Dynamics of hardwood-redcedar clusters /
Aspects of hardwood-redcedar clusters of the Post Oak Savanna in Texas were studied at 3 levels: 1) landscape level patterns, 2) growth and mortality of trees within clusters, and 3) the death process within the center oak of clusters. Two distinct patterns were present at the landscape scale: disti...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=743267201&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Aspects of hardwood-redcedar clusters of the Post Oak Savanna in Texas were studied at 3 levels: 1) landscape level patterns, 2) growth and mortality of trees within clusters, and 3) the death process within the center oak of clusters. Two distinct patterns were present at the landscape scale: distinct cluster structures of redcedar and medium-size oak aggregated around large oak trees as well as colonization of open spaces between clusters by both post oak and redcedar. This pattern of redcedar colonization suggests that Post Oak Savanna may be shifting to closed-canopy redcedar woodland via both cluster formation and oldfield succession processes. Comparison of tree growth between 1984 and 1993 revealed that the average height growth of redcedar was nearly twice that of the center post oaks: average redcedar height growth was 1.4 m while average post oak height growth over this period was only 0.8 m. Overall mortality rates of both species in clusters were similar: post oak = 16% and redcedar = 15%. However, few large redcedar died. In contrast all dead or dying center hardwoods were large trees. Mortality of large redcedar was low relative to that of large post oak over the 1 0 year period. Leaf area comparisons of post oak in intact versus dismantled clusters indicated that redcedar penetrating the post oak canopies were reducing the leaf area of the center post oaks. Cause of death in oak trees of hardwood-redcedar clusters was hypothesized from shade competition of surrounding redcedar. Predictions of time of death were generated using a simple model of tree height growth. Average time to death for the center oaks in clusters studied in this research was 68 years. |
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| Item Description: | Vita. "Major Subject: Bioengineering". |
| Physical Description: | xv, 175 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |