Leaf ultraviolet optical properties along a latitudinal gradient in the Arctic-Alpine life zone

Journal Article · Sun Jun 01 00:00:00 EDT 1980 · Ecology; (United States)

DOI:https://doi.org/10.2307/1937427· OSTI ID:5061700

Robberecht, R ^[1]; Caldwell, M M; Billings, W D

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1. Utah State Univ., Logan

Leaf epidermal transmittance of terrestrial solar ultraviolet-B radiation (295 to 320 nm) was examined along a latitudinal gradient of solar uv-B radiation. In high uv-B radiation zones, e.g., equatorial and tropical regions, mean epidermal transmittance for the species examined was less than 2%. At higher latitudes, mean epidermal transmittance exceeded 5%. Although this latitudinal solar uv-B gradient represents more than a seven-fold difference in daily integrated uv-B irradiance, the calculated mean effective uv-B irradiance at the mesophyll of low-latitude species is not substantially different from that of species at higher latitudes. Species in high uv-B radiation environments appear to attenuate this radiation more effectively than those in lower irradiance environments. In most cases, absorption of uv-B in the epidermis is the major parameter effecting low transmittance. Reflectance from glabrous leaves is generally less than 10%. In some species, pubescent or glaucous leaf surfaces can reflect more than 40% of the uv-B radiation incident on a horizontal leaf, although such surface characteristics do not necessarily indicate high uv-B reflectance. Under controlled conditions, epidermal transmittance in Pisum sativum L. decreased in response to uv-B irradiation. The modification of epidermal transmittance, resulting in lower uv-B irradiance at the mesophyll, may represent a mechanism of plant acclimation to uv-B radiation. Such acclimation may have occurred in several wildland species of temperate-latitude origin that have invaded high uv-B irradiance equatorial and tropical regions.

• OSTI ID: 5061700
• Journal Information: Ecology; (United States), Vol. 61:3
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
LEAVES
TRANSMISSION
ULTRAVIOLET RADIATION
BIOLOGICAL RADIATION EFFECTS
DOSE-RESPONSE RELATIONSHIPS
EPIDERMIS
GEOGRAPHICAL VARIATIONS
PISUM
BIOLOGICAL EFFECTS
BODY
ELECTROMAGNETIC RADIATION
EPITHELIUM
LEGUMINOSAE
ORGANS
PLANTS
RADIATION EFFECTS
RADIATIONS
SKIN
TISSUES
VARIATIONS
560141* - Radiation Effects on Plants- Basic Studies- (-1987)