No description available.

Grassland bird species have declined more than birds of any other region in North America, and industrial development may exert additional pressure on these species. I evaluated the effects of natural gas infrastructure on the relative abundances of grassland songbirds in southeastern Alberta, Canada using point counts at sites with well densities ranging from 0 to 20 per 1×1 mile. Generalized Linear Mixed Models were used to evaluate effects of infrastructure on birds, and parsimonious models were selected using Akaike’s Information Criterion. Vegetation near infrastructure was shorter and sparser than locations farther away, but was unlikely to have driven responses to infrastructure by birds. Gas wells may have acted as “artificial shrubs” attracting species such as vesper sparrow (Pooecetes gramineus) and western meadowlark (Sturnella neglecta) that use vegetation for perching, while other species, such as Sprague’s pipit (Anthus spragueii) and chestnut-collared longspur (Calcarius ornatus), had higher abundances farther from wells.

Grassland bird species have declined more than birds of any other region in North America, and industrial development may exert additional pressure on these species. I evaluated the effects of natural gas infrastructure on the relative abundances of grassland songbirds in southeastern Alberta, Canada using point counts at sites with well densities ranging from 0 to 20 per 1×1 mile. Generalized Linear Mixed Models were used to evaluate effects of infrastructure on birds, and parsimonious models were selected using Akaike’s Information Criterion. Vegetation near infrastructure was shorter and sparser than locations farther away, but was unlikely to have driven responses to infrastructure by birds. Gas wells may have acted as “artificial shrubs” attracting species such as vesper sparrow (Pooecetes gramineus) and western meadowlark (Sturnella neglecta) that use vegetation for perching, while other species, such as Sprague’s pipit (Anthus spragueii) and chestnut-collared longspur (Calcarius ornatus), had higher abundances farther from wells.

No description available.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2007. / Thesis documentation sheet inserted. Includes appendix of four papers and manuscripts co-authored with others. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.

Thesis (Ph.D.) - University of Glasgow, 1996. / Ph.D. thesis submitted to the Environmental Sciences Department, Scottish Agricultural College, 1996. Includes bibliographical references. Print version also available.

Thesis (M.S.)--Montana State University, 2003. / Title from PDF title page (viewed Jan. 6, 2005). Includes bibliographical references (p. 56-63).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 102-105.

Thesis (M.S.)--University of North Texas, Dec., 2009. / Title from title page display. Includes bibliographical references.

Semi-natural grasslands are one of the most threatened habitats in Scandinavia. The grassland in this study is situated in the northern part of the nature preserve of Haväng och Vitemölla strandbackar in the province of Skåne and consists of grey dunes and a pasture which partly consists of calcareous grassland and the vegetation type sand steppe which is very rare in Sweden. There are several threatened plants in the area and during the summer of 2017 their distribution was registered to be able to protect them during conservation management. The results showed that most of the area contained important species and the most important areas to protect were the sand steppe areas. This is probably due to the dry, sandy, calcareous and nutrient poor conditions in these areas which many of the threatened plants are connected to. Most of the threatened plants were found in abundance in the area but have a limited distribution in Sweden. The population of Eryngium maritimum however was very small and is threatened by extinction. The plants in the area are threatened by a long-term process of nutrient enrichment and continuous leakage of calcium which may lead to lower pH and a more nutrient rich soil which leads to a higher availability of phosphorous. This may lead to a change in species composition and loss of species richness. Continuous grazing, soil disturbance to expose lime-rich sand and also removal of litter to minimize the nutrient levels are needed to maintain favorable conditions in the area. However, the number of important species requires attention and careful planning, especially in the sand steppe areas. / Ängs-och hagmarker är några av de mest hotade och viktiga habitattyperna i Skandinavien. Gräsmarken som studerades i detta projekt ligger i norra delarna av naturreservatet Haväng och Vitemölla strandbackar i Skåne och består av gräsbevuxna sanddyner och en hage med inslag av kalkgräsmark och marktypen sandstäpp som är väldigt sällsynt i Sverige. I reservatet finns flera skyddsvärda kärlväxter och under sommaren 2017 kartlades deras utbredning för att bättre kunna skydda dem vid skötsel- och restaureringsåtgärder. Resultatet visade att större delen av området innehåller skyddsvärda arter och att de mest skyddsvärda områdena var de delar av området där det fanns inslag av sandstäpp. Detta beror med stor sannolikhet på att de flesta skyddsvärda arterna i området var knutna till de torra, sandiga, kalkhaltiga och näringsfattiga förhållanden som rådde där. De flesta skyddsvärda arter fanns i stora antal i det undersökta området men har en begränsad utbredning i Sverige. Populationen av Eryngium maritimum var dock så litet att det hotas av utrotning. I övrigt hotas växterna i området på längre sikt av ökad tillsättning av näringsämnen och långvarig urlakning av kalk. Detta kan leda till lägre pH och mer näringsrik mark och gör att den nuvarande artsammansättningen kan försvinna och ersättas. För att området ska fortsätta ha en gynnsam status kommer det krävas fortsatt bete, skapande av sandblottor för att röra upp kalkrik sand samt åtgärder så som avlägsnande av förna och ytskikt för att hålla nere näringshalten. Det stora antalet rödlistade och skyddsvärda arter i området gör dock att det krävs varsamhet och noggrann planering vid en åtgärd, framför allt i sandstäppsområdena.