across an environmental disturbance gradient

Conservation outcomes could be greatly enhanced if strategies addressing anthropogenic land-use change considered the impacts of these changes on entire communities as well as on individual species. Examining how species interactions change across gradients of habitat disturbance allows us to predict the cascading consequences of species extinctions and the response of ecological networks to environmental change. We conducted the first detailed study of changes in a commensalist network of mammals and dung beetles across an environmental disturbance gradient, from primary tropical forest to plantations, which varied in above-ground carbon density (ACD) and mammal communities. Mammal diversity changed only slightly across the gradient, remaining high even in oil palm plantations and fragmented forest. Dung beetle species richness, however, declined in response to lower ACD and was particularly low in plantations and the most disturbed forest sites. Three of the five network metrics (nestedness, network specialization, and functionality) were significantly affected by changes in dung beetle species richness and ACD, but mammal diversity was not an important predictor of network structure. Overall, the interaction networks remained structurally and functionally similar across the gradient, only becoming simplified (i.e., with fewer dung beetle species and fewer interactions) in the most disturbed sites. We suggest that the high diversity of mammals, even in disturbed forests, combined with the generalist feeding patterns of dung beetles, confer resilience to the commensalist dung beetle-mammal networks. This study highlights the importance of protecting logged and fragmented forests to maintain interaction networks and potentially prevent extinction cascades in human-modified systems.

A global review of rubber plantations: Impacts on ecosystem functions, mitigations, future directions, and policies for sustainable cultivation

The growing global need for latex is driving rubber plantation (RP) expansion since the last century, with >2 Mha of cultivation area being established in the last decade. Southeast Asia is the hotspot for rubber cultivation at other land-use costs. Although rubber cultivation has improved the economic status of farmers, it has altered the habitat's ecology and ecosystem functions (EF). However, studies on the impacts of RP on EF are limited, and a clear overview is not available. To bridge this gap, we conducted an inclusive review of the EF of RP, including soil carbon storage, aboveground biomass (AGB) and belowground biomass (BGB), litter production and decomposition, respiration, and biodiversity (plants, animals, soil fauna, and microbes). We compared the EF in RP (monoculture) with those in forests because the conversion of forests to RP is prevalent in the tropics and because most RP studies used forests as reference ecosystems. We found RP generally have lower EF than forests. The impacts of RP on some EF are more severe (e.g., AGB, BGB, and plant diversity), causing decreases of >55%, and the effects are consistently negative irrespective of plantation age. However, including agroforestry or polyculture, integrated pest management, cover cropping, mulching, and composting can improve the EF in RP to some extent. We highlighted research gaps, particularly substantial research gaps concerning the influence of plant diversity treatments (i.e., agroforestry) performed in RP on EF. Additionally, more empirical data on the significance of spatial and temporal levels are required, such as how the impact on EF could vary with climate and RP age, as we showed some examples where EF differs spatially and temporally. More importantly, further research on plantation management to offset EF losses is needed. Finally, we emphasized knowledge gaps and suggested future directions and policies for improving EF in RP.

Improvement of vegetation structure enhances bird functional traits and habitat resilience in an area of ongoing restoration in the Atlantic Forest

Ecological restoration is a traditional option for recovering biodiversity and ecosystem functions. Birds perform pollination, seed dispersal, and pest-control services, which catalyze increases in habitat structure. Habitat complexity changes bird composition, but there is little evidence of its effects on bird functional diversity in Neotropical restorations. We tested whether bird functional diversity and composition respond to increased habitat complexity. Point-counts were performed (January-December 2015) in an area undergoing restoration (536 ha) in the Atlantic Forest of southeastern Brazil, in restorations with less and more structured vegetation and pastures and forest-fragments. The functional bird traits considered were diet, habitat, biomass, environmental sensitivity, and foraging strata. Increased habitat complexity was evaluated using plant characteristics (exotic grass, canopy, herbaceous cover, and diameter at breast height). A total of 172 bird species (5% endemic; 12% migratory) were recorded. Increased vegetation structure in both restored sites and forest-fragments drove a reorganization and addition of functional bird traits, which positively influenced functional richness, dispersion, and evenness. Shifts in plant-characteristics rearranged bird functional traits (diet-forest-dependence and diet-strata-foraging). The rapid development of vegetation structure is a key factor for restoration because it provides additional habitat for semi-dependent forest birds and enhances resilience and sustainability in new man-made forests.