Calcareous glade
A calcareous glade is a type of ecological
The usage of the words "glades" and "barrens" to describe dry, rocky communities in the United States is not uniform, and the terms are often used interchangeably.[1] Calcareous glade communities can intergrade with dry rocky prairies, particularly in sloping habitats. Due to their unsuitability for agriculture, glade communities have survived to the present day at a higher rate than deeper-soil prairie communities.[1]
Interior Low Plateau glades
The
Central Basin cedar glades
The limestone glades of the Central Basin in Tennessee are often called "cedar glades". The name comes from the abundance of eastern red cedar (Juniperus virginiana) that occurs on the margins of the glades or in cracks in the bedrock where the roots can gain a foothold.
Many of the characteristic plants that grow in the limestone glades of the Central Basin are endemics that occur nowhere else, or disjunct populations of plants that are widespread in the
These glades can be saturated with water in the winter and spring, leading to "xerohydric" (dry/wet alternating) conditions.[4]
Threats to the cedar glades
The central basin (or Nashville Basin) of Tennessee is one of the largest areas containing limestone glades. Because of the rapid growth of metropolitan Nashville and the surrounding cities of Murfreesboro and Lebanon, many of the limestone glades have been destroyed by development. The State of Tennessee and the Nature Conservancy have established a number of parks and preserves to protect important plant populations. Cedars of Lebanon State Park in Wilson County and Long Hunter State Park in Davidson County both protect substantial limestone glade ecosystems.
Limestone slope glades
The limestone slope glades of Kentucky are a globally vulnerable habitat consisting of limestone glades found on hillsides, which are wet in the spring but become very dry in the rest of the year. This provides habitat for unique species such as necklace glade cress, Butler's quillwort, and Crawe's sedge.[5]
Endemic plant species
This is a list of calcareous glade-adapted plant species considered endemic to the Interior Low Plateau region. Some are found in only a single county of a single state. [6]
- Astragalus bibullatus
- Astragalus tennesseensis
- Castilleja kraliana (Cahaba paintbrush)
- Clinopodium glabellum
- Dalea cahaba
- Dalea foliosa
- Dalea gattingeri
- Delphinium alabamicum
- Echinacea tennesseensis
- Eleocharis bifida (Cedar glade spike rush)
- Erigeron dolomiticola (Cahaba daisy fleabane)
- Hypericum dolabriforme (Glade St. John's wort)
- Leavenworthia uniflora
- Lithospermum decipiens (Deceptive marbleseed)
- Lobelia gattingeri (Gattinger's lobelia)
- Marshallia mohrii (Coosa Barbara's-buttons)
- Pediomelum subacaule
- Penstemon tenuiflorus (Limestone beardtongue)
- Phemeranthus calcaricus (Limestone fameflower)
- Physaria filiformis
- Rudbeckia grandiflora (Largeflower coneflower)
- Silphium glutinosum (Sticky rosinweed)
- Sisyrinchium calciphilum (Glade blue-eyed grass)
- Spigelia alabamensis (Alabama pinkroot)
- Symphyotrichum kentuckiense (Miss Price's aster)
Ozark Mountains glades
Calcareous glades are well developed in the
Ridge and Valley glades
The Ridge-and-Valley Appalachians, which extend north from Pennsylvania south to Alabama, have significant calcareous glade communities.[7] These glades often have dolomitic soils, resulting in a high magnesium content (in contrast to the glades of the Nashville Basin). In Virginia, these glades provide habitat for rare magnesiophiles such as Addison's leatherflower (Clematis addisonii), tall larkspur (Delphinium exaltatum), smooth coneflower (Echinacea laevigata), and glade wild quinine (Parthenium auriculatum).[8]
At the southern end of the Ridge and Valley in Alabama in Bibb County, species endemism of glade communities peaks. This area, known as a Ketona Dolomite Outcrops, was first recognized as ecologically significant in 1992. Since its discovery, eight new plant taxa to science have been described from this region, in addition to the 60 species of conservation concern found in or around this community.[9] Endemic species of this area include Castilleja kraliana, Dalea cahaba, Liatris oligocephala, Lithospermum decipiens, and Spigelia alabamensis.
References
- ^ a b c d e Yatskievych, George (1999). Flora of Missouri, Volume 1. Missouri Botanical Garden Press.
- ISBN 9780813123318.
- ^ Cedar Glades Brochure Center For Cedar Glade Studies
- ^ Glades Archived 2018-02-13 at the Wayback Machine Austin Peay State University Herbarium
- ^ Yahn, Brian. "In the Spotlight: Limestone slope glades" (PDF). eec.ky.gov.
- ^ Weakley, Alan S. (2022). Flora of the Southeastern United States. Chapel Hill NC: University of North Carolina at Chapel Hill Herbarium.
- JSTOR 4033660.
- ^ Limestone / Dolomite Woodlands and Barrens The Natural Communities of Virginia Classification of Ecological Groups and Community Types
- ^ Allison, Jim; Stevens, Timothy (2001) [March/June]. "Vascular Flora of Ketona Dolomite Outcrops in Bibb County, Alabama". Castanea. 66 (1–2): 154–205. Revised edition of January 21, 2011