Contrasting Hydraulic Strategies during Dry Soil Conditions in Quercus rubra and Acer rubrum in a Sandy Site in Michigan

Forests

Julia E. Thomsen¹  Gil Bohrer²  Ashley M. Matheny²  Valeriy Y. Ivanov⁴  Lingli He⁴  Heidi J. Renninger³ 

[1] Department of Earth and Environmental Sciences, Wesleyan University, 45 Wyllys Avenue, Middletown, CT 06459, USA; E-Mail:;Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, 2070 Neil Avenue, Columbus, OH 43210, USA; E-Mail:;Department of Biological Sciences, Rutgers University, 195 University Avenue, Newark, NJ 07102, USA; E-Mails:;Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, 105 EWRE, Ann Arbor, MI 48109, USA; E-Mails:

关键词: ecohydrology;    leaf water potential;    plant functional type;    stomatal conductance;    succession;    transpiration;    water relations;   

DOI  :  10.3390/f4041106

来源: mdpi

【 摘 要 】

Correlation analyses were carried out for the dynamics of leaf water potential in two broad-leaf deciduous tree species in a sandy site under a range of air vapor pressure deficits and a relatively dry range of soil conditions. During nights when the soil is dry, the diffuse-porous, isohydric and shallow-rooted Acer rubrum does not recharge its xylem and leaf water storage to the same capacity that is observed during nights when the soil is moist. The ring-porous, deep-rooted Quercus rubra displays a more anisohydric behavior and appears to be capable of recharging to capacity at night-time even when soil moisture at the top 1 m is near wilting point, probably by accessing deeper soil layers than A. rubrum. Compared to A. rubrum, Q. rubra displays only a minimal level of down-regulation of stomatal conductance, which leads to a reduction of leaf water potential during times when vapor pressure deficit is high and soil moisture is limiting. We determine that the two species, despite typically being categorized by ecosystem models under the same plant functional type—mid-successional, temperate broadleaf—display different hydraulic strategies. These differences may lead to large differences between the species in water relations, transpiration and productivity under different precipitation and humidity regimes.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.