Influence of irradiation, soil water potential, and leaf temperature on leaf morphology of a desert broadleaf, Encelia farinosa Gray (Compositae)

Journal Article · Sat Apr 01 04:00:00 EST 1978 · Am. J. Bot.; (United States)

DOI:https://doi.org/10.2307/2442699· OSTI ID:6932239

Smith, W K; Nobel, P S

Laboratory experiments were performed to evaluate observed seasonal changes in leaf morphology of the desert perennial shrub, Encelia farinosa Gray. Plants were grown under low or high conditions of photosynthetically active irradiation, soil water potential (Psi/sup soil/), and leaf temperature (8 different experimental regimes). The relative growth rate, leaf water vapor conductance, leaf water potential, and leaf length were all greater for the high Psi/sup soil/ regimes, the largest leaves occurring at low irradiation. High irradiation during growth led to thicker leaves with a higher internal to external leaf area ratio (A/sup mes//A); low Psi/sup soil/ tended to increase A/sup mes//A somewhat. High irradiation also led to decreased absorptance to solar irradiation caused by increased pubescence. High leaf temperature during development resulted in slightly smaller, thicker leaves with higher A/sup mes//A. Thus, irradiation appeared to have its major influence on leaf thickness. A/sup mes//A, and absorptance, with a secondary effect on leaf length: Psi/sup soil/ affected primarily leaf length, growth rate, and water status, and secondarily A/sup mes//A. Results are discussed with regard to recent ecophysiological studies on the observed seasonal changes in leaf morphology of E. farinosa.

• Research Organization: Univ. of California, Los Angeles
• OSTI ID: 6932239
• Journal Information: Am. J. Bot.; (United States), Journal Name: Am. J. Bot.; (United States) Vol. 65:4; ISSN AJBOA
• Country of Publication: United States
• Language: English

Related Subjects

510100* -- Environment
Terrestrial-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ARID LANDS
BIOLOGICAL EFFECTS
BIOMASS
BUILDINGS
CHEMICAL REACTIONS
DESERTS
ELECTROMAGNETIC RADIATION
ENERGY SOURCES
GREENHOUSES
GROWTH
HYDROGEN COMPOUNDS
IRRADIATION
LEAVES
MORPHOLOGICAL CHANGES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
RADIATIONS
RENEWABLE ENERGY SOURCES
SEASONAL VARIATIONS
SEASONS
SHRUBS
SOILS
SYNTHESIS
TEMPERATURE EFFECTS
VARIATIONS
VISIBLE RADIATION
WATER