Call number:
ZSP-202-301
In:
Research report
Description / Table of Contents:
CONTENTS: Introduction. - 1.The flow of organic nutrients in plants in cold-dominated ecosystems and the influence of man's activities on this flow. - Methodology for extraction and estimation of plant lipids, alcohol and water-soluble carbohydrates, starch and fructans. - Seasonal cycles in lipids and alcohol-soluble carbohydrates in plants at Barrow, Alaska. - Biochemical changes in plants at the heated soil experiment at Barrow. - Literature cited. - II. Contributions of carbon dioxide from frozen soil into the arctic atmosphere. - Introduction. - Laboratory study. - Field study. - Conclusions. - Literature cited. - III. Biochemical estimations of underground plant biomass. - Appendix A. Methodology. - Abstract.
Description / Table of Contents:
Two approaches were used to study the carbon cycling in a cold-dominated ecosystem at Barrow, Alaska. One involved a detailed analysis of the flow of CO2 between the atmosphere, soil and biota and the other concentrated on the internal carbon cycling in plants. A pilot study was also conducted which investigated the possibility of estimating underground plant biomass by biochemical means. Both laboratory and field studies were conducted to analyze the input of CO2 to the arctic atmosphere by frozen tundra soils. Data are presented which indicate that frozen soil is a major source of CO2. It is hypothesized that CO2 trapped in soils during bi-directional freezing in the fall and winter is released during the spring thaw, thus producing a spring rise in CO2 content of the atmosphere. A procedure for the extraction and estimation of organic nutrients (lipids and carbohydrates) was developed and used to follow the seasonal cycle of these nutrients of plants obtained at Barrow, Alaska. No cycling in levels of carbohydrates (alcohol-soluble) was observed in the foliage during the season, however a definite cycling in lipid levels was seen for all the species studied. The species were synchronous. Plant survival and organic nutrient levels were followed during the winter over a heated-soil experiment at Barrow, Alaska. During the winter, the heating of the soil caused ponding which resulted in the elimination of Dupontia fischeri by mid-winter and the eventual death of all plants by spring. The carbohydrate levels indicated a starvation condition was created where a marked decrease in storage polymers (starch and fructans) occurred without a concurrent large increase in the alcohol-soluble carbohydrate levels. An increase in the fresh/dry weight ratios was also observed indicating etiolated, succulent growth in early winter. Four techniques were tried for estimating the below-ground biomass of plants. Two of these were eliminated as unsuitable, however two other methods(ATP and phospholipid-levels) remain to be fully evaluated.
Type of Medium:
Series available for loan
Pages:
iii, 26 Seiten
,
Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 301
URL:
http://www.worldcat.org/oclc/5973881
Language:
English
Branch Library:
AWI Library
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