The Use of Water and Minerals by Evergreen and Deciduous Shrubs in Okefenokee Swamp

Shoot water potentials, leaf diffusion resistances, and foliar concentrations of Ca++, Mg++, K+, N, and P were measured in an evergreen shrub (Lyonia lucida [Lam.] K. Koch) and a deciduous shrub (Clethra alnifolia L.) in Okefenokee Swamp, Georgia. An upland, evergreen species (L. ferruginea [Walt.] Nutt.) was included for comparison. Clethra alnifolia generally had the highest mineral contents (percentage of dry weight) and the highest water loss in transpiration. During several 24-h monitoring periods, the lowest observed shoot water potentials (L. lucida, -10.1 bars; C. alnifolia, -12.5 bars; L. ferruginea, -17.2 bars) did not suggest "physiological drought" in the swamp species. Only L. lucida showed any evidence of midday stomatal closure. In this warm-temperate swamp, evergreen species have the potential for greater efficiency of mineral use and productivity, largely due to their leaf longevity. In addition, sclerophyllous tissue is probably useful in defense against herbivores.

[1]  W. Schlesinger.  On the Relative Dominance of Shrubs in Okefenokee Swamp , 1978, The American Naturalist.

[2]  D. F. Grigal,et al.  Phosphorus conservation by evergreenness of mountain laurel , 1976 .

[3]  P. Feeny,et al.  Plant apparency and chemical defense , 1976 .

[4]  George M. Woodwell,et al.  Nutrient Concentrations in Plants in the Brookhaven Oak-Pine Forest , 1975 .

[5]  D. Janzen.  Tropical blackwater rivers, animals, and mast fruiting by the Dipterocarpaceae , 1974 .

[6]  P. Tobiessen,et al.  Drought‐Stress Avoidance in Three Pioneer Tree Species , 1974 .

[7]  Anthony E. Hall,et al.  Interpreting Leaf Water Potential Measurements with a Model of the Soil‐Plant‐Atmosphere Continuum , 1972 .

[8]  E. Small.  Photosynthetic rates in relation to nitrogen recycling as an adaptation to nutrient deficiency in peat bog plants , 1972 .

[9]  E. Small.  Water Relations of Plants in Raised Sphagnum Peat Bogs , 1972 .

[10]  S. Burrage.  Atlas of energy budgets of plant leaves , 1972 .

[11]  C. Monk.  Leaf Decomposition and Loss of 45 Ca from Deciduous and Evergreen Trees , 1971 .

[12]  E. O. Hellmuth.  Eco-Physiological Studies on Plants in Arid and Semi-Arid Regions in Western Australia: III. Comparative Studies on Photosynthesis, Respiration and Water Relations of Ten Arid Zone and Two Semi-Arid Zone Plants Under Winter and Late Summer Climatic Conditions , 1971 .

[13]  R. Slatyer,et al.  Leaf resistance measurements with diffusion porometers: precautions in calibration and use , 1971 .

[14]  H. Mooney,et al.  Photosynthetic Systems of Mediterranean-Climate Shrubs and Trees of California and Chile , 1970, The American Naturalist.

[15]  H. Mooney,et al.  CONVERGENT EVOLUTION OF MEDITERRANEAN‐CLIMATE EVERGREEN SCLEROPHYLL SHRUBS , 1970, Evolution; international journal of organic evolution.

[16]  D. M. Gates,et al.  Some field methods for obtaining meaningful leaf diffusion resistances and transpiration rates. , 1970 .

[17]  G. Likens,et al.  Chemical Analyses of Plant Tissues from the Hubbard Brook Ecosystem in New Hampshire , 1970 .

[18]  G. M. Woodwell,et al.  DIMENSION AND PRODUCTION RELATIONS OF TREES AND SHRUBS IN THE BROOKHAVEN FOREST, NEW YORK. , 1968 .

[19]  R. Waring,et al.  Plant Moisture Stress: Evaluation by Pressure Bomb , 1967, Science.

[20]  N. Beadle.  Soil Phosphate and Its Role in Molding Segments of the Australian Flora and Vegetation, with Special Reference to Xeromorphy and Sclerophylly , 1966 .

[21]  C. Monk.  AN ECOLOGICAL SIGNIFICANCE OF EVERGREENNESS , 1966 .

[22]  Foliar Nitrogen and Phosphorus Level Related to Site Quality in a Northern Minnesota Spruce Bog , 1965 .

[23]  A. Loveless.  Further Evidence to Support a Nutritional Interpretation of Sclerophylly , 1962 .

[24]  A. Loveless.  A Nutritional Interpretation of Sclerophylly Based on Differences in the Chemical Composition of Sclerophyllous and Mesophytic Leaves , 1961 .

[25]  E. Gorham.  The Development of Peat Lands , 1957, The Quarterly Review of Biology.

[26]  H. Mckenzie,et al.  The Kjeldahl determination of nitrogen : a critical study of digestion conditions-temperature, catalyst, and oxidizing agent. , 1954 .

[27]  E. Gorham.  Chemical studies on the soils and vegetation of waterlogged habitats in the English Lake District , 1953 .

[28]  M. Caughey,et al.  WATER RELATIONS OF POCOSIN OR BOG SHRUBS. , 1945, Plant physiology.

[29]  M. Mellon,et al.  Colorimetric Determination of Phosphorus as Molybdivanadophosphoric Acid , 1944 .

[30]  A. Galston.  Plant Physiology , 1967, Nature.

[31]  Frederic E. Clements.  Pflanzengeographie auf Physiologischer Grundlage , 1899 .