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It is largely unknown how South America’s Andean forests affect the global carbon cycle, and thus regulate climate change. Here, we measure aboveground carbon dynamics over the past two decades in 119 monitoring plots spanning a range of >3000 m elevation across the subtropical and tropical Andes. Our results show that Andean forests act as strong sinks for aboveground carbon (0.67 ± 0.08 Mg C ha −1 y −1 ) and have a high potential to serve as future carbon refuges. Aboveground carbon dynamics of Andean forests are driven by abiotic and biotic factors, such as climate and size-dependent mortality of trees. The increasing aboveground carbon stocks offset the estimated C emissions due to deforestation between 2003 and 2014, resulting in a net total uptake of 0.027 Pg C y −1 . Reducing deforestation will increase Andean aboveground carbon stocks, facilitate upward species migrations, and allow for recovery of biomass losses due to climate change. Here, the authors investigate the aboveground carbon sink efficiency of Andean forests. The study shows the high potential of these forests to serve as future carbon refuges, and urges to reduce deforestation and increase restoration.

Why do forest productivity and biomass decline with elevation? To address this question, research to date generally has focused on correlative approaches describing changes in woody growth and biomass with elevation. We present a novel, mechanistic approach to this question by quantifying the autotrophic carbon budget in 16 forest plots along a 3300m elevation transect in Peru. Low growth rates at high elevations appear primarily driven by low gross primary productivity (GPP), with little shift in either carbon use efficiency (CUE) or allocation of net primary productivity (NPP) between wood, fine roots and canopy. The lack of trend in CUE implies that the proportion of photosynthate allocated to autotrophic respiration is not sensitive to temperature. Rather than a gradual linear decline in productivity, there is some limited but nonconclusive evidence of a sharp transition in NPP between submontane and montane forests, which may be caused by cloud immersion effects within the cloud forest zone. Leaf-level photosynthetic parameters do not decline with elevation, implying that nutrient limitation does not restrict photosynthesis at high elevations. Our data demonstrate the potential of whole carbon budget perspectives to provide a deeper understanding of controls on ecosystem functioning and carbon cycling.

Aim: Tropical elevation gradients are natural laboratories to assess how changing climate can influence tropical forests. However, there is a need for theory and integrated data collection to scale from traits to ecosystems. We assess predictions of a novel trait-based scaling theory, including whether observed shifts in forest traits across a broad tropical temperature gradient are consistent with local phenotypic optima and adaptive compensation for temperature. Location: An elevation gradient spanning 3,300 m and consisting of thousands of tropical tree trait measures taken from 16 1-ha tropical forest plots in southern Perú, where gross and net primary productivity (GPP and NPP) were measured. Time period: April to November 2013. Major taxa studied: Plants; tropical trees. Methods: We developed theory to scale from traits to communities and ecosystems and tested several predictions. We assessed the covariation between climate, traits, biomass and GPP and NPP. We measured multiple traits linked to variation in tree growth and assessed their frequency distributions within and across the elevation gradient. We paired these trait measures across individuals within 16 forests with simultaneous measures of ecosystem net and gross primary productivity. Results: Consistent with theory, variation in forest NPP and GPP primarily scaled with forest biomass, but the secondary effect of temperature on productivity was much less than expected. This weak temperature dependence appears to reflect directional shifts in several mean community traits that underlie tree growth with decreases in site temperature. Main conclusions: The observed shift in traits of trees that dominate in more cold environments is consistent with an 'adaptive/acclimatory' compensation for the kinetic effects of temperature on leaf photosynthesis and tree growth. Forest trait distributions across the gradient showed overly peaked and skewed distributions, consistent with the importance of local filtering of optimal growth traits and recent shifts in species composition and dominance attributable to warming from climate change. Trait-based scaling theory provides a basis to predict how shifts in climate have and will influence the trait composition and ecosystem functioning of tropical forests.

General patterns of forest dynamics and productivity in the Andes Mountains are poorly characterized. Here we present the first large-scale study of Andean forest dynamics using a set of 63 permanent forest plots assembled over the past two decades. In the North-Central Andes tree turnover (mortality and recruitment) and tree growth declined with increasing elevation and decreasing temperature. In addition, basal area increased in Lower Montane Moist Forests but did not change in Higher Montane Humid Forests. However, at higher elevations the lack of net basal area change and excess of mortality over recruitment suggests negative environmental impacts. In North-Western Argentina, forest dynamics appear to be influenced by land use history in addition to environmental variation. Taken together, our results indicate that combinations of abiotic and biotic factors that vary across elevation gradients are important determinants of tree turnover and productivity in the Andes. More extensive and longer-term monitoring and analyses of forest dynamics in permanent plots will be necessary to understand how demographic processes and woody biomass are responding to changing environmental conditions along elevation gradients through this century.

As Open Science practices become more commonplace, there is a need for the next generation of scientists to be well versed in these aspects of scientific research. Yet, many training opportunities for early career researchers (ECRs) could better emphasize or integrate Open Science elements. Field courses provide opportunities for ECRs to apply theoretical knowledge, practice new methodological approaches, and gain an appreciation for the challenges of real-life research, and could provide an excellent platform for integrating training in Open Science practices. Our recent experience, as primarily ECRs engaged in a field course interrupted by COVID-19, led us to reflect on the potential to enhance learning outcomes in field courses by integrating Open Science practices and online learning components. Specifically, we highlight the opportunity for field courses to align teaching activities with the recent developments and trends in how we conduct research, including training in: publishing registered reports, collecting data using standardized methods, adopting high-quality data documentation, managing data through reproducible workflows, and sharing and publishing data through appropriate channels. We also discuss how field courses can use online tools to optimize time in the field, develop open access resources, and cultivate collaborations. By integrating these elements, we suggest that the next generation of field courses will offer excellent arenas for participants to adopt Open Science practices.

The COVID-19 crisis has forced researchers in Ecology to change the way we work almost overnight. Nonetheless, the pandemic has provided us with several novel components for a new way of conducting science. In this perspective piece, we summarize eight central insights that are helping us, as early career researchers, navigate the uncertainties, fears, and challenges of advancing science during the COVID-19 pandemic. We highlight how innovative, collaborative, and often Open Science-driven developments that have arisen from this crisis can form a blueprint for a community reinvention in academia. Our insights include personal approaches to managing our new reality, maintaining capacity to focus and resilience in our projects, and a variety of tools that facilitate remote collaboration. We also highlight how, at a community level, we can take advantage of online communication platforms for gaining accessibility to conferences and meetings, and for maintaining research networks and community engagement while promoting a more diverse and inclusive community. Overall, we are confident that these practices can support a more inclusive and kinder scientific culture for the longer term.

Andean bears ( Tremarctos ornatus ) forage extensively on bromeliads ( Puya spp.) across their range, although their selectivity for bromeliads is less understood. We report on foraging activity by Andean bears on two species of bromeliad, Puya leptostachya and Puya membranacea , in high elevation puna grasslands (3499–3806 m.a.s.l) within and near Manu National Park (MNP) in SE Peru. We established two ridgeline transects (inside and outside MNP) with perpendicular transects running downslope. We recorded whether bromeliad plants were foraged by Andean bears on four separate sampling occasions that included wet and dry seasons from July 2017 to August 2018. We observed foraging by Andean bears at 6.8% of the available individual plants spread across 16.7% of the available patches. We utilized Resource Selection Functions to evaluate the environmental factors influencing the selection of bromeliad patches by Andean bears for foraging. Andean bears showed selection for Puya leptostachya over Puya membranacea , preferring to forage during the dry season at higher density patches of younger vegetative-stage bromeliads, possibly due to the increased bioavailability of nutrients in the basal meristematic plant tissue the bears prefer to eat. Andean bears selected bromeliad patches growing on east-facing, steep, high-altitude slopes, in a band near the cloud forest edge, which likely reflected a combination of optimal growing conditions for the bromeliads and habitat selection by the bears. Observations of foraging on grassland bromeliads occurred almost exclusively within the boundaries of MNP, which may in part reflect bears avoiding cattle impacts outside of the park. Andean bears showed active behavioral selection for bromeliads within the puna grasslands, and we recommend that grassland buffers around the cloud forest should be considered as primary habitat in conservation management plans.

Precise ecological information about the life‐history strategies of different species of tropical trees is required for effective management. (a, b) Three genera of trees from the nutmeg family have very different maximum sizes and growth rates, but are all typically harvested under the same guidelines. (c) The species of palm Euterpe precatoria has very high recruitment and mortality rates compared to most tropical trees, and an understanding of these high turnover rates need to be incorporated in efforts to manage this species. Societal Impact Statement The approach that we take to our science is as important as the questions that we address if we would like our research to inform management. Here, we discuss our experience of using networks of permanent forest inventory plots to support sustainable management and conservation of intact tropical forests. A key conclusion is that to maximize the use of data from such large international networks within policymaking, it is crucial that leadership is widely shared among participants. Such an approach helps to address ethical concerns surrounding international collaborations and also achieves greater policy impact. Summary Long‐term data from permanent forest inventory plots have much to offer the management and conservation of intact tropical forest landscapes. Knowledge of the growth and mortality rates of economically important species, forest carbon balance, and the impact of climate change on forest composition are all central to effective management. However, this information is rarely integrated within the policymaking process. The problem reflects broader issues in using evidence to influence environmental management, and in particular, the need to engage with potential users beyond the collection and publication of high‐quality data. To ensure permanent plot data are used, (a) key “policy windows”—opportunities to integrate data within policy making—need to be identified; (b) long‐term relationships need to be developed between scientists and policy makers and policymaking organizations; and (c) leadership of plot networks needs to be shared among all participants, and particularly between institutions in the global north and those in tropical countries. Addressing these issues will allow permanent plot networks to make tangible contributions to ensuring that intact tropical forest persists over coming decades.

Aim: Understanding patterns of species turnover along environmental gradients and their consistency across taxonomic groups is central to the study of biodiversity. We may expect congruence in diversity patterns across groups whose ranges could be influenced by species interactions. We explore associations between bird and vegetation communities in the tropical Andes to determine whether patterns of species richness and turnover in birds and trees are congruent with elevation, and whether tree species composition, vegetation structure, elevation, or a combination of these best predicts bird species composition. Location: A forested 2600-m elevational gradient on the eastern slope of the Peruvian Andes. Methods: Bird surveys and vegetation measurements were conducted at 172 points, and a subset of these were spatially matched with fourteen 1-ha tree inventory plots. Diversity patterns were described for trees, birds, and avian foraging guilds. We used dissimilarity matrices to examine patterns of turnover and nestedness. Turnover of birds and trees was examined by comparing compositional change of adjacent plots along the gradient. Multiple regression on distance matrices was employed to determine contributions of tree species composition, vegetation structure and elevation to explaining variation in bird species composition. Results: Species richness was higher for trees than for birds, and whereas diversity in both taxa decreased with elevation, tree richness showed a low-elevation plateau before declining at higher elevations. Tree species had narrower distributions compared to birds, but patterns of turnover were largely congruent between taxa. Nestedness contributed much less to dissimilarity than turnover, although birds showed higher nestedness, particularly at high elevations. Tree species composition, elevation and vegetation structure were all important predictors of bird species composition; the best model explained 78% of bird dissimilarity across plots. Tree species composition was always included in the best models, for all birds and foraging guilds. Main conclusions: Our assessment of Andean bird and vegetation communities suggests strong correspondence, perhaps due to direct interactions or similar underlying drivers. We hypothesize that with climate change, range shifts in these groups may not occur independently. Rather, birds may have delayed upslope shifts or may be limited to high-elevation patches where appropriate vegetation communities exist.

K.Wurdack & Farfan, , from the wet sub-Andean cordilleras of Ecuador (Cordillera del Cóndor) and Peru (Cusco, Oxapampa) is described and illustrated. This recently discovered large canopy tree with a narrow elevational range presents an unusual combination of rare morphological characters in Hippomaneae including mucilage-secreting sheathing stipules, conduplicate ptyxis, and large, woody fruits. The broader significance of these characters in Hippomaneae is discussed. The morphology and anatomy of were investigated, highlighting its fruit similarities with Guiana Shield endemic , and the systematics value of ptyxis variation, which remains poorly studied for the family.