Limits...
Committed changes in tropical tree cover under the projected 21st century climate change.

Zeng Z, Piao S, Chen A, Lin X, Nan H, Li J, Ciais P - Sci Rep (2013)

Bottom Line: We show that compared to present-day (2000-2009) conditions, MPTC will be reduced by 1 to 15% in the tropical band under equilibrium future (2090-2099) climate conditions predicted by 19 IPCC climate models.Tropical forests are found to regress or disappear mainly in the current transition zones between forest and savanna ecosystems.This climate pressure on tropical forests, added to human-caused land use pressure, poses a grand challenge to the sustainability of the world's largest biomass carbon pool.

View Article: PubMed Central - PubMed

Affiliation: College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

ABSTRACT
Warming and drought pose a serious threat to tropical forest. Yet the extent of this threat is uncertain, given the lack of methods to evaluate the forest tree cover changes under future climate predicted by complex dynamic vegetation models. Here we develop an empirical approach based on the observed climate space of tropical trees to estimate the maximum potential tropical tree cover (MPTC) in equilibrium with a given climate. We show that compared to present-day (2000-2009) conditions, MPTC will be reduced by 1 to 15% in the tropical band under equilibrium future (2090-2099) climate conditions predicted by 19 IPCC climate models. Tropical forests are found to regress or disappear mainly in the current transition zones between forest and savanna ecosystems. This climate pressure on tropical forests, added to human-caused land use pressure, poses a grand challenge to the sustainability of the world's largest biomass carbon pool.

No MeSH data available.


Related in: MedlinePlus

Spatial distribution of multi-year average tree cover fraction during the early 21st century (2000–2009) across the tropics (35°S–15°N).(a), The maximum potential tree cover fraction (MPTC) estimated using present-day climate conditions from CRU datasets. (b), The tree cover fraction derived from MODIS satellite measurements. (c), The multi-model mean tree cover fraction averaged over four DGVMs (i.e., HYL, LPJ, ORC and TRI) under SRES A2. (d), The difference between MPTC and MODIS-derived tree cover fraction across the tropics. Maps were generated using Matlab (http://www.mathworks.co.uk/products/matlab/).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3674425&req=5

f3: Spatial distribution of multi-year average tree cover fraction during the early 21st century (2000–2009) across the tropics (35°S–15°N).(a), The maximum potential tree cover fraction (MPTC) estimated using present-day climate conditions from CRU datasets. (b), The tree cover fraction derived from MODIS satellite measurements. (c), The multi-model mean tree cover fraction averaged over four DGVMs (i.e., HYL, LPJ, ORC and TRI) under SRES A2. (d), The difference between MPTC and MODIS-derived tree cover fraction across the tropics. Maps were generated using Matlab (http://www.mathworks.co.uk/products/matlab/).

Mentions: The spatial distribution of MPTC based on empirical regression with T, P predictors, under present-day (2000–2009) climate conditions (see Methods; Fig. 3a) is similar to the tree cover fraction (Fig. 3c) simulated by four DGVM ecosystem models8. The DGVM model results also consistently show higher tree cover than the MODIS satellite observed actual tree cover (Fig. 3b), especially in regions currently dominated by C4 grassland and savanna, like in the southeast of South America, around the Congo basin rainforest and Madagascar. In those regions, the overestimation of MPTC can be related to the effects of tree-grass competition, nutrients limitations, fire disturbance that suppresses trees, herbivories, and human caused deforestation1115. In the rainforest regions, the discrepancy between potential MPTC and satellite observed actual tree cover fraction is smaller (on average 22% in the rainforest area vs. 34% in the savanna area) (Fig. 3d). Overall, the MODIS observed tree cover is on average 51% only of the potential MPTC (R = 0.78, p < 0.001).


Committed changes in tropical tree cover under the projected 21st century climate change.

Zeng Z, Piao S, Chen A, Lin X, Nan H, Li J, Ciais P - Sci Rep (2013)

Spatial distribution of multi-year average tree cover fraction during the early 21st century (2000–2009) across the tropics (35°S–15°N).(a), The maximum potential tree cover fraction (MPTC) estimated using present-day climate conditions from CRU datasets. (b), The tree cover fraction derived from MODIS satellite measurements. (c), The multi-model mean tree cover fraction averaged over four DGVMs (i.e., HYL, LPJ, ORC and TRI) under SRES A2. (d), The difference between MPTC and MODIS-derived tree cover fraction across the tropics. Maps were generated using Matlab (http://www.mathworks.co.uk/products/matlab/).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3674425&req=5

f3: Spatial distribution of multi-year average tree cover fraction during the early 21st century (2000–2009) across the tropics (35°S–15°N).(a), The maximum potential tree cover fraction (MPTC) estimated using present-day climate conditions from CRU datasets. (b), The tree cover fraction derived from MODIS satellite measurements. (c), The multi-model mean tree cover fraction averaged over four DGVMs (i.e., HYL, LPJ, ORC and TRI) under SRES A2. (d), The difference between MPTC and MODIS-derived tree cover fraction across the tropics. Maps were generated using Matlab (http://www.mathworks.co.uk/products/matlab/).
Mentions: The spatial distribution of MPTC based on empirical regression with T, P predictors, under present-day (2000–2009) climate conditions (see Methods; Fig. 3a) is similar to the tree cover fraction (Fig. 3c) simulated by four DGVM ecosystem models8. The DGVM model results also consistently show higher tree cover than the MODIS satellite observed actual tree cover (Fig. 3b), especially in regions currently dominated by C4 grassland and savanna, like in the southeast of South America, around the Congo basin rainforest and Madagascar. In those regions, the overestimation of MPTC can be related to the effects of tree-grass competition, nutrients limitations, fire disturbance that suppresses trees, herbivories, and human caused deforestation1115. In the rainforest regions, the discrepancy between potential MPTC and satellite observed actual tree cover fraction is smaller (on average 22% in the rainforest area vs. 34% in the savanna area) (Fig. 3d). Overall, the MODIS observed tree cover is on average 51% only of the potential MPTC (R = 0.78, p < 0.001).

Bottom Line: We show that compared to present-day (2000-2009) conditions, MPTC will be reduced by 1 to 15% in the tropical band under equilibrium future (2090-2099) climate conditions predicted by 19 IPCC climate models.Tropical forests are found to regress or disappear mainly in the current transition zones between forest and savanna ecosystems.This climate pressure on tropical forests, added to human-caused land use pressure, poses a grand challenge to the sustainability of the world's largest biomass carbon pool.

View Article: PubMed Central - PubMed

Affiliation: College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

ABSTRACT
Warming and drought pose a serious threat to tropical forest. Yet the extent of this threat is uncertain, given the lack of methods to evaluate the forest tree cover changes under future climate predicted by complex dynamic vegetation models. Here we develop an empirical approach based on the observed climate space of tropical trees to estimate the maximum potential tropical tree cover (MPTC) in equilibrium with a given climate. We show that compared to present-day (2000-2009) conditions, MPTC will be reduced by 1 to 15% in the tropical band under equilibrium future (2090-2099) climate conditions predicted by 19 IPCC climate models. Tropical forests are found to regress or disappear mainly in the current transition zones between forest and savanna ecosystems. This climate pressure on tropical forests, added to human-caused land use pressure, poses a grand challenge to the sustainability of the world's largest biomass carbon pool.

No MeSH data available.


Related in: MedlinePlus