An error in the printing process resulted in the transposition of photographs for Figures 3 and 7 of this manuscript appearing in Volume 55(1):1-21 (1990). Since these photographs will be useful to researchers monitoring long-term vegetation trends and using permanent photo-points established in this study, they have been reprinted in this article with correct captions.
Species diversity was determined for 53 woody plant communities within the Trinity River Basin, Texas, using the Shannon-Weiner Diversity Index. Trees with diameters of 1 cm or greater at about 1.4 m above ground were measured. Community species diversity was correlated with a precipitation gradient associated with the basin. The general hypothesis that community species diversity increases with lessening stress was substantiated. Less moist upper basin and the more moist lower basin and swamp communities had lower species diversity values than the moist mid-basin communities.
The introduction of this carefully and thoughtfully written book contains some interesting botanical philosophy, including the notion that learning to identify plants requires real effort. This task is made easier as Dr. Godfrey continues with a non-technical glossary; very good keys and descriptions in the taxonomic treatments of families, genera and species; five pages of references; and separate indexes to common and scientific names.
Seven hundred and seven forest stands dominated by Quercus, Carya, and Castanea species from 32 states in eastern North America were classified into eight forest community types; (1) Pinus palustris-Quercus laevis sandhill community, (2) southern mixed hardwoods, (3) Quercus alba, (4) Quercus prinus, (5) Quercus stellata-Quercus marilandica, (6) Quercus macrocarpa-Quercus muehlenbergii, (7) Pinus rigida-Quercus coccinea pine barrens, and (8) Castanea dentata. Several of the above may be represented by several phases. No real evidence was found for a regional oak-hickory forest. A better designation would be oak or mixed oak forests for what formerly has been called oak-hickory forests.
The authors describe the general reproductive strategy of Zizaniopsis miliacea and discuss an asexual reproductive strategy in this grass. This involves utilization of the fertile culm as a site of production of up to three vegetative buds, each of which can potentially become an independent plant. Such buds are long range dispersal propagules.
Murdannia keisak, a constituent of the freshwater wetland flora of the southeastern United States and of eastern Asia, is a weedy species whose range is expanding. Most authorities believe M. keisak to have been introduced into the U.S. from Asia. The first published report of M. keisak in the U.S. was of a 1935 collection near the site of rice introduction to the Carolinas. It is likely that M. keisak was introduced accidentally with rice cultivation, but was kept from escaping from rice fields by diligent weed control. We discuss the available evidence in an attempt to clarify how and when M. keisak came to the U.S. and what factors may account for its relatively recent spread.
Seasonally flooded bottomland hardwoods along the Middle Fork-Forked Deer River have been replaced by a shallow-water marsh as a result of blockage in a lateral drain to the river. This study compares the shallow-water marsh with a nearby seasonally flooded bottomland hardwood forest. Plant species diversity and the diversity of microhabitats have been reduced due to shallow-water impoundment during the growing season. If the obstruction to the lateral drain were removed, the shallow-water marsh area would likely be replaced by a viable hardwood stand with a seasonal flooding regime. Not only would removal of the obstruction improve flood control but also, as shown by this study, increase species diversity and enhance wildlife habitat.
Seventeen species of Myxomycetes not previously known from West Virginia are reported. Two of these, Arcyria margino-undulata and Physarum luteonodum, appear to be new records for North America.
During studies made for our book, Shrubs of the Southeastern United States (in progress), we investigated the character of “spines” on two Celtis species.