Date of Award

1988

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

First Advisor

John R. Toliver

Abstract

Louisiana contains the largest volume of baldcypress (Taxodium distichum (L.) Rich.) timber in the United States, with 70% of the volume located in the south central part of the state. Baldcypress regeneration was studied in the Barataria and Verret Basins during 1982-1987. Overall, natural regeneration was poor in both basins. There was some recruitment during the dry years 1984 and 1986 but these seedlings did not grow tall enough to survive subsequent flooding. Coppice regeneration in logged areas was excellent after logging, but a majority of the sprouts died in succeeding years. In three projects where baldcypress seedlings were planted in logged and unlogged stands, nearly all of the seedlings were destroyed by nutria (Myocastor coypus) even though half were protected with Vexar seedling protectors. Height growth of the seedlings that were not destroyed averaged 30 cm/year. Chickenwire fences were also used to protect one planting, and survival ranged from 64 to 91% and height growth ranged from 12 to 27 cm/year. In another project baldcypress seedlings were planted in a crawfish pond in February and July of 1983 and 1984. Summer planted seedlings exhibited the poorest survival rates. February planted seedlings that experienced one growing season before flooding had the best survival (97%) and growth rates (40 cm/year). After three years, annual growth rates of all both February and July planted seedlings were similar. Relative water level rise in both basins was greater than 1 m/century and both areas have experienced significant increases in the number of days flooded each year since 1956. Natural regeneration in the study areas is not sufficient to replace dying or logged trees. Bottomland forests on the study plots in the two basins will decline in the next 50 years and even the flood-tolerant baldcypress will eventually disappear. Under certain conditions, managed regeneration is possible but more research is needed on how to plant and protect baldcypress seedlings to ensure adequate stocking of stands. Growth and yield information is also needed for evaluating management alternatives for long-term objectives.

Pages

164

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