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The carbon fertilization effect over a century of anthropogenic CO2 emissions: higher intracellular CO2 and more drought resistance among invasive and native grass species contrasts with increased water use efficiency for woody plants in the US Southwest
- Source :
-
Global Change Biology . Feb2017, Vol. 23 Issue 2, p782-792. 11p. - Publication Year :
- 2017
-
Abstract
- From 1890 to 2015, anthropogenic carbon dioxide emissions have increased atmospheric CO2 concentrations from 270 to 400 mol mol−1. The effect of increased carbon emissions on plant growth and reproduction has been the subject of study of free-air CO2 enrichment ( FACE) experiments. These experiments have found (i) an increase in internal CO2 partial pressure ( c i) alongside acclimation of photosynthetic capacity, (ii) variable decreases in stomatal conductance, and (iii) that increases in yield do not increase commensurate with CO2 concentrations. Our data set, which includes a 115-year-long selection of grasses collected in New Mexico since 1892, is consistent with an increased c i as a response to historical CO2 increase in the atmosphere, with invasive species showing the largest increase. Comparison with Palmer Drought Sensitivity Index ( PDSI) for New Mexico indicates a moderate correlation with Δ13C ( r2 = 0.32, P < 0.01) before 1950, with no correlation ( r2 = 0.00, P = 0.91) after 1950. These results indicate that increased c i may have conferred some drought resistance to these grasses through increased availability of CO2 in the event of reduced stomatal conductance in response to short-term water shortage. Comparison with C3 trees from arid environments ( Pinus longaeva and Pinus edulis in the US Southwest) as well as from wetter environments ( Bromus and Poa grasses in New Mexico) suggests differing responses based on environment; arid environments in New Mexico see increased intrinsic water use efficiency ( WUE) in response to historic elevated CO2 while wetter environments see increased c i. This study suggests that (i) the observed increases in c i in FACE experiments are consistent with historical CO2 increases and (ii) the CO2 increase influences plant sensitivity to water shortage, through either increased WUE or c i in arid and wet environments, respectively. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 13541013
- Volume :
- 23
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Global Change Biology
- Publication Type :
- Academic Journal
- Accession number :
- 120689616
- Full Text :
- https://doi.org/10.1111/gcb.13449