The interspecific mass-density relationship and plant geometry.

We present an a priori theoretical framework for the interspecific allometric relationship between stand mass and plant population density. Our model predicts a slope of -1/3 between the logarithm of stand mass and the logarithm of stand density, thus conflicting with a previously assumed slope of -1/2. Our model rests on a heuristic separation of resource-limited living mass and structural mass in the plant body. We point out that because of similar resource requirements among plants of different sizes, a nonzero plant mass-density slope is primarily defined by structural mass. Specifically, the slope is a result of (i) the physical size-dependent relationship between stem width and height, (ii) foliage-dependent demands of conductance, and (iii) the cumulative nature of structural mass. The data support our model, both when the potential sampling bias of taxonomic relatedness is accounted for and when it is not. Independent contrasts analyses show that observed relationships among variables are not significantly different from the assumptions made to build the model or from its a priori predictions. We note that the dependence of the plant mass-density slope on the functions of structural mass provides a cause for the difference from the zero slope found in the animal population mass-density relationship; for the most part, animals do not have a comparable cumulative tissue type.

[1]  J. Damuth.  Interspecific allometry of population density in mammals and other animals: the independence of body mass and population energy‐use , 1987 .

[2]  S. Long,et al.  A Comparison of the Growth of the C4 Grass Spartina anglica with the C3 Grass Lolium perenne at Different Temperatures , 1987 .

[3]  J. White,et al.  CORRELATED CHANGES IN PLANT SIZE AND NUMBER IN PLANT POPULATIONS , 1970 .

[4]  Donald E. Weller,et al.  A Reevaluation of the ‐3/2 Power Rule of Plant Self‐Thinning , 1987 .

[5]  Martin H. Zimmermann,et al.  The hydraulic architecture of balsam fir (Abies balsamea) , 1984 .

[6]  Thomas J. Givnish,et al.  Biomechanical constraints on self-thinning in plant populations , 1986 .

[7]  R. Waring,et al.  Evaluating stem conducting tissue as an estimator of leaf area in four woody angiosperms , 1977 .

[8]  Paul M. Rich,et al.  Mechanical Structure of the Stem of Arborescent Palms , 1987, Botanical Gazette.

[9]  Michael LaBarbera,et al.  ANALYZING BODY SIZE AS A FACTOR IN ECOLOGY AND EVOLUTION , 1989 .

[10]  D. Sprugel.  The Relationship of Evergreenness, Crown Architecture, and Leaf Size , 1989, American Naturalist.

[11]  Boris Zeide,et al.  Analysis of the 3/2 power law of self-thinning , 1987 .

[12]  Allometric Theory Explains Self‐Thinning Relationships of Mountain Beech and Red Pine , 1993 .

[13]  James White,et al.  The allometric interpretation of the self-thinning rule , 1981 .

[14]  P. Marks,et al.  STAND STRUCTURE AND ALLOMETRY OF TREES DURING SELF-THINNING OF PURE STANDS , 1978 .

[15]  Richard H. Waring,et al.  Estimating Forest Growth and Efficiency in Relation to Canopy Leaf Area , 1983 .

[16]  D. Penny.  The comparative method in evolutionary biology , 1992 .

[17]  P. J. Wood,et al.  World Forest Biomass and Primary Production Data. , 1983 .

[18]  W. M. Lonsdale,et al.  The Self-Thinning Rule: Dead or Alive? , 1990 .

[19]  T. Garland,et al.  Procedures for the Analysis of Comparative Data Using Phylogenetically Independent Contrasts , 1992 .

[20]  F. Woodward,et al.  Ecological Correlates of Carbon Isotope Composition of Leaves: A Comparative Analysis Testing for the Effects of Temperature, CO 2 and O 2 Partial Pressures and Taxonomic Relatedness on δ 13 C , 1995 .

[21]  D. Weller.  Will the Real Self-Thinning Rule Please Stand Up?--A Reply to Osawa and Sugita , 1990 .

[22]  J. Black.  AN ASSESSMENT OF THE ROLE OF PLANTING DENSITY IN COMPETITION BETWEEN RED CLOVER (TRIFOLIUM PRATENSE L.) AND LUCERNE (MEDICAGO SATIVA L.) IN THE EARLY VEGETATIVE STAGE , 1960 .

[23]  Boris Zeide,et al.  Tolerance and self-tolerance of trees , 1985 .

[24]  Richard H. Waring,et al.  Forest Ecosystems: Concepts and Management. , 1987 .

[25]  M. Zimmermann,et al.  The hydraulic architecture of eastern hemlock (Tsuga canadensis) , 1984 .

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

[27]  Francis E. Putz,et al.  INFLUENCE OF NEIGHBORS ON TREE FORM: EFFECTS OF LATERAL SHADE AND PREVENTION OF SWAY ON THE ALLOMETRY OF LIQUIDAMBAR STYRACIFLUA (SWEET GUM) , 1989 .

[28]  T. McMahon,et al.  Tree structures: deducing the principle of mechanical design. , 1976, Journal of theoretical biology.

[29]  F. Woodward.  From ecosystems to genes. The importance of shade tolerance , 1990 .

[30]  D. Weller.  The Interspecific Size-Density Relationship Among Crowded Plant Stands and Its Implications for the -3/2 Power Rule of Self-Thinning , 1989, The American Naturalist.

[31]  Donald E. Weller,et al.  Self-Thinning Exponent Correlated with Allometric Measures of Plant Geometry , 1987 .

[32]  Mark Westoby,et al.  The Self-Thinning Rule , 1984 .

[33]  M. Pagel.  A method for the analysis of comparative data , 1992 .

[34]  Donald E. Weller,et al.  THE SELF- THINNING RULE: DEAD OR UNSUPPORTED?- A REPLY TO LONSDALE , 1991 .

[35]  A. Osawa,et al.  The Self‐Thinning Rule: Another Interpretation of Weller's Results , 1989 .

[36]  M. Zimmermann.  Xylem Structure and the Ascent of Sap , 1983, Springer Series in Wood Science.

[37]  Mark Westoby,et al.  The Place of the Self-Thinning Rule in Population Dynamics , 1981, The American Naturalist.