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While much research has focused on genetic variation in plants in relation to abiotic clines in temperate and boreal forests, few studies have examined similar relationships in tropical forests. Genetic variation in desirable performance traits of trees, such as drought tolerance, fast‐growth, and carbon sequestration rates, is widely used to improve reforestation efforts in nontropical systems. However, evolutionary processes such as local adaptation are poorly understood in tropical forests making it difficult to locate desired phenotypes. To test for genetic variation in growth rate in relationship to climatic clines, we conducted a common garden study over 18 months in a nursery using four dipterocarp tree species, represented by 9–12 half‐sib families, sourced across an elevational gradient ranging from lowland to hill forests (circa 130–470 m above sea‐level) in Malaysian Borneo. We found genetic variation in growth for all four species with fast‐growing half‐sib families growing 42–88% faster than poorly performing half‐sib families. Furthermore, in three species we found that elevation of seedling origin predicted seedling performance; in Shorea fallax and S. johorensis, half‐sib families originating from low elevations performed the best. In S. argentifolia half‐sib families' seedlings from low elevations grew slowly. Because elevation is a good proxy for climate, the finding of elevational clines predicting genetic variation in growth provides evidence of evolution affecting the function of tropical tree species. Our research highlights opportunities to better understand evolutionary processes in tropical forests and to use such information to improve seed source selection in reforestation. [ABSTRACT FROM AUTHOR]

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Restoration is effective for improving ecosystem health and protecting biodiversity. However, restoration initiatives often neglect socioeconomic dimensions that affect local communities. When these factors are included, they are often under the purview of managers whose perspectives of public engagement remain understudied. Here, we focused on mangroves and surveyed restoration project managers in Latin America and the Caribbean to explore if and how they have engaged in socioeconomic best practices such as including the community, local knowledge, and social monitoring. We also sought to understand how these activities related to perceptions of project outcomes. Most managers (n = 182) reported that they engaged in some best practices, such as community engagement in various project stages and incorporating local information. Differences existed as to which types of information were included, which project stages included the community, and how frequently the community was involved. Overall, managers, especially those who engaged the community more frequently and throughout the entire restoration process, believed projects were successful and provided numerous community benefits. However, despite the reported number of benefits, less than half of the respondents conducted social monitoring to assess the actualization of these benefits or other social indicators. We provide suggestions for how mangrove restoration projects, and restoration efforts more broadly, can increase the inclusion of communities, their knowledge, and social monitoring to better assess the achievement of project outcomes. [ABSTRACT FROM AUTHOR]

Effective reforestation of degraded tropical forests depends on selecting planting material suited to the stressful environments typical at restoration sites that can be exacerbated by increased duration and intensity of dry spells expected with climate change. While reforestation efforts in nontropical systems are incorporating drought‐adapted genotypes into restoration programs to cope with drier conditions, such approaches have not been tested or implemented in tropical forests. As the first effort to examine genetic variation in plant response to drought in a tropical wet forest, we established a watering experiment using five replicated maternal lines (i.e. seedlings from different maternal trees) of five dipterocarp species native to Borneo. Apart from the expected species level variation in growth and herbivory (3‐fold variation in both cases), we also found intraspecific variation so that growth in some cases varied 2‐fold, and herbivory 3‐fold, among genetically different maternal lines. In two species we found that among‐maternal line variation in growth rate was negatively correlated with tolerance to water limitation, that is, the maternal lines that performed the best in the high water treatment lost proportionally more of their growth during water limitation. We argue that selection for tolerance to future drier conditions is not only likely to impact population genetics of entire forests, but likely extends from forest trees to the communities of canopy arthropods associated with these trees. In tropical reforestation efforts where increased drought is predicted from climate change, including plant material resilient to drier conditions may improve restoration effectiveness. [ABSTRACT FROM AUTHOR]

We analyzed 18 years of post-logging data from Sabah, Borneo to evaluate the impact of two selective logging methods – Supervised logging (SL) including pre-aligned skid trails and directional felling, and conventional logging (CL), where trees were felled before the crawler tractor was called in for skidding and the fellers had no formal training in felling techniques – on net standing volume recovery, survivor growth, ingrowth and mortality of trees (⩾10 cm DBH). The logging treatments were either combined with- (CC) or without (NCC) pre-harvest climber cutting in a randomized 2 × 2 factorial design consisting 16 one-hectare treatment plots. We investigated the effect on the complete stand including all trees (⩾10 cm DBH) regardless of species, but also distinguished between the effects on the commercially interesting species of dipterocarps ( Dipterocarpaceae family) and pioneer species (mainly Macaranga species). Supervised logging in combination with climber cutting was in many ways beneficial to stand development and these effects were mainly expressed at higher harvest intensities. For example, supervised logging reduced the ingrowth and survivor growth of pioneer Macaranga spp.; at high harvest intensities approximately 50% fewer pioneers grew in when SL was used in comparision to CL. In addition, climber cutting increased the ingrowth as well as decreased the mortality of highly valuable dipterocarp species with increasing harvest intensity. These effects appeared also to have stand level consequences as forests treated with the combination of supervised logging and climber cutting also exhibited faster recovery in standing volume of high value dipterocarps compared to any other combination of treatments. We conclude that, with improved ingrowth of dipterocarps, reduced overall mortality and generally better stand volume recovery; supervised logging (SL) in combination with climber cutting (CC) could be an attractive forest management system in mixed dipterocarp forests. [ABSTRACT FROM AUTHOR]