Relationship between water quality, watermilfoil frequency, and weevil distribution in the State of Washington

During the summer of 1997, we surveyed 50 waterbodies in Washington State to determine the distribution of the aquatic weevil Euhrychiopsis lecontei Dietz. We collected data on water quality and the frequency of occurrence of watermilfoil species within selected watermilfoil beds to compare the waterbodies and determine if they were related to the distribution E. lecontei . We found E. lecontei in 14 waterbodies, most of which were in eastern Washington. Only one lake with weevils was located in western Washington. Weevils were associated with both Eurasian ( Myriophyllum spicatum L.) and northern watermilfoil ( M. sibiricum K.). Waterbodies with E. lecontei had significantly higher ( P < 0.05) pH (8.7 ± 0.2) (mean ± 2SE), specific conductance (0.3 ± 0.08 mS cm -1 ) and total alkalinity (132.4 ± 30.8 mg CaCO 3 L -1 ). We also found that weevil presence was related to surface water temperature and waterbody location ( = 24.3, P ≤ 0.001) and of all the models tested, this model provided the best fit (Hosmer- Lemeshow goodness-of-fit = 4.0, P = 0.9). Our results suggest that in Washington State E. lecontei occurs primarily in eastern Washington in waterbodies with pH ≥ 8.2 and specific conductance ≥ 0.2 mS cm -1 . Furthermore, weevil distribution appears to be correlated with waterbody location (eastern versus western Washington) and surface water temperature

Non-target Impacts to Eelgrass from Treatments to Control Spartina in Willapa Bay, Washington

Four methods to control the smooth cordgrass Spartina (Spartina alterniflora) and the footwear worn by treatment personnelat several sites in Willapa Bay, Washington were evaluatedto determine the non-target impacts to eelgrass (Zostera japonica). Clone-sized infestations of Spartina were treated bymowing or a single hand-spray application of Rodeo® formulatedat 480 g L-1acid equivalence (ae) of the isopropylaminesalt of glyphosate (Monsanto Agricultural Co., St. Louis, MO;currently Dow AgroSciences, Indianapolis, IN) with the nonionic surfactant LI 700® (2% v/v) or a combination of mowing and hand spraying. An aerial application of Rodeo® with X-77 Spreader® (0.13% v/v) to a 2-ha meadow was also investigated. Monitoring consisted of measuring eelgrass shoot densities and percent cover pre-treatment and 1-yr post-treatment. Impacts to eelgrass adjacent to treated clones were determined 1 m from the clones and compared to a control 5-m away. Impacts from footwear were assessed at 5 equidistant intervals along a 10-m transect on mudflat and an untreated control transect at each of the three clone treatment sites. Impacts from the aerial application were determined by comparing shoot densities and percent cover 1, 3 and 10 m from the edge of the treated Spartina meadow to that at comparable distances from an untreated meadow. Methods utilized to control Spartina clones did not impact surrounding eelgrass at two of three sites. Decreases in shoot densities observed at the third site were consistent across treatments. Most impacts to eelgrass from the footwear worn by treatment personnel were negligible and those that were significant were limited to soft mud substrate. The aerial application of the herbicide was associated with reductions in eelgrass (shoot density and percent cover) at two of the three sampling distances, but reductions on the control plot were greater. We conclude that the unchecked spread of Spartina is a far greater threat to the survival and health of eelgrass than that from any of the control measures we studied. The basis for evaluating control measures for Spartina should be efficacy and logistical constraints and not impacts to eelgrass. PDF is 7 pages

Habitat Requirements of Breeding Scaled Quail in Texas

Habitat variables were correlated with scaled quail (Callipep/,a squamata) whistle counts on 133 (24-km) random transects in Texas. Whether or not a particular habitat variable was correlated with whistle counts appeared to depend upon abundance and distribution of other habitat types and structural features. If \u3e= 1 requisite for quail survival and reproduction (food, water, cover, nest sites) was limited, habitat types and structural features were usually positively correlated with whistle counts (P \u3c 0.10). Conversely, abundant habitat types which did not provide all of these requisites were usually negatively correlated with whistle counts (P\u3c 0.10). Correlations indicated breeding scaled quail selected the more dense, shorter shrub habitats. Mesquite (Prosopsis spp.) habitats were especially important to scaled quail in the Trans-Pecos region

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Classification, inventory, analysis, and evaluation of the breeding habitat of the mourning dove (Zenaida macroura) in Texas

Vita.The objectives of this study were to develop standardized techniques for evaluating mourning dove breeding habitat along call-count transects from a vehicle ("windshield approach"), and identify those habitat parameters correlated with dove densities obtained from call-count surveys in Texas. A habitat classification was developed in which 562 habitat types were recognized. Habitat type was defined as a unique combination of ground cover height and composition, canopy composition, and spatial distribution (physiognomic class). Structural features (fences, powerlines, windbreaks, etc.) were also considered. Call-count and habitat surveys were conducted on 133 random transects in Texas between 20 May and 10 June 1976. Linear distance of each habitat type intersecting a transect and number of structural features within 0.8 km were recorded. Habitat parameters were analyzed for correlations with call counts using stepwise multiple regression. Habitat interspersion and diversity were included. Analyses were conducted by transect interval (1.6 km) and transect within ecological areas and statewide. Simplifications of the habitat classification were evaluated based on R-squares and number of parameters within models. The simplified habitat classification (26 habitat types) including physiognomic class with canopy composition and cropland divisions was selected. Estimates of ground cover height and composition were not necessary to effectively evaluate breeding dove habitat.

Classification, inventory, analysis, and evaluation of the breeding habitat of the mourning dove (Zenaida macroura) in Texas

Vita.The objectives of this study were to develop standardized techniques for evaluating mourning dove breeding habitat along call-count transects from a vehicle ("windshield approach"), and identify those habitat parameters correlated with dove densities obtained from call-count surveys in Texas. A habitat classification was developed in which 562 habitat types were recognized. Habitat type was defined as a unique combination of ground cover height and composition, canopy composition, and spatial distribution (physiognomic class). Structural features (fences, powerlines, windbreaks, etc.) were also considered. Call-count and habitat surveys were conducted on 133 random transects in Texas between 20 May and 10 June 1976. Linear distance of each habitat type intersecting a transect and number of structural features within 0.8 km were recorded. Habitat parameters were analyzed for correlations with call counts using stepwise multiple regression. Habitat interspersion and diversity were included. Analyses were conducted by transect interval (1.6 km) and transect within ecological areas and statewide. Simplifications of the habitat classification were evaluated based on R-squares and number of parameters within models. The simplified habitat classification (26 habitat types) including physiognomic class with canopy composition and cropland divisions was selected. Estimates of ground cover height and composition were not necessary to effectively evaluate breeding dove habitat.