Current land use and extensive modifications of natural ecosystems across the state of Louisiana are generally similar to those across the southeastern USA where rainfall supports forest ecosystems. ...Both intentional and unintentional consequences of ecosystem modifications from the scales of water and sediment movement across a field edge to state-wide loss of functional grasslands are legacies from previous development across the state. While major investments and large-scale, long-term plans are aspects of some continuing ecological issues across the state, small-scale, volunteer-led restoration of native grassland plant communities in the Louisiana Coastal Prairie illustrates the value associated with the restoration of natural ecosystem function in drastically disturbed environments. As is now becoming increasingly recognized, Louisiana grasslands represent less obvious components of forest, woodland, and wetland landscapes across the state, where they have contributed essential wildlife habitat, and ecosystem functions. These are now largely missing from many landscapes across the state and region. The strategic restoration of grassland functions combining novel native grass pastures and fully functional native grassland plant communities as landscape components could provide both economic and ecosystem benefits. Specific native grassland seed resources are needed for various restoration activities to enhance ecosystem function at a range of scales across the state and region.
Knowledge and understanding about how the Earth functions and supports life create the foundation for ecological literacy. Industrialisation, urbanisation and population growth have resulted in ...changed relationships between many human communities and the natural world. A potential consequence is a compromised capability to make well-informed decisions about how to live sustainably. To gain a measure of ecological literacy within the South Australian community, we collaborated with senior scientists and educators to develop and apply an instrument with the capacity to determine indicative levels of ecological knowledge and understanding. A formal, variable credit, multiple-choice assessment instrument was distributed online to groups and individuals within diverse community sectors and industries. Quantitative analyses of scores indicated that levels of ecological knowledge and understanding within a self-selected sample of over one thousand individuals ranged from very low to extremely high, with the majority of respondents achieving moderate to high scores. This instrument has a demonstrated capacity to determine indicative levels of ecological literacy within and between individuals and groups. It is able to capture mastery of ecological knowledge and understanding achieved through both formal and informal pathways. Using the results, we have been able to establish a range of standards and an aspirational target score for the South Australian community. The value of this work is in its potential to deliver insights into relationships between humans and the rest of the natural world, and into characteristics of eco-literate individuals and communities, that might not otherwise emerge.
Context
Agricultural landscapes across the southeastern US are typically managed with little consideration for landscape scale ecosystem function despite potential hazards and benefits from ecosystem ...processes. Enhanced landscape function from less-intensive use of less-productive, erosive soils within large cropland landscapes combined with buffer areas along natural drainage patterns are potential approaches to ameliorate recognized limitations of large-scale intensive crop production. Similar consideration of intensive plantation forestry approaches also provides opportunities for strategic land-use where less intensive use of lower producing sites across forest landscapes and harvest patterns may provide increased landscape function with only limited loss of production across the landscape.
Objective
The objective was to characterize environmental shortcomings of production environments in the southeastern US and identify potential approaches to overcome these shortcomings along with identification of public policy and land-user approaches to enhance landscape function.
Methods
Literature searches were used to identify publications contributing to characterization of the regional environment and effects of agricultural production on the environment. These results were assessed in relation to concepts and approaches of landscape ecology to identify potential opportunities to overcome shortcomings of current production approaches.
Results
Mixtures of land use across the region occur as forests, croplands, and pastures providing opportunity for diverse landscapes contributing multiple benefits. Initial unsustainable, low-input crop production across much of the region, however, led to soil depletion across large areas of marginally productive soils. Extensive conversion of these areas to plantation forestry followed the initial unsustainable farming. Large-scale crop production was subsequently developed on the more productive soils with management focused on the production enterprises to provide the inputs required for high levels of production. Reductions in provisioning of some ecosystem services essential for sustainability have been identified as consequences of these systems. Repeated recommendations of multifunctional landscape approaches for sustainable production in various environments have occurred in the sustainability and landscape ecology literature, and these appear to be particularly relevant to production landscapes of the southeastern US.
Conclusions
Management of many production environments in the southeastern US to address effects of crop production fields and forest plantations on overall function of production landscapes could increase production efficiency and substantially enhance environmental contributions such as improved water quality and enhanced wildlife habitat along with providing other potential benefits including additional production enterprises. Recognition of the concept of landscape function and the role of individual land managers in providing the components for multifunctional landscapes could lead to greater appreciation of individual land-use effects on the landscape. The matrix of production land uses across the region and the varied land capabilities to fit these land uses provide a framework for highly functional landscapes. USDA programs are in place to facilitate such landscape diversification with appropriate program direction. Development of such functional landscapes in the region could provide an example of effective land-sharing complementing land-sparing efforts rather than presenting a distinct dichotomy of competing approaches.
Knowledge and understanding about how the ecological systems of the Earth support life form the foundation for ecological literacy, which, in turn, is of critical importance for sustainability. There ...is widespread concern that levels of ecological literacy within many contemporary human societies are too low to enable effective decision-making about how to live sustainably. This paper presents and discusses the findings of an ecological literacy assessment of South Australian adults. The assessment tested for knowledge and understanding of ecological systems and interconnections with human society. Analyses revealed significant relationships between assessment scores and a range of value-based and behavioural characteristics. Such characteristics included the value placed on nature, time spent outdoors and in nature, involvement in nature-based activities, and perceived sources of ecological knowledge and understanding. Higher average scores were correlated with higher values accorded to involvement in outdoor activities, importance of the outdoors to enjoyment of life, importance of nature in the household, volunteer environmental activity and growing food. Higher scores were also correlated with higher education, research activities, outdoor lifestyles, place-based experiences, volunteer activities, mentors and colleagues, and books and magazines. Lower scores were achieved by those who considered media, natural disasters and environmental marketing to be major contributors to their ecological knowledge. These findings contribute to a broader study of the relationships between ecological literacy and a range of both socio-demographic and psychographic characteristics. They invite serious consideration from any society that values the participation of an informed population with the capacity to make sustainable environmental decisions.
Sweet sorghum Sorghum bicolor (L.) Moench is recognized as a promising biomass energy crop for meeting the increasing demand for bioenergy feedstocks. Field experiments were conducted at sites in ...northern and southern Louisiana for 2 yr to assess planting date and harvest maturity effects on yield from primary plantings and ratoon crops. The cultivar M81‐E was evaluated using a split plot arrangement of treatments in randomized complete block designs. Planting date from mid‐March to early July was the primary plot treatment. Harvest maturity at the early heading (EH) or hard dough (HD) stage was assigned as the subplot treatment. A range of planting dates from mid‐March to early June produced substantial yields of biomass and fermentable sugar with appropriate harvest maturity and could support sugar mill operation for up to three additional months. However, sweet sorghum planted in early May and harvested at the HD stage produced 30 to 210% more fermentable sugar than other tested planting dates and maturity combinations. Ratoon crop production was not dependable showing inconsistent tiller growth with resultant low biomass yields. Correlation coefficients of sugar yield with biomass or other quantitative agronomic characteristics were higher than 0.79, while that with brix was only 0.32 (P < 0.0001). Production management in Louisiana from long season cultivars such as M81‐E based on a single harvest 150 to 160 d from planting at the HD stage can provide more biomass and fermentable sugar than can production management targeting a ratoon crop.
Preservation of forage crops as silage offers opportunity to avoid the high risk of rain-damaged hay in the humid south-central USA. Recent developments with baled silage or baleage make silage a ...less expensive option than typical chopped silage. Silage has been important in the region primarily for dairy production, but baleage has become an option for the more extensive beef cattle industry in the region. Silage samples submitted to the Louisiana State University Agricultural Center Forage Quality Lab from 2006 through 2013 were assessed for dry matter (DM) and forage nutritive characteristics of chopped silage and baleage of the different forage types from commercial farms primarily in Louisiana and Mississippi. Of the 1,308 silage samples submitted, 1,065 were annual ryegrass (AR) with small grains (SG), the warm-season annual (WA) grasses, sorghums and pearl millet, and the warm-season perennial (WP) grasses, bermudagrass and bahiagrass, providing the remaining samples. Concentration of DM was used to indicate an effective ensiling opportunity, and AR silage was more frequently within the target DM range than was the WA forage group. The AR samples also indicated a high-quality forage with average crude protein (CP) of 130 g/kg and total digestible nutrient (TDN) near 600 g/kg. The cooler winter weather at harvest apparently complicated harvest of SG silage with chopped SG silage lower in both CP and TDN (104 and 553 g/kg, respectively) than either AR silage or baleage of SG (137 and 624 g/kg for CP and TDN, respectively). The hot, humid summer weather along with large stems and large forage quantities of the WA grasses and the inherently higher fiber concentration of WP grasses at harvest stage indicate that preservation of these forage types as silage will be challenging, although successful commercial silage samples of each forage type and preservation approach were included among samples of silages produced in the region.
Although big bluestem (Andropogon gerardii Vitman) is used for forage and conservation in the Great Plains, potentially useful Louisiana ecotypes have received little attention. Cloned plants from a ...robust big bluestem plant collected near Rosepine, LA were assessed for responses to fertilizer and defoliation in a field evaluation of potential forage value. Annual application of nitrogen fertilizer at 50 kg ha⁻¹ did not increase herbage yield until the third year. Clipping twice annually decreased productivity compared to once annually after the second year. Fertilizer effects on forage nutritive value were small. Clipping improved late-season nutritive value largely due to greater stem development of previously undefoliated plants. Limited responsiveness to fertilization and detrimental effects of repeated defoliation on productivity indicate that even this robust local big bluestem ecotype provides little potential as a pasture plant. Potential is indicated for other uses including wildlife habitat and grassland ecosystems managed for conservation purposes.
The Gram-negative anaerobe Dichelobacter nodosus is the primary etiologic agent of ovine footrot. Few studies of the genetic diversity and epidemiology of D. nodosus have been done, despite the ...economic cost and welfare implications of the disease. This study examined a large collection of Australian isolates; 735 isolates from footrot-infected sheep from 247 farms in Western Australia (WA) were tested by pulsed-field gel electrophoresis (PFGE), and a subset of 616 isolates was tested by infrequent restriction site PCR (IRS-PCR). The genetic diversity of WA isolates was compared to that of 61 isolates from three other Australian states. WA isolates were genetically diverse, with 181 molecular types resolved by PFGE, resulting in a simple diversity ratio (SDR) of 1:4 and a Simpson's index of discrimination value (D) of 0.98. IRS-PCR resolved 77 molecular types (SDR = 1:8 and D = 0.95). The isolates were grouped into 67 clonal groups by PFGE (SDR = 1:11, D = 0.90) and 36 clonal groups by IRS-PCR (SDR = 1:17, D = 0.87). Despite the high genetic diversity, three common clonal groups predominated in WA and were found in other Australian states. On some farms, molecular type was stable over a number of years, whereas on other farms genetically diverse isolates occurred within a flock of sheep or within a hoof. This study provides a large database from which to appropriately interpret molecular types found in epidemiological investigations and to identify common and unknown types that may compromise footrot eradication or control programs.
Although Hodgkin lymphoma-like posttransplantation lymphoproliferative disorder (HL-like PTLD) has been grouped with classic Hodgkin lymphoma type PTLD (HL-PTLD), controversy remains as to whether it ...is truly a form of HL or whether it should be more appropriately classified as a form of B-cell PTLD. Because only few cases of HL-like PTLD have been reported, their pathologic nature and clinical behavior have not been well defined. This report characterized 5 cases of HL-like PTLD with respect to their immunophenotype, EBV status, clonality, and clinical outcome. All of the patients were male, with ages ranging from 1.5 to 55 years at diagnosis. PTLD developed from 4 months to 6 years following solid organ transplantation (3 hearts, 1 kidney, 1 liver), and involved both nodal and extranodal sites. All were EBV-related (EBER+) with the large neoplastic cells CD20/CD79a positive but CD15 negative. Immunoglobulin gene rearrangements were detected in 3 of 5 tested. All patients were managed by initial reduction/withdrawal of immunosuppression, with 2 also receiving chemotherapy for non-HL. Three patients died of progressive disease within 2 to 3 months after diagnosis, 1 is alive and well 2 years later, and the fifth was disease free but died of unrelated causes (graft coronary disease) 2 years later. We conclude that, although HL-like PTLD morphologically simulates classic HL PTLD, there are important immunophenotypic, molecular genetic, and clinical differences, suggesting it is in fact most often a B-cell PTLD. Distinction between HL and HL-like PTLD may be important for clinical management and prognosis.
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