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The carbon sink capacity of tropical forests is substantially affected by tree mortality. However, the main drivers of tropical tree death remain largely unknown. Here we present a pan-Amazonian assessment of how and why trees die, analysing over 120,000 trees representing > 3800 species from 189 long-term RAINFOR forest plots. While tree mortality rates vary greatly Amazon-wide, on average trees are as likely to die standing as they are broken or uprooted—modes of death with different ecological consequences. Species-level growth rate is the single most important predictor of tree death in Amazonia, with faster-growing species being at higher risk. Within species, however, the slowest-growing trees are at greatest risk while the effect of tree size varies across the basin. In the driest Amazonian region species-level bioclimatic distributional patterns also predict the risk of death, suggesting that these forests are experiencing climatic conditions beyond their adaptative limits. These results provide not only a holistic pan-Amazonian picture of tree death but large-scale evidence for the overarching importance of the growth–survival trade-off in driving tropical tree mortality. Tree mortality has been shown to be the dominant control on carbon storage in Amazon forests, but little is known of how and why Amazon forest trees die. Here the authors analyse a large Amazon-wide dataset, finding that fast-growing species face greater mortality risk, but that slower-growing individuals within a species are more likely to die, regardless of size.

Hunting impacts tropical vertebrate populations, causing declines of species that function as seed dispersers and predators, or that browse seedlings and saplings. Whether and how the resulting reductions in seed dispersal, seed predation, and browsing translate to changes in the tree composition is poorly understood. Here, we assess the effect of defaunation on the functional composition of com

The debt-peonage system is an agreement between patrons and laborers in different economic activities worldwide. A common feature is social exploitation of laborers that generate profits to the patrons. In recent literature it has been argued that debt-peonage can be an economically sound arrangement that secures the needs of actors. The paper evaluates to what extent traditionally strong debt-peonage in forest-dwelling communities in the Bolivian Amazon, has developed in a way that better secures the needs and economic interest of multiple actors. Case studies in sixteen communities yielded qualitative information on debt relations between peasants, traders and former patrons. Debt-peonage changed from a mechanism to provide and keep workforce indebted to new social relationships, equitable commercial links, opportunity to access work capital and production chain diversification. This rapid shift was caused by important changes in land and forest regulations.

For comparison, the total amount of carbon emitted due to tropical deforestation is estimated to be 1.5 Gt y -1 (or 20% of global anthropogenic emissions [1]). [...]the potential for emission reductions through improved forest management is at least 10% of that obtainable by curbing tropical deforestation. [...]substantial occupational health and safety benefits can be achieved from training workers in one of the world's most dangerous professions.

A demographic study was carried out on Bertholletia excelsa, the Brazil nut tree, in two primary forest sites in Northern Bolivia where Brazil nuts have been harvested for several decades. In spite of the large proportion (93%) of seeds that are harvested, reasonable densities of recently emerged seedlings were found. Seeds of Bertholletia are contained in woody fruits that are primarily opened by agoutis. Most fruits are left untouched on the forest floor for 1–2 y before they are opened, possibly due to high energetic costs of fruit opening just after fruit fall. However, the proportion of viable seeds is strongly reduced in older fruits. Growth in diameter at breast height (dbh) was low for pole-sized trees (< 15 cm dbh) and adult trees (> 100 cm dbh) and peaked for intermediate-sized trees (30–60 cm). These trees often attained a growth rate of > 1.5 cm y−1, which is high compared with other non-pioneer tropical trees. This, and the strong growth response to increased light availability found for seedlings and saplings, suggest that Bertholletia excelsa can be classified as a gap-dependent species. Matrix population models were constructed for both study populations. Population growth rates (λ) were close to one, and were most sensitive to persistence in one size category. Age estimates revealed that age at first reproduction (at dbh > 60 cm) amounts to over 120 y, and age in the last category (dbh > 160 cm) to almost 300 y. Given the continuous rejuvenation of the population, the stable population size, the high age at maturity and the long reproductive period, it is concluded that current levels of Brazil nut extraction may be sustained at least for several decades and perhaps for even longer periods.

A Correction to this paper has been published: https://doi.org/10.1038/s41467-020-20537-x

There is broad consensus that policymakers must work with indigenous peoples and local communities (IPLCs) to protect biodiversity and carbon stocks in the remaining tropical forests. However, the success of community forest magement initiatives around the world has been mixed. Collaboration between policymakers and IPLCs requires a nuanced understanding of the socio-economic and cultural realities, motivations, and long-term conservation needs of IPLCs. In this study, we examine the factors that influence the interl rulemaking in forest communities for the sustaible magement of their forests. We collected social and ecological data from 57 local communities located in the tropical peatland forests of the Pastaza Marañon Foreland Basin in northern Peru—an area of global importance for its carbon storage and biodiversity. These communities are engaged in harvesting M. flexuosa palm fruit (locally called aguaje). This practice often involves the cutting of palms, which contributes to the increasing degradation of peatland forests. Using chi-squared alysis, we found that the commercialization of forest resources by community members predicts the presence of rules in communities. Resource scarcity is not associated with the existence of restrictive rules. In addition, we found that the adoption of rules by a community strongly associated with its participation in a community of practice (COP). In the context of sustaible forest magement, COPs are networks that link IPLCs with exterl forest professiols for mutual learning and practical assistance. They must be horizontal partnerships that ensure equitable participation and mutual respect. While IPLCs have an invaluable traditiol ecological knowledge (TEK) about their forest, their remote locations often prevent them from accessing innovative magement solutions or scientific knowledge about the broader landscape-level status of the forest and its species, such as regeneration capacity and population size. Trusted partners can play a critical role in facilitating dialogue about sustaible forest magement, reassuring communities about the implementation of restrictive rules, providing tangible visions of viable and sustaible altertives, and offering practical support.

In many cases, government institutions insufficiently consider the traditional land use of community areas in spatial planning policy. Although numerous investigations into the participatory mapping of community lands have occurred, their results have not been adequately incorporated into the policy realm. In Indonesia, Spatial Planning Regulation (SPR), or locally known as Rencana Tata Ruang Wilayah (RTRW) is an instrument to guide land use practices in the categories of development and protected areas. Using a case study for the Merauke district in Papua province in Indonesia, we demonstrate how participatory mapping results of important community areas were integrated into district-level spatial planning through Participatory GIS (PGIS). There are three phases to the process of integrating PGIS into Spatial Planning Regulation. The first phase is to develop a shared vision between the customary communities and the district government and gain a commitment from both parties to use the results in further planning processes. The second phase is to facilitate the PGIS process, which is conducted by the community and a facilitator – in this case a team of WWF Indonesia Sahul Papua Region Office –, and the final phase is to integrate the PGIS results of the important community areas into spatial planning regulation. The results of our case study showed that of the total area adopted by the RTRW, about 69% were important community areas designated as cultural preservation areas. The remaining important community areas were allocated to two other land use categories: protected areas (22%) and development areas (9%). In this case, 91% of the community areas (647,850 hectares) were secured from other land use purposes such as large-scale agriculture, mining, forestry, and infrastructure. The PGIS approach can be applied to districts across Indonesia for mapping community land use practices and integrating them into Spatial Planning Regulation.

Phytolith analysis is a well-established archaeobotanical tool, having provided important insights into pre-Columbian crop cultivation and domestication across Amazonia through the Holocene. Yet, its use as a palaeoecological tool is in its infancy in Amazonia and its effectiveness for reconstructing pre-Columbian land-use beyond archaeological sites (i.e., ‘off-site’) has so far received little critical attention. This paper examines both new and previously published soil phytolith data from SW Amazonia to assess the robustness of this proxy for reconstructing pre-Columbian land-use. We conducted the study via off-site soil pits radiating 7.5 km beyond a geoglyph in Acre state, Brazil, and 50 km beyond a ring-ditch in northern Bolivia, spanning the expected gradients in historical land-use intensity. We found that the spatio-temporal patterns in palm phytolith data across our soil-pit transects support the hypothesis that pre-Columbian peoples enriched their forests with palms over several millennia, although phytoliths are limited in their ability to capture small-scale crop cultivation and deforestation. Despite these drawbacks, we conclude that off-site soil phytolith analysis can provide novel insights into pre-Columbian land use, provided it is effectively integrated with other land-use (e.g., charcoal) and archaeological data.

Higher levels of taxonomic and evolutionary diversity are expected to maximize ecosystem function, yet their relative importance in driving variation in ecosystem function at large scales in diverse forests is unknown. Using 90 inventory plots across intact, lowland, terra firme, Amazonian forests and a new phylogeny including 526 angiosperm genera, we investigated the association between taxonomic and evolutionary metrics of diversity and two key measures of ecosystem function: aboveground wood productivity and biomass storage. While taxonomic and phylogenetic diversity were not important predictors of variation in biomass, both emerged as independent predictors of wood productivity. Amazon forests that contain greater evolutionary diversity and a higher proportion of rare species have higher productivity. While climatic and edaphic variables are together the strongest predictors of productivity, our results show that the evolutionary diversity of tree species in diverse forest stands also influences productivity. As our models accounted for wood density and tree size, they also suggest that additional, unstudied, evolutionarily correlated traits have significant effects on ecosystem function in tropical forests. Overall, our pan-Amazonian analysis shows that greater phylogenetic diversity translates into higher levels of ecosystem function: tropical forest communities with more distantly related taxa have greater wood productivity. Inventory data from 90 lowland Amazonian forest plots and a phylogeny of 526 angiosperm genera were used to show that taxonomic and phylogenetic diversity are both predictive of wood productivity but not of biomass variation.