Human population growth offsets climate-driven increase in woody vegetation in sub-Saharan Africa

Martin Stefan Brandt; Kjeld Rasmussen; Josep Peñuelas; Feng Tian; Guy Schurgers; Aleixandre Verger; Ole Mertz; John  R. B. Palmer; Rasmus Fensholt

doi:10.1038/s41559-017-0081

Human population growth offsets climate-driven increase in woody vegetation in sub-Saharan Africa

Martin Stefan Brandt, Kjeld Rasmussen, Josep Peñuelas, Feng Tian, Guy Schurgers, Aleixandre Verger, Ole Mertz, John R. B. Palmer, Rasmus Fensholt

Geography

86 Citations (Scopus)

144 Downloads (Pure)

Abstract

The rapidly growing human population in sub-Saharan Africa generates increasing demand for agricultural land and forest products, which presumably leads to deforestation. Conversely, a greening of African drylands has been reported, but this has been difficult to associate with changes in woody vegetation. There is thus an incomplete understanding of how woody vegetation responds to socio-economic and environmental change. Here we used a passive microwave Earth observation data set to document two different trends in land area with woody cover for 1992–2011: 36% of the land area (6,870,000 km2) had an increase in woody cover largely in drylands, and 11% had a decrease (2,150,000 km2), mostly in humid zones. Increases in woody cover were associated with low population growth, and were driven by increases in CO2 in the humid zones and by increases in precipitation in drylands, whereas decreases in woody cover were associated with high population growth. The spatially distinct pattern of these opposing trends reflects, first, the natural response of vegetation to precipitation and atmospheric CO2, and second, deforestation in humid areas, minor in size but important for ecosystem services, such as biodiversity and carbon stocks. This nuanced picture of changes in woody cover challenges widely held views of a general and ongoing reduction of the woody vegetation in Africa

Original language	English
Article number	0081
Journal	Nature Ecology & Evolution
Volume	1
Number of pages	6
ISSN	2397-334X
DOIs	https://doi.org/10.1038/s41559-017-0081
Publication status	Published - 6 Mar 2017

Access to Document

10.1038/s41559-017-0081

revision2_Population_growth_offsets_climateAccepted author manuscript, 313 KB

Cite this

@article{d808a4c3c509436da11f0ecb2a8e210a,

title = "Human population growth offsets climate-driven increase in woody vegetation in sub-Saharan Africa",

abstract = "The rapidly growing human population in sub-Saharan Africa generates increasing demand for agricultural land and forest products, which presumably leads to deforestation. Conversely, a greening of African drylands has been reported, but this has been difficult to associate with changes in woody vegetation. There is thus an incomplete understanding of how woody vegetation responds to socio-economic and environmental change. Here we used a passive microwave Earth observation data set to document two different trends in land area with woody cover for 1992–2011: 36% of the land area (6,870,000 km2) had an increase in woody cover largely in drylands, and 11% had a decrease (2,150,000 km2), mostly in humid zones. Increases in woody cover were associated with low population growth, and were driven by increases in CO2 in the humid zones and by increases in precipitation in drylands, whereas decreases in woody cover were associated with high population growth. The spatially distinct pattern of these opposing trends reflects, first, the natural response of vegetation to precipitation and atmospheric CO2, and second, deforestation in humid areas, minor in size but important for ecosystem services, such as biodiversity and carbon stocks. This nuanced picture of changes in woody cover challenges widely held views of a general and ongoing reduction of the woody vegetation in Africa",

author = "Brandt, {Martin Stefan} and Kjeld Rasmussen and Josep Pe{\~n}uelas and Feng Tian and Guy Schurgers and Aleixandre Verger and Ole Mertz and {R. B. Palmer}, John and Rasmus Fensholt",

year = "2017",

month = mar,

day = "6",

doi = "10.1038/s41559-017-0081",

language = "English",

volume = "1",

journal = "Nature Ecology & Evolution",

issn = "2397-334X",

publisher = "nature publishing group",

}

TY - JOUR

T1 - Human population growth offsets climate-driven increase in woody vegetation in sub-Saharan Africa

AU - Brandt, Martin Stefan

AU - Rasmussen, Kjeld

AU - Peñuelas, Josep

AU - Tian, Feng

AU - Schurgers, Guy

AU - Verger, Aleixandre

AU - Mertz, Ole

AU - R. B. Palmer, John

AU - Fensholt, Rasmus

PY - 2017/3/6

Y1 - 2017/3/6

N2 - The rapidly growing human population in sub-Saharan Africa generates increasing demand for agricultural land and forest products, which presumably leads to deforestation. Conversely, a greening of African drylands has been reported, but this has been difficult to associate with changes in woody vegetation. There is thus an incomplete understanding of how woody vegetation responds to socio-economic and environmental change. Here we used a passive microwave Earth observation data set to document two different trends in land area with woody cover for 1992–2011: 36% of the land area (6,870,000 km2) had an increase in woody cover largely in drylands, and 11% had a decrease (2,150,000 km2), mostly in humid zones. Increases in woody cover were associated with low population growth, and were driven by increases in CO2 in the humid zones and by increases in precipitation in drylands, whereas decreases in woody cover were associated with high population growth. The spatially distinct pattern of these opposing trends reflects, first, the natural response of vegetation to precipitation and atmospheric CO2, and second, deforestation in humid areas, minor in size but important for ecosystem services, such as biodiversity and carbon stocks. This nuanced picture of changes in woody cover challenges widely held views of a general and ongoing reduction of the woody vegetation in Africa

AB - The rapidly growing human population in sub-Saharan Africa generates increasing demand for agricultural land and forest products, which presumably leads to deforestation. Conversely, a greening of African drylands has been reported, but this has been difficult to associate with changes in woody vegetation. There is thus an incomplete understanding of how woody vegetation responds to socio-economic and environmental change. Here we used a passive microwave Earth observation data set to document two different trends in land area with woody cover for 1992–2011: 36% of the land area (6,870,000 km2) had an increase in woody cover largely in drylands, and 11% had a decrease (2,150,000 km2), mostly in humid zones. Increases in woody cover were associated with low population growth, and were driven by increases in CO2 in the humid zones and by increases in precipitation in drylands, whereas decreases in woody cover were associated with high population growth. The spatially distinct pattern of these opposing trends reflects, first, the natural response of vegetation to precipitation and atmospheric CO2, and second, deforestation in humid areas, minor in size but important for ecosystem services, such as biodiversity and carbon stocks. This nuanced picture of changes in woody cover challenges widely held views of a general and ongoing reduction of the woody vegetation in Africa

U2 - 10.1038/s41559-017-0081

DO - 10.1038/s41559-017-0081

M3 - Journal article

C2 - 28812661

SN - 2397-334X

VL - 1

JO - Nature Ecology & Evolution

JF - Nature Ecology & Evolution

M1 - 0081

ER -