Dueling Land Ethics: Uncovering Agricultural Stakeholder Mental Models to Better Understand Recent Land Use Conversion

The aim of this paper is to investigate how alternative land ethics of agricultural stakeholders may help explain recent land use changes. The paper first explores the historical development of the land ethic concept in the United States and how those ethics have impacted land use policy and use of private lands. Secondly, primary data gathered from semi-structured interviews of farmers, ranchers, and influential stakeholders are then analyzed using stakeholder analysis methods to identify major factors considered in land use decisions, priorities of factors of each group, and to define relevant mental models describing each group’s view of the land ethic concept. Results show that these stakeholder groups prioritize land use factors qualitatively differently and possess strikingly different land ethics. It is concluded that shifts in stakeholder land ethics have contributed to recent land use changes. Lastly, we discuss how current agricultural policy sends mixed signals about preferred land use and the potential ramifications based on the different land ethics we’ve described.     

Monitoring seasonal bat activity on a coastal barrier island in Maryland, USA

Research on effects of wind turbines on bats has increased dramatically in recent years because of significant numbers of bats killed by rotating wind turbine blades. Whereas most research has focused on the Midwest and inland portions of eastern North America, bat activity and migration on the Atlantic Coast has largely been unexamined. We used three long-term acoustic monitoring stations to determine seasonal bat activity patterns on the Assateague Island National Seashore, a barrier island off the coast of Maryland, from 2005 to 2006. We recorded five species, including eastern red bats (Lasiurus borealis), big brown bats (Eptesicus fuscus), hoary bats (Lasiurus cinereus), tri-colored bats (Perimyotis subflavus), and silver-haired bats (Lasionycteris noctivagans). Seasonal bat activity (number of bat passes recorded) followed a cosine function and gradually increased beginning in April, peaked in August, and declined gradually until cessation in December. Based on autoregressive models, inter-night bat activity was autocorrelated for lags of seven nights or fewer but varied among acoustic monitoring stations. Higher nightly temperatures and lower wind speeds positively affected bat activity. When autoregressive model predictions were fitted to the observed nightly bat pass totals, model residuals >2 standard deviations from the mean existed only during migration periods, indicating that periodic increases in bat activity could not be accounted for by seasonal trends and weather variables alone. Rather, the additional bat passes were attributable to migrating bats. We conclude that bats, specifically eastern red, hoary, and silver-haired bats, use this barrier island during migration and that this phenomenon may have implications for the development of near and offshore wind energy.     

The influence of nitrate on selenium in irrigated agricultural groundwater systems

Selenium (Se) contamination of groundwater is an environmental concern especially in areas where aquifer systems are underlain by Se-bearing geologic formations such as marine shale. This study examined the influence of nitrate (NO?) on Se species in irrigated soil and groundwater systems and presents results from field and laboratory studies that further clarify this influence. Inhibition of selenate (SeO?) reduction in the presence of NO? and the oxidation of reduced Se from shale by autotrophic denitrification were investigated. Groundwater sampling from piezometers near an alluvium-shale interface suggests that SeO? present in the groundwater was due in part to autotrophic denitrification. Laboratory shale oxidation batch studies indicate that autotrophic denitrification is a major driver in the release of SeO? and sulfate. Similar findings occurred for a shale oxidation flow-through column study, with 70 and 31% more reduced Se and S mass, respectively, removed from the shale material in the presence of NO? than in its absence. A final laboratory flow-through column test was performed with shallow soil samples to assess the inhibition of SeO? reduction in the presence of NO?, with results suggesting that a concentration of NO? of approximately 5 mg L or greater will diminish the reduction of SeO?. The inclusion of the fate and transport of NO? and dissolved oxygen is imperative when studying or simulating the fate and transport of Se species in soil and groundwater systems.     

Molecular characterization of symbiotic algae (Symbiodinium spp.) in soritid foraminifera (Sorites orbiculus) and a scleractinian coral (Orbicella annularis) from St John,US Virgin Islands

The exchange of Symbiodinium symbionts among scleractinian and soritid hosts could facilitate acclimatization to changing conditions by establishing novel symbiotic unions better tuned to prevailing conditions. In this study, we compare the communities of Symbiodinium spp. in neighboring populations of Orbicella annularis and Sorites orbiculus from St. John, US Virgin Islands, using operational taxonomic unit (OTU) clustering of cloned internal transcribed spacer 2 (ITS-2) rDNA sequences. We tested for partitioning of Symbiodinium OTUs by host and depth within and between two sites to explore the potential for symbiont exchange between hosts and light-dependent microhabitat specialization. An apparent lack of overlap in Symbiodinium communities (13 OTUs representing 7 clades) hosted by O. annularis and S. orbiculus suggests that exchange among these hosts does not occur. A low number of novel clade G ITS-2 sequences were found in one O. annularis and one S. orbiculus. A phylogenetic analysis of these sequences revealed them to be sub-clade G2 Symbiodinium, which are most commonly hosted by excavating clionid sponges. A permutational MANOVA revealed within host differences in the partitioning of Symbiodinium OTUs by site but not depth. This finding highlights the potential roles of either dissimilar environmental conditions between sites, or at least partial separation between populations, in determining the types of Symbiodinium contained in different hosts on a spatial scale of a few kilometers.