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Contrasting effects of elevated CO 2 and water deficit on two native herbs
Author(s) -
FERRIS RACHEL,
TAYLOR GAIL
Publication year - 1995
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1995.tb03086.x
Subject(s) - water use efficiency , shoot , chemistry , horticulture , dry weight , zoology , botany , carbon dioxide , biology , photosynthesis , organic chemistry
summary This study investigated the effects of carbon dioxide (CO) 2 enrichment and soil water deficit on the water use efficiency (WUE) and growth of Sanguisorba minor Scop, (salad burnet I and Anthyllis vulneraria L. (kidney vetch), growing in controlled environments. Instantaneous WL E (IWUE) increased in both species in elevated CO 2 , with a higher average increase in unwatered (UW) A. vulneraria over the drying cycle. Total plant WUE of A. vulneraria increased in elevated CO, and under water deficit: the UW plants in elevated CO., had higher WUE and reduced water loss. By contrast, thee was only an effect of water supply on S. minor: total plant WUE increased and water loss decreased in the UV plants in both CO 2 , treatments. Total apparent root length (ARL) of both species increased with CO 2 , enrichment and in UW S. minor total ARL was increased. By contrast, for A. vulneraria , total ARL of UV plants increased in ambient CO 2 , but decreased in elevated CO 2 as compared with well‐watered (WW) plants. Shoot dry weight (SDW) and root dry weight increased in both species (WW and UW) with CO 2 . enrichment. For UW S. minor , SDW decreased relative to WW plants in both CO 2 treatments. By contrast, ANOVA showed no significant effect of water supply on SDW of A. vulneraria . Leafier length increased in both species in elevated CO 2 , and decreased following drought. Cell wall tensiometric extensibility (%P) increased in expanding leaves of S. minor in elevated CO., and for both species % P decreased in the UW plants as compared with those WW. Leaf water potential (f) of both species was lower in growing leaves of WAV plants in elevated CO 2 Water deficit reduced the Ψ of growing leaves in both CO 2 , treatments. The different responses of these species suggest that in a drier, enriched CO 2 , environment survival in a community might depend on their ability to maintain growth at the same time as conserving water.