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Item type:Publication, Variation of non-structural carbohydrates across the fast-slow continuum in Amazon forest canopy trees(Wiley, 2021-11-20)Tropical tree species span a range of life‐history strategies within a fast–slow continuum. The position of a species within this continuum is thought to reflect a negative relationship between growth and storage, with fast‐growing species allocating more carbon to growth and slow‐growing species investing more in storage. For tropical species, the relationship between storage and life‐history strategies has been largely studied on seedlings and less so in adult trees. We evaluated how stored non‐structural carbohydrates (NSC) vary across adult trees spanning the fast–slow continuum in the Peruvian Amazon by: (a) analysing whole‐tree NSC in two species of contrasting growth and (b) investigating the relationships with key life‐history traits across a broader set of species. Our results are consistent with a growth–storage trade‐off. The analysis of whole‐tree NSC revealed that the slow‐growing Eschweilera coriacea stored about 2.7 times as much NSC as the fast‐growing Bixa arborea due to markedly higher storage in woody stems and roots. B. arborea also had higher seasonality in NSC, reflecting its strong seasonality in stem growth. Across a range of species, stem starch was negatively related to species growth rate and positively related to wood density. Given the role of NSC in mediating plants' response to stress, our results suggest that slow‐growing species with greater storage reserves may be more resilient to drought than fast‐growing species. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Non-structural carbohydrates mediate seasonal water stress across Amazon forests(Nature Research, 2021-12-01)Non-structural carbohydrates (NSC) are major substrates for plant metabolism and have been implicated in mediating drought-induced tree mortality. Despite their significance, NSC dynamics in tropical forests remain little studied. We present leaf and branch NSC data for 82 Amazon canopy tree species in six sites spanning a broad precipitation gradient. During the wet season, total NSC (NSCT) concentrations in both organs were remarkably similar across communities. However, NSCT and its soluble sugar (SS) and starch components varied much more across sites during the dry season. Notably, the proportion of leaf NSCT in the form of SS (SS:NSCT) increased greatly in the dry season in almost all species in the driest sites, implying an important role of SS in mediating water stress in these sites. This adjustment of leaf NSC balance was not observed in tree species less-adapted to water deficit, even under exceptionally dry conditions. Thus, leaf carbon metabolism may help to explain floristic sorting across water availability gradients in Amazonia and enable better prediction of forest responses to future climate change. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Aboveground biomass in secondary montane forests in Peru: slow carbon recovery in agroforestry legacies(Elsevier, 2021-08-01)Andean tropical montane forests (TMF) are hotspots of biodiversity that provide fundamental hydrological services as well as carbon sequestration and storage. Agroforestry systems occupy large areas in the Andes but climatic pressures, market volatility and diseases may result inagroforest abandonment, promoting secondary succession. Secondary forests are well-adapted and efficient carbon sinks whose conservation is vital to mitigate and adapt to climate change and to support biodiversity. Little is known, however, about how secondary TMF recover their aboveground biomass (AGB) and composition after abandonment. We established a 1.5 ha plot at 1780 masl on a 30-year old abandoned agroforest and compared it against two control forest plots at similar elevations. Agroforestry legacies influenced AGB leading to far lower stocks (42.3 ± 5.4–59.6 ± 7.9 Mg ha−1 using allometric equations) than those expected after 30 years (106 ± 33 Mg ha−1) based on IPCC standard growth rates for secondary montane forests. This suggests a regional overestimation of mitigation potentials when using IPCC standards. Satellite-derived AGB largely overestimated our plot values (179 ± 27.3 Mg ha−1). Secondary growth rates (1.41–2.0 Mg ha−1 yr−1 for DBH ≥ 10 cm) indicate recovery times of ca. 69 to 97 years to reach average control AGB values (137 ± 12.3 Mg ha−1). This is 26 years above the average residence time of montane forests at our elevation (71 ± 1.91 years) suggesting a non-recovery or far slower recovery to control AGB values. Three variables appear to define this outcome compared to the control plots: lower DBH (15.8 ± 5.9 cm vs 19.8 ± 11.0 cm), lower basal area (12.67 ± 0.7 vs 28.03 ± 1.5 m2 ha−1) and higher abundance of lighter-wood tree genera (0.46 ± 0.10 vs 0.57 ± 0.11 gr cm3) such as Inga, a common shade-tree in Andean agroforests. With 3.2 million hectares committed to restoration, Peru needs to target currently neglected TMF recovery schemes to support biodiversity, water and carbon storage and fulfill its international commitments. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Combined –omics framework reveals how ant symbionts benefit the Neotropical ant-plant Tococa quadrialata at different levels(Elsevier Inc., 2022-10-21)Ant-plant defensive mutualism is a widely studied phenomenon, where ants protect their host plants (myrmecophytes) against herbivores in return for the provision of nesting sites and food. However, few studies addressed the influence of ant colonization and herbivory on the plant's metabolism. We chose the Amazonian plant Tococa quadrialata , living in association with Azteca cf. tonduzi ants for an ant-exclusion study to reveal the chemistry behind this symbiosis. We found that colonized plants did not only benefit from protection but also from increased amino acid and nitrogen content, enabling better performance even in an herbivore-free environment. In contrast, ant-deprived T. quadrialata plants accumulated more ellagitannins, a major class of constitutive defense compounds. Moreover, herbivory-induced jasmonate-mediated defense responses, including the upregulation of signaling and defense genes and the emission of volatiles irrespective of colonization status. Altogether, we show how ant-colonization can influence the general and defense-related metabolism and performance of myrmecophytes. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Secondary forests in Peru: differential provision of ecosystem services compared to other post-deforestation forest transitions(Resilience Alliance, 2022-08-01)While tropical forests are undergoing rapid transformation as a result of direct human impacts, many deforested areas are reverting to forest through natural or human-assisted regeneration. This situation provides a window of opportunity to implement forest management strategies to achieve environmental objectives while promoting social development and contributing to local livelihoods. Successful forest management policy, however, depends on how well we can appraise environmental consequences as well as on the value of ecosystem services that these regrowing forests provide. Here, we review the published literature to synthesize the ecosystem services provided by three types of forest transitions: naturally-regenerated secondary forests, agroforestry systems, and tree plantations, in the coastal, Andean, and Amazonian regions of Peru. We then discuss the potential of these regrowing forests as nature-based solutions that can help in the adoption of policies that promote their sustainable use and conservation. Our literature analysis reveals that forest transitions provide significant services in offsetting carbon emissions, providing habitats for biodiversity, and regulating hydrological services. However, the amount and importance of ecosystem services vary depending on the forest transition type. Secondary forests offer multiple services, representing a low-cost, immediate, and highly effective strategy in mitigating the climate and biodiversity crises and ultimately providing vital ecosystem services to society, such as water provision. In contrast, exotic tree plantations have negative effects on water regulation services. We highlight the potential of secondary forests for land management that supports multiple and integrated environmental initiatives. This framework can guide policy decisions to choose appropriate options on forest transition types most suitable to achieve specific end goals at local and regional scales, considering both ecosystem services and disservices to avoid trade-offs in which the achievement of one goal is detrimental to another. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Amazonian and Andean tree communities are not tracking current climate warming(EarthArXiv, 2024-12-18)Climate change is shifting species distributions, leading to changes in community composition and novel species assemblages worldwide. However, the responses of tropical forests to climate change across large-scale environmental gradients remain largely unexplored. Using long-term data over 66,000 trees of more than 2,500 species occurring over 3,500 m elevation along the hyperdiverse Amazon-to-Andes elevational gradient, we assessed community-level shifts in species composition through a 44-year time span. We tested for the predicted increase in relative abundances of species from warmer climates (thermophilization) along the Amazon-to-Andes elevational gradients in Peru and Bolivia. Additionally, we examined the relative contributions of tree mortality, recruitment, and growth to observed compositional changes. Mean thermophilization rates across the Amazon-to-Andes gradient were slow relative to concordant changes in regional temperatures. Thermophilization rates were positive and more variable among Andean forest plots compared to Amazonian plots but were fastest at mid-elevations around the cloud base. Across all elevations, thermophilization rates were driven primarily by tree mortality and decreased growth of highland species rather than an influx of lowland species with higher thermal optima. Given the high variability of community-level responses to warming along the elevational gradients and the generally slower-than-warming rates of compositional change, we conclude that most tropical tree species, and especially Amazonian tree species, will not be able to escape current or future climate change through upward range shifts.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Assessing Peru’s land monitoring system contributions towards fulfilment of its international environmental commitments(Multidisciplinary Digital Publishing Institute (MDPI), 2024-02-01)Land use change (LUC) is recognized as one of the major drivers of the global loss of biodiversity and represents a major threat to ecosystems. Deforestation through LUC is mainly driven by fire regimes, logging, farming (cropping and ranching), and illegal mining, which are closely linked with environmental management policies. Efficient land management strategies, however, require reliable and robust information. Land monitoring is one such approach that can provide critical information to coordinate policymaking at the global, regional, and local scales, and enable a programmed implementation of shared commitments under the Rio Conventions: the United Nations Convention on Biological Diversity (CBD), Convention to Combat Desertification (UNCCD), and Framework Convention on Climate Change (UNFCCC). Here we use Peru as a case study to evaluate how a land monitoring system enables environmental policy decisions which appear in the country’s international commitment reports. Specifically, we synthesize how effective the ongoing land monitoring system has been in responding to current and future environmental challenges; and how improvements in land monitoring can assist in the achievement of national commitments under the Rio Conventions. We find that Peruvian policies and commitments need to be improved to be consistent with the 1.5 °C temperature limit of the Paris agreement. Regarding the Aichi targets, Peru has achieved 17% land area with sustainable management; however, the funding deficit is a great challenge. Even though Peru commits to reducing GHG emissions by reducing LUC and improving agricultural and land use forestry practices, it needs policy improvements in relation to land tenure, governance, and equity. Potential explanations for the observed shortcomings include the fragmentation and duplication of government roles across sectors at both a national and regional scale. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Evapotranspiration, carbon dynamics and water use efficiency in a drip-irrigated olive orchard in arid coastal western South America(Elsevier B.V., 2024-05-31)The primary climatic characteristic of olive cultivation in Peru is the coastal desert environment with moderate temperatures, minimal precipitation, and high atmospheric water content during the winter season. This report presents a comprehensive study on water and carbon fluxes in a drip-irrigated olive orchard in Pisco Province, Peru, addressing the current lack of information on olive physiology and water management under these environmental conditions. The eddy covariance system installed in September 2019 showed an average ET of 2.18 ± 0.38 mm d−1, with seasonal variation. Drip irrigation was set at 60 m3 ha−1 d−1 during the growing season and reduced to half that amount in the winter. The study suggests that using deficit irrigation based on affordable dendrometry sensors could reduce water use by close to 30% while potentially preserving biomass gain and fruit yields. This could help improve water management in olive cultivation in coastal Peru. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Wood density variation across an Andes-to-Amazon elevational gradient(2024-12-18)1. Understanding how functional traits are related to species diversity and ecosystem properties is a central goal of ecology. Wood density is a trait that integrates many aspects of plant form and function and is highly variable among species. Previous studies of wood density across elevational gradients have been based on limited sampling and have reported declines with increasing elevation, though even this simple pattern remains unknown, much less its underlying functional and evolutionary relationships. 2. Here, we use one of the longest and most speciose elevational gradients in the world, extending from the Andean tree line to the Amazon basin, to test the extent to which elevation, species composition, phylogenetic affinity, and forest structure determine variation in wood density. Using field-collected wood samples and global databases, we assigned wood density to 1231 species and 31,330 stems across 41 (47.5 ha) mature forest plots arrayed across a 3,500 m vertical gradient. 3. Our results show that mean wood density, either weighted by abundance, basal area, or species, was highly variable but tended to decline from low to middle elevations and increase again from mid-elevations to the tree line. As a result of this non-linearity, forests at the Andean tree line had higher wood density than their lowland Amazon counterparts. We observed an abrupt transition in wood density at the lower limit of persistent cloud formation (cloud base), where the lowest wood density values were found. The decline of wood density is attributed to a significant shift in life forms, with an abundance of tree ferns at middle elevations and a higher probability of landslides and disturbances favoring a suite of traits associated with low wood density, such as softer wood and higher elasticity. Species turnover explained most of the among-species variation across the gradient, with elevation having no consistent effect on within-species variation in wood density. 4. Together, both gradual compositional changes and sharp local changes in the importance of non-dicot life forms, such as arborescent ferns and palms, define patterns of forest-level carbon density, with wood density per se controlling ecosystem properties across the Andes-to-Amazon elevational gradient. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Tropical Forest Lianas Have Greater Non-Structural Carbohydrate Concentrations in the Stem Xylem Than Trees(Oxford University Press, 2023-08-16)Lianas (woody vines) are important components of tropical forests and are known to compete with host trees for resources, decrease tree growth and increase tree mortality. Given the observed increases in liana abundance in some forests and their impacts on forest function, an integrated understanding of carbon dynamics of lianas and liana-infested trees is critical for improved prediction of tropical forest responses to climate change. Non-structural carbohydrates (NSC) are the main substrate for plant metabolism (e.g. growth, respiration), and have been implicated in enabling tree survival under environmental stress, but little is known of how they vary among life-forms or of how liana infestation impacts host tree NSC. We quantified stem xylem total NSC concentrations and its fractions (starch and soluble sugars) in trees without liana infestation, trees with ˃50% of the canopy covered by lianas, and the lianas infesting those trees. We hypothesized that (i) liana infestation depletes NSC storage in host trees by reducing carbon assimilation due to competition for resources; (ii) trees and lianas, which greatly differ in functional traits related to water transport and carbon uptake, would also have large differences in NSC storage. As water availability has a significant role in NSC dynamics of Amazonian tree species, we tested these hypotheses within a moist site in western Amazonia and a drier site in southern Amazonia. We did not find any difference in NSC, starch or soluble sugar concentrations between infested and non-infested trees, in either site. This result suggests that negative liana impact on trees may be mediated through mechanisms other than depletion of host tree NSC concentrations. We found lianas have higher stem NSC and starch than trees in both sites. The consistent differences in starch concentrations, a long-term NSC reserve, between life forms across sites reflect differences in lianas and trees carbon gain and use. Soluble sugar concentrations were higher in lianas than in trees in the moist site but indistinguishable between life forms in the dry site. The lack of difference in soluble sugars between trees and lianas in the dry site emphasizes the importance of this NSC fraction for the metabolism of plants occurring in water limited environments. Abstracts in Portuguese and Spanish are available in the supplementary material.