Graduate Thesis Or Dissertation
 

Leaf area index and specific leaf weight : keys to interpreting canopy photosynthesis and stand growth

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/cj82kb41t

Descriptions

Attribute NameValues
Creator
Abstract
  • Two physiological factors are of major importance to tree and stand growth: (1) the photosynthetic rate of foliage and (2) the amount of foliage. If carbohydrate allocation patterns remain constant, stand growth should be related directly to total canopy photosynthesis. From a literature analysis I assess methods of relating photosynthetic rates to biochemical, anatomical, and structural characteristics of foliage. A number of these foliage characteristics were found to be interrelated. Specific leaf weight was shown to be a valuable index for comparing photosynthesis by various parts of a tree canopy over a season or throughout an entire year. Mean annual photosynthetic rate in five separate portions of a spruce canopy was directly proportional to observed differences in specific leaf weight (r2 = 0.99). Annual carbon uptake was a function of total foliage biomass (r2 = 0.96). When foliage biomass at each crown segment was adjusted for differences in specific leaf weight, reflecting differences in photosynthetic rates, the predictive equation further improved C r2 = 0.99). Specific leaf weight is recommended as an index for comparing the relative effects of various silvicultural treatments on photosynthesis. I then evaluated how stand growth and canopy leaf area were related by analyzing 24 years of growth records from a Pinus ponderosa (Laws.) experiment. The experiment included a wide range in initial stocking and partial control of understory vegetation (Barrett 1982). I found that treatment effects on tree growth can be evaluated at low values of stand leaf area from comparison of growth efficiencies (wood produced per unit leaf area) among plots of similar canopy leaf area. By comparing stand growth with stand leaf area, I concluded that the major effect of removing understory vegetation was to speed the development of the canopy. This interpretation was also supported by a comparison of the rate of leaf area development on plots with and without understory vegetation at comparable levels of canopy leaf area. Comparing stands at a similar canopy leaf area is advised for assessing how treatment affects stand development. This is a valuable alternative to analyzing treatment effects at one point in time and helps to explain the results of many fertilization experiments.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Language
Digitization Specifications
  • Master files scanned at 600 ppi (256 Grayscale) using Capture Perfect 3.0 on a Canon DR-9080C in TIF format. PDF derivative scanned at 300 ppi (256 B&W), using Capture Perfect 3.0, on a Canon DR-9080C. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details Oren_Ram_1984.pdf 2017-08-14 Public Download