Assessing the Impact of Land-Use Land-Cover Change on Stream Water and Sediment Yields at a Watershed Level Using SWAT

Flint River watershed is located in northern Alabama and southern Tennessee, USA and is home to several species of rare, threatened, or endangered plants and animals in a rapidly urbanizing area. Dominant land uses are forest and agricultural, with row crops and livestock production as major farm enterprises. Soil and Water Assessment Tool (SWAT), a deterministic hydrologic model that can predict hydrologic conditions over various temporal and spatial scales, was used to simulate the hydrologic response of the watershed to land-use/land cover (LULC) change. Analysis between observed and predicted stream flow demonstrated that the initial SWAT model run requires calibration of stream parameters in order to give a more accurate output from the model. The calibration was performed with sequential uncertainty fitting, ver. 2 (SUFI-2) in the SWAT Calibration Uncertainty Program. After calibration, stream sediment yield values were compared by sub-basin between a current (2001) and three future (2030) land use scenarios, in order to identify areas in the watershed that were the most susceptible to increased sediment yield in the future. The future growth scenarios (smart, plan and sprawl) were created using the ArcGIS extension, Prescott Spatial Growth Model. Sub-basins with the greatest sensitivity for larger sediment yields were identified and prioritized for conservation efforts.

Future Land-Use Land-Cover Scenarios for the Flint River Watershed in Northern Alabama Using the Prescott Spatial Growth Model

A changing mosaic of natural vegetation and human land uses has evolved within and around the Flint River Watershed (FRW) in Alabama and Tennessee over the past several decades. To determine the cause of change and linkage between human activities and environmental change can prove problematic. Subsequently, there is a need to produce projections of future environments based on planning instruments and socio-economic parameters. Scenarios of potential future land use land cover (LULC) change are required in order to better manage potential impacts on many environmental issues. This study creates future scenarios for the year 2030 from baseline land use of 2001, relative to three projected land use scenarios which include differences related to conservation, planning, and development. The future growth scenarios were created using the ArcGIS tool, Prescott Spatial Growth Model (PSGM). The model allows users to build different future growth scenarios based on socio-economic projections such as population, employment and other controlling factors. The simulation results indicate that LULC changes associated with future urbanization can increase by ~23% - 43% within the FRW, which will lead to significant environmental issues if not managed properly. The overall analysis and model results demonstrate the ability of future growth scenarios to explore and evaluate options for a future environment. Spatial modeling and analysis tools, such as PSGM, provide a powerful approach to evaluate potential impacts of LULC change in the future and should be used to manage urbanization in areas with more intense development.

Genetic outcomes from the translocations of the critically endangered woylie

Translocations are an important conservation strategy for many species. However simply observing demographic growth of a translocated population is not sufficient to infer species recovery. Adequate genetic representation of the source population（s） and their long-term viability should also be considered. The woylie Bettongia penicillata ogilbyi has been subject to more formal translocations for conservation than any other marsupial that, up until recently, has resulted in one of the most suc- cessful species recoveries in Australia. We used mitochondrial and nuclear DNA markers to assess the genetic outcomes of trans- located woylie populations. These populations have lost genetic variability, differentiated fxom their source population and the supplementation program on two island populations appears to have failed. We discuss the conservation implications that our re- suits have for managing threatened species, outline some general recommendations for the management of present and future translocations and discuss the appropriate sampling design for the establishment of new populations or captive breeding programs that may mitigate the genetic ＇erosion＇ seen in our study species. This research provides some practical outcomes and a pragmatic understanding of translocation biology. The findings are directly applicable to other translocation programs .

Biodiversity change in heathland and its relationships with shifting local fire regimes and native species expansion

Aims Understanding the relationships among disturbance,invasion and species change is essential for effective management of many sys-tems.We investigated relationships among fire history,invasion by a native tree species,Allocasuarina huegeliana,and diversity change to understand the potential drivers of plant community alteration in a complex and biodiverse system.Methods We used plant species surveys from 1983 and 2011 to quantify spe-cies loss/gain and thence compositional changes.Additionally,we surveyed population densities of the invasive species and collated long-term fire history data for each site.General linear models and non-parametric models were used to assess the strength of relation-ships between the three variables of interest.Important Findings Within the last 30 years,~11%of the plant species richness was lost from the reserve.At an individual site level,we found only a 4%average decrease in overall plant species richness,but large species losses and gains that imply considerable compositional shifts.Though such shifts might be expected over 30 years,many of the gained species were common,potentially opportunistic species,while those lost were often locally rare woody perennials.In addi-tion,gained species tended to be expanding their recorded range westward suggesting that they may be responding to the regional drying climate.The relationship between invasion density and spe-cies loss was strong over all spatial scales.We identified a poten-tial state change to dominance by the native invasive particularly as high densities prevented species gain at the site scale.In these extreme cases of high invasive density and high biodiversity loss,we argue that there may be a need to directly address the expanding native population.