Effect of altered precipitation on osmotic potentials of several species in a forest ecosystem

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · Bulletin of the Ecological Society of America

OSTI ID:95789

Gebre, G M; Shirshac, T L; Gunderson, C A ^[1]

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1. Oak Ridge National Lab., TN (United States)

The effect of altered precipitation on osmotic potential of several species in an upland oak forest was investigated. Leaf samples were collected from a treatment whose precipitation was either unaltered (ambient) or altered by intercepting 33% of throughfall (dry) and diverting it to another treatment (wet). Treatment as well as species differences in osmotic potential at saturation were evident with the oaks generally exhibiting lower osmotic potentials than sugar maple, red maple, dogwood, and black gum. Leaves of chestnut oak had lower osmotic potentials than other species, throughout the growing season. Osmotic potential at saturation of chestnut oak leaves collected in August increased in response to an increase in soil moisture content. The osmotic potential of dogwood leaves declined in the dry treatment, with the largest osmotic adjustment occurring in June, coinciding with the period of greatest drought. Among the species sampled from May to September; only chestnut oak, white oak, and sugar maple continued to lower their osmotic potentials in the dry treatment. These first year data indicate that a 33% reduction of the throughfall precipitation was sufficient to alter water relations of some species and identify those species capable of osmotic adjustment to drought. Chestnut oak trees lowered their osmotic potentials sooner than other species and maintained lower baseline osmotic potentials at saturation, indicative of their drought tolerance capability.

• OSTI ID: 95789
• Report Number(s): CONF-9507129--
• Journal Information: Bulletin of the Ecological Society of America, Journal Name: Bulletin of the Ecological Society of America Journal Issue: 2 Vol. 76; ISSN BECLAG; ISSN 0012-9623
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ATMOSPHERIC PRECIPITATIONS
BIOLOGICAL ADAPTATION
COMPARATIVE EVALUATIONS
DROUGHTS
LEAVES
OAKS
OSMOSIS
THROUGHFALL
TREES