Tree allometry, leaf size and adult tree size in old-growth forests of western Oregon.

Relationships between tree height and crown dimensions and trunk diameter were determined for shade-tolerant species of old-growth forests of western Oregon. The study included both understory and overstory species, deciduous and evergreen angiosperms and evergreen conifers. A comparison of adult understory species with sapling overstory species of similar height showed greater crown width and trunk diameter in the former, whether the comparison is made among conifers or deciduous trees. Conifer saplings had wider crowns than deciduous saplings, but the crown widths of the two groups converged with increase in tree height. Conifer saplings had thicker trunks than deciduous saplings of similar crown width, possibly because of selection for resistance to stem bending under snow loads. The results suggest that understory species have morphologies that increase light interception and persistence in the understory, whereas overstory species allocate their biomass for efficient height growth, thereby attaining the high-light environment of the canopy. The greater crown widths and the additional strength requirements imposed by snow loads on conifer saplings result in less height growth per biomass increment in conifer saplings than in deciduous saplings. However, the convergence in crown width of the two groups at heights greater than 20 m, and the proportionately smaller effect of snow loads on large trees, may result in older conifers equalling or surpassing deciduous trees in biomass allocation to height growth.

[1]  D. A. King.  Allometry of saplings and understorey trees of a Panamanian forest. , 1990 .

[2]  M. Cannell,et al.  Branch breakage under snow and ice loads. , 1989, Tree physiology.

[3]  G. B. Williamson,et al.  Radial Gradients in the Specific Gravity of Wood in Some Tropical and Temperate Trees , 1989, Forest Science.

[4]  A. McKee,et al.  Climatic summaries and documentation for the primary meteorological station, H.J. Andrews Experimental Forest, 1972 To 1984. , 1989 .

[5]  J. Sperry,et al.  Do woody plants operate near the point of catastrophic xylem dysfunction caused by dynamic water stress? : answers from a model. , 1988, Plant physiology.

[6]  B. Wilson,et al.  Total wood, sapwood, and heartwood in branch bases of three conifers , 1988 .

[7]  M. Tyree,et al.  A dynamic model for water flow in a single tree: evidence that models must account for hydraulic architecture. , 1988, Tree physiology.

[8]  C. T. Dyrness,et al.  Natural Vegetation of Oregon and Washington , 1988 .

[9]  M. Cannell,et al.  Young's modulus of sections of living branches and tree trunks. , 1987, Tree physiology.

[10]  Load bearing capacity of understory treelets of a tropical wet forest , 1987 .

[11]  M. Cannell.  Photosynthesis, foliage development and productivity of Sitka spruce , 1987 .

[12]  T. Kohyama.  Significance of architecture and allometry in saplings , 1987 .

[13]  D. A. King,et al.  Tree form, height growth, and susceptibility to wind damage in Acer saccharum , 1986 .

[14]  P. Rich,et al.  Height and stem diameter relationships for dicotyledonous trees and arborescent palms of Costa Rican tropical wet forest , 1986 .

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

[16]  H. Mooney,et al.  Physiological ecology of plants of the wet tropics , 1984, Tasks for vegetation Science.

[17]  P. White.  Corner's Rules in Eastern Deciduous Trees: Allometry and Its Implications for the Adaptive Architecture of Trees , 1983 .

[18]  R. Lawton.  WIND STRESS AND ELFIN STATURE IN A MONTANE RAIN FOREST TREE: AN ADAPTIVE EXPLANATION , 1982 .

[19]  R. D. Harr,et al.  Some characteristics and consequences of snowmelt during rainfall in western Oregon , 1981 .

[20]  F. Smith,et al.  The role of Douglas-fir stem sapwood and heartwood in the mechanical and physiological support of crowns and development of stem form , 1981 .

[21]  J. Petty,et al.  Stability of Coniferous Tree Stems in Relation to Damage by Snow , 1981 .

[22]  R. Waring,et al.  Evergreen Coniferous Forests of the Pacific Northwest , 1979, Science.

[23]  Glenn M. Hawk,et al.  H.J. Andrews Experimental Forest reference stand system : establishment and use history , 1978 .

[24]  C. C. Grier,et al.  Old‐Growth Pseudotsuga menziesii Communities of a Western Oregon Watershed: Biomass Distribution and Production Budgets , 1977 .

[25]  T. McMahon,et al.  Size and Shape in Biology , 1973, Science.

[26]  G. Baskerville.  Use of Logarithmic Regression in the Estimation of Plant Biomass , 1972 .

[27]  H. S. Horn.  The adaptive geometry of trees , 1971 .

[28]  R. T. Bradley,et al.  Forest management tables (metric) , 1971 .

[29]  T. Kozlowski.  Growth and Development of Trees , 1971 .

[30]  L. S. Jahnke,et al.  Influence of Photosynthetic Crown Structure on Potential Productivity of Vegetation, Based Primarily on Mathematical Models , 1965 .

[31]  Stebbins Gl.  International Biological Program. , 1962 .

[32]  T. R. Wilson,et al.  Strength and Related Properties of Woods Grown in the United States , 1935 .

[33]  G. B. Sudworth.  Forest trees of the Pacific slope , 1908 .