ABSTRACT Yalobusha shire located i...

ABSTRACT

Yalobusha shire located in the north-central portion of Mississippi, consists of 130535 hectares. Vascular plants were garnered and documented between August 1998 and April 2001 A total of 805 species is documented, representing 414 genera and 133 families. Poaceae is the largest family (113%) followed by dint of Asteraceae (10.6%) and Cyperaceae (90%) individual hundred eighteen species can be considered exotic. A strange state record, the fern Deparia petersenii, is reported. Eight state-listed species, Scleria reticularis (S1) Carex stricter (S2) Celastrus scandens (S2/S3) Chelone glabra (S3) Matelea carolinensis (S3) Panax quinquefolium (S3) Staphylea trifolia (S3) and Muhlenbergia sylvatica (SU) are reported. Voucher specimens of each species are deposited at Delta State University (DSC)

INTRODUCTION

Yalobusha shire is located in the north central portion of Mississippi (Figure 1) The shire is approximately 38.6 km drawn out and 32.2 km wide with a total area of 130535 ha (Huddleston et al. 1978) Of the total area, 9129 ha are part of the Grenada and Enid floodcontrol lakes. Elevation ranges from 58 m along the Skuna River in the southern part of the shire to about 152 m forward ridges in the northeastern part of the shire

The climate of Yalobusha shire is strongly influenced by the subtropical latitude, the large land mass to the north, the drifts of the warm waters of the whirlpool of Mexico, and prevailing southerly winds (Trewartha 1954) These factors combine to yield a climate that, while moist and tropical in the summer may bring reach forthed periods without rain. A typical winter will alternate moist, tropical air with free from moisture polar air. Most rainfall come into views in the winter and spring moreover seasonal rainfall differences are frequently relatively small. Precipitation in the summer and fall is frequently in the form of localized and intermittent thunderstorms.

Rainfall totals for principally of the months in 1999 were below normal, and the temperature averages were above normal (National Weather Service, bys comm. January 15, 2001). In 1999 128 cm of rainfall was recorded, 15 cm les than normal. Rainfall was especially grave in the latter part of the year. The mean temperature in 1999 was 17 deg C 2 deg C above normal. The first six month of 2000 showed similar turns with below average rainfall totals and above average temperatures.

The western animation of the county is veiled with a thin veneer of Pleistocene loes (Turner 1952) Tertiary sediments of the Claiborne cluster of Eocene age underlie the central and western portions of the shire Underlying the eastern part of the shire are sediments of the Wilcox arrange of Paleocene age.

Ten soil associations come into one's head in Yalobusha County (Huddleston et al. 1978) However, four associations account for above 75% of the soils in the shire Yalobusha County soils tend to be earnestly acidic. The well-drained loams of the Smithdale-Providence association include about 51% of the soils and arise on slopes throughout the shire Predominant on narrow stream flats are the well-drained silty soils of the Collins-Oaklimiter Association that have a seasonally high water table and account for 11% of the soils in the shire The less well-drained Oaklimiter-- Gillsburg soils meet the eye along larger streams and make up about 9% of the shire In the western part of the shire Loring-Memphis soils comprise about 7% of the shire total. These are silty soils with a significant loes constituent

Creeks in the northern part of the shire drain into Enid Reservoir. Main drainages into the Enid Reservoir are Otoucalofa small bay Billy's Creek, Frost Creek, and extended Branch Creek. Most main drainages in the eastern or southern portion of the shire flow into Grenada Reservoir, Turkey rivulet or the Skuna River (Figure 1)

According to Lowe (1921) greatest in quantity of Yalobusha County is located in the North Central Plateau Physiographic Region (Figure 1) The highest western border is located in the Loes or blunt and frank Physiographic Region. Braun (1950) placed the shire in the Mississippi Embayment Section of the Western Mesophytic Forest Region. The Mississippi Embayment Section is a northern extension of the opening Coastal Plain and includes a variety of vegetation emblems Oak-- hickory communities are for the use of all on forested upland slopes, whereas more mesic assemblages are of common occurrence on lower slopes and narrow stream flats. Bottomland hardwood forests and remnants of swamp forests can be set near the flood control reservoirs.

Floristic studies that have been bearinged near Yalobusha County are Grenada shire (Morris 1987), Monroe County (MacDonald 1996) Attala shire (Winstead 1990), northern Tippah shire (Meeks 1984), Choctaw County (Massey 1974) Clay shire (Simmons 1968), and DeSoto shire (Ferrari 1970). Alford (1999) provided a listing of floristic scans for counties in Mississippi and parishes in Louisiana.

METHOD

Vascular plants were deduceed between August 1998 and April 2001 Sampling took place in each season at greater than 40 habitats in the shire Most habitats sampled showed evidence of human disturbance. Efforts were made to sample representative locations of all major habitats lay the foundation of in Yalobusha County. Voucher specimens were catalogued along with pertinent field data and can be originate in the herbarium of Delta State University (DSC) The collections of the Institute for Botanical Exploration (IBE), the Southern Weed Science Lab (SWSL) the University of Mississippi (MISS), and Charles T Bryson's personal collection (ctb) were checked for additional shire records. Identification of most plants was done using Radford et al. (1968) and Smith (1994) Other sources used include Clewell (1985) Yatskievych (1999) and Flora of North America (FNA 1993)