Tropical woody plants store similar to 230 petagrams of carbon (PgC) in their above-ground living biomass. This review suggests that these stocks are currently growing in primary forests at rates that have decreased in recent decades. Droughts are an important mechanism in reducing forest C uptake and stocks by decreasing photosynthesis, elevating tree mortality, increasing autotrophic respiration, and promoting wildfires. Tropical forests were a C source to the atmosphere during the 2015-2016 El Nino-related drought, with some estimates suggesting that up to 2.3 PgC were released. With continued climate change, the intensity and frequency of droughts and fires will likely increase. It is unclear at what point the impacts of severe, repeated disturbances by drought and fires could exceed tropical forests' capacity to recover. Although specific threshold conditions beyond which ecosystem properties could lead to alternative stable states are largely unknown, the growing body of scientific evidence points to such threshold conditions becoming more likely as climate and land use change across the tropics.
Droughts have reduced forest carbon uptake and stocks by elevating tree mortality, increasing autotrophic respiration, and promoting wildfires.
Threshold conditions beyond which tropical forests are pushed into alternative stable states are becoming more likely as effects of droughts intensify.
1.Woods Hole Res Ctr, Falmouth, MA 02540 USA 2.Inst Pesquisa Ambiental Amazonia IPAM, BR-71503505 Brasilia, DF, Brazil 3.Univ Fed Lavras, Dept Biol, Setor Ecol & Conservacao, BR-37200000 Lavras, MG, Brazil 4.Woods Hole Oceanog Inst, Dept Phys Oceanog, Woods Hole, MA 02543 USA 5.Harvard Univ, Dept Organism & Evolutionary Biol, Cambridge, MA 02138 USA 6.Carnegie Inst Sci, Dept Global Ecol, Stanford, CA 94305 USA 7.Arizona State Univ, Ctr Global Discovery & Conservat Sci, Tempe, AZ 85281 USA 8.Max Planck Inst Biogeochem, Dept Biogeochem Proc, D-07745 Jena, Germany 9.Univ Colorado, Earth Lab, CIRES, Boulder, CO 80303 USA 10.Commiss Forets Afrique Cent COMIFAC, Yaounde 20818, Cameroon 11.Univ Colorado, Dept Geog, Boulder, CO 80309 USA
Recommended Citation:
Brando, Paulo M.,Paolucci, Lucas,Ummenhofer, Caroline C.,et al. Droughts, Wildfires, and Forest Carbon Cycling: A Pantropical Synthesis[J]. ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES, VOL 47,2019-01-01,47:555-581