Open AccessRain use efficiency as affected by climate warming and biofuel harvest: results from a 12‐year field experiment
Author(s) -
Yan Liming,
Luo Yiqi,
Sherry Rebecca A.,
Bell Jesse E.,
Zhou Xuhui,
Xia Jianyang
Publication year - 2014
Publication title -
gcb bioenergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.378
H-Index - 63
eISSN - 1757-1707
pISSN - 1757-1693
DOI - 10.1111/gcbb.12081
Subject(s) - environmental science , global warming , climate change , biomass (ecology) , agronomy , water use efficiency , transpiration , surface runoff , biofuel , growing season , dominance (genetics) , ecosystem , precipitation , evapotranspiration , atmospheric sciences , ecology , irrigation , biology , geography , botany , photosynthesis , biochemistry , geology , gene , meteorology
The efficiency of a terrestrial ecosystem to use rainfall in production is critical in regulating the ecological functions of the earth system under global change. However, it remains unclear how rain use efficiency ( RUE ) will be altered by changes in climate and human activities such as biofuel harvest. In this study, we used RUE data from a long‐term experiment in a tallgrass prairie to analyze the effects of warming and biofuel harvest (clipping). From 2000 to 2011, experimental warming enhanced RUE in most years, with larger positive effects in normal and wet than dry hydrological years. Clipping decreased RUE in dry and normal hydrological years, but had no impact on RUE in wet years. The observed RUE responses resulted from treatment‐induced changes in both biologically ineffective (i.e., runoff and soil evaporation) and effective (i.e., transpiration) parts of precipitation. For example, litter cover was increased in warming plots, but reduced by clipping, leading to negative and positive effects on runoff and soil evaporation, respectively. The dominance of C 4 species, which usually have higher water use efficiency than C 3 species, was enhanced by warming, but reduced by clipping. Moreover, RUE was positively correlated with ratios of rainfall in the late growing season (June–August), when the growth of C 4 plants was most active, relative to that in the other seasons. Our results indicate that RUE is positively influenced by climate warming, but negatively affected by biofuel harvest in tallgrass prairie of the Great Plains. These findings highlight the important roles of plant community structure and temporal distribution of precipitation in regulating ecosystem RUE .