Tropenbos International

Abstract The density of wood is a key indicator of trees’ carbon investment strategies, impacting productivity and carbon storage. Despite its importance, the global variation in wood density and its environmental controls remain poorly understood, preventing accurate predictions of global forest carbon stocks. Here, we analyze information from 1.1 million forest inventory plots alongside wood density data from 10,703 tree species to create a spatially-explicit understanding of the global wood density distribution and its drivers. Our findings reveal a pronounced latitudinal gradient, with wood in tropical dry forests being up to twice as dense as that in boreal forests. In both angiosperms and gymnosperms, temperature and water availability emerged as the primary factors influencing the variation in wood density globally. This indicates similar environmental filters and evolutionary adaptations among distinct plant groups, underscoring the essential role of abiotic factors in determining wood density in forest ecosystems. Additionally, our study highlights the prominent role of disturbance, such as human modification and fire risk, in influencing wood density at more local scales. Factoring in the spatial variation of wood density notably changes the estimates of forest carbon stocks, leading to differences of up to 21% within biomes. Therefore, our research contributes to a deeper understanding of terrestrial biomass distribution and how environmental changes and disturbances impact forest ecosystems.

The tropical forest carbon sink is known to be drought sensitive, but it is unclear which forests are the most vulnerable to extreme events. Forests with hotter and drier baseline conditions may be protected by prior adaptation, or more vulnerable because they operate closer to physiological limits. Here we report that forests in drier South American climates experienced the greatest impacts of the 2015–2016 El Niño, indicating greater vulnerability to extreme temperatures and drought. The long-term, ground-measured tree-by-tree responses of 123 forest plots across tropical South America show that the biomass carbon sink ceased during the event with carbon balance becoming indistinguishable from zero (−0.02 ± 0.37 Mg C ha−1 per year). However, intact tropical South American forests overall were no more sensitive to the extreme 2015–2016 El Niño than to previous less intense events, remaining a key defence against climate change as long as they are protected.

Donors and non-governmental organizations are showing increased interest in integrated landscape initiatives (ILIs), where landscape stakeholders work together to achieve common goals related to development, climate change and conservation. In order to support the work of ILIs, we developed a novel methodology with which stakeholders—organized in multi-stakeholder partnerships—can assess how financial flows in the landscape are impacting their common goals and to identify funding gaps. Piloting the methodology in three landscapes in Indonesia, Ghana and Vietnam, we found that there were trade-offs between ensuring broad stakeholder participation in the assessments (to capture different perspectives) and the level of technical and quantifiable detail that could be acquired. The methodology effectively contributed to a common understanding among landscape-level stakeholders and triggered discussions on methods in which financial flows can be adapted to reduce their negative impacts or increase their positive impacts. It also functioned as a basis for the development of joint action plans and to initiate collaborations with the providers of financial flows that have potential to contribute to common landscape objectives. In addition to promoting common understanding and providing a basis for the development of action plans, we conclude that implementing the methodology also helped with strengthening the landscape partnerships themselves.

ContextIntegrated landscape approaches (ILAs) that aim to balance conservation and development targets are increasingly promoted through science, policy, and the donor community. Advocates suggest that ILAs are viable implementing pathways for addressing global challenges such as biodiversity loss, poverty alleviation, and climate change mitigation and adaptation. However, we argue that recent advances in ILA research and discourse have tended to emphasize the social and governance dimensions, while overlooking ecological factors and inadequately considering potential trade-offs between the two fields.ObjectivesBy raising the issue of inadequate integration of ecology in ILAs and providing some general design suggestions, we aim to support and incentivise better design and practice of ILAs, supplementing existing design principles.MethodsIn this perspective we draw on the recent literature and our collective experience to highlight the need, and the means, to re-integrate ecology into landscape approaches.ResultsWe suggest that better incorporation of the ecological dimension requires the integration of two approaches: one focusing on conventional scientific studies of biodiversity and biophysical parameters; and the other focusing on the engagement of relevant stakeholders using various participatory methods. We provide some general guidelines for how these approaches can be incorporated within ILA design and implementation.ConclusionRe-integrating ecology into ILAs will not only improve ecological understanding (and related objectives, plans and monitoring), but will also generate insights into local and traditional knowledge, encourage transdisciplinary enquiry and reveal important conservation-development trade-offs and synergies.

Abstract AimLarge tropical trees form the interface between ground and airborne observations, offering a unique opportunity to capture forest properties remotely and to investigate their variations on broad scales. However, despite rapid development of metrics to characterize the forest canopy from remotely sensed data, a gap remains between aerial and field inventories. To close this gap, we propose a new pan‐tropical model to predict plot‐level forest structure properties and biomass from only the largest trees.LocationPan‐tropical.Time periodEarly 21st century.Major taxa studiedWoody plants.MethodsUsing a dataset of 867 plots distributed among 118 sites across the tropics, we tested the prediction of the quadratic mean diameter, basal area, Lorey's height, community wood density and aboveground biomass (AGB) from the ith largest trees.ResultsMeasuring the largest trees in tropical forests enables unbiased predictions of plot‐ and site‐level forest structure. The 20 largest trees per hectare predicted quadratic mean diameter, basal area, Lorey's height, community wood density and AGB with 12, 16, 4, 4 and 17.7% of relative error, respectively. Most of the remaining error in biomass prediction is driven by differences in the proportion of total biomass held in medium‐sized trees (50–70 cm diameter at breast height), which shows some continental dependency, with American tropical forests presenting the highest proportion of total biomass in these intermediate‐diameter classes relative to other continents.Main conclusionsOur approach provides new information on tropical forest structure and can be used to generate accurate field estimates of tropical forest carbon stocks to support the calibration and validation of current and forthcoming space missions. It will reduce the cost of field inventories and contribute to scientific understanding of tropical forest ecosystems and response to climate change.

There is a growing disconnect between the international conferences where grand solutions for tropical conservation are designed and the complex local realities in tropical landscapes where plans need to be implemented. Every tropical landscape is different and no “one size will fit all.” There is a tendency for global processes to prescribe simple generalized solutions that provide good sound bites that can be communicated with political actors and the media. Sustainable outcomes in tropical landscapes require locally adapted, unique approaches supported by long-term processes of learning and adaptation. Tropical biologists and conservationists can play a key role by establishing effective local–global links and by directly engaging in local policy discourses while remaining connected to evolving political imperatives.

In this chapter, you are going to program the main gameplay for the Penguin Pairs game. You will learn how to move penguins around on the board and what to do when a penguin collides with another game object, such as a shark or another penguin.