Influence of Habitat Type and Prescribed Burning on Feral Swine Depredation of Artificial Quail Nests

Feral swine (Sus scrofa) have increased both spatially and numerically in the Rolling Plains of northwest Texas. Resource managers have little information on the interrelationships between feral swine and native species such as the northern bobwhite (Colinus virginianus). Nest predation by feral swine could adversely affect bobwhite reproduction. Honey mesquite (Prosopis glandulosa) and redberry juniper (Juniperus pinchotii) are the dominant woody plants in northwestern Texas and prescribed burning is used to manage both species. Two experiments were conducted to determine the extent of feral swine depredation on artificial quail nests. In 1992-93, we monitored nest loss in mesquite and juniper habitats for six weeks. Total depredation reached 85 and 98% after three and six weeks respectively, during 1992, compared to 60 and 92% in 1993. Feral swine depredation of artificial bobwhite nests was 33% across years and was evenly distributed between vegetation types. During three-week periods in June and July 1994, depredation was greater (P\u3c0.001) in an unburned (90%) pasture than in unburned areas within a burned (32%) pasture. Decreased predator activity in the burned pasture was probably due to temporary prey displacement and less forage. Feral swine depredation of artificial bobwhite nests was 14% in 1994. Feral swine could potentially have negative impacts for northern bobwhites in mesquite and juniper habitats of northwest Texas

Utility of Satellite and Aerial Images for Quantification of Canopy Cover and Infilling Rates of the Invasive Woody Species Honey Mesquite (Prosopis Glandulosa) on Rangeland

Woody plant encroachment into grasslands and rangelands is a world-wide phenomenon but detailed descriptions of changes in geographical distribution and infilling rates have not been well documented at large land scales. Remote sensing with either aerial or satellite images may provide a rapid means for accomplishing this task. Our objective was to compare the accuracy and utility of two types of images with contrasting spatial resolutions (1-m aerial and 30-m satellite) for classifying woody and herbaceous canopy cover and determining woody infilling rates in a large area of rangeland (800 km<sup>2</sup>) in north Texas that has been invaded by honey mesquite (<em>Prosopis glandulosa</em>). Accuracy assessment revealed that the overall accuracies for the classification of four land cover types (mesquite, grass, bare ground and other) were 94 and 87% with kappa coefficients of 0.89 and 0.77 for the 1-m and 30-m images, respectively. Over the entire area, the 30-m image over-estimated mesquite canopy cover by 9 percentage units (10 <em>vs.</em> 19%) and underestimated grass canopy cover by the same amount when compared to the 1-m image. The 30-m resolution image typically overestimated mesquite canopy cover within 225 4-ha sub-cells that contained a range of mesquite covers (1–70%) when compared to the 1-m image classification and was not suitable for quantifying infilling rates of this native invasive species. Documenting woody and non-woody canopy cover on large land areas is important for developing integrated, regional-scale management strategies for rangeland and grassland regions that have been invaded by woody plants

C\u3csub\u3e3\u3c/sub\u3e Perennial Grass Dominates Mixed C\u3csub\u3e3\u3c/sub\u3e/C\u3csub\u3e4\u3c/sub\u3e Grasslands After Invasion by a C\u3csub\u3e3\u3c/sub\u3e Woody Sprouter

Honey mesquite (Prosopis glandulosa) encroachment has resulted in decreased C4 mid-grass production and increased C3 mid-grass in the Southern Great Plains of the US. Woody legumes have had similar effects in Africa, Australia, and South America. Prosopis initially facilitates Texas wintergrass (Nassella leucotricha) growth under canopies, in part because N-fixation by this woody legume enriches subcanopy soils, favoring C3 species. As stand density increases, Nassella extends into interspaces between trees as well. Here we report Nassella responses in several studies that either reduced Prosopis to indirectly impact Nassella or treated Nassella directly. In a 9-year study following mechanical top-kill of Prosopis, Nassella increased production for the first 3 years before slowly declining to pre-treatment levels. C4 mid-grass production increased, but was limited to only a third of its potential by drought and Prosopis regrowth. Following a root-killing treatment of Prosopis, Nassella production and total herbaceous production were greater in treated than untreated intercanopy and subcanopy microsites 1-yr post-treatment. Nassella and perennial grass production declined in treated microsites 2-yrs post-treatment; however, total herbaceous production remained greater in treated than untreated microsites due to increased annual forb production. Targeted grazing reduced Nassella cover and reproduction, but increased bare ground. Multiple-stemmed Prosopis with low-hanging limbs protected Nassella, thus limiting targeted grazing success when trees were not removed. The Prosopis/Nassella state appears to be resistant to change and may permanently limit transition back to C4 grassland unless Prosopis is root-killed, though our results indicate that even root-killing Prosopis does not guarantee an immediate increase in C4 production. If so, managing Prosopis height and canopy cover, C:N ratios of the vegetative layer, and grazing Nassella during peak production and nutritional quality may allow profitable production until anthropogenic or natural processes result in large scale mortality of the Prosopis overstory

INTEC Groundwater Monitoring Report 2006

This report summarizes 2006 perched water and groundwater monitoring activities at the Idaho Nuclear Technology and Engineering Center (INTEC) located at the Idaho National Laboratory (INL). During 2006, groundwater samples were collected from a total of 22 Snake River Plain Aquifer (SRPA) monitoring wells, plus six aquifer wells sampled for the Idaho CERCLA Disposal Facility (ICDF) monitoring program. In addition, perched water samples were collected from 21 perched wells and 19 suction lysimeters. Groundwater and perched water samples were analyzed for a suite of radionuclides and inorganic constituents. Laboratory results in this report are compared to drinking water maximum contaminant levels (MCLs). Such comparison is for reference only and it should be noted that the Operable Unit 3-13 Record of Decision does not require that perched water comply with drinking water standards

Design and Development of On-orbit Servicing CubeSat-class Satellite

The long term vision of the Naval Academy Satellite Team for Autonomous Robotics (NSTAR) is to lower both the risk and cost of on-orbit space system construction and repair through the use of a CubeSat robotic arm system. NSTAR developments will enable space agencies and private companies to construct large, complex structures in space at a reduced cost with greater diagnostic assessment ability. Robotic Experimental Construction Satellite (RECS) is designed as NSTAR’s second project iteration and works to meet five different capabilities for semi-autonomous orbit assembly. RECS is a 3U CubeSat with two extendable robotic arms, each with six degrees of freedom. In coordination with the launch manifest, RECS has been designed, completed, and is awaiting launch to the ISS where it will conduct testing. This type of on-orbit demonstration has never been completed on CubeSat-scale systems. A successful mission will indicate entry into a new frontier of satellites, where space systems remain in operation longer, missions are of lower cost, and the ability to complete space-based scientific research is expanded. This paper provides the details of the design and capabilities of the NSTAR system