Lesser prairie-chicken (Tympanuchus pallidicinctus) populations have declined rangewide, and one of the principal causes is thought to be low nest success. Little is known about the relationship of vegetation structure and human intrusion to lesser prairie-chicken nest location and success. We conducted our study from 1997 to 2002 in southwestern Kansas, USA, on 2 sand-sagebrush (Artemisia filifolia) prairie areas managed for livestock production. We determined apparent nest success (26%) for 200 of 209 lesser prairie-chicken nests located. Nest sites had taller grass, greater sand-sagebrush density, and higher visual obstruction than random locations in the surrounding prairie. We recorded the distances from nests to 6 anthropogenic features (wellheads, buildings, improved roads, unimproved roads, transmission lines, center-pivot irrigation fields) to determine whether the features were related to nest location and success. Sand-sagebrush habitat around 5 of 6 features (all except unimproved roads) was avoided for 80 m (wellheads) to >1,000 m (buildings) by nesting lesser prairie-chickens, but distances to the features were not substantial predictors of apparent nest success. Grass height, sagebrush plant density, and sagebrush height were the most important vegetation characteristics influencing nest success.

https://www.fws.gov/southwest/es/documents/R2ES/LitCited/LPC_2012/Pitman_et_al_2005.pdf

Location and success of lesser prairie-chicken nests in relation to vegetation and human disturbance

High-frequency remote monitoring of large lakes with MODIS 500 m imagery

Mean annual concentration of \({\textrm{SO}}_{4}^{2-}\) in wet-only deposition has decreased between 1988 and 2006 at the paired watershed study at Bear Brook Watershed in Maine, USA (BBWM) due to substantially decreased emissions of SO2. Emissions of NOx have not changed substantially, but deposition has declined slightly at BBWM. Base cations, \({\textrm{NH}}_{4}^{+}\), and Cl − concentrations were largely unchanged, with small irregular changes of <1 μeq L − 1 per year from 1988 to 2006. Precipitation chemistry, hydrology, vegetation, and temperature drive seasonal stream chemistry. Low flow periods were typical in June–October, with relatively greater contributions of deeper flow solutions with higher pH; higher concentrations of acid-neutralizing capacity, Si, and non-marine Na; and low concentrations of inorganic Al. High flow periods during November–May were typically dominated by solutions following shallow flow paths, which were characterized by lower pH and higher Al and DOC concentrations. Biological activity strongly controlled \({\textrm{NO}}_{3}^{-}\) and K + . They were depressed during the growing season and elevated in the fall. Since 1987, East Bear Brook (EB), the reference stream, has been slowly responding to reduced but still elevated acid deposition. Calcium and Mg have declined fairly steadily and faster than \({\textrm{SO}}_{4}^{2-}\), with consequent acidification (lower pH and higher inorganic Al). Eighteen years of experimental treatment with (NH4)2SO4 enhanced acidification of West Bear Brook’s (WB) watershed. Despite the manipulation, \({\textrm{NH}}_{4}^{+}\) concentration remained below detection limits at WB, while leaching of \({\textrm{NO}}_{3}^{-}\) increased. The seasonal pattern for \({\textrm{NO}}_{3}^{-}\) concentrations in WB, however, remained similar to EB. Mean monthly concentrations of \({\textrm{SO}}_{4}^{2-}\) have increased in WB since 1989, initially only during periods of high flow, but gradually also during base flow. Increases in mean monthly concentrations of Ca2 + , Mg2 + , and K + due to the manipulation occurred from 1989 until about 1995, during the depletion of base cations in shallow flow paths in WB. Progressive depletion of Ca and Mg at greater soil depth occurred, causing stream concentrations to decline to pre-manipulation values. Mean monthly Si concentrations did not change in EB or WB, suggesting that the manipulation had no effect on mineral weathering rates. DOC concentrations in both streams did not exhibit inter- or intra-annual trends.

Twenty-year inter-annual trends and seasonal variations in precipitation and stream water chemistry at the Bear Brook Watershed in Maine, USA.

Rapid climate warming has resulted in shrub expansion, mainly of erect deciduous shrubs in the Low Arctic, but the more extreme, sparsely vegetated, cold and dry High Arctic is generally considered to remain resistant to such shrub expansion in the next decades. Dwarf shrub dendrochronology may reveal climatological causes of past changes in growth, but is hindered at many High Arctic sites by short and fragmented instrumental climate records. Moreover, only few High Arctic shrub chronologies cover the recent decade of substantial warming. This study investigated the climatic causes of growth variability of the evergreen dwarf shrub Cassiope tetragona between 1927 and 2012 in the northernmost polar desert at 83°N in North Greenland. We analysed climate-growth relationships over the period with available instrumental data (1950-2012) between a 102-year-long C. tetragona shoot length chronology and instrumental climate records from the three nearest meteorological stations, gridded climate data, and North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) indices. July extreme maximum temperatures (JulTemx), as measured at Alert, Canada, June NAO, and previous October AO, together explained 41% of the observed variance in annual C. tetragona growth and likely represent in situ summer temperatures. JulTemx explained 27% and was reconstructed back to 1927. The reconstruction showed relatively high growing season temperatures in the early to mid-twentieth century, as well as warming in recent decades. The rapid growth increase in C. tetragona shrubs in response to recent High Arctic summer warming shows that recent and future warming might promote an expansion of this evergreen dwarf shrub, mainly through densification of existing shrub patches, at High Arctic sites with sufficient winter snow cover and ample water supply during summer from melting snow and ice as well as thawing permafrost, contrasting earlier notions of limited shrub growth sensitivity to summer warming in the High Arctic. (Less)

High Arctic summer warming tracked by increased Cassiope tetragona growth in the world's northernmost polar desert

The lagoon system of Navachiste-Macapule is located in northern Mexico, in the state of Sinaloa, with an area of 24,000 ha. The main economic activity in the area is agriculture, and the lagoon lies next to the irrigation district ID-063 which covers 116,615 ha. The purpose of this study is to evaluate the levels of pollution generated by organochlorine pesticides (OC) in the surface sediments of the lagoon and in the agricultural drains of the ID-063 that are supposedly transported into the system as a result of agricultural activities and runoff from adjacent land. For this, between 2006 and 2007, 45 surface sediment samples were collected (warm dry, rainy and cold dry) from 15 sampling sites, during the three climatic seasons. Of these, eight were located inside the lagoon in marine conditions (salinity >31 PSU) and seven in the agricultural drains of the ID-063 in freshwater conditions (salinity <5 PSU). The average concentration of the OC in the sediments was 44.75 ng g − 1, among which the group of the alicyclic compounds presented the greatest concentrations. The average value of the total organic carbon (TOC) in the sediments of the system was 0.90%. The sediments collected inside the lagoon had an average OC concentration of 18.97 ng g − 1, and the predominant type of sediment was fine to very fine sand. The average OC concentration in the sediments collected in the agricultural drains was 75.69 ng g − 1, where fine sediments (silt) were predominant. The presence of methoxychlor, endrin and heptachlor suggested that these compounds were continuously used in the system, even though their use is forbidden in Mexico.

Pollution by organochlorine pesticides in Navachiste-Macapule, Sinaloa, Mexico.

The National Oceanic and Atmospheric Administration (NOAA) multibeam surveys within the US Exclusive Economic Zone (EEZ) are providing a new data base of bathymetric information significantly superior to existing bathymetric maps compiled from prior survey information. Surveys made with the new Sea Beam and Bathymetric Swath Survey System are intended to provide 100% coverage of selected areas of the continental shelf, slope, and upper rise off the west coast of the US. During the next 2 years, surveys will expand to Hawaii and Alaska. Areas were selected through a cooperative agreement between NOAA and the US Geological Survey (USGS). The intent of the program is to provide detailed bathymetry conducted in conformance with international map standards for use in making geologic interpretations and assessments in conjunction with the GLORIA image data acquired by USGS. The primary objective of the program is to provide high-resolution data to support the development and management of offshore resources, particularly within the US EEZ. Within NOAA, the data are to be used to provide new and revised map and chart products. Also, to maximize the utility of the surveys, arrangements are being sought to acquire other geophysical measurements and ancillary marine data in conjunction withmore » the bathymetric surveys Dissemination of the NOAA data is undecided due to national security concerns. However, efforts are underway in cooperation with the Department of Defense to devise a public product of value to scientific and industrial needs without compromising national security.« less

C. Andreasen

Papers

National Oceanic and Atmospheric Administration mapping surveys