Contrasting effects of defaunation on aboveground carbon storage across the global tropics.
Defaunation is causing declines of large-seeded animal-dispersed trees in tropical forests worldwide, but whether and how these declines will affect carbon storage across this biome is unclear. Here we show, using a pan-tropical data set, that simulated declines of large-seeded animal-dispersed trees have contrasting effects on aboveground carbon stocks across Earth's tropical forests. In our simulations, African, American and South Asian forests, which have high proportions of animal-dispersed species, consistently show carbon losses (2-12%), but Southeast Asian and Australian forests, where there are more abiotically dispersed species, show little to no carbon losses or marginal gains (±1%). These patterns result primarily from changes in wood volume, and are underlain by consistent relationships in our empirical data (∼2,100 species), wherein, large-seeded animal-dispersed species are larger as adults than small-seeded animal-dispersed species, but are smaller than abiotically dispersed species. Thus, floristic differences and distinct dispersal mode-seed size-adult size combinations can drive contrasting regional responses to defaunation.
National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, Karnataka 560 065, India.|Nature Conservation Foundation, 3076/5, IV Cross, Gokulam Park, Mysore, Karnataka 570 002, India.
Anand M
0000-0001-9909-5633
AM
Osuri
National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, Karnataka 560 065, India.
Jayashree
J
Ratnam
National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, Karnataka 560 065, India.
Varun
V
Varma
Center for Tropical Conservation, Duke University, Durham, North Carolina 27705, USA.
Patricia
P
Alvarez-Loayza
La Selva Biological Station, Organization for Tropical Studies, Puerto Viejo de Sarapiquí, Heredia, Costa Rica.
Johanna
J
Hurtado Astaiza
CSIRO Land and Water, Tropical Forest Research Centre, PO Box 780, Atherton, Queensland 4883, Australia.
Matt
M
Bradford
Forest Research Institute Malaysia (FRIM), Kepong, Selangor Darul Ehsan 52109, Malaysia.
Christine
C
Fletcher
Wildlife Conservation Society (WCS) Congo-Program, Brazzaville B.P. 14537, Republic of Congo.
Mireille
M
Ndoundou-Hockemba
Centre for Tropical Forest Science, Smithsonian Tropical Research Institute, Apartado 0843-03092, Panamá, Republic of Panama.|Department of Environmental Sciences, Wageningen University, Box 47, 6700 AA Wageningen, The Netherlands.
Patrick A
PA
Jansen
Department of Botany, CTFS-ForestGEO, NMNH - MRC 166, Smithsonian Institution, PO Box 37012, Washington, District Of Columbia 20013-7012, USA.
David
D
Kenfack
Environment Department, CIRCLE, University of York, York YO10 5DD, UK.|Flamingo Land Ltd., Kirby Misperton, North Yorkshire YO17 6UX, UK.
Andrew R
AR
Marshall
Institut Français de Pondichéry, 11, Saint Louis Street, Pondicherry 605 001, India.
B R
BR
Ramesh
MUSE - Science Museum of Trento, Corso del Lavoro e della Scienza 3, 38122 Trento, Italy.
Francesco
F
Rovero
National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, Bangalore, Karnataka 560 065, India.|School of Biology, University of Leeds, Leeds LS2 9JT, UK.
Mahesh
0000-0002-1661-6542
M
Sankaran
D063147:Animal Distribution; D000818:Animals; D002244:Carbon / Q000032:analysis*; D003247:Conservation of Natural Resources; D017753:Ecosystem; D065928:Forests; D058614:Seed Dispersal; D014197:Trees / Q000737:chemistry / Q000254:growth & development; D014329:Tropical Climate
D002244:Carbon