Relating Wet and Dry Year Ecophysiology to Leaf Structure in Contrasting Temperate Tree Species

Leaf structure in 17 temperate, broad-leaved tree species on xeric, mesic, and wet-mesic sites in central Pennsylvania (USA) was compared to leaf gas exchange and tissue-water relations data for these species measured during wet (1990) and dry (1991) growing seasons. We tested the hypothesis that ecophysiological responses across contrast- ing species, sites, and growing-season conditions can be related to specific aspects of leaf structure. Species guard-cell length (GCL), leaf mass per area (LMA), and leaf thickness were positively correlated and increased as sites became drier. Mesic species had lower stomatal density than xeric and wet-mesic species. During the wet year, xeric and mesic species had higher area-based net photosynthesis (A) and leaf conductance (gj) and lower osmotic potentials (*',) than wet-mesic species. Unlike the xeric species, mesic and wet- mesic species had decreased A and g,, in the dry vs. the wet year. Thus, gas exchange in mesic species resembled that of xeric species in the wet year and that of wet-mesic species in the dry year, which may be due to differences in leaf structure. Maximum A rates and mean gw, were positively related to species LMA, whereas wet and dry year mean A and gV increased with increasing leaf thickness and GCL across the study sites. Minimum and mean midday leaf water potential and I, at zero turgor decreased with increasing LMA, GCL, and leaf thickness. Stomatal density and ecophysiology were not significantly related across the study sites, but they were related within sites. Intrasite comparisons indicated that, in general, gas exchange parameters increased and tissue water parameters decreased with increases in leaf parameters, trends that were consistent with intersite comparisons. These results suggest that both gas exchange and tissue-water relations during wet and dry years were related to specific aspects of species leaf morphology, and that leaf structure has an important predictive role in evaluating ecophysiological responses to environmental stress at the community and landscape level.

[1]  G. Unwin,et al.  Leaf water relations and anatomy of a tropical rainforest tree species vary with crown position , 1987, Oecologia.

[2]  M. Sobrado.  Aspects of tissue water relations and seasonal changes of leaf water potential components of evergreen and deciduous species coexisting in tropical dry forests , 1986, Oecologia.

[3]  R. Oren,et al.  Estimating photosynthetic rate and annual carbon gain in conifers from specific leaf weight and leaf biomass , 1986, Oecologia.

[4]  G. Farquhar,et al.  Some relationships between the biochemistry of photosynthesis and the gas exchange of leaves , 1981, Planta.

[5]  J. Berry,et al.  A biochemical model of photosynthetic CO2 assimilation in leaves of C3 species , 1980, Planta.

[6]  M. Abrams,et al.  Seasonal ecophysiology and leaf morphology of four successional Pennsylvania barrens species in open versus understory environments , 1993 .

[7]  M. Abrams,et al.  Photosynthesis, water relations, and leaf morphology of xeric versus mesic Quercusrubra ecotypes in central Pennsylvania in relation to moisture stress , 1992 .

[8]  P. Reich,et al.  Leaf age and season influence the relationships between leaf nitrogen, leaf mass per area and photosynthesis in maple and oak trees , 1991 .

[9]  M. Abrams,et al.  Pressure-volume relationships in non-rehydrated tissue at various water deficits. , 1990 .

[10]  M. Abrams,et al.  Drought adaptations and responses in five genotypes of Fraxinus pennsylvanica Marsh.: photosynthesis, water relations and leaf morphology. , 1990, Tree physiology.

[11]  I. E. Woodrow,et al.  Control of photosynthetic carbon dioxide fixation by the boundary layer, stomata and ribulose 1,5‐biphosphate carboxylase/oxygenase , 1990 .

[12]  M. Abrams,et al.  Leaf structural characteristics of 31 hardwood and conifer tree species in central Wisconsin: influence of light regime and shade-tolerance rank. , 1990 .

[13]  P. Reich,et al.  Response of Ulmus americana seedlings to varying nitrogen and water status. 1 Photosynthesis and growth. , 1989, Tree physiology.

[14]  G. Goldstein,et al.  Leaf anatomy and water relations in tropical elfin cloud forest tree species. , 1989 .

[15]  F. Woodward,et al.  The Responses of Stomatal Density to CO2 Partial Pressure , 1988 .

[16]  T. Koike.  Leaf Structure and Photosynthetic Performance as Related to the Forest Succession of Deciduous Broad‐Leaved Trees1 , 1988 .

[17]  F. I. Woodward,et al.  Stomatal numbers are sensitive to increases in CO2 from pre-industrial levels , 1987, Nature.

[18]  T. W. Jurik,et al.  Temporal and spatial patterns of specific leaf weight in successional northern hardwood tree species , 1986 .

[19]  S. Oberbauer,et al.  EFFECTS OF CANOPY POSITION AND IRRADIANCE ON THE LEAF PHYSIOLOGY AND MORPHOLOGY OF PENTACLETHRA MACROLOBA (MIMOSACEAE) , 1986 .

[20]  Christopher B. Field,et al.  photosynthesis--nitrogen relationship in wild plants , 1986 .

[21]  M. Abrams,et al.  Seasonal water relations of three gallery forest hardwood species in Northeast Kansas , 1986 .

[22]  A. Knapp,et al.  Response of Andropogon gerardii (Poaceae) to fire-induced high vs. low irradiance environments in tallgrass prairie: leaf structure and photosynthetic pigments , 1985 .

[23]  P. Reich.  LEAF STOMATAL DENSITY AND DIFFUSIVE CONDUCTANCE IN THREE AMPHISTOMATOUS HYBRID POPLAR CULTIVARS , 1984 .

[24]  T. Givnish.  Leaf and Canopy Adaptations in Tropical Forests , 1984 .

[25]  H. Flint,et al.  Genecology of Eastern Redbud (Cercis Canadensis) , 1982 .

[26]  S. B. Carpenter,et al.  A comparative study of leaf thickness among southern Appalachian hardwoods , 1981 .

[27]  Neil C. Turner,et al.  Turgor maintenance by osmotic adjustment: a review and evaluation. , 1980 .

[28]  Paul J. Kramer,et al.  Physiology of Woody Plants , 1983 .

[29]  T. Hinckley,et al.  Conductance and Photosynthesis in Species of the Oak. Hickory Forest Type , 1978 .

[30]  N. Boardman.  Comparative photosynthesis of sun and shade plants. , 1977 .

[31]  W. Smith,et al.  Relation between Mesophyll Surface Area, Photosynthetic Rate, and Illumination Level during Development for Leaves of Plectranthus parviflorus Henckel. , 1975, Plant physiology.

[32]  W. Davies,et al.  Stomatal responses of five woody angiospasms to light intensity and humidity , 1974 .

[33]  T. Kozlowski,et al.  Relationship of Gas‐Exchange Resistance to Tree‐Seedling Ecology , 1971 .

[34]  W. W. Payne.  HELICOCYTIC AND ALLELOCYTIC STOMATA: UNRECOGNIZED PATTERNS IN THE DI COTYLEDON AE , 1970 .

[35]  L. W. Jackson.  Effect of Shade on Leaf Structure of Deciduous Tree Species , 1967 .

[36]  E. Salisbury.  On the Causes and Ecological Significance of Stomatal Frequency, with Special Reference to the Woodland Flora , 1928 .