Resilience Of Tropical Forests Research Articles

Different model assumptions about plant hydraulics and photosynthetic temperature acclimation yield diverging implications for tropical forest gross primary production under warming

AbstractTropical forest photosynthesis can decline at high temperatures due to (1) biochemical responses to increasing temperature and (2) stomatal responses to increasing vapor pressure deficit (VPD), which is associated with increasing temperature. It is challenging to disentangle the influence of these two mechanisms on photosynthesis in observations, because temperature and VPD are tightly correlated in tropical forests. Nonetheless, quantifying the relative strength of these two mechanisms is essential for understanding how tropical gross primary production (GPP) will respond to climate change, because increasing atmospheric CO2 concentration may partially offset VPD‐driven stomatal responses, but is not expected to mitigate the effects of temperature‐driven biochemical responses. We used two terrestrial biosphere models to quantify how physiological process assumptions (photosynthetic temperature acclimation and plant hydraulic stress) and functional traits (e.g., maximum xylem conductivity) influence the relative strength of modeled temperature versus VPD effects on light‐saturated GPP at an Amazonian forest site, a seasonally dry tropical forest site, and an experimental tropical forest mesocosm. By simulating idealized climate change scenarios, we quantified the divergence in GPP predictions under model configurations with stronger VPD effects compared with stronger direct temperature effects. Assumptions consistent with stronger direct temperature effects resulted in larger GPP declines under warming, while assumptions consistent with stronger VPD effects resulted in more resilient GPP under warming. Our findings underscore the importance of quantifying the role of direct temperature and indirect VPD effects for projecting the resilience of tropical forests in the future, and demonstrate that the relative strength of temperature versus VPD effects in models is highly sensitive to plant functional parameters and structural assumptions about photosynthetic temperature acclimation and plant hydraulics.

Identifying the impact of climate extremes on radial growth in young tropical trees: A comparison of inventory and tree-ring based estimates

The loss of tropical forest resilience has been linked to increased climate variability and associated droughts, but the response of tropical trees to climate extremes remains poorly understood. This limits our ability to design effective forest adaptation strategies in the tropics. Here we analyse the potential of using young trees to analyse climate variability and extremes, which opens new avenues given the increasing area of secondary forests and tree plantations. We used annual tree diameter measurements and stem discs from 139 16-year-old trees belonging to five native species planted in the Sardinilla tree diversity experiment in Panama and compared three methods to determine annual radial growth. Employing inventory measurements, visual stem disc analysis, and wood density measurements, series of radial growth were calculated to compare relative growth during wet and dry extreme events, and to compute continuous climate-growth correlations. Our results show that annual radial growth data derived from wood density profiles are best suited for climate-growth relationships, as they could capture a common growth signal within the high intraspecific variability of young trees to seasonal climatic variables. Annual radial growth data derived visually and from inventories are still useful for quantifying growth responses during extreme drought. The highest similarity among methods to determine annual radial growth, combined with the strongest climate-growth relationships, were found for Cedrela odorata, a species that shows a pronounced decrease in water use and cambial dormancy during the dry season. Stem discs from young trees planted in tropical forest plantations may thus offer a suitable source for dendroecological analyses.

Response of tropical forest productivity to seasonal drought mediated by potassium and phosphorus availability

Tropical forest productivity is increasingly reported to be nutrient limited, which may affect its response to seasonal droughts. Yet experimental evidence on nutrient limitation from Afrotropical forests remains rare. We conducted an ecosystem-scale, full factorial nitrogen (N)–phosphorus (P)–potassium (K) addition experiment in a moist forest in Uganda to investigate nutrient controls on fine litter production and foliar chemistry. The eight factorial treatments were replicated four times in 32 plots of 40 × 40 m each. During the three-year nutrient additions, we found K and P limitations on leaf litter production, exhibiting strong links to ecosystem responses to seasonal drought. Specifically, leaf litterfall consistently decreased in dry seasons with K additions, whereas P additions caused a reduction only during prolonged drought in the first year. Leaf litterfall was not significantly affected by N additions. Furthermore, K additions delayed the timing of leaf litterfall peak, underscoring the crucial role of K in regulating stomatal aperture and signalling during water-stress conditions and suggesting a prolonged leaf lifespan. Foliar N increased with N and P additions whereas K was the most resorbed nutrient. We conclude that the productivity and resilience of tropical forests, particularly under drier conditions, may depend on terrestrial K and P availability.

Constraints on avian seed dispersal reduce potential for resilience in degraded tropical forests

Abstract Seed dispersal is fundamental to tropical forest resilience. Forest loss or degradation typically leads to defaunation, altering seed transfer dynamics and impairing the ability of forested habitats to regenerate or recover from perturbation. However, the extent of defaunation, and its likely impacts on the seed dispersers needed to restore highly degraded or clear‐felled areas, remains poorly understood in tropical forest landscapes. To quantify defaunation of seed‐dispersing birds, we used field survey data from 499 transects in three forested regions of Brazil, first comparing the observed assemblages with those predicted by geographic range maps, and then assessing habitat associations of frugivores across land cover gradients. We found that current bird assemblages have lower functional diversity (FD) than predicted by species range maps in Amazonia (4%–6%), with a greater reduction in FD (28%) for the Atlantic Forest, which has been more heavily deforested for a longer period. Direct measures of seed dispersal are difficult to obtain, so we focused on potential seed transfer inferred from shared species occurrence. Of 83 predominantly frugivorous bird species recorded in relatively intact forests, we show that 10% were absent from degraded forest, and 57% absent from the surrounding matrix of agricultural land covers, including many large‐gaped species. Of 112 frugivorous species using degraded forest, 47% were absent from matrix habitats. Overall, frugivores occurring in both intact forest and matrix habitats were outnumbered by (mostly small‐gaped) frugivores occurring in both degraded forest and matrix habitats (23 additional species; 64% higher diversity). These findings suggest that birds have the potential to disperse seeds from intact and degraded forest to adjacent cleared lands, but that direct seed transfer from intact forests is limited, particularly for large‐seeded trees. Degraded forests may play a vital role in supporting natural regeneration of small‐seeded tree species as well as providing a ‘stepping‐stone’ in the regeneration pathway for large‐seeded trees. We propose that both intact and degraded forests will support the restoration potential of tropical forest landscapes, and that bird‐assisted seed dispersal can be enhanced by maintaining buffer zones of degraded or secondary forests around remaining intact forest patches. Read the free Plain Language Summary for this article on the Journal blog.

Regional and local determinants of drought resilience in tropical forests.

The increase in severity of droughts associated with greater mortality and reduced vegetation growth is one of the main threats to tropical forests. Drought resilience of tropical forests is affected by multiple biotic and abiotic factors varying at different scales. Identifying those factors can help understanding the resilience to ongoing and future climate change. Altitude leads to high climate variation and to different forest formations, principally moist or dry tropical forests with contrasted vegetation structure. Each tropical forest can show distinct responses to droughts. Locally, topography is also a key factor controlling biotic and abiotic factors related to drought resilience in each forest type. Here, we show that topography has key roles controlling biotic and abiotic factors in each forest type. The most important abiotic factors are soil nutrients, water availability, and microclimate. The most important biotic factors are leaf economic and hydraulic plant traits, and vegetation structure. Both dry tropical forests and ridges (steeper and drier habitats) are more sensitive to droughts than moist tropical forest and valleys (flatter and wetter habitats). The higher mortality in ridges suggests that conservative traits are not sufficient to protect plants from drought in drier steeper habitats. Our synthesis highlights that altitude and topography gradients are essential to understand mechanisms of tropical forest's resilience to future drought events. We described important factors related to drought resilience, however, many important knowledge gaps remain. Filling those gaps will help improve future practices and studies about mitigation capacity, conservation, and restoration of tropical ecosystems.

Hydroclimatic adaptation critical to the resilience of tropical forests.

Forest and savanna ecosystems naturally exist as alternative stable states. The maximum capacity of these ecosystems to absorb perturbations without transitioning to the other alternative stable state is referred to as ‘resilience’. Previous studies have determined the resilience of terrestrial ecosystems to hydroclimatic changes predominantly based on space‐for‐time substitution. This substitution assumes that the contemporary spatial frequency distribution of ecosystems’ tree cover structure holds across time. However, this assumption is problematic since ecosystem adaptation over time is ignored. Here we empirically study tropical forests’ stability and hydroclimatic adaptation dynamics by examining remotely sensed tree cover change (ΔTC; aboveground ecosystem structural change) and root zone storage capacity (S r; buffer capacity towards water‐stress) over the last two decades. We find that ecosystems at high (>75%) and low (<10%) tree cover adapt by instigating considerable subsoil investment, and therefore experience limited ΔTC—signifying stability. In contrast, unstable ecosystems at intermediate (30%–60%) tree cover are unable to exploit the same level of adaptation as stable ecosystems, thus showing considerable ΔTC. Ignoring this adaptive mechanism can underestimate the resilience of the forest ecosystems, which we find is largely underestimated in the case of the Congo rainforests. The results from this study emphasise the importance of the ecosystem's temporal dynamics and adaptation in inferring and assessing the risk of forest‐savannah transitions under rapid hydroclimatic change.

The other side of tropical forest drought: do shallow water table regions of Amazonia act as large-scale hydrological refugia from drought?

Tropical forest function is of global significance to climate change responses, and critically determined by water availability patterns. Groundwater is tightly related to soil water through the water table depth (WT), but historically neglected in ecological studies. Shallow WT forests (WT < 5 m) are underrepresented in forest research networks and absent in eddy flux measurements, although they represent c. 50% of the Amazon and are expected to respond differently to global-change-related droughts. We review WT patterns and consequences for plants, emerging results, and advance a conceptual model integrating environment and trait distributions to predict climate change effects. Shallow WT forests have a distinct species composition, with more resource-acquisitive and hydrologically vulnerable trees, shorter canopies and lower biomass than deep WT forests. During 'normal' climatic years, shallow WT forests have higher mortality and lower productivity than deep WT forests, but during moderate droughts mortality is buffered and productivity increases. However, during severe drought, shallow WT forests may be more sensitive due to shallow roots and drought-intolerant traits. Our evidence supports the hypothesis of neglected shallow WT forests being resilient to moderate drought, challenging the prevailing view of widespread negative effects of climate change on Amazonian forests that ignores WT gradients, but predicts they could collapse under very strong droughts.

Rare and common species contribute disproportionately to the functional variation within tropical forests

Understanding how functional traits and functional entities (FEs, i.e., unique combinations of functional traits) are distributed within plant communities can contribute to the understanding of vegetation properties and changes in species composition. We utilized investigation data on woody plants (including trees, shrubs and lianas) from 17 1-ha plots across six old-growth tropical forest types on Hainan island, China. Plant species were categorized as common (>1 individuals/ha) and rare species (≤1 individuals/ha) according to their abundance to determine how they contributed to different ecosystem functions. First, we assessed the differences in traits between common and rare species, and second, we examined functional redundancy, functional over-redundancy, and functional vulnerability for common and rare species of the forests. We found that both common species and rare species in each of the forest types were placed into just a few FEs, leading to functional over-redundancy and resulting in functional vulnerability. Rare species tended to have different trait values than those of common species, and were differently distributed among FEs, indicating different contributions to ecosystem functioning. Our results highlighted the disproportionate contribution of rare species in all of the studied forests. Rare species are more likely than common species to possess unique FEs, and thus, they have a disproportionately large contribution to community trait space. The loss of such species may impact the functioning, redundancy, and resilience of tropical forests.

Functional diversity and redundancy of tropical forests shift with elevation and forest‐use intensity

Abstract Change and intensification of forest use alter tropical ecosystems, influencing biodiversity and, subsequently, ecosystem functioning. The implications of eroding biodiversity may go beyond decreases in species diversity, resulting in changes of functional diversity, that is, the diversity of ecological strategies present in the community, and functional redundancy, that is, how redundant these strategies are to biodiversity loss. However, how environmental conditions and anthropogenic influences shape functional diversity and redundancy in tropical forests remains poorly understood. Here, we examine how tropical forests respond to forest‐use intensity along an extensive elevational gradient in Mexico from the tropical lowlands to high‐elevational mountain forests (0–3,500 m), in terms of functional diversity and functional redundancy, and how these biodiversity facets are related to forest structure. In our study, elevation was crossed with three levels of forest‐use intensity: old‐growth, degraded and secondary forests. At eight elevational sites, five replicate plots were inventoried for each level of forest‐use intensity (total n = 120 plots). Functional diversity and redundancy were calculated using leaf and wood traits of 144 tree species for Hill numbers zero, one and two. Interactive effects between elevation and forest‐use intensity significantly affected biodiversity facets. However, interactive effects resulted from forest‐use intensity influencing biodiversity facets at only a few elevations, and not from a consistent, negative impact of forest‐use intensity. Forest structure, specifically stem density and the Gini coefficient, explained variation across biodiversity facets when these facets gave equal weight to common and rare species. Synthesis and applications. High functional diversity and functional redundancy from lowland to mid‐elevation tropical forests suggest that these ecosystems can be resilient to future disturbances. Our results indicate that the ability of high‐elevation forests may be particularly susceptible to climate change and increasing forest‐use intensity. For these high‐elevation forests, we recommend that forest managers implement enrichment plantings with native species that can tolerate future environmental conditions. Finally, our study shows that efforts to conserve structurally heterogeneous forests and actively managing forests to increase structural heterogeneity will enhance the resilience of tropical forests while conserving their biodiversity.

Detecting vulnerability of humid tropical forests to multiple stressors

Detecting vulnerability of humid tropical forests to multiple stressors

Recovery of dung beetle assemblages in regenerating Caatinga dry forests following slash-and-burn agriculture

Understanding patterns of tropical forest resilience is a central challenge in conservation ecology particularly in seasonally-dry tropical forests, where anthropogenic disturbance and climate change are pervasive threats. Here, we investigate the recovery rate and community organization of dung beetles along a Caatinga dry forest regeneration cline in the context of slash-and-burn agriculture in northeast Brazil. Assemblages were described considering a wide set of attributes, including abundance, taxonomic (Hill orders D0, D1 and D2) and functional diversity (functional richness, evenness and redundancy) and taxonomic/functional composition, across a chronosequence consisting of regenerating and old-growth forest stands exposed to different levels of aridity and chronic disturbance. In addition, we use body mass, diet, food relocation behaviour and habitat specificity of dung beetles as ecological attributes. Our results show that Caatinga dry forests supports dense but relatively impoverished dung beetle assemblages at both local and landscape scales, with the same small set of species dominating local assemblages. Dung beetles do not experience successional replacements along the regeneration gradient, with evidence of high resilience. Moreover, disturbance-associated dung beetle species (predominantly small-bodied generalists) resulted in assemblage convergence across the regeneration cline. Finally, chronic anthropogenic disturbance was a decisive driver of changes in abundance and taxonomic diversity, while aridity positively affected species composition and functional richness. These patterns resulted in the occurrence of spatially structured assemblages in response to a combination of both natural and anthropogenic variables, while under little or no influence of forest regeneration status across human-modified Caatinga landscapes. We conclude that the absence of directional changes in dung beetle assemblages through the forest succession pathway of regenerating second-growth forest is associated with the effect of aridity and human disturbances on community organization, including selection for certain species and functional groups, which in turn, can alter important ecological functions and consequently the resilience of dry forests.

Functional diversity improves tropical forest resilience: Insights from a long‐term virtual experiment

Abstract Human activities modify the disturbance regimes of tropical forests. Since tropical forests host high biological diversity, understanding the role of biodiversity in ecosystem recovery pathways and the underlying ecological mechanisms is crucial to predict the fate of tropical ecosystems. Studies relying on regularly censused forest plots, rarely include disturbed forests, are not long enough to assess long‐term forest dynamics and often lack repeatability. We used an individual‐based model of tropical forest growth to assess the effect of species and functional diversity on long‐term ecosystem recovery from disturbance. We manipulated the number of species and functional assemblages across a large number of simulations and simulated different levels of disturbance. To investigate the ecological mechanisms that underlie the effect of biodiversity on forest functioning along recovery pathways, we partitioned the net effect of biodiversity on ecosystem properties into complementarity and selection effects over time. We found that functional diversity improved tropical forest resilience after a disturbance. The complementarity effect dominated soon after the disturbance but was progressively surpassed by a selection effect as more competitive species dominated the forest community. This pattern increased with the intensity of the disturbance. Synthesis. We found that the mechanisms through which biodiversity influences forest functioning depend on the ecosystem state, shifting from a dominant complementarity effect in recently disturbed systems to a selection effect in systems disturbed a long time ago. Our results thus suggest that the time since the last disturbance is a key to understanding biodiversity–ecosystem functioning relationships in tropical forests and can help reconcile previous contrasting results obtained with snapshots of ecosystem state in empirical studies.

Are extinction debts reflected in temporal changes of life history trait profiles? A fifteen-year reappraisal of bryophyte metacommunities in a fragmented landscape

Forest fragmentation impacts community structure at both local and regional scales over time. Understanding the resilience of tropical forests to anthropogenic impacts and the period for communities to recover are critical steps for conservation policy implementation. We took advantage of a dynamic group of land plants to study temporal changes in their community structure over a period of 15years at a landscape-scale experimental fragmentation site in central Amazonia. We observed an overall increase in estimated epiphyll abundances and species richness in smaller fragments (1- and 10-ha reserves) suggesting recovery rather than a belated accumulation of local extinction events. However, higher turnover in smaller fragments, when compared to larger ones, was driven by increased presence of core species indicating interspecific differences in survivability. These disproportionate changes in occupancy patterns and relative abundances in fragments were best explained by life history traits reflecting increased dispersal capacity and physiological tolerances suggesting recovery of the phyllosphere community in smaller fragments (1- and 10-ha) over 15years. Even for this group renowned for fast generation times and high reproductive output, epiphyll metacommunities of smaller fragments have yet to recover from local extinctions accrued following the initial fragmentation nearly 40years ago. However, the interaction of dispersal capacities and physiological tolerances are playing a significant role in the recovery of their spatiotemporal distributional patterns in this experimentally fragmented landscape.

Taxonomic and functional ant diversity along a secondary successional gradient in a tropical forest

AbstractThe taxonomic diversity (TD) of tropical flora and fauna tends to increase during secondary succession. This increase may be accompanied by changes in functional diversity (FD), although the relationship between TD and FD is not well understood. To explore this relationship, we examined the correlations between the TD and FD of ants and forest age in secondary forests at the α‐ and β‐diversity levels using single‐ and multi‐trait‐based approaches. Our objectives were to understand ant diversity patterns and to evaluate the role of secondary forests in the conservation of biodiversity and in the resilience of tropical forests. Ant assemblages were sampled across a chronosequence in the Lacandon region, Mexico. All species were characterized according to 12 functional ecomorphological traits relevant to their feeding behavior. We found that TD and FD were related to forest age at the alpha level, but not at the beta level. α‐functional richness and divergence increased linearly with species richness and diversity, respectively. Also, the relationship between taxonomic and functional turnover was linear and positive. Our results indicated that functional traits were complementary across the chronosequence. The increase in FD was mainly driven by the addition of rare species with relevant traits. The older secondary forests did not recover all of the functions of old growth forest but did show a tendency to recovery. Because older successional stages support more TD and FD, we suggest developing agriculture and forestry management practices that facilitate rapid post‐agricultural succession and thereby better preserve the functionality of tropical forests.

Remotely sensed resilience of tropical forests

Remote sensing of tropical forest activity indicates that temporal autocorrelation—an indicator of slow recovery from stress—rises steeply as precipitation falls sufficiently. This offers some support for a tipping point for forest collapse.

Resilience of tropical dry forests – a meta‐analysis of changes in species diversity and composition during secondary succession

Assessing the recovery of species diversity and composition after major disturbance is key to understanding the resilience of tropical forests through successional processes, and its importance for biodiversity conservation. Despite the specific abiotic environment and ecological processes of tropical dry forests, secondary succession has received less attention in this biome than others and changes in species diversity and composition have never been synthesised in a systematic and quantitative review. This study aims to assess in tropical dry forests 1) the directionality of change in species richness and evenness during secondary succession, 2) the convergence of species composition towards that of old‐growth forest and 3) the importance of the previous land use, precipitation regime and water availability in influencing the direction and rate of change. We conducted meta‐analyses of the rate of change in species richness, evenness and composition indices with succession in 13 tropical dry forest chronosequences. Species richness increased with succession, showing a gradual accumulation of species, as did Shannon evenness index. The similarity in species composition of successional forests with old‐growth forests increased with succession, yet at a low rate. Tropical dry forests therefore do show resilience of species composition but it may never reach that of old‐growth forests. We found no significant differences in rates of change between different previous land uses, precipitation regimes or water availability. Our results show high resilience of tropical dry forests in term of species richness but a slow recovery of species composition. They highlight the need for further research on secondary succession in this biome and better understanding of impacts of previous land‐use and landscape‐scale patterns.SynthesisSecondary forests account for an increasing proportion of remaining tropical forest. Assessing their resilience is key to conservation of their biodiversity. Our study is the first meta‐analysis of species changes during succession focussing on tropical dry forests, a highly threatened yet understudied biome. We show a gradual species accumulation and convergence of composition towards that of old‐growth forests. While secondary tropical dry forests offer good potential for biodiversity conservation, their capacity for recovery at a sufficient rate to match threats is uncertain. Further research on this biome is needed to understand the effect of land use history and landscape processes.

Assessing the economic impact of climate change on forest resource use in Nigeria: A Ricardian approach

Quantifying the impact of climate change at a regional scale is important in trying to develop adaptation policies. We estimated the economic impact of climate change on forest resource use in Nigeria using the Ricardian model in the STATA statistical software. Using a structured questionnaire, data were collected from 400 rural households in forest communities, sampled from five broad ecological regions across Nigeria to estimate income and potential impact on this as a result of climate change. Estimated average value of annual household income from the forest was $3380. The age of the household head, level of education, mode of transport, hudrology (river flow) significantly and positively affected net revenue from the forest, while noticing of climate change negatively affected net revenue. Also while winter and spring precipitation had positive impacts on net revenue ($1.5 and $0.28 respectively), summer and autumn precipitation had negative impacts; (−$0.073 and −$0.05 respectively). Marginal impact analysis shows that increasing rainfall during winter and spring seasons significantly increases the net revenue per household by $62 and $75 respectively, while increasing precipitation marginally during the summer and autumn seasons reduce the net revenue per household by $42 and $18 respectively. This underscores the place of rainfall as a limiting factor in tropical ecosystem productivity and the growing impact of changing rainfall on household income and efforts to moderate water supply in agriculture and forestry will be an effort in the right direction. Annual marginal increase in rainfall increases net revenue per household by $77. The model shows that a 1°C increase in temperature will lead to an annual loss of $39×10−7 in net income per household, after which further increase in temperature or decreases in precipitation shows no significant change in net revenue, thus underscoring the resilience of tropical forest to climate change.

Recovery and resilience of tropical forests after disturbance.

The time taken for forested tropical ecosystems to re-establish post-disturbance is of widespread interest. Yet to date there has been no comparative study across tropical biomes to determine rates of forest re-growth, and how they vary through space and time. Here we present results from a meta-analysis of palaeoecological records that use fossil pollen as a proxy for vegetation change over the past 20,000 years. A total of 283 forest disturbance and recovery events, reported in 71 studies, are identified across four tropical regions. Results indicate that forests in Central America and Africa generally recover faster from past disturbances than those in South America and Asia, as do forests exposed to natural large infrequent disturbances compared with post-climatic and human impacts. Results also demonstrate that increasing frequency of disturbance events at a site through time elevates recovery rates, indicating a degree of resilience in forests exposed to recurrent past disturbance.

Modeling forest dynamics along climate gradients in Bolivia

AbstractDynamic vegetation models have been used to assess the resilience of tropical forests to climate change, but the global application of these modeling experiments often misrepresents carbon dynamics at a regional level, limiting the validity of future projections. Here a dynamic vegetation model (Lund Potsdam Jena General Ecosystem Simulator) was adapted to simulate present‐day potential vegetation as a baseline for climate change impact assessments in the evergreen and deciduous forests of Bolivia. Results were compared to biomass measurements (819 plots) and remote sensing data. Using regional parameter values for allometric relations, specific leaf area, wood density, and disturbance interval, a realistic transition from the evergreen Amazon to the deciduous dry forest was simulated. This transition coincided with threshold values for precipitation (1400 mm yr−1) and water deficit (i.e., potential evapotranspiration minus precipitation) (−830 mm yr−1), beyond which leaf abscission became a competitive advantage. Significant correlations were found between modeled and observed values of seasonal leaf abscission (R2 = 0.6, p &lt;0.001) and vegetation carbon (R2 = 0.31, p &lt;0.01). Modeled Gross Primary Productivity (GPP) and remotely sensed normalized difference vegetation index showed that dry forests were more sensitive to rainfall anomalies than wet forests. GPP was positively correlated to the El Niño–Southern Oscillation index in the Amazon and negatively correlated to consecutive dry days. Decreasing rainfall trends were simulated to reduce GPP in the Amazon. The current model setup provides a baseline for assessing the potential impacts of climate change in the transition zone from wet to dry tropical forests in Bolivia.

Simulated resilience of tropical rainforests to CO2-induced climate change

Assessing potential future carbon loss from tropical forests is important for evaluating the efficacy of programmes for reducing emissions from deforestation and degradation (REDD). An exploration of results from 22 climate models in conjunction with a land surface scheme suggests that in the Americas, Africa and Asia, the resilience of tropical forests to climate change is higher than expected, although uncertainties are large.