Soil Chemistry Properties Under Two Different Management Practices: Clipped Saint Augustine Grass Lawn and Annually Burned Cajun Prairie

Prescribed burning every two or more years is the recommended management practice to remove unnecessary invasive plants and to enhance the regrowth of desirable plants for the development of a fire-dependent plant community native to southwestern Louisiana. A portion of Saint Augustine grass lawn at Louisiana State University at Eunice (LSUE) was converted into a Cajun Prairie restoration plot in 1989. Since 1991, the adjacent lawn has been clipped weekly, whereas the prairie has been burned every January. The objective of this study was to determine the soil chemical properties of clipped lawn and burned prairie plots. Each plot (12 m x 104 m) had four blocks (replications). Soil samples from the 0-10 cm depth were taken from each block for each plot in December 2002, March 2003, and June 2003. They were analyzed in the laboratory for soil chemical properties: pH, organic carbon (OC), electrical conductivity (EC) as a measure of soluble salts, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), zinc (Zn) and copper (Cu). Extractable soil P, Ca, Mg and Na were significantly greater in the burned prairie than in the clipped lawn. In the burned prairie from December to June, Fe increased, whereas pH, EC, P, K, Na, Cu, and Zn decreased. The results suggest that the annually burned restored Cajun Prairie provided greater nutrient deposition into the soil than the clipped Saint Augustine lawn

Watson Brake, A Middle Archaic Mound Complex in Northeast Louisiana

Middle Archaic earthen mound complexes in the lower Mississippi valley are remote antecedents of the famous but much younger Poverty Point earthworks. Watson Brake is the largest and most complex of these early mound sites. Wry extensive coring and stratigraphic studies, aided by 25 radiocarbon dates and six huninescence dates, show that minor earthworks were begun here at ca. 3500 B.C. in association with an oval arrangement of burned rock middens at the edge of a stream terrace. The full extent of the first earthworks is not yet known. Substantial moundraising began ca. 3350 B.C. and continued in stages until some time after 3000 B.C. when the site was abandoned. All 11 mounds and their connecting ridges were occupied between building bursts. Soils,formed on some of these temporary surfaces, while lithics. fire-cracked rock. and,fired clay/loam objects became scattered throughout the mound fills. Faunal and floral remains from a basal midden indicate all-season occupation, supported by broad-spectrum foraging centered on nuts, fish, and deer All the overlying fills are so acidic that organics have not survived. The area enclosed by the mounds was kept clean of debris, suggesting its use as ritual space. The reasons why such elaborate activities first occurred here remain elusive. However some building bursts covary with very well-documented increases in El Nino/Southern Oscillation events. During such rapid increases in ENSO frequencies, rainfall becomes extremely erratic and unpredictable. It may be that early moundraising was a communal response to new stresses of droughts and flooding that created a suddenly more unpredictable food base

Freshwater Mussels (Bivalvia: Unionidae) in the Cajun Prairie Ecosystem in Southwestern Louisiana

Freshwater mussels (Bivalvia: Unionidae) once cobbled the stream bottoms in the Cajun Prairie ecosystem in south-western Louisiana. The development of canal systems for aboveground irrigation of rice fields during the last century provided additional habitat-often the canals were likewise cobbled with mussels that formed diverse communities. This paper introduces the 31 known species, their general ecology and their distributions. These mussels develop a \u27reef\u27-like benthic community that is home to a variety of plants and animals as parasites and haptobenthos. Freshwater mussels are on the decline numerically as well as in diversity as a result of human activity, namely loss of seepage or spring-feeding (shallow groundwater discharge) by agricultural/urban compaction of soil, sedimentation from erosion, channeling of natural streams by dredging, and poisoning of waterways from urban and industrial runoff and dumping. The once-spring-fed streams flow intermittently functioning more as drainage canals as a result of the destruction of prairies by agriculture and urbanization. The return of prairies and forests reinitiates the spring-feeding by shallow groundwater discharge to streams and minimizes runoff of agrochemicals and urban chemicals, thus providing an opportunity for revitalizing freshwater mussel communities

Two new sympatric water-mites (Acari: Hydrachnidia: Unionicolidae) from the mutelid bivalve Aspatharia sinuata (von Martens) in Nigeria with some data on unionicoline-bivalve relationships

Gledhill, Terence, Vidrine, Malcolm F. (2002): Two new sympatric water-mites (Acari: Hydrachnidia: Unionicolidae) from the mutelid bivalve Aspatharia sinuata (von Martens) in Nigeria with some data on unionicoline-bivalve relationships. Journal of Natural History 36 (11): 1351-1381, DOI: 10.1080/00222930110051734, URL: http://www.tandfonline.com/doi/abs/10.1080/0022293011005173

A Floristic Quality Assessment System for the Coastal Prairie of Louisiana

Evaluation systems to assess the biotic integrity of plant communities exist for some ecosystems, but not the increasingly rare coastal prairies of Louisiana. A list of plant species occurring in Louisiana\u27s coastal prairie was created and coefficients of conservatism (C) were assigned for each species. A Floristic Quality Index (FQI), which is calculated using the C values provided by a panel of experts, can be used to evaluate prairie remnants and restorations. We assigned C values from 0-10 based on their estimated degree of association with prairies of various levels of natural quality and their tolerance of disturbance. Those species given a rank of 0-3 are deemed to be colonizing species found in a variety of habitats and are adapted to fairly severe disturbance. Species with C values of 4-6 are those that are often common in fairly high~quality coastal prairie, occur in other community types and are moderately tolerant of disturbance. Species with rankings of 7-8 are associated with high quality natural prairie habitat and slight disturbance. Those species ranking 9-10 are those restricted to very high-quality habitat and have a high fidelity to coastal prairie. Unlike FQI systems devised for other areas, we also weight the coefficients assigned to nonnative species found in coastal prairie. We believe that the presence of exotic species in a native plant community lowers the conservation value of that community. Consequently, we assigned C values from -1 to -3 to nonnative species based on the perceived threat of their invasive potential and ability to exclude native species. Including the C values of exotic species allows the calculation of an adjusted floral quality index that provides an additional dimension to floristic quality analysis. This index will be of value to restorationists, managers and others involved in assessing the integrity of natural areas and developing management strategies based on these criteria

Blockage of transforming growth factor β receptors prevents progression of pig serum-induced rat liver fibrosis

Published records for the six species of North American freshwater aspidogastrid trematodes from molluscs and vertebrates have been compiled, listing both hosts and localities for state or province. Seventeen new unionid mussel hosts (Bivalvia) are reported for Aspidogaster conchicola along with new state records for Arkansas, Connecticut, Delaware, Maryland, Mississippi, North Carolina, New York, Virginia, and San Luis Potosi (Mexico); 12 new unionid host species for Cotylaspis insignis, with new state records for Arkansas, Delaware, Massachusetts, Mississippi, New Jersey, Rhode Island, and Wisconsin; five new unionid hosts for Cotylogaster occidentalis, with new state records for Connecticut, Delaware, Florida, and Texas; and a new unionid host record for Lophotaspis interiora. No new records are given for Cotylaspis cokeri nor for C. stunkardi from turtles

New Molecular-Based Phylogeny of Mussel-Associated Mites Reveals a New Subgenus and Three New Species Representing an Example of a Host-Driven Radiation in Indochina and Confirms the Concept of Division of the Genus Unionicola Haldeman, 1842 (Acari: Unionicolidae) into Numerous Subgenera

Here we describe a new subgenus and three new species of parasitic water mites in the genus Unionicola (Acari: Hydrachnidia) from Myanmar: Myanmaratax subgen. nov., Unionicola (Myanmaratax) savadiensis subgen. and sp. nov. (hosts: Lamellidens savadiensis and L. generosus), U. (My.) generosa sp. nov. (the same hosts), and U. (My.) trapezidenssp. nov. (hosts: Trapezidens dolichorhynchus and T. angustior). These taxa were identified based on a two-gene phylogenetic analysis (COI + 28S), which also confirms the division of the genus Unionicola into numerous subgenera. The new species are cryptic species, which are morphologically indistinguishable but strongly resemble U. (Prasadatax) brandti Vidrine, 1985 described from Thailand (hosts: Lens spp. and Ensidens spp.). We also transfer the latter taxon from Prasadatax to Myanmaratax based on a set of morphological evidence and propose U. (My.) brandti comb. nov. The new subgenus contains a total of five species, one of which needs future sampling efforts and will be described elsewhere. Additionally, 56 valid subgenera, which were placed in the synonymy of the genus and in one case raised to the genus level, are restored here until robust phylogenetic evidence on their taxonomic status is available. Our results also confirm that Unionicola mites are narrow host specialists that are associated with either one or a few closely related freshwater mussel species belonging to one or two sister genera

A Mound Complex in Louisiana at 5400-5500 Years Before the Present

An 11-mound site in Louisiana predates other known mound complexes with earthen enclosures in North America by 1900 years. Radiometric, luminescence, artifactual, geomorphic, and pedogenic data date the site to over 5000 calendar years before present. Evidence suggests that the site was occupied by hunter-gatherers who seasonally exploited aquatic resources and collected plant species that later became the first domesticates in eastern North America