Toward understanding Ecosystems
DAVID M. GATES
Missouri Botanical Garden, St. Louis, Missouri, U.S.A.
I. Iritroduction .........................................................
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11. Ecological Questionu. ...............................
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111. Energy Exchange between Plant and Environment.. ..................
A. Simultaneity of Factors.. .......................................
C. Energy Budget.. . . . . . . . . .
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A. Radiation Abaorptivity. .............................
B. Conduction Coefficient. ............................................
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C. Conveation Coefficient .............................................
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D. Transpiration Resistance..
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V; Energy Budget Equation for a
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A. Energy Exchange for Special ECOE~S~~IIIS. ...........................
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B. Leaf Temperat ura ................................................
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VI. Eco-Physiolo gy ......................................................
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A. Photosynthesis and Itespiretion .....................................
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B. Physiological Consequences of D i d Climate. .......................
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C. Climate and Physiology of a Tree. ..................................
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D. Stands.... .
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A. Plant and Envi~nment ............................................
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B. Genotypic and Phenotypic Plant Properties.. ........................
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C. ~ m p e t i t i o n
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I). Succemion.. . . . . . . . . . .........................................
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E. Productivity .....................................................
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Acknowledgment ..........................................................
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References. .......
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B. Energy ..........................................................
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IV. Coupling Factors between Plan
Environment. ........
VII. Methods for Answering Ecological Questions. ..................
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I. INTRODUCTION
The complexity of an ecosystem is enormous for, by definition, it is
the total aum of the organisms, the environment, and the processes of
interaction between and within all parts of the system. In this paper the
difficulties confronting the ecologist attempting to understand the complexities of ecosystems is reviewed, specific questions are asked concerning ecosystems, the coupling of the environment to the organism is
described in terms of energy flow, and an analytical, quantitative
methodology ie given for answering the ecological questions. Ecosystems
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