35 research outputs found

    Expanding tropical forest monitoring into Dry Forests: The DRYFLOR protocol for permanent plots

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    This is the final version. Available on open access from Wiley via the DOI in this recordSocietal Impact Statement 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.Newton FundNatural Environment Research Council (NERC)Fundação de Amparo à Pesquisa do Estado de São PauloCYTE

    Long-term thermal sensitivity of Earth’s tropical forests

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    The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (‚ąí9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per ¬įC in the hottest forests (>32.2¬įC). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth‚Äôs climate

    The global abundance of tree palms

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    Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location Tropical and subtropical moist forests. Time period Current. Major taxa studied Palms (Arecaceae). Methods We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ‚Č•10 cm diameter at breast height) abundance relative to co‚Äźoccurring non‚Äźpalm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‚Äźterm climate stability. Life‚Äźform diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‚Äźtree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‚Äźground biomass, but the magnitude and direction of the effect require additional work. Conclusions Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests

    Mapping density, diversity and species-richness of the Amazon tree flora

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    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth‚Äôs most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10‚ÄČcm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth‚Äôs 800 billion tropical trees with trunk diameters of at least 10‚ÄČcm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world‚Äôs most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

    Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology

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    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 eight times more of local relative abundances than constraints based on directional 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

    Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology

    Get PDF
    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 eight times more of local relative abundances than constraints based on directional 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

    Mapping density, diversity and species-richness of the Amazon tree flora

    Get PDF
    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

    Rarity of monodominance in hyperdiverse Amazonian forests.

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    Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees‚ÄČ‚Č•‚ÄČ10‚ÄČcm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

    Taking the pulse of Earth's tropical forests using networks of highly distributed plots

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    Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to measure and monitor them have been largely disconnected. Networking is essential to discover the answers to questions that transcend borders and the horizons of funding agencies. Here we 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. We review the major scientific discoveries of this work and show how this process is changing tropical forest science. Our core approach involves linking long-term grassroots initiatives with standardized protocols and data management to generate robust scaled-up results. By connecting tropical researchers and elevating their status, our Social Research Network model recognises the key role of the data originator in scientific discovery. Conceived in 1999 with RAINFOR (South America), our permanent plot networks have been adapted to Africa (AfriTRON) and Southeast Asia (T-FORCES) and widely emulated worldwide. Now these multiple initiatives are integrated via ForestPlots.net cyber-infrastructure, linking colleagues from 54 countries across 24 plot networks. Collectively these are transforming understanding of tropical forests and their biospheric role. Together we have discovered how, where and why forest carbon and biodiversity are responding to climate change, and how they feedback on it. This long-term pan-tropical collaboration has revealed a large long-term carbon sink and its trends, as well as making clear which drivers are most important, which forest processes are affected, where they are changing, what the lags are, and the likely future responses of tropical forests as the climate continues to change. By leveraging a remarkably old technology, plot networks are sparking a very modern revolution in tropical forest science. In the future, humanity can benefit greatly by nurturing the grassroots communities now collectively capable of generating unique, long-term understanding of Earth's most precious forests. Resumen Los bosques tropicales son los ecosistemas m√°s diversos y productivos del mundo y entender su funcionamiento es cr√≠tico para nuestro futuro colectivo. Sin embargo, hasta hace muy poco, los esfuerzos para medirlos y monitorearlos han estado muy desconectados. El trabajo en redes es esencial para descubrir las respuestas a preguntas que trascienden las fronteras y los plazos de las agencias de financiamiento. Aqu√≠ mostramos c√≥mo una comunidad global est√° respondiendo a los desaf√≠os de la investigaci√≥n en ecosistemas tropicales a trav√©s de diversos equipos realizando mediciones √°rbol por √°rbol en miles de parcelas permanentes de largo plazo. Revisamos los descubrimientos m√°s importantes de este trabajo y discutimos c√≥mo este proceso est√° cambiando la ciencia relacionada a los bosques tropicales. El enfoque central de nuestro esfuerzo implica la conexi√≥n de iniciativas locales de largo plazo con protocolos estandarizados y manejo de datos para producir resultados que se puedan trasladar a m√ļltiples escalas. Conectando investigadores tropicales, elevando su posici√≥n y estatus, nuestro modelo de Red Social de Investigaci√≥n reconoce el rol fundamental que tienen, para el descubrimiento cient√≠fico, quienes generan o producen los datos. Concebida en 1999 con RAINFOR (Suram√©rica), nuestras redes de parcelas permanentes han sido adaptadas en √Āfrica (AfriTRON) y el sureste asi√°tico (T-FORCES) y ampliamente replicadas en el mundo. Actualmente todas estas iniciativas est√°n integradas a trav√©s de la ciber-infraestructura de ForestPlots.net, conectando colegas de 54 pa√≠ses en 24 redes diferentes de parcelas. Colectivamente, estas redes est√°n transformando nuestro conocimiento sobre los bosques tropicales y el rol de √©stos en la bi√≥sfera. Juntos hemos descubierto c√≥mo, d√≥nde y porqu√© el carbono y la biodiversidad de los bosques tropicales est√° respondiendo al cambio clim√°tico y c√≥mo se retroalimentan. Esta colaboraci√≥n pan-tropical de largo plazo ha expuesto un gran sumidero de carbono y sus tendencias, mostrando claramente cu√°les son los factores m√°s importantes, qu√© procesos se ven afectados, d√≥nde ocurren los cambios, los tiempos de reacci√≥n y las probables respuestas futuras mientras el clima contin√ļa cambiando. Apalancando lo que realmente es una tecnolog√≠a antigua, las redes de parcelas est√°n generando una verdadera y moderna revoluci√≥n en la ciencia tropical. En el futuro, la humanidad puede beneficiarse enormemente si se nutren y cultivan comunidades de investigadores de base, actualmente con la capacidad de generar informaci√≥n √ļnica y de largo plazo para entender los que probablemente son los bosques m√°s preciados de la tierra. Resumo Florestas tropicais s√£o os ecossistemas mais diversos e produtivos da Terra. Embora uma boa compreens√£o destas florestas seja crucial para o nosso futuro coletivo, at√© muito recentemente os esfor√ßos de medi√ß√Ķes e monitoramento foram amplamente desconexos. √Č essencial formarmos redes para obtermos respostas que transcendem fronteiras e horizontes de ag√™ncias financiadoras. Neste estudo n√≥s mostramos como uma comunidade global est√° respondendo aos desafios da pesquisa de ecossistemas tropicais, com equipes diversas medindo florestas, √°rvore por √°rvore, em milhares de parcelas monitoradas √† longo prazo. N√≥s revisamos as maiores descobertas cient√≠ficas deste trabalho, e mostramos tamb√©m como este processo est√° mudando a ci√™ncia de florestas tropicais. Nossa abordagem principal envolve unir iniciativas de base a protocolos padronizados e gerenciamento de dados a fim de gerar resultados robustos em escalas ampliadas. Ao conectar pesquisadores tropicais e elevar seus status, nosso modelo de Rede de Pesquisa Social reconhece o papel-chave do produtor dos dados na descoberta cient√≠fica. Concebida em 1999 com o RAINFOR (Am√©rica do Sul), nossa rede de parcelas permanentes foi adaptada para √Āfrica (AfriTRON) e Sudeste asi√°tico (T-FORCES), e tem sido extensamente reproduzida em todo o mundo. Agora estas m√ļltiplas iniciativas est√£o integradas atrav√©s de uma infraestrutura cibern√©tica do ForestPlots.net, conectando colegas de 54 pa√≠ses de 24 redes de parcelas. Estas iniciativas est√£o transformando coletivamente o entendimento das florestas tropicais e seus pap√©is na biosfera. Juntos n√≥s descobrimos como, onde e por que o carbono e a biodiversidade da floresta est√£o respondendo √†s mudan√ßas clim√°ticas, e seus efeitos de retroalimenta√ß√£o. Esta duradoura colabora√ß√£o pantropical revelou um grande sumidouro de carbono persistente e suas tend√™ncias, assim como tem evidenciado quais direcionadores s√£o mais importantes, quais processos florestais s√£o mais afetados, onde eles est√£o mudando, seus atrasos no tempo de resposta, e as prov√°veis respostas das florestas tropicais conforme o clima continua a mudar. Dessa forma, aproveitando uma not√°vel tecnologia antiga, redes de parcelas acendem fa√≠scas de uma moderna revolu√ß√£o na ci√™ncia das florestas tropicais. No futuro a humanidade pode se beneficiar incentivando estas comunidades basais que agora s√£o coletivamente capazes de gerar conhecimentos √ļnicos e duradouros sobre as florestas mais preciosas da Terra. R√©sume Les for√™ts tropicales sont les √©cosyst√®mes les plus diversifi√©s et les plus productifs de la plan√®te. Si une meilleure compr√©hension de ces for√™ts est essentielle pour notre avenir collectif, jusqu'√† tout r√©cemment, les efforts d√©ploy√©s pour les mesurer et les surveiller ont √©t√© largement d√©connect√©s. La mise en r√©seau est essentielle pour d√©couvrir les r√©ponses √† des questions qui d√©passent les fronti√®res et les horizons des organismes de financement. Nous montrons ici comment une communaut√© mondiale rel√®ve les d√©fis de la recherche sur les √©cosyst√®mes tropicaux avec diverses √©quipes qui mesurent les for√™ts arbre apr√®s arbre dans de milliers de parcelles permanentes. Nous passons en revue les principales d√©couvertes scientifiques de ces travaux et montrons comment ce processus modifie la science des for√™ts tropicales. Notre approche principale consiste √† relier les initiatives de base √† long terme √† des protocoles standardis√©s et une gestion de donn√©es afin de g√©n√©rer des r√©sultats solides √† grande √©chelle. En reliant les chercheurs tropicaux et en √©levant leur statut, notre mod√®le de r√©seau de recherche sociale reconna√ģt le r√īle cl√© de l'auteur des donn√©es dans la d√©couverte scientifique. Con√ßus en 1999 avec RAINFOR (Am√©rique du Sud), nos r√©seaux de parcelles permanentes ont √©t√© adapt√©s √† l'Afrique (AfriTRON) et √† l'Asie du Sud-Est (T-FORCES) et largement imit√©s dans le monde entier. Ces multiples initiatives sont d√©sormais int√©gr√©es via l'infrastructure ForestPlots.net, qui relie des coll√®gues de 54 pays √† travers 24 r√©seaux de parcelles. Ensemble, elles transforment la compr√©hension des for√™ts tropicales et de leur r√īle biosph√©rique. Ensemble, nous avons d√©couvert comment, o√Ļ et pourquoi le carbone forestier et la biodiversit√© r√©agissent au changement climatique, et comment ils y r√©agissent. Cette collaboration pan-tropicale √† long terme a r√©v√©l√© un important puits de carbone √† long terme et ses tendances, tout en mettant en √©vidence les facteurs les plus importants, les processus forestiers qui sont affect√©s, les endroits o√Ļ ils changent, les d√©calages et les r√©actions futures probables des for√™ts tropicales √† mesure que le climat continue de changer. En tirant parti d'une technologie remarquablement ancienne, les r√©seaux de parcelles d√©clenchent une r√©volution tr√®s moderne dans la science des for√™ts tropicales. √Ä l'avenir, l'humanit√© pourra grandement b√©n√©ficier du soutien des communaut√©s de base qui sont maintenant collectivement capables de g√©n√©rer une compr√©hension unique et √† long terme des for√™ts les plus pr√©cieuses de la Terre. Abstrak Hutan tropika adalah di antara ekosistem yang paling produktif dan mempunyai kepelbagaian biodiversiti yang tinggi di seluruh dunia. Walaupun pemahaman mengenai hutan tropika amat penting untuk masa depan kita, usaha-usaha untuk mengkaji dan mengawas hutah-hutan tersebut baru sekarang menjadi lebih diperhubungkan. Perangkaian adalah sangat penting untuk mencari jawapan kepada soalan-soalan yang menjangkaui sempadan dan batasan agensi pendanaan. Di sini kami menunjukkan bagaimana sebuah komuniti global bertindak balas terhadap cabaran penyelidikan ekosistem tropika melalui penglibatan pelbagai kumpulan yang mengukur hutan secara pokok demi pokok dalam beribu-ribu plot jangka panjang. Kami meninjau semula penemuan saintifik utama daripada kerja ini dan menunjukkan bagaimana proses ini sedang mengubah bidang sains hutan tropika. Teras pendekatan kami memberi tumpuan terhadap penghubungan inisiatif akar umbi jangka panjang dengan protokol standar serta pengurusan data untuk mendapatkan hasil skala besar yang kukuh. Dengan menghubungkan penyelidik-penyelidik tropika dan meningkatkan status mereka, model Rangkaian Penyelidikan Sosial kami mengiktiraf kepentingan peranan pengasas data dalam penemuan saintifik. Bermula dengan pengasasan RAINFOR (Amerika Selatan) pada tahun 1999, rangkaian-rangkaian plot kekal kami kemudian disesuaikan untuk Afrika (AfriTRON) dan Asia Tenggara (T-FORCES) dan selanjutnya telah banyak dicontohi di seluruh dunia. Kini, inisiatif-inisiatif tersebut disepadukan melalui infrastruktur siber ForestPlots.net yang menghubungkan rakan sekerja dari 54 negara di 24 buah rangkaian plot. Secara kolektif, rangkaian ini sedang mengubah pemahaman tentang hutan tropika dan peranannya dalam biosfera. Kami telah bekerjasama untuk menemukan bagaimana, di mana dan mengapa karbon serta biodiversiti hutan bertindak balas terhadap perubahan iklim dan juga bagaimana mereka saling bermaklum balas. Kolaborasi pan-tropika jangka panjang ini telah mendedahkan sebuah sinki karbon jangka panjang serta arah alirannya dan juga menjelaskan pemandu-pemandu perubahan yang terpenting, di mana dan bagaimana proses hutan terjejas, masa susul yang ada dan kemungkinan tindakbalas hutan tropika pada perubahan iklim secara berterusan di masa depan. Dengan memanfaatkan pendekatan lama, rangkaian plot sedang menyalakan revolusi yang amat moden dalam sains hutan tropika. Pada masa akan datang, manusia sejagat akan banyak mendapat manfaat jika memupuk komuniti-komuniti akar umbi yang kini berkemampuan secara kolektif menghasilkan pemahaman unik dan jangka panjang mengenai hutan-hutan yang paling berharga di dunia
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