Drought stress and tree size determine stem CO 2 efflux in a tropical forest.

Autor: Rowland L; College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK., da Costa ACL; Instituto de Geosciências, Universidade Federal do Pará, Belém, PA, 66075-110, Brasil., Oliveira AAR; Museu Paraense Emílio Goeldi, Belém, PA, 66040-170, Brasil., Oliveira RS; Instituto de Biologia, UNICAMP, Campinas, SP, 13083-970, Brasil., Bittencourt PL; Instituto de Biologia, UNICAMP, Campinas, SP, 13083-970, Brasil., Costa PB; Instituto de Biologia, UNICAMP, Campinas, SP, 13083-970, Brasil., Giles AL; Instituto de Biologia, UNICAMP, Campinas, SP, 13083-970, Brasil., Sosa AI; Instituto de Biologia, UNICAMP, Campinas, SP, 13083-970, Brasil., Coughlin I; Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, SP, 14040-900, Brasil., Godlee JL; School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3FF, UK., Vasconcelos SS; EMBRAPA Amazônia Oriental, 14, Belém, PA, 66095-903, Brasil., Junior JAS; Instituto de Geosciências, Universidade Federal do Pará, Belém, PA, 66075-110, Brasil., Ferreira LV; Museu Paraense Emílio Goeldi, Belém, PA, 66040-170, Brasil., Mencuccini M; CREAF, Campus UAB, Cerdanyola del Vallés, 08193, Spain.; ICREA, Barcelona, 08010, Spain., Meir P; School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3FF, UK.; Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia.
Jazyk: angličtina
Zdroj: The New phytologist [New Phytol] 2018 Jun; Vol. 218 (4), pp. 1393-1405. Date of Electronic Publication: 2018 Feb 03.
DOI: 10.1111/nph.15024
Abstrakt: CO 2 efflux from stems (CO 2_stem ) accounts for a substantial fraction of tropical forest gross primary productivity, but the climate sensitivity of this flux remains poorly understood. We present a study of tropical forest CO 2_stem from 215 trees across wet and dry seasons, at the world's longest running tropical forest drought experiment site. We show a 27% increase in wet season CO 2_stem in the droughted forest relative to a control forest. This was driven by increasing CO 2_stem in trees 10-40 cm diameter. Furthermore, we show that drought increases the proportion of maintenance to growth respiration in trees > 20 cm diameter, including large increases in maintenance respiration in the largest droughted trees, > 40 cm diameter. However, we found no clear taxonomic influence on CO 2_stem and were unable to accurately predict how drought sensitivity altered ecosystem scale CO 2_stem , due to substantial uncertainty introduced by contrasting methods previously employed to scale CO 2_stem fluxes. Our findings indicate that under future scenarios of elevated drought, increases in CO 2_stem may augment carbon losses, weakening or potentially reversing the tropical forest carbon sink. However, due to substantial uncertainties in scaling CO 2_stem fluxes, stand-scale future estimates of changes in stem CO 2 emissions remain highly uncertain.
(© 2018 The Authors New Phytologist © 2018 New Phytologist Trust.)
Databáze: MEDLINE
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