Showing papers by "Oliver L. Phillips published in 2021"
TL;DR: In this paper, the authors show how a global community is responding to the challenges of tropical ecosystem research with diverse teams measuring forests tree-by-tree in thousands of long-term plots.
66 citations
Environmental Change Institute1, University of Oxford2, Lund University3, Northern Arizona University4, University of Exeter5, National Institute for Space Research6, University of New South Wales7, Naturalis8, Lancaster University9, The Catholic University of America10, Museu Paraense Emílio Goeldi11, Sonoma State University12, Forestry Research Institute of Ghana13, Australian National University14, University of Edinburgh15, University of Leeds16
TL;DR: The Global Ecosystems Monitoring Network (GEM) as mentioned in this paper provides valuable insights by linking field-based ecosystem ecology with the needs of Earth system science, particularly in tropical ecosystems.
41 citations
Francesco Maria Sabatini1, Jonathan Lenoir2, Tarek Hattab, Elise A. Arnst3 +172 more•Institutions (106)
TL;DR: The sPlotOpen dataset as discussed by the authors is the largest open-access dataset of vegetation plots ever released and contains 3.5 million plots from 105 local-to-regional datasets.
Abstract: Motivation. Assessing biodiversity status and trends in plant communities is critical for understanding, quantifying and predicting the effects of global change on ecosystems. Vegetation plots record the occurrence or abundance of all plant species co-occurring within delimited local areas. This allows species absences to be inferred, information seldom provided by existing global plant datasets. Although many vegetation plots have been recorded, most are not available to the global research community. A recent initiative, called ‘sPlot’, compiled the first global vegetation plot database, and continues to grow and curate it. The sPlot database, however, is extremely unbalanced spatially and environmentally, and is not open-access. Here, we address both these issues by (a) resampling the vegetation plots using several environmental variables as sampling strata and (b) securing permission from data holders of 105 local-to-regional datasets to openly release data. We thus present sPlotOpen, the largest open-access dataset of vegetation plots ever released. sPlotOpen can be used to explore global diversity at the plant community level, as ground truth data in remote sensing applications, or as a baseline for biodiversity monitoring. Main types of variable contained. Vegetation plots (n = 95,104) recording cover or abundance of naturally co-occurring vascular plant species within delimited areas. sPlotOpen contains three partially overlapping resampled datasets (c. 50,000 plots each), to be used as replicates in global analyses. Besides geographical location, date, plot size, biome, elevation, slope, aspect, vegetation type, naturalness, coverage of various vegetation layers, and source dataset, plot-level data also include community-weighted means and variances of 18 plant functional traits from the TRY Plant Trait Database. Spatial location and grain. Global, 0.01–40,000 m². Time period and grain. 1888–2015, recording dates. Major taxa and level of measurement. 42,677 vascular plant taxa, plot-level records. Software format. Three main matrices (.csv), relationally linked.
40 citations
Norwegian University of Life Sciences1, University of York2, University of Leeds3, Manchester Metropolitan University4, International Union for Conservation of Nature and Natural Resources5, University College London6, Royal Museum for Central Africa7, Ghent University8, University of Jos9, University of Helsinki10, Academy of Sciences of the Czech Republic11, Charles University in Prague12, Addis Ababa University13, University of Yaoundé I14, Mbarara University of Science and Technology15, Gembloux Agro-Bio Tech16, University of Erlangen-Nuremberg17, United Nations Environment Programme18, University of Canterbury19, National Park Service20, Wageningen University and Research Centre21, University of Guelph22, Sewanee: The University of the South23, University of Montpellier24, University of Kisangani25, World Agroforestry Centre26, Missouri Botanical Garden27, University of Burundi28, Smithsonian Tropical Research Institute29, Kunming Institute of Botany30, Université libre de Bruxelles31, American Museum of Natural History32, University of Bayreuth33, Helmholtz Centre for Environmental Research - UFZ34, Karatina University35, Colorado State University36, Environmental Change Institute37, University of the Sunshine Coast38, College of African Wildlife Management39, University of Edinburgh40, University of Dundee41, Cape Peninsula University of Technology42, University of Gothenburg43, National University of Rwanda44, Mountains of the Moon University45, University of Southampton46, University of Cambridge47, Wuhan University48, BirdLife International49, University of Lincoln50, University of Florence51, University of Bonn52, University of Freiburg53, University of Dschang54, African Wildlife Foundation55, Center for International Forestry Research56, University of British Columbia57, Czech University of Life Sciences Prague58, Bioversity International59, National University of Singapore60, University of Toronto61, Yale University62, Florida International University63, Bangor University64, Rothamsted Research65, University of Liberia66
TL;DR: In this paper, the authors assemble and analyse a dataset of structurally intact old-growth forests spanning 44 montane sites in 12 African countries and find that the average AGC stock of these sites has a value of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1-164.2).
Abstract: Tropical forests store 40–50 per cent of terrestrial vegetation carbon1. However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests2. Owing to climatic and soil changes with increasing elevation3, AGC stocks are lower in tropical montane forests compared with lowland forests2. Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1–164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network4 and about 70 per cent and 32 per cent higher than averages from plot networks in montane2,5,6 and lowland7 forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa8. We find that the low stem density and high abundance of large trees of African lowland forests4 is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse9,10 and carbon-rich ecosystems.
37 citations
University of Leeds1, State University of Campinas2, University of Exeter3, Pontifical Catholic University of Peru4, National University of Saint Anthony the Abbot in Cuzco5, Universidade Federal do Acre6, Universidad Autónoma Gabriel René Moreno7, National Institute for Space Research8, University of Arizona9, Amazon.com10, Jorge Basadre Grohmann National University11, Environmental Change Institute12, Autonomous University of Barcelona13
TL;DR: In this paper, the authors present leaf and branch NSC data for 82 Amazon canopy tree species in six sites spanning a broad precipitation gradient and find that the proportion of leaf NSC in the form of soluble sugar (SS) and starch components varied much more across sites during the dry season.
Abstract: 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.
35 citations
National Museum of Natural History1, University of Oxford2, Sonoma State University3, Mendel University4, University of New England (United States)5, Imperial College London6, University of Amsterdam7, Université libre de Bruxelles8, Washington University in St. Louis9, Missouri Botanical Garden10, National University of Saint Anthony the Abbot in Cuzco11, National Institute of Amazonian Research12, Universidade do Estado de Mato Grosso13, Empresa Brasileira de Pesquisa Agropecuária14, Forestry Research Institute of Ghana15, University of Stirling16, Arizona State University17, Museu Paraense Emílio Goeldi18, University of Aberdeen19, University of Cambridge20, James Cook University21, University of Leeds22, University of Arizona23, State University of Campinas24, University College London25, Pontifical Catholic University of Peru26, Wake Forest University27, Newcastle University28
TL;DR: In this paper, the spatial positions of individual trees above 10 cm diameter at breast height (DBH) were mapped and their canopy size and shape recorded using geo-located tree canopy sizes and shape data, community-level trait values were estimated at the same spatial resolution as Sentinel-2 imagery.
31 citations
National University of Colombia1, Universidad de las Américas Puebla2, University of Minnesota3, University of Leeds4, Deakin University5, National University of Tucumán6, Higher University of San Andrés7, Missouri Botanical Garden8, Washington University in St. Louis9, University of Göttingen10, Environmental Change Institute11, National University of Jujuy12, Université du Québec à Montréal13, Columbus State University14, California Institute of Technology15, University of Miami16
TL;DR: The 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 and reduce deforestation will increase AndeanAboveground carbon stocks, facilitate upward species migrations, and allow for recovery of biomass losses due to climate change.
Abstract: 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.
25 citations
University of Leeds1, University College London2, University of York3, University of Kisangani4, Royal Museum for Central Africa5, Ghent University6, World Wide Fund for Nature7, Wildlife Conservation Society8, Environmental Change Institute9, Manchester Metropolitan University10, Forestry Research Institute of Ghana11, Forestry Commission12, Center for International Forestry Research13, University of Yaoundé I14, Marien Ngouabi University15, Gembloux Agro-Bio Tech16, Duke University17, University of Buea18, University of Exeter19, Smithsonian Tropical Research Institute20, Université libre de Bruxelles21, Royal Botanic Garden Edinburgh22, University of Stirling23, University of British Columbia24, Yale University25, Florida International University26, University of Liberia27
TL;DR: In this article, the authors report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON), using 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015-2016 El Nino event.
Abstract: The responses of tropical forests to environmental change are critical uncertainties in predicting the future impacts of climate change. The positive phase of the 2015–2016 El Nino Southern Oscillation resulted in unprecedented heat and low precipitation in the tropics with substantial impacts on the global carbon cycle. The role of African tropical forests is uncertain as their responses to short-term drought and temperature anomalies have yet to be determined using on-the-ground measurements. African tropical forests may be particularly sensitive because they exist in relatively dry conditions compared with Amazonian or Asian forests, or they may be more resistant because of an abundance of drought-adapted species. Here, we report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON). We use 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015–2016 El Nino event. These plots experienced the highest temperatures and driest conditions on record. The record temperature did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality, but the record drought did significantly decrease net carbon uptake. Overall, the long-term biomass increase of these forests was reduced due to the El Nino event, but these plots remained a live biomass carbon sink (0.51 ± 0.40 Mg C ha−1 y−1) despite extreme environmental conditions. Our analyses, while limited to African tropical forests, suggest they may be more resistant to climatic extremes than Amazonian and Asian forests.
24 citations
25 Mar 2021
24 citations
Marien Ngouabi University1, University of Exeter2, University of Bristol3, University of Leeds4, University of Florida5, Smithsonian Tropical Research Institute6, Lancaster University7, University College London8, Forestry Commission9, University of California, Los Angeles10, Wageningen University and Research Centre11, Universidad Autónoma Gabriel René Moreno12, Royal Museum for Central Africa13, Dresden University of Technology14, University of Edinburgh15, Indiana University16, Paul Sabatier University17, University of Cambridge18, Goethe University Frankfurt19, Forestry Research Institute of Ghana20, Université libre de Bruxelles21, Swedish University of Agricultural Sciences22, Ghent University23, University of Lubumbashi24, Jomo Kenyatta University of Agriculture and Technology25, National University of Benin26, University of Cape Town27, French Institute of Pondicherry28, NatureServe29, University of New Hampshire30, Catholic University of the Most Holy Conception31, Swedish Museum of Natural History32, University of Göttingen33, Manchester Metropolitan University34, University of Glasgow35, Chinese Academy of Sciences36, Forest Research Institute Malaysia37
TL;DR: Pantropical variability in tree crown allometry Grace Jopaul Loubota Panzou, Adeline Fayolle, Tommaso Jucker, Oliver Phillips, Stephanie Bohlman, Lindsay Banin, Simon Lewis, Kofi Affum-baffoe, Luciana Alves, Cécile Antin, et al.
Abstract: Aim: Tree crowns determine light interception, carbon and water exchange. Thus, understanding the factors causing tree crown allometry to vary at the tree and stand level matters greatly for the development of future vegetation modelling and for the calibration of remote sensing products. Nevertheless, we know little about large-scale variation and determinants in tropical tree crown allometry. In this study, we explored the continental variation in scaling exponents of site-specific crown allometry and assessed their relationships with environmental and stand-level variables in the tropics. Location: Global tropics. Time period: Early 21st century. Major taxa studied: Woody plants. Methods: Using a dataset of 87,737 trees distributed among 245 forest and savanna sites across the tropics, we fitted site-specific allometric relationships between crown dimensions (crown depth, diameter and volume) and stem diameter using power-law models. Stand-level and environmental drivers of crown allometric relationships were assessed at pantropical and continental scales. Results: The scaling exponents of allometric relationships between stem diameter and crown dimensions were higher in savannas than in forests. We identified that continental crown models were better than pantropical crown models and that continental differences in crown allometric relationships were driven by both stand-level (wood density) and environmental (precipitation, cation exchange capacity and soil texture) variables for both tropical biomes. For a given diameter, forest trees from Asia and savanna trees from Australia had smaller crown dimensions than trees in Africa and America, with crown volumes for some Asian forest trees being smaller than those of trees in African forests. Main conclusions: Our results provide new insight into geographical variability, with large continental differences in tropical tree crown allometry that were driven by stand-level and environmental variables. They have implications for the assessment of ecosystem function and for the monitoring of woody biomass by remote sensing techniques in the global tropics.
23 citations
TL;DR: In this article, the authors report large-scale estimates of Amazonian gap dynamics using a novel approach with large datasets of airborne light detection and ranging (lidar), including five multi-temporal and 610 single-date lidar datasets.
Abstract: We report large-scale estimates of Amazonian gap dynamics using a novel approach with large datasets of airborne light detection and ranging (lidar), including five multi-temporal and 610 single-date lidar datasets. Specifically, we (1) compared the fixed height and relative height methods for gap delineation and established a relationship between static and dynamic gaps (newly created gaps); (2) explored potential environmental/climate drivers explaining gap occurrence using generalized linear models; and (3) cross-related our findings to mortality estimates from 181 field plots. Our findings suggest that static gaps are significantly correlated to dynamic gaps and can inform about structural changes in the forest canopy. Moreover, the relative height outperformed the fixed height method for gap delineation. Well-defined and consistent spatial patterns of dynamic gaps were found over the Amazon, while also revealing the dynamics of areas never sampled in the field. The predominant pattern indicates 20-35% higher gap dynamics at the west and southeast than at the central-east and north. These estimates were notably consistent with field mortality patterns, but they showed 60% lower magnitude likely due to the predominant detection of the broken/uprooted mode of death. While topographic predictors did not explain gap occurrence, the water deficit, soil fertility, forest flooding and degradation were key drivers of gap variability at the regional scale. These findings highlight the importance of lidar in providing opportunities for large-scale gap dynamics and tree mortality monitoring over the Amazon.
Frederick C. Draper1, Frederick C. Draper2, Frederick C. Draper3, Flávia R. C. Costa4 +148 more•Institutions (61)
TL;DR: In this paper, the authors use a large floristic dataset to show that, while hyperdominance is a universal phenomenon across forest strata, different species dominate the forest understory, mid-story and canopy.
Abstract: The forests of Amazonia are among the most biodiverse plant communities on Earth. Given the immediate threats posed by climate and land-use change, an improved understanding of how this extraordinary biodiversity is spatially organized is urgently required to develop effective conservation strategies. Most Amazonian tree species are extremely rare but a few are common across the region. Indeed, just 227 ‘hyperdominant’ species account for >50% of all individuals >10 cm diameter at 1.3 m in height. Yet, the degree to which the phenomenon of hyperdominance is sensitive to tree size, the extent to which the composition of dominant species changes with size class and how evolutionary history constrains tree hyperdominance, all remain unknown. Here, we use a large floristic dataset to show that, while hyperdominance is a universal phenomenon across forest strata, different species dominate the forest understory, midstory and canopy. We further find that, although species belonging to a range of phylogenetically dispersed lineages have become hyperdominant in small size classes, hyperdominants in large size classes are restricted to a few lineages. Our results demonstrate that it is essential to consider all forest strata to understand regional patterns of dominance and composition in Amazonia. More generally, through the lens of 654 hyperdominant species, we outline a tractable pathway for understanding the functioning of half of Amazonian forests across vertical strata and geographical locations. Most Amazon tree species are rare but a small proportion are common across the region. The authors show that different species are hyperdominant in different size classes and that hyperdominance is more phylogenetically restricted for larger canopy trees than for smaller understory ones.
Royal Botanic Garden Edinburgh1, University of Leeds2, University of Edinburgh3, University of Exeter4, Venezuelan Institute for Scientific Research5, Alexander von Humboldt Biological Resources Research Institute6, National Agrarian University7, Smithsonian Conservation Biology Institute8, Imperial College London9, State University of Norte Fluminense10, Pontificia Universidad Católica del Ecuador11, Universidad Autónoma Gabriel René Moreno12, Federal University of Bahia13, National Chung Hsing University14, Federal University of Ceará15, Federal University of Campina Grande16, State University of Feira de Santana17, National University of Colombia18, Universidad Michoacana de San Nicolás de Hidalgo19, Universidade do Estado de Mato Grosso20, Empresa Brasileira de Pesquisa Agropecuária21, Universidade Federal de Minas Gerais22, University of São Paulo23, Sao Paulo State University24, Universidade Federal de Viçosa25, Universidade Federal de Lavras26, Universidade Federal Rural de Pernambuco27, Wageningen University and Research Centre28
TL;DR: In this article, the authors provide a protocol for permanent monitoring plots in tropical dry forests. But despite increasing appreciation of their threatened status, biodiversity, and importance to the global carbon cycle, monitoring in tropical drier forests is still in its infancy.
Abstract: Understanding of tropical forests has been revolutionized by monitoring in permanent plots. Data from global plot networks have transformed our knowledge of forests? diversity, function, contribution to global biogeochemical cycles, and sensitivity to climate change. Monitoring has thus far been concentrated in rain forests. Despite increasing appreciation of their threatened status, biodiversity, and importance to the global carbon cycle, monitoring in tropical dry forests is still in its infancy. We provide a protocol for permanent monitoring plots in tropical dry forests. Expanding monitoring into dry biomes is critical for overcoming the linked challenges of climate change, land use change, and the biodiversity crisis.
University of Birmingham1, University of Leeds2, University of Plymouth3, Manchester Metropolitan University4, National Chung Hsing University5, University of Exeter6, National Institute of Amazonian Research7, Imperial College London8, University of Oxford9, Universidade do Estado de Mato Grosso10, Wageningen University and Research Centre11, Universidade Federal do Acre12, University of California, Berkeley13, University of Los Andes14, Amazon.com15, Federal University of Western Pará16, Duke University17, National Institute for Space Research18, Universidad Autónoma Gabriel René Moreno19, University of the French West Indies and Guiana20, Florida International University21, University of São Paulo22, Centre de coopération internationale en recherche agronomique pour le développement23, Woods Hole Research Center24, Centre national de la recherche scientifique25, United States Geological Survey26, Federal University of Pará27, University of Texas at Austin28, Smithsonian Institution29, Jorge Basadre Grohmann National University30, Museu Paraense Emílio Goeldi31, Venezuelan Institute for Scientific Research32, Polytechnic University of Valencia33, National University of Colombia34, James Cook University35, University College London36, George Mason University37, University of Edinburgh38, Australian National University39, Universidad Mayor40, Field Museum of Natural History41, University of La Serena42, Forestry Commission43, Federal University of Alagoas44, University of Florida45, University of Nottingham46, Van Hall Larenstein University of Applied Sciences47, State University of Campinas48, University of San Francisco49, Tropenbos International50
TL;DR: The original version of this article contained an error in Table 2, where the number of individuals in the “All Amazonia” row was reported as 11,6431 instead of 116,431 as mentioned in this paper.
Abstract: The original version of this Article contained an error in Table 2, where the number of individuals in the “All Amazonia” row was reported as 11,6431 instead of 116,431. Also, the original version of this Article contained an error in the Methods, where the R2 for the proportion of broken/uprooted dead trees increase per year was reported as 0.12, the correct value being 0.06. The original version of this Article contained errors in the author affiliations. The affiliation of Gerardo A. Aymard C. with UNELLEZGuanare, Herbario Universitario (PORT), Portuguesa, Venezuela Compensation International Progress S.A. Ciprogress–Greenlife.
TL;DR: In this paper, the authors applied 15 N tracers to examine the fates of deposited ammonium (NH4 + ) and nitrate (NO3 - ) separately over three years in a primary and a secondary tropical montane forest in southern China.
Abstract: The effects of nitrogen (N) deposition on forests largely depend on its fate after entering the ecosystem. While several studies have addressed the forest fate of N deposition using 15 N tracers, the long-term fate and redistribution of deposited N in tropical forests remains unknown. Here, we applied 15 N tracers to examine the fates of deposited ammonium (NH4 + ) and nitrate (NO3 - ) separately over three years in a primary and a secondary tropical montane forest in southern China. Three months after 15 N tracer addition, over 60% of 15 N was retained in the studied forests. Total ecosystem retention did not change over the study period, but between three months and three years following deposition 15 N recovery in plants increased from 10% to 19% and 13% to 22% in the primary and secondary forest, respectively, while 15 N recovery in the organic soil declined from 16% to 2% and 9% to 2%. Mineral soil retained 50% and 35% of 15 N in the primary and secondary forests, with retention being stable over time. The total ecosystem retention of the two N forms did not differ significantly, but plants retained more 15 NO3 - than 15 NH4 + and the organic soil more 15 NH4 + than 15 NO3 - . Mineral soil did not differ in 15 NH4 + and 15 NO3 - retention. Compared to temperate forests, proportionally more 15 N was distributed to mineral soil and plants in these tropical forests. Overall, our results suggest that atmospherically deposited NH4 + and NO3 - is rapidly lost in the short-term (months) but thereafter securely retained within the ecosystem, with retained N becoming redistributed to plants and mineral soil from the organic soil. This long-term N retention may benefit tropical montane forest growth and enhance ecosystem carbon sequestration.
01 May 2021
TL;DR: In this paper, the Gordon and Betty Moore Foundation provided a grant for monitoring Protected Areas in Peru to Increase Forest Resilience to Climate Change (#5349), which funded the expansion and integration of the permanent plot network in Peru, 2017-2020.
Abstract: Funded by Natural Environment Research Council (NERC; grants NE/R000751/1 and NE/H011773/1) and the Leverhulme Trust (grant RPG‐2018‐306). We thank the Gordon and Betty Moore Foundation for the grant “Monitoring Protected Areas in Peru to Increase Forest Resilience to Climate Change” (#5349), which funded the expansion and integration of the permanent plot network in Peru, 2017‐2020. We also thank the many funding agencies that have supported the establishment and maintenance of long‐term plots in Peru, including NERC, the National Geographic Society, the Gordon and Betty Moore Foundation, the European Research Council, and the US National Science Foundation Long‐Term Research in Environmental Biology Program.
Smithsonian Environmental Research Center1, Environmental Change Institute2, University of Montpellier3, James Cook University4, Sonoma State University5, University of New South Wales6, University of California, Berkeley7, Naturalis8, Commonwealth Scientific and Industrial Research Organisation9, Australian National University10, New Mexico State University11, University of Leeds12
TL;DR: In this article, the authors examined how multiannual tree growth responds to both climate means and anomalies, and how species' functional traits mediate these growth responses to climate, and showed that anomalous increases in atmospheric evaporative demand and solar radiation consistently reduced tree growth.
Abstract: A better understanding of how climate affects growth in tree species is essential for improved predictions of forest dynamics under climate change. Long-term climate averages (mean climate) drives spatial variations in species’ baseline growth rates, whereas deviations from these averages over time (anomalies) can create growth variation around the local baseline. However, the rarity of long-term tree census data spanning climatic gradients has so far limited our understanding of their respective role, especially in tropical systems. Furthermore, tree growth sensitivity to climate is likely to vary widely among species, and the ecological strategies underlying these differences remain poorly understood. Here, we utilise an exceptional dataset of 49 years of growth data for 509 tree species across 23 tropical rainforest plots along a climatic gradient to examine how multiannual tree growth responds to both climate means and anomalies, and how species’ functional traits mediate these growth responses to climate. We show that anomalous increases in atmospheric evaporative demand and solar radiation consistently reduced tree growth. Drier forests and fast-growing species were more sensitive to water stress anomalies. In addition, species traits related to water use and photosynthesis partly explained differences in growth sensitivity to both climate means and anomalies. Our study demonstrates that both climate means and anomalies shape tree growth in tropical forests, and that species traits can provide insights into understanding these demographic responses to climate change, offering a promising way forward to forecast tropical forest dynamics under different climate trajectories.
TL;DR: The results showed that the dominant oak species in tropical forests respond to environmental change by modulating traits at multiple levels, from that of the individual cell, through tissue, and up to the whole leaf scale.
Abstract:
Understanding variation and coordination of leaf traits at multi-scales along elevational gradients can help predict the likely responses of dominant species to climate change. We seek to determine the extent to which variation in leaf stomatal, anatomical and morphological traits is associated with environmental factors, and whether ecological strategies of Cyclobalanopsis species shift with elevations.
In a tropical forest landscape in Jianfengling, South China, we determined leaf traits related to stomata, anatomy and morphology of six evergreen oak species (Cyclobalanopsis bambusaefolia, C. hui, C. patelliformis, C. fleuryi, C. tiaoloshanica, C. phanera) along a long elevational gradient (400 - 1400 m above sea level).
We found that stomatal density and stomatal pore index increased, whereas spongy mesophyll thickness to leaf thickness ratios decreased, significantly with elevation. The leaf area and leaf dry matter content increased and decreased, respectively, with elevation. Variations in stomatal, anatomical and morphological traits were mainly correlated to the mean annual temperature, mean annual sum precipitation, and soil pH. At low and high elevations, the oak species exhibited strong stress-tolerance combined with competition strategy, while they shifted toward more clearly the competitive strategy at intermediate elevations. And the changes in soil phosphorus concentration and soil pH along the elevation may drive the shift of ecological strategy. The results showed that the dominant oak species in tropical forests respond to environmental change by modulating traits at multiple levels, from that of the individual cell, through tissue, and up to the whole leaf scale.
University of Massachusetts Boston1, Boston University2, Xishuangbanna Tropical Botanical Garden3, Universitas Nasional4, Makerere University5, University of Guelph6, University of Leeds7, University of Kisangani8, Universidade do Estado de Mato Grosso9, University of Lincoln10, University of Yaoundé I11, Harvard University12
TL;DR: In this article, researchers share their experiences and perspectives in dealing with the ethical issues that arise during research activities and cannot be ignored, including economic inequalities, cultural differences, supporting the local communities as much as possible, and sharing the knowledge produced by the research.
TL;DR: In this article, the geographical patterns of key isotopic measures of ecosystem function were determined across China's forests covering ~ 21 latitude (~22-43˚ N) and ~28 longitude (~93-121˚ E) degree and investigated how a suite of soil, plant, and atmospheric factors regulate them.
Abstract: Global changes, eg, global warming, elevated nitrogen deposition, and shifts of precipitation regime, exert a major influence on forests via affecting plant water use efficiency (WUE) and plant nitrogen (N) availability Large-scale ecological sampling can help us to better understand variation across regions and provide opportunities to investigate the potential impacts of multiple aspects of global change on forest ecosystem responses Here, we determine the geographical patterns of key isotopic measures of ecosystem function –plant WUE (calculated from foliar δ13C values) and plant N availability (assessed by foliar δ15N values) – across China's forests covering ~ 21 latitude (~22–43˚ N) and ~28 longitude (~93–121˚ E) degree, and investigate how a suite of soil, plant, and atmospheric factors regulate them We found that plant WUE increased but N availability decreased with latitude, while plant WUE and N availability did not vary with longitudinal gradient Different factors regulate the large-scale patterns in WUE and N availability The mean annual temperature, atmospheric N deposition, and soil water content exhibit considerable effects on plant WUE over both the north-to-south and east-to-west transects, while the mean annual precipitation, soil potassium content, foliar N, and precipitation seasonality considerably affect the latitudinal patterns of plant N availability In addition, the east-to-west spatial pattern in plant N availability is associated with the variation in solar radiation Our results suggest that key forest ecological functions respond to an array of environmental factors, and imply that changes in many different environmental attributes need to be considered in order to successfully assess plant WUE and N availability responses to global changes this century
TL;DR: In this article, mass dynamics of deadwood (necromass) from tropical forest ecosystems subject to some of the highest frequency of tropical cyclones in the world and to regular, persistent seasonal monsoon winds were monitored.
Abstract: The relationships between climate and forest dynamics can help us to interpret patterns of ecosystem carbon and to predict how forests react to climatic changes. We report mass dynamics of deadwood (necromass) from tropical forest ecosystems subject to some of the highest frequency of tropical cyclones in the world and to regular, persistent seasonal monsoon winds. Plots that are influenced by typhoons but exposed to different degrees of monsoon winds were monitored. We expected that stocks and inputs of necromass would reflect the seasonal intensity of wind events and be higher in the high wind exposure forest than in the low wind exposure forest, especially for fallen woody debris. The results showed that necromass input was indeed influenced by the magnitude of typhoons and aggravated by monsoon winds. However, while there was no significant difference in stock of necromass between plots, inputs of standing necromass were significantly higher in the high wind exposure plot; these were mostly derived from dead resprouts. Both our forests had very low values of total necromass stocks (3.47–4.32 Mg C ha−1) and inputs (2.1–2.5 Mg C ha−1 y−1) compared with tropical forests worldwide. Our results show that both monsoon and typhoon winds shape these tropical forests, favouring low stature individuals and trees with ability to resprout and that these strategies provide these forests with remarkable resistance and resilience to wind disturbances. Our findings from some of the most wind-affected forests in the world indicate how woody carbon dynamics and forest structure in other regions may respond to future changes in the frequency and intensity of winds.
TL;DR: Assessment of regeneration traits of tree communities of the Amazon-Cerrado transition aims to understand how they differ among and within the markedly different vegetation types, and to increase the understanding about the dynamics of tree Communities in neotropical forests and savannas.
TL;DR: Peatland pole forests are floristically distinctive and dominated by thin-stemmed woody species such as Pachira nitida (Malvaceae), Platycarpum loretense (Rubiaceae), and Hevea guianensis (Euphorbiaceae) as discussed by the authors.
Abstract: Peatland pole forest is the most carbon-dense ecosystem in Amazonia, but its spatial distribution and species composition are poorly known. To address this knowledge gap, we quantified variation in the floristic composition, peat thickness, and the amount of carbon stored above and below ground of 102 forest plots and 53 transects in northern Peruvian Amazonia. This large dataset includes 571 ground reference points of peat thickness measurements across six ecosystem types. These field data were also used to generate a new land-cover classification based on multiple satellite products using a random forest classification. Peatland pole forests are floristically distinctive and dominated by thin-stemmed woody species such as Pachira nitida (Malvaceae), Platycarpum loretense (Rubiaceae), and Hevea guianensis (Euphorbiaceae). In contrast, palm swamps and open peatlands are dominated by Mauritia flexuosa (Arecaceae). Peatland pole forests have high peat thickness (274 ± 22 cm, mean ± 95% CI, n = 184) similar to open peatlands (282 ± 46 cm, n = 46), but greater than palm swamps (161 ± 17 cm, n = 220) and seasonally-flooded forest, terra firme, and white-sand forest where peat is rare or absent. As a result, peatland pole forest has exceptional carbon density (1,133 ± 93 Mg C ha−1). The new sites expand the known distribution of peatland pole forest by 61% within the Pastaza-Maranon Foreland basin, mainly alongside the Tigre river, to cover a total of 7540 km2 in northern Peruvian Amazonia. However, only 15% of the pole forest area is within a protected area, whilst an additional 26% lies within indigenous territories. The current low levels of protection and forest degradation but high threat from road paving projects makes the Tigre river basin a priority for conservation. The long-term conservation of peatland pole forests has the potential to make a large contribution towards international commitments to mitigate climate change.
Environmental Change Institute1, Smithsonian Environmental Research Center2, University of Montpellier3, James Cook University4, Sonoma State University5, University of New South Wales6, Naturalis7, Commonwealth Scientific and Industrial Research Organisation8, Australian National University9, New Mexico State University10, University of Leeds11
TL;DR: In this article, the authors combined 49 years of growth data for 509 tree species across 23 tropical rainforest plots along a climatic gradient to examine how tree growth responds to both climate means and anomalies, and how species functional traits mediate these tree growth responses to climate.
Abstract: A better understanding of how climate affects growth in tree species is essential for improved predictions of forest dynamics under climate change. Long-term climate averages (mean climate) and short-term deviations from these averages (anomalies) both influence tree growth, but the rarity of long-term data integrating climatic gradients with tree censuses has so far limited our understanding of their respective role, especially in tropical systems. Here, we combined 49 years of growth data for 509 tree species across 23 tropical rainforest plots along a climatic gradient to examine how tree growth responds to both climate means and anomalies, and how species functional traits mediate these tree growth responses to climate. We showed that short-term, anomalous increases in atmospheric evaporative demand and solar radiation consistently reduced tree growth. Drier forests and fast-growing species were more sensitive to water stress anomalies. In addition, species traits related to water use and photosynthesis partly explained differences in growth sensitivity to both long-term and short-term climate variations. Our study demonstrates that both climate means and anomalies shape tree growth in tropical forests, and that species traits can be leveraged to understand these demographic responses to climate change, offering a promising way forward to forecast tropical forest dynamics under different climate trajectories.
Edwin Pos1, Luiz de Souza Coelho2, Diogenes de Andrade Lima Filho2, Rafael de Paiva Salomão3 +239 more•Institutions (86)
TL;DR: In this article, the authors apply the constrained maximization of information entropy (EME) to the Amazonian tree inventories to understand the complex system dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions.
Abstract: In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain almost ten times more of local relative abundances then constraints based on either directional or stabilizing selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics.