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Huge areas of tropical forests are degraded, reducing their biodiversity, carbon, and timber value. The recovery of these degraded forests can be significantly inhibited by climbing plants such as lianas. Removal of super‐abundant climbers thus represents a restoration action with huge potential for application across the tropics. While experimental studies largely report positive impacts of climber removal on tree growth and biomass accumulation, the efficacy of climber removal varies widely, with high uncertainty as to where and how to apply the technique. Using meta‐analytic techniques, we synthesize results from 26 studies to quantify the efficacy of climber removal for promoting tree growth and biomass accumulation. We find that climber removal increases tree growth by 156% and biomass accumulation by 209% compared to untreated forest, and that efficacy remains for at least 19 years. Extrapolating from these results, climber removal could sequester an additional 32 Gigatons of CO2 over 10 years, at low cost, across regrowth, and production forests. Our analysis also revealed that climber removal studies are concentrated in the Neotropics (N = 22), relative to Africa (N = 2) and Asia (N = 2), preventing our study from assessing the influence of region on removal efficacy. While we found some evidence that enhancement of tree growth and AGB accumulation varies across disturbance context and removal method, but not across climate, the number and geographical distribution of studies limits the strength of these conclusions. Climber removal could contribute significantly to reducing global carbon emissions and enhancing the timber and biomass stocks of degraded forests, ultimately protecting them from conversion. However, we urgently need to assess the efficacy of removal outside the Neotropics, and consider the potential negative consequences of climber removal under drought conditions and for biodiversity. Climber removal roughly doubles tree growth and triples aboveground biomasss accumulation in degraded tropical forests. The restoration method could provide substantial climate mitigation benefits.

Tropical forests have long been thought to be in stable state, but recent insights indicate that global change is leading to shifts in forest dynamics and species composition. These shifts may be driven by environmental changes such as increased resource availability, increased drought stress, and/or recovery from past disturbances. The relative importance of these drivers can be inferred from analyzing changes in trait values of tree communities. Here, we evaluate a decade of change in species and trait composition across five old-growth Neotropical forests in Bolivia, Brazil, Guyana, and Costa Rica that cover large gradients in rainfall and soil fertility. To identify the drivers of compositional change, we used data from 29 permanent sample plots and measurements of 15 leaf, stem, and whole-plant traits that are important for plant performance and should respond to global change drivers. We found that forests differ strongly in their community-mean trait values, resulting from differences in soil fertility and annual rainfall seasonality. The abundance of deciduous species with high specific leaf area increases from wet to dry forests. The community-mean wood density is high in the driest forests to protect xylem vessels against drought cavitation, and is high in nutrient-poor forests to increase wood longevity and enhance nutrient residence time in the plant. Interestingly, the species composition changed over time in three of the forests, and the community-mean wood density increased and the specific leaf area decreased in all forests, indicating that these forests are changing toward later successional stages dominated by slow-growing, shade-tolerant species. We did not see changes in other traits that could reflect responses to increased drought stress, such as increased drought deciduousness or decreased maximum adult size, or that could reflect increased resource availability (CO2, rainfall, or nitrogen). Changes in species and trait composition in these forests are therefore most likely caused by recovery from past disturbances. These compositional changes may also lead to shifts in ecosystem processes, such as a lower carbon sequestration and \"slower\" forest dynamics.

Reducing emissions from deforestation and forest degradation (REDD+) is a climate change mitigation policy in which rich countries provide payments to developing countries for protecting their forests. In 2009, the countries of Norway and Guyana entered into one of the first bilateral REDD+ programs, with Norway offering to pay US$250 million to Guyana if annual deforestation rates remained below 0.056% from 2010 to 2015. To quantify the impact of this national REDD+ program, we construct a counterfactual times-series trajectory of annual tree cover loss using synthetic matching. This analytical approach allows us to quantify tree cover loss that would have occurred in the absence of the Norway-Guyana REDD+ program. We found that the Norway-Guyana REDD+ program reduced tree cover loss by 35% during the implementation period (2010 to 2015), equivalent to 12.8 million tons of avoided CO₂ emissions. Our analysis indicates that national REDD+ payments attenuated the effect of increases in gold prices, an internationally traded commodity that is the primary deforestation driver in Guyana. Overall, we found strong evidence that the program met the additionality criteria of REDD+. However, we found that tree cover loss increased after the payments ended, and therefore, our results suggest that without continued payments, forest protection is not guaranteed. On the issue of leakage, which is complex and difficult to quantify, a multinational REDD+ program for a region could address leakage that results from differences in forest policies between neighboring countries.

What is meant by sustainability depends on what is sustained and at what level. Sustainable forest management, for example, requires maintenance of a variety of values not the least of which is sustained timber yields (STYs). For the 1 Bha of the world's forests subjected to selective or partial logging, failure to maintain yields can be hidden by regulatory requirements and questionable auditing practices such as increasing the number of commercial species with each harvest, reducing the minimum size at which trees can be harvested and accepting logs of lower quality. For assertions of STY to be credible, clarity is needed about all these issues, as well as about the associated ecological and economic tradeoffs. Lack of clarity about sustainability heightens risks of unsubstantiated claims and unseen losses. STY is possible but often requires cutting cycles that are longer and logging intensities that are lower than prescribed by law, as well as effective use of low-impact logging practices and application of silvicultural treatments to promote timber stock recovery. These departures from business-as-usual practices will lower profit margins but generally benefit biodiversity and ecosystem services.

Gold mining is a major driver of Amazonian forest loss and degradation. As mining activity encroaches on primary forest in remote and inaccessible areas, satellite imagery provides crucial data for monitoring mining‐related deforestation. High‐resolution imagery, in particular, has shown promise for detecting artisanal gold mining at the forest frontier. An important next step will be to establish relationships between satellite‐derived land cover change and biodiversity impacts of gold mining. In this study, we set out to detect artisanal gold mining using high‐resolution imagery and relate mining land cover to insects, a taxonomic group that accounts for the majority of faunal biodiversity in tropical forests. We applied an object‐based image analysis (OBIA) to classify mined areas in an Indigenous territory in Guyana, using PlanetScope imagery with ~3.7 m resolution. We complemented our OBIA with field surveys of insect family presence or absence in field plots (n = 105) that captured a wide range of mining disturbances. Our OBIA was able to identify mined objects with high accuracy (>90% balanced accuracy). Field plots with a higher proportion of OBIA‐derived mine cover had significantly lower insect family richness. The effects of mine cover on individual insect taxa were highly variable. Insect groups that respond strongly to mining disturbance could potentially serve as bioindicators for monitoring ecosystem health during and after gold mining. With the advent of global partnerships that provide universal access to PlanetScope imagery for tropical forest monitoring, our approach represents a low‐cost and rapid way to assess the biodiversity impacts of gold mining in remote landscapes. Gold mining is a major driver of Amazonian forest loss and degradation. As mining activity encroaches on primary forest in remote and inaccessible areas, satellite imagery provides crucial data for monitoring mining‐related deforestation. We apply high‐resolution satellite imagery to detect artisanal gold mining and relate mining land cover to insects, a taxonomic group that accounts for the majority of faunal biodiversity in tropical forests. We were able to detect mining land cover with >90% using an object‐based image analysis. Field plots with higher mine cover had significantly lower insect family richness. Insect groups that respond strongly to mining disturbance could potentially serve as bioindicators for monitoring ecosystem health during and after gold mining. With the advent of global partnerships that provide universal access to PlanetScope imagery for tropical forest monitoring, our approach represents a low‐cost and rapid way to assess the biodiversity impacts of gold mining in remote landscapes.

The selective logging that characterizes most timber extraction operations in the tropics leaves large patches of logging blocks (i.e., areas allocated for harvesting) intact, without evidence of direct impacts. For example, in ~10,000 ha sampled in 48 forest management enterprises in Africa (Gabon, Republic of Congo, and the Democratic Republic of Congo), Indonesia, Suriname, and Mexico, an average of 69% (range 20–97%) of the area in logging blocks was not directly affected by timber harvests. The proportion of intact forest within logging blocks decreased very slightly with increases in harvest intensity in the accessed portion of the logging blocks (9–86 m 3 ha −1 ) but decreased strongly with harvest intensity in entire logging blocks (0.3–48.2 m 3 ha −1 ). More forest was left intact in areas farther from roads, on slopes >40%, and within 25 m of perennial streams, but the effect sizes of each of these variables was small (~8%). It is less clear how much of the intact forest left after one harvest will remain intact through the next. Conservation benefits without reductions in timber yields will derive from better management planning so that sensitive and ecologically critical areas, such as steep slopes and riparian buffers, constitute large and permanent proportions of the intact forest in selectively logged landscapes in the tropics.

Ecotourism is developing rapidly in biodiversity hotspots worldwide, but there is limited and mixed empirical evidence that ecotourism achieves positive biodiversity outcomes. We assessed whether ecotourism influenced forest loss rates and trajectories from 2000 to 2017 in Himalayan temperate forests. We compared forest loss in 15 ecotourism hubs with nonecotourism areas in 4 Himalayan countries. We used matching statistics to control for local-level determinants of forest loss, for example, population density, market access, and topography. None of the ecotourism hubs was free of forest loss, and we found limited evidence that forest-loss trajectories in ecotourism hubs were different from those in nonecotourism areas. In Nepal and Bhutan, differences in forest loss rates between ecotourism hubs and matched nonecotourism areas did not differ significantly, and the magnitude of the estimated effect was small. In India, where overall forest loss rates were the lowest of any country in our analysis, forest loss rates were higher in ecotourism hubs than in matched nonecotourism areas. In contrast, in China, where overall forest loss rates were highest, forest loss rates were lower in ecotourism hubs than where there was no ecotourism. Our results suggest that the success of ecotourism as a forest conservation strategy, as it is currently practiced in the Himalaya, is context dependent. In a region with high deforestation pressures, ecotourism may be a relatively environmentally friendly form of economic development relative to other development strategies. However, ecotourism may stimulate forest loss in regions where deforestation rates are low. El ecoturismo está desarrollándose rápidamente en los puntos calientes de biodiversidad en todo el mundo, pero existe evidencia empírica mixta y limitada de los resultados positivos que se logran con el ecoturismo. Valoramos si el ecoturismo influyó sobre las tasas de pérdida forestal y sus trayectorias entre el 2000 y el 2017 en los bosques templados del Himalaya. Comparamos la pérdida forestal en quince focos ecoturísticos con la pérdida forestal en las áreas sin ecoturismo de cuatro países del Himalaya. Utilizamos estadística correspondiente para controlar las determinantes a nivel local de la pérdida del bosque, por ejemplo, la densidad poblacional, el acceso al mercado y la topografía. Ninguno de los focos ecoturísticos estaba libre de pérdida forestal, además de que encontramos evidencia limitada de que las trayectorias de la pérdida forestal en los focos ecoturísticos eran diferentes a las trayectorias en las áreas sin ecoturismo. En Nepal y en Bután, las diferencias en la pérdida forestal entre los focos ecoturísticos y las áreas sin ecoturismo correspondidas no difirieron significativamente y la magnitud del efecto estimado fue menor. En la India, donde las tasas generales de pérdida forestal fueron las más bajas de cualquier país en nuestro análisis, las tasas de pérdida forestal fueron más altas en los focos ecoturísticos que en las áreas sin ecoturismo correspondidas. Como contraste, en China, donde las tasas generales de pérdida forestal fueron más altas, las tasas de pérdida forestal fueron más bajas en los focos ecoturísticos que en donde no existe el ecoturismo. Nuestros resultados sugieren que el éxito del ecoturismo como estrategia de conservación del bosque, a como se práctica actualmente en el Himalaya, depende del contexto. En una región con presiones altas de deforestación, el ecoturismo puede ser una forma de desarrollo económico relativamente amigable con el ambiente comparado con otras estrategias de desarrollo. Sin embargo, el ecoturismo puede estimular la pérdida forestal en regiones en las que las tasas de deforestación son bajas. 全球范围内，生物多样性热点地区的生态旅游芷在快速发展，但缺少明确的实证证据来证明生态旅游对生 物多样性保护有积极作用。本研究评估了生态旅游是否对2000-2017年间喜马拉雅温带森林的森林丧失率和森林丧失轨迹产生影响。我们比较了喜马拉雅地区四个国家的十五个生态旅游区与非生态旅游区的森林丧失情 况。我们用配对的统计数据来控制当地影响森林丧失的其它因素, 如人口密度，幵放市场程度和地形等。我们 发现所有生态旅游区都遭受了森林丧失，且有限的证据表明，生态旅游区与非生态旅游区森林丧失轨迹并不一 致。在尼泊尔和不丹，生态旅游区与相配对的非生态旅游区的森林丧失率没有显著差异，我们估计的生态旅游 影响程度也很低。在本研究中，印度的森林总体丧失率最低，生态旅游区的森林丧失率比相配对的非生态旅游 区更高。相比之下，在森林总体丧失率最高的中国，生态旅游区的森林丧失率却比非生态旅游区的更低。我们 的结果表明，以目前喜马拉雅地区的实践为例, 生态旅游能否成为ー种成功的森林保护策略要依据具#:情况 在森林砍伐压力较大的地区，生态旅游可能是相比于其它发展策略较为坏境友好的经济发展形式,但在森林砍 伐率低的地区，生态旅游则可能加速森林丧失。

Based on intensive field courses on tropical forest management and conservation in Belize, Guyana, Indonesia, and Mexico, we recommend a pedagogical approach designed to help fill scientific mentor gaps where they impede publication by relatively inexperienced scientists. Participants in these 8–12 day field sessions were provided what instructors judged to be novel research topics but then were tasked with refining hypotheses, developing and implementing field studies, analyzing data, rehearsing formal oral presentations, and preparing complete manuscript drafts. Over the subsequent months, the manuscripts were revised for submission to peer-reviewed journals; to date, six were published, one is in review, and two others are close to submission. These were the first publications of most of the participants, some of whom are evaluated by their home institutions partially on the basis of their publication records. These low cost workshops were fun and benefited participants and instructors alike.

Growing demand for food coupled with climate commitments to reduce emissions will result in more land development for agriculture and renewable energy. Simultaneously, conserving land for biodiversity and nature’s contributions to people (NCP) is imperative for achieving international climate, sustainable development, and biodiversity goals. Meeting these interconnected objectives requires efficient land allocation across sectors. Here, we present a flexible, multiple-objective framework for strategically allocating land to mitigate threats to biodiversity and NCP under climate change while supporting development. Application of this framework at a global scale through country-level targets shows that if future development is planned without consideration of nature, demands for land could impact nearly 1 million km 2 of high-priority conservation areas. Multi-sector planning can mitigate potential conflict, reducing carbon loss and species exposure. Our findings underscore the need to conserve critical areas for nature, reduce land demand for food and energy, and intentionally coordinate land use across sectors.