Dataset Information

Root functioning modifies seasonal climate.

ABSTRACT: Hydraulic redistribution (HR), the nocturnal vertical transfer of soil water from moister to drier regions in the soil profile by roots, has now been observed in Amazonian trees. We have incorporated HR into an atmospheric general circulation model (the National Center for Atmospheric Research Community Atmospheric Model Version 2) to estimate its impact on climate over the Amazon and other parts of the globe where plants displaying HR occur. Model results show that photosynthesis and evapotranspiration increase significantly in the Amazon during the dry season when plants are allowed to redistribute soil water. Plants draw water up and deposit it into the surface layers, and this water subsidy sustains transpiration at rates that deep roots alone cannot accomplish. The water used for dry season transpiration is from the deep storage layers in the soil, recharged during the previous wet season. We estimate that HR increases dry season (July to November) transpiration by approximately 40% over the Amazon. Our model also indicates that such an increase in transpiration over the Amazon and other drought-stressed regions affects the seasonal cycles of temperature through changes in latent heat, thereby establishing a direct link between plant root functioning and climate.

SUBMITTER: Lee JE

PROVIDER: S-EPMC1308914 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature

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Root functioning modifies seasonal climate.

Lee Jung-Eun JE Oliveira Rafael S RS Dawson Todd E TE Fung Inez I

Proceedings of the National Academy of Sciences of the United States of America 20051121 49

Hydraulic redistribution (HR), the nocturnal vertical transfer of soil water from moister to drier regions in the soil profile by roots, has now been observed in Amazonian trees. We have incorporated HR into an atmospheric general circulation model (the National Center for Atmospheric Research Community Atmospheric Model Version 2) to estimate its impact on climate over the Amazon and other parts of the globe where plants displaying HR occur. Model results show that photosynthesis and evapotrans ...[more]

PMID: 16301519

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Dataset Information

Root functioning modifies seasonal climate.

Publications

Root functioning modifies seasonal climate.

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