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Article Excerpt
ABSTRACT. Although the ecological importance of Atlantic white-cedar (Chamaecyparis thyoides), New Jersey's only obligate wetland tree species, has been well documented, it was not known whether the geographic origin of the propagule had any effect on the growth rate of the individual. To determine the effect of geographic origin on the rate of propagule growth, measurements were retaken during the fifth growing season of a previously undertaken provenance study in Jackson, New Jersey in which qualitative but not significant quantitative differences were found between one North Carolina and three New Jersey populations following two growing seasons. After three additional growing seasons, however, a highly significant difference in height was found among the populations, with the North Carolina provenance consistently averaging taller heights than the three New Jersey provenances. Trees of the southern and central New Jersey provenances were also significantly taller than those of the High Point, New Jersey p rovenance. Although no significant quantitative difference could be found for diameter, provenance differences appeared to be present and may become statistically significant in subsequent growing seasons.
KEY WORDS: Atlantic white-cedar, Chamaecyparis, Cedar Swamp, Provenance
INTRODUCTION
Atlantic white-cedar, Chamaecyparis thyoides (family Cupressaceae), is New Jersey's only obligate wetland tree species. Its historic range once covered perhaps 200,000 ha, fragmented and isolated in non-continuous populations ranging down a narrow strip of the Atlantic seaboard from Maine to Florida, and west into parts of Mississippi (Little and Garrett, 1990; Kuser and Zimmermann, 1995). Today, it covers significantly less area within the same range - approximately 44,000 ha - most of which occurs in pure stands or mixed hardwood forests with wetland swamp conditions (Little and Garrett, 1990; Kantor and Pierson, 1985; Kuser and Zimmermann, 1995). Its narrow ecological amplitude is associated with specific abiotic factors - pH, hydrologic conditions, substrate below root zone, and total incident light penetration (Little, 1950; Ehrenfeld, 1995a, b). Historic loss of habitat has had its origins in agricultural clearings and human alteration of hydrological and ethological (increased deer and rabbit populatio ns, decreased beaver populations) conditions (Kuser and Zimmermann, 1995). Other reasons for habitat loss have included logging for the cedar's decay resistant wood, boat building, and the production of buckets, shingles, stakes, and utility poles (Little, 1950; Kuser and Zimmermann, 1995). Still other sources of destruction have resulted from an indifferent attitude towards cedar's ecologic role, an historic attitude applied towards wetlands in general. Many hectares of cedar swamp were even burned in the Hacken sack Meadowlands in 1791 as a means of protection from pirates, who were using the swamp for cover (Kantor and Pierson, 1985).
More recent times, however, have seen a resurgence in appreciation of wetlands, now recognized as stabilizers of streams, storage basins for storm waters, and filterers and purifiers of ground and surface waters. Additionally, cedar wetlands contain rare plant species, such as the curly grass fern (Schizaea pusilla) and swamp pink (Helonias bullata), and various animal species, such as migratory thrushes and warblers, small mammals, and amphibians (Wander, 1980; Zappalorti, 1994). This resurgence has led to the desire for cedar swamp restoration, which has proven to be difficult and expensive. It is our hope that some of this difficulty may be alleviated through a faster rate of growth, which is not only advantageous in...
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