Abstract
1. Tree death is a key process for our understanding of how forests are and will respond to global change. The extensive forests across the southern Amazonia edge—the driest, warmest and most fragmented of the Amazon regions—provide a window onto what the future of large parts of Amazonia may look like. Understanding tree mortality and its drivers here is essential to anticipate the process across other parts of the basin.
2. Using 10 years of data from a widespread network of long-term forest plots, we assessed how trees die (standing, broken or uprooted) and used generalised mixed-effect models to explore the contribution of plot-, species- and tree-level factors to the likelihood of tree death.
3. Most trees died from stem breakage (54%); a smaller proportion died standing (41%), while very few were uprooted (5%). The mortality rate for standing dead trees was greatest in forests subject to the most intense dry seasons.
4. While trees with the crown more exposed to light were more prone to death from mechanical damage, trees less exposed were more susceptible to death from drought.
5. At the species level, mortality rates were lowest for those species with the greatest wood density. At the individual tree level, physical damage to the crown via branch breakage was the strongest predictor of tree death.
6. Synthesis. Wind- and water deficit-driven disturbances are the main causes of tree death in southern Amazonia edge which is concerning considering the predicted increase in seasonality for Amazonia, especially at the edge. Tree mortality here is greater than any in other Amazonian region, thus any increase in mortality here may represent a tipping point for these forests.
2. Using 10 years of data from a widespread network of long-term forest plots, we assessed how trees die (standing, broken or uprooted) and used generalised mixed-effect models to explore the contribution of plot-, species- and tree-level factors to the likelihood of tree death.
3. Most trees died from stem breakage (54%); a smaller proportion died standing (41%), while very few were uprooted (5%). The mortality rate for standing dead trees was greatest in forests subject to the most intense dry seasons.
4. While trees with the crown more exposed to light were more prone to death from mechanical damage, trees less exposed were more susceptible to death from drought.
5. At the species level, mortality rates were lowest for those species with the greatest wood density. At the individual tree level, physical damage to the crown via branch breakage was the strongest predictor of tree death.
6. Synthesis. Wind- and water deficit-driven disturbances are the main causes of tree death in southern Amazonia edge which is concerning considering the predicted increase in seasonality for Amazonia, especially at the edge. Tree mortality here is greater than any in other Amazonian region, thus any increase in mortality here may represent a tipping point for these forests.
| Original language | English |
|---|---|
| Pages (from-to) | 876-888 |
| Number of pages | 13 |
| Journal | Journal of Ecology |
| Volume | 110 |
| Issue number | 4 |
| Early online date | 22 Feb 2022 |
| DOIs | |
| Publication status | Published - Apr 2022 |
Bibliographical note
Funding Information:CNPq/PELD (403725/2012–7, 401279/2014–6 and 441244/2016–5); CAPES (177/2012, 138459/2017 and 185186/2018); PPBIO (457602/2012–0); FAPEMAT (164131/2013); European Research Council AdG (291585, T‐FORCES and 758873, TreeMort), British Council Newton Fund Institutional Links (275556724); NERC (NERC NE/N011570/1, NE/N012542/1 and 2015/50517–5, BIORED) and Royal Society (FORAMA‐ ICA\R1\180100).
Funding Information:
We thank the team of the —Plant Ecology Laboratory at the UNEMAT (Universidade do Estado de Mato Grosso) in Nova Xavantina, especially Mônica Forsthofer, Eder Carvalho das Neves, Bianca de Oliveira, Ricardo Keichi Umetsu, Nayane Cristina Prestes, Wesley J. Alves da Cruz, Henrique Augusto Mews, Leonardo Maracahipes, Leandro Maracahipes, Marco Bruno Xavier Valadão, Silvio Gonçalves Longhi, Denis da Silva Nogueira and Claudinei Oliveira dos Santos for help collecting field data. We thank the National Council for Scientific and Technological Development (CNPq) for financial support of the projects PELD ‘Cerrado‐Amazonia Transition: ecological and socio‐environmental bases for Conservation’ (stages II and III)—403725/2012‐7 and 441244/2016‐5, PVE ‘special visiting researcher’ (CNPq 401279/2014‐6 & CAPES 177/2012), PPBIO ‘Phytogeography of the Amazon‐Cerrado Transition Zone’ (457602/2012‐0) and FAPEMAT (164131/2013). O.L.P acknowledges support from an ERC Advanced Grant 291585 (‘T‐FORCES’), a Royal Society‐Wolfson Research Merit Award and a Royal Society International Collaboration Award, ‘FORAMA’. T.R.F. and O.L.P. were supported by NERC grant NE/N011570/1. A.E.‐M. was funded by TREMOR and by two ERC awards (T‐FORCES 291585, TreeMort 758873). We also thank CNPq for research productivity grants to B.S.M. and B.H.M.Jr, and international doctoral grants to S.M.R. and P.S.M., and ‘PVE’ to O.L.P. (401279/2014‐6), and CAPES for an international doctoral grant to E.A.O. and ‘PVE’ to T.R.F. (177/2012). We are grateful to CAPES (Finance Code 001) and FAPEMAT for scholarships to S.M.R., P.S.M., F.E. and E.A.O. S.M.R. is funded by a postdoctoral Fellowship from NERC and FAPESP (BIO‐RED 2015/50517‐5). P.S.M. and E.A.O. also acknowledge support from CAPES to postdoctoral Fellowship (138459/2017, 185186/2018 and 88887‐504562/2020‐0). Laboratório de Ecologia Vegetal campus
Funding Information:
We thank the team of the Laborat?rio de Ecologia Vegetal?Plant Ecology Laboratory at the UNEMAT (Universidade do Estado de Mato Grosso) campus in Nova Xavantina, especially M?nica Forsthofer, Eder Carvalho das Neves, Bianca de Oliveira, Ricardo Keichi Umetsu, Nayane Cristina Prestes, Wesley J. Alves da Cruz, Henrique Augusto Mews, Leonardo Maracahipes, Leandro Maracahipes, Marco Bruno Xavier Valad?o, Silvio Gon?alves Longhi, Denis da Silva Nogueira and Claudinei Oliveira dos Santos for help collecting field data. We thank the National Council for Scientific and Technological Development (CNPq) for financial support of the projects PELD ?Cerrado-Amazonia Transition: ecological and socio-environmental bases for Conservation? (stages II and III)?403725/2012-7 and 441244/2016-5, PVE ?special visiting researcher? (CNPq 401279/2014-6 & CAPES 177/2012), PPBIO ?Phytogeography of the Amazon-Cerrado Transition Zone? (457602/2012-0) and FAPEMAT (164131/2013). O.L.P acknowledges support from an ERC Advanced Grant 291585 (?T-FORCES?), a Royal Society-Wolfson Research Merit Award and a Royal Society International Collaboration Award, ?FORAMA?. T.R.F. and O.L.P. were supported by NERC grant NE/N011570/1. A.E.-M. was funded by TREMOR and by two ERC awards (T-FORCES 291585, TreeMort 758873). We also thank CNPq for research productivity grants to B.S.M. and B.H.M.Jr, and international doctoral grants to S.M.R. and P.S.M., and ?PVE? to O.L.P. (401279/2014-6), and CAPES for an international doctoral grant to E.A.O. and ?PVE? to T.R.F. (177/2012). We are grateful to CAPES (Finance Code 001) and FAPEMAT for scholarships to S.M.R., P.S.M., F.E. and E.A.O. S.M.R. is funded by a postdoctoral Fellowship from NERC and FAPESP (BIO-RED 2015/50517-5). P.S.M. and E.A.O. also acknowledge support from CAPES to postdoctoral Fellowship (138459/2017, 185186/2018 and 88887-504562/2020-0).
Publisher Copyright:
© 2022 The Authors. Journal of Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.
Keywords
- climate change
- disturbance
- forest dynamics
- forest structure
- growth rate
- tree death
- water deficit
- wood density
