Drought in the Southern United States over the 20th century: variability and its impacts on terrestrial ecosystem productivity and carbon storage

Drought is one of the most devastating natural hazards faced by the Southern United States (SUS). Drought events and their adverse impacts on the economy, society and environment have been extensively reported during 1895–2007. Our aim is thus to characterize drought conditions in the SUS and explor...

Full description

Saved in:
Bibliographic Details
Published in:Climatic change 2012-09, Vol.114 (2), p.379-397
Main Authors: Chen, Guangsheng, Tian, Hanqin, Zhang, Chi, Liu, Mingliang, Ren, Wei, Zhu, Wenquan, Chappelka, Arthur H., Prior, Stephen A., Lockaby, Graeme B.
Format: Article
Language:English
Subjects:
20th century
Animal and plant ecology
Animal, plant and microbial ecology
Atmospheric Sciences
Biological and medical sciences
Carbon
Carbon sequestration
Climate change
Climate Change/Climate Change Impacts
Climatology. Bioclimatology. Climate change
Drought
Droughts
Earth and Environmental Science
Earth Sciences
Earth, ocean, space
Economics
Ecosystems
Exact sciences and technology
External geophysics
Forests
Fundamental and applied biological sciences. Psychology
Grasslands
Laboratories
Land area
Mathematical models
Meteorology
Precipitation
Productivity
Rain
Regions
Synecology
Temperature
Terrestrial ecosystems
Vegetation
Water shortages
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Drought is one of the most devastating natural hazards faced by the Southern United States (SUS). Drought events and their adverse impacts on the economy, society and environment have been extensively reported during 1895–2007. Our aim is thus to characterize drought conditions in the SUS and explore the impacts on terrestrial ecosystem function (i.e., net primary productivity (NPP) and net carbon exchange (NCE)). Standard precipitation index (SPI) was used to characterize drought intensity and duration, and a process-based ecosystem model was used to explore the relationship between drought and ecosystem function. Combining overall information on growing-season SPI, drought area and duration, we concluded there was no significant change in drought conditions for the SUS during 1895–2007. However, increased drought intensity was found for many areas in the east, resulting in significant decreases in NPP for these areas, with the largest decrease up to 40% during extreme droughts. Changes in precipitation patterns increased C emissions of 0.16 Pg (1 Pg = 10 15  g) in the SUS during 1895–2007. The west (dry region) acted as a C sink due to increased precipitation, while the east (water-rich region) acted as a C source due to increased drought intensity. Both NPP and NCE significantly increased along a gradient of declining drought intensity. Changes in precipitation resulted in C sources in forest, wetland, and cropland ecosystems, while C sinks in shrubland and grassland ecosystems. Changes in air temperature could either enhance or reduce drought impacts on NPP and NCE across different vegetation types.
ISSN:0165-0009
1573-1480
DOI:10.1007/s10584-012-0410-z