Book Review: The Vascular Flora of Pennsylvania: Annotated Checklist and Atlas
Book Review: The Vascular Flora of Pennsylvania: Annotated Checklist and Atlas
Book Review: The Vascular Flora of Pennsylvania: Annotated Checklist and Atlas
ABSTRACT Many have speculated that fire suppression and the subsequent woody encroachment have contributed to the demise of the barrens. Prescribed fire is becoming a common tool for barrens reconstruction; however, information on presettlement fire frequencies in xeric forests is limited. In an attempt to document presettlement and postsettlement fire frequencies of these xeric communities, this study was initiated. Four study sites, which had been logged recently, were selected from the Ozark and Shawnee Hills of southern Illinois. Trees were examined for age and evidence of fire scars. A total of 299 trees were examined. No trees examined dated to presettlement times. Fire frequency was greatest 60 to 80 years ago with few fires occurring in the past 50 years. It appears that reduction in fire frequency has contributed to the recent increase of woody species coverage and the consequent reduction in the herbaceous component of the barrens.
ABSTRACT Brown Shale Barrens and Wolf Creek Chert Barrens are small, high-quality natural forest openings in extreme southwestern Illinois. Brown Barrens, dominated by Quercus stellata and Schizachyrium scoparium, and Wolf Creek Barrens, dominated by Quercus stellata, Ulmus alata and Fraxinus americana, are increasing in woody cover as documented by examining aerial photographs. To obtain preburn floristics and vegetation data, thirty 0.005 ha circular permanent plots were sampled in 1988 at Brown Barrens using a modified Daubenmire canopy cover method. In 1989, twenty-eight similar plots were established and sampled at Wolf Creek. Both sites were resampled in 1990 following spring prescribed burns. The fires did not significantly reduce the arboreal component nor increase the herbaceous component of either study site during the 1990 growing season.
ABSTRACT Indigenous plant communities are being rapidly destroyed by expanding conifer populations in remaining serpentine “barrens” of Maryland. The main purpose of this study was to determine herbacous layer effects of two restoration treatments in Soldiers Delight Natural Environmental Area near Baltimore, Maryland. The cleared-only treatment consisted of post-growing season manual removal cf all conifers, and the cleared-and-burned treatment consisted of the latter followed by two consecutive post-growing season prescribed burns. Clearing occurred in November 1989, prescribed burning in November 1990 and 1991, and sampling for presence and percent cover data occurred during the growing seasons of 1989 through 1992. Analysis of covariance was used to detect significant treatment effects to the frequency, percent cover, and community importance percentage of each species. Major results included (1) the community dominant, Schizachyrium scoparium (Michx.) Nash, did not respond to either treatment, (2) each treatment affected a completely different set of species, and
ABSTRACT A wide variety of landtype associations (sensu Smalley 1980) occurs on the Mississippian limestone karst plain of Kentucky and Tennessee. Thus, although much of this region is in agriculture, it supports a diversity of native plant communities. These include limestone cedar glades (edaphic climax communities on nearly flat areas of limestone bedrock and shallow soil dominated by annual or perennial forbs, annual grasses, cryptogams, or some combination of these); xeric limestone prairies of anthropogenic origin dominated by native perennial grasses and/or forbs; barrens (deep-soil, culturally-derived and maintained grasslands dominated by native perennial grasses); forests of dry, mesic, and wetland sites; and aquatic vegetation of sinkhole ponds. The historical occurrence of extensive areas of grassland interspersed with stunted trees and shrubs (“barrens”) on the Kentucky Karst Plain is well documented. Transeau included these Big Barrens on his original (1935) and revised (1956) maps of the Prairie Peninsula, implying that they
ABSTRACT The barrens in Tennessee are small openings in the forest; the openings are dominated by perennial grasses which are usually the same grass taxa that dominate the Tallgrass Prairies of the Middle West. The flora of the barrens comprises nearly 40 percent of the presently known Tennessee flora. The taxa are mainly intraneous but there are significant northern, southern and western elements. There are few or no barrens endemics, but the number of taxa listed in Tennessee as rare exceed, for example, the numbers of rare taxa in the Great Smoky Mountains. Barrens today appear to be successional and are chiefly those maintained as open communities by human action. Maintenance before arrival of European settlers was presumably due to periodic drought, especially on shallow soils, and grazing-browsing-trampling, and fire. Although known areas are few, they are still being found and opportunities for their study are great.
ABSTRACT Indiana barrens are defined as terrestrial ecosystems where edaphic drought and infertility prevail. Causative factors for dryness include excessive drainage due to soil particle size (e.g., sand), southern or western aspect of site, excessive steepness of slope, presence of a hardpan or bedrock at or near surface, and fire. Soil chemistry is an important regulating factor of barrens vegetation, as most barrens are nutrient deficient. Barrens vegetation consists of a varied admixture of shrubs, small trees, grasses and forbs adapted to drought; such vegetation is commonly in the form of open scrub, but physiognomy alone does not define the community, because barrens may range from mostly graminoid to possessing a closed canopy (this dependent on substrate, and fire history or other environmental perturbations). A rather consistent suite of species characterize each type of Indiana barrens, depending on the type of substrate and the geographic location within the state. Chert,
ABSTRACT The common term used by early travelers to describe lands in the Midwestern wilderness that were neither “good prairie” nor “good forest” is barrens. This natural type changed quickly after settlement, and few examples are left to document its original character. Confusion exists among ecologists today as to the definition and proper use of the term. Some doubt that it has any place in modern classification systems. Very few sites have been recognized by the barrens name in modern inventories. After studying and comparing historical descriptions of the barrens, and after examining original barrens areas in several of the Midwestern states, it appears that the barrens term was, and still is, a legitimate name for a natural community type distinct from forest and prairie. A definition is proposed, but the main emphasis of this presentation is to describe the barrens. Although all have been affected by unnatural disturbance, good
Barrens of the Midwest: A Review of the Literature
Contributions of the Barrens Symposium