Dissertations / Theses: 'Grassland ecology'

1

Wang, Zhi-gang. "Comparative ecology of pauciennials in chalk grassland." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315978.

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Zaloumis, Nicholas Paul. "South African grassland ecology and its restoration." Master's thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/6629.

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The aim of this study is to investigate how human related disturbances affect mesic grasslands. I identified what was lost from the system after a disturbance and what biological constraints ecologists and managers will face when approaching their restoration. I then investigated biological limitations to grassland restoration by attempting species reintroduction into secondary grasslands and exploring the interaction between grasses and forbs.

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Hadden, Susan A. "Composition and ecology of the flora and fauna of remnant native grasslands of the western basalt plains and northern plains of Victoria : implications for management on private property." Thesis, Federation University Australia, 1998. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/157195.

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"This thesis investigated a) the effects of the removal of grazing on the botanical composition, structure and biomass of two long-grazed species-rich grassland remnants, b) the habitat use and requirements of the ground-dwelling mammal, reptile and amphibian fauna and c) the composition, and abundance of the beetle, ant and spider assemblages."
Doctor of Philosophy

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Ismail, A. "Ecology and toxicology of arsenic in contaminated grassland." Thesis, University of Essex, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376741.

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Baharith, Osama. "Ecological studies on some grassland Auchenorrhyncha." Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254616.

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Wright, Philip John. "Population ecology of Lasius flavius F. on chalk grassland." Thesis, Goldsmiths College (University of London), 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394318.

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Lasius flavus F. is a common ant species on chalk grasslands in the south of England. This thesis examines the effects of the management regimes and environmental conditions of these grasslands, on the characteristics of the ant populations. The null hypothesis of the study was that the characteristics of L. flavus populations are not significantly affected by variation in: 1) management procedures, 2) the physical environment, 3) the biological environment. The ant populations, management regimes and environmental characteristics of twenty sample areas were investigated and subjected to intensive analysis to examine this hypothesis. The null hypothesis was rejected. The population of ants that an area of chalk grassland supports, depends on both the management of that area and the environmental conditions. In the short term (2 to 4 years) more intense management leads to significant reductions in the sizes of the soil mounds built by the ant colonies, and reductions in the sexual productivity and sexual investment ratios of the colonies. In the longer term (over 10 years) the density of mounds is also reduced. The most important environmental characteristic of the grasslands is the soil water regime. Drier areas support a lower density of colonies with smaller mounds. The numbers of root aphids (the major food source of the ant) are reduced by increased grazing intensity. Other invertebrate groups are also affected by the management regime and the physical environment of the sample areas.

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Herse, Mark Richard. "Landscape ecology of two species of declining grassland sparrows." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/35786.

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Master of Science
Department of Biology
Alice Boyle
Species extinctions over the past two centuries have mainly been caused by habitat destruction. Landscape change typically reduces habitat area, and can fragment contiguous habitat into remnant patches that are more subject to anthropogenic disturbance. Furthermore, changes in the landscape matrix and land-use intensification within remaining natural areas can reduce habitat quality and exacerbate the consequences of habitat loss and fragmentation. Accordingly, wildlife conservation requires an understanding of how landscape structure influences habitat selection. However, most studies of habitat selection are conducted at fine spatial scales and fail to account for landscape context. Temperate grasslands are a critically endangered biome, and remaining prairies are threatened by woody encroachment and disruptions to historic fire-grazing regimes. Here, I investigated the effects of habitat area, fragmentation, woody cover, and rangeland management on habitat selection by two species of declining grassland-obligate sparrows: Henslow’s Sparrows (Ammodramus henslowii) and Grasshopper Sparrows (A. savannarum). I conducted >10,000 bird surveys at sites located throughout eastern Kansas, home to North America’s largest remaining tracts of tallgrass prairie, during the breeding seasons of 2015 and 2016. I assessed the relative importance of different landscape attributes in determining occurrence and within-season site-fidelity of Henslow’s Sparrows using dynamic occupancy models. The species was rare, inhabited <1% of sites, and appeared and disappeared from sites within and between seasons. Henslow’s Sparrows only settled in unburned prairie early in spring, but later in the season, inhabited burned areas and responded to landscape structure at larger scales (50-ha area early in spring vs. 200-ha during mid-season). Sparrows usually settled in unfragmented prairie, strongly favored Conservation Reserve Program (CRP) fields embedded within rangeland, avoided trees, and disappeared from hayfields after mowing. Having identified fragmentation as an important determinant of Henslow’s Sparrow occurrence, I used N-mixture models to test whether abundance of the more common Grasshopper Sparrow was driven by total habitat area or core habitat area (i.e. grasslands >60 m from woodlands, croplands, or urbanized areas). Among 50-ha landscapes containing the same total grassland area, sparrows favored landscapes with more core habitat, and like Henslow’s Sparrows, avoided trees; in landscapes containing ~50–70% grassland, abundance decreased more than threefold if half the grassland area was near an edge, and the landscape contained trees. Effective conservation requires ensuring that habitat is suitable at spatial scales larger than that of the territory or home range. Protecting prairie remnants from agricultural conversion and woody encroachment, promoting CRP enrollment, and maintaining portions of undisturbed prairie in working rangelands each year are critical to protecting threatened grassland species. Both Henslow’s Sparrows and Grasshopper Sparrows were influenced by habitat fragmentation, underscoring the importance of landscape features in driving habitat selection by migratory birds. As habitat loss threatens animal populations worldwide, conservation efforts focused on protecting and restoring core habitat could help mitigate declines of sensitive species.

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Bossenbroek, Jonathan Mark. "Spatial structure and scaling of beetle, bird and plant communities in North American grasslands." Access citation, abstract and download form; downloadable file 10.52 Mb, 2004. http://wwwlib.umi.com/dissertations/fullcit/3131657.

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Mello, Maeve Brito de. "Studies on the structure of grassland spider communities." Thesis, University of Sunderland, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241504.

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Blake, Shona. "Effects of management practices on the ground beetle assemblages of grassland and related habitats (Coleoptera: Carabidae)." Thesis, Connect to e-thesis, 1996. http://theses.gla.ac.uk/702/.

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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.

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Pagnotta, Mario A. "The ecology and ecological genetics of pasture legumes in Syria." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292668.

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Dalgleish, Harmony J. "Belowground bud banks as regulators of grassland dynamics." Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/312.

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Turnbull, Lindsay Ann. "The role of spatial processes in a limestone grassland." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286743.

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Peet, Nicholas B. "Biodiversity and the management of tall grassland in Nepal." Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267318.

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Tolsma, Arn Douwe. "The Effects of fire and grazing on the energy reserves of resprouting plants in Victoria's alpine grasslands /." Connect to thesis, 2002. http://eprints.unimelb.edu.au/archive/00000331.

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Lynas, P. "The ecology of skylarks Alauda arvensis in grassland dominated farmland." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426765.

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Gordon, Caleb Edward. "Community ecology and management of wintering grassland sparrows in Arizona." Diss., The University of Arizona, 1999. http://hdl.handle.net/10150/283995.

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This dissertation presents a four year field study on the movement patterns, community dynamics, and management of granivorous wintering grassland sparrows in Arizona. Chapter one focuses on within winter, local scale movement patterns. Recapture statistics and radiotelemetry both showed strong interspecific differences in movement, consistent with the idea that these species may partition niche space according to the regional coexistence mechanism. Both techniques ranked species from most to least sedentary as follows: Cassin's and Grasshopper sparrows, Baird's, Vesper, and Savannah and Brewer's sparrows. Data also indicated that fixed home range movements, and within-species constancy of movement behavior across years and study sites are generally the rule in this group. Correlations between bird abundance and summer rainfall suggest that movement may constrain large scale habitat selection processes. Chapter two presents larger scale movement data from grassland sparrows, along with a general discussion of facultative migration in birds. High between-year abundance fluctuations and low and variable rates of between-year recapture suggest that facultative migration strategies may be the rule in grassland sparrows. The use of alternative wintering sites by individual Grasshopper Sparrows provides direct evidence of limited facultative migration behavior. These patterns contrast with the largely non-facultative migration strategies that are the rule in birds. The evolution of facultative migration strategies is linked with unpredictable temporal variation in the spatial distribution of habitat conditions in the landscape. Chapter three presents three years of data on the effects of spring/summer burning and cattle grazing on wintering grassland sparrows. Vesper and Savannah sparrows responded positively to fire, while Cassin's Sparrows responded negatively. The ecologically and geographically restricted Baird's and Grasshopper sparrows utilized burned areas during the first post-bum winter and did not significantly respond to fire. Both Ammodramus sparrows also utilized the grazed pasture; they were more abundant there than in the ungrazed study area in one year. While field observations and a prior study suggest that heavy grazing can have a strong detrimental effect on Ammodramus sparrows, the results of this study suggest that moderate cattle grazing may be compatible with the conservation of these species.

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Jones-Walters, Lawrence Merlin. "The management of chalk grassland for the conservation of invertebrates." Thesis, Birkbeck (University of London), 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281807.

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Kell, Gladie Victoria. "Agro-environmental factors influencing leatherjacket (Diptera: Tipulidae) populations in grassland." Thesis, Queen's University Belfast, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356935.

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Woldu, Zerihun. "Variation in grassland vegetation on the central plateau of Shewa, Ethiopia in relation to edaphic factors and grazing conditions /." Vaduz : J. Cramer, 1985. http://catalog.hathitrust.org/api/volumes/oclc/12384853.html.

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21

Aplin, David. "The effects of temporal heterogeneity in nutrient supply on grassland species." Thesis, University of Sussex, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249098.

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22

Mahdi, Abdul-Khaliq Saleh. "The plant ecology of limestone grassland community : spatial organization and coexistance." Thesis, University of Sheffield, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358966.

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23

Gustavsson, Eva. "Grassland plant diversity in relation to historical and current land use /." Uppsala : Dept. of Ecology, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/2007106.pdf.

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GATTI, RENATA. "Ecology and management of grassland in Umbria-Marches Apennine (central Italy)." Doctoral thesis, Università degli Studi di Camerino, 2009. http://hdl.handle.net/11581/401749.

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The grasslands, like the majority of the terrestrial systems, are complex ecosystems and such complexity comes from the high number of biotic and abiotic elements which form this systems and from the interactions between the same elements, which could vary in time and space their nature and intensity. Keeping attention to this complexity and knowing that there is an equilibrium state in which the plant community has the maximum possible number of species, for a certain soil-climate context, this research work is centred on the description of the components of the grassland ecosystem, of the relations which exist between them and on the possible way of management, to achieve improvements in the future, in terms of productivity of phytocoenosis, of soil defending, of biodiversity conservation and also in terms of improving the life conditions of human population. In particular, the main target of this phD was to create an exhaustive knowledge structure about Apennines grasslands, because until now, all the studies made were partial, tending to characterize the herbaceous communities from a phytosociological viewpoint, but not ecological-functional. Moreover, considering the size of the study area and the complexity of the research and of the management of grassland ecosystems, we thought to share the research work in the three years, the timing and the operations. In fact, the research plan was structured like a ''pyramid'' at the base of which there is the phytosociological research which is the support to all the other studies, while regarding on the timing we decided to concentrate each year in a bioclimatic belt, following this scheme: 1th year: âˆ’ bibliography research âˆ’ phytosociological survey of grassland of higher mesotemperate and lower supratemperate belts âˆ’ set up a sampling method for the ecological survey 2th year: âˆ’ phytosociological survey of grassland of higher supratemperate belt âˆ’ Ecological structure analysis of grassland of higher mesotemperate and lower supratemperate belts âˆ’ sinecological analysis of grassland of higher mesotemperate and lower supratemperate belts âˆ’ analysis of the vegetation for a zootechnical characterization of grasslands of higher mesotemperate and higher/lower supratemperate belts 3th year: âˆ’ phytosociological survey of grassland of orotemperate and criotemperate belts âˆ’ ecological structure analysis of grassland of higher supratemperate belts âˆ’ sinecological analysis of grassland of higher supratemperate belt âˆ’ zootechnical characterization of grassland of higher mesotemperate and higher/lower supratemperate belts [...] In the three years it was possible to finish all the phytosociological, ecological and zootechnical researches for the grasslands of higher mesotemperate and lower/higher supratemperate belts; then it was possible to implement phytosociological and sinecological knowledges of the grasslands of orotemperate belt and to realize a phytosociological placement of the herbaceous commmunities of criotemperate belt.

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Slaviero, Antonio <1986&gt. "Ecology and conservation strategies of target dry grassland orchid species (Orchidaceae)." Doctoral thesis, Università Ca' Foscari Venezia, 2015. http://hdl.handle.net/10579/8345.

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A causa del loro elevato livello di specializzazione ecologica, le Orchidaceae sono specie altamente vulnerabili e minacciate a scala globale ma anche bioindicatori dello stato degli habitat in cui vivono. Al fine di salvaguardare la biodiversità si rende necessario un approccio conservativo basato sulla conoscenza dell’ecologia delle specie, degli habitat in cui vivono e dei rapporti con altri organismi. Questa tesi considera tre orchidee (A. morio; H. adriaticum, O. sphegodes) quali target di studio per comprendere quali fattori ecologici siano i driver della loro fitness in un habitat particolarmente ricco di specie ma anche minacciato a livello europeo, la prateria arida semi-naturale su substrato calcareo. Vengono analizzati la struttura della vegetazione, i rapporti con i pronubi, la topografia locale e l’ambiente edafico, ottenendo interessanti pattern rispetto alla copertura e fitness riproduttiva delle specie target. Un approfondimento è dedicato ai processi di germinazione evidenziando l’utilità dell’impollinazione artificiale per superare l’imbreeding e testando un nuovo metodo di scarificazione enzimatica.

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Pfeil, Erin. "Spatial and Temporal Dependent Shifts in Grassland Invasibility." Youngstown State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1289941507.

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Clarke, Ian Peter. "Recruitment dynamics in a southern calcareous grassland : effects of climate change." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300964.

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Swanepoel, Barbara Anna. "The vegetation ecology of Ezemvelo Nature Reserve, Bronkhorstspruit, South Africa." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-09142007-143511.

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Porter, Erica. "The roots of invasion: Belowground traits of invasive and native Australian grasses." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/134392/1/Erica_Porter_Thesis.pdf.

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Non-native grasses, originally introduced for pasture improvement, threaten Australia's iconic low-resource grasslands and a thorough understanding of the life-history strategies associated with these species is essential for effective management. Comparing invasive qualities across four congener pairs of native and non-native grasses, it was revealed that non-natives displayed a unique combination of morphological and physiological traits compared to natives. This study applied a novel technique of microdialysis and found that native and non-native grasses use soil nitrogen differently, likely contributing to the competitive advantage shown by non-native grasses across Australia.

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McLellan, Andrew John. "The plant ecology of a limestone grassland : competition and spatio-temporal dynamics." Thesis, University of York, 1995. http://etheses.whiterose.ac.uk/2448/.

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Welti, Ellen A. R. "Ecological networks of grassland plants and arthropods." Diss., Kansas State University, 2017. http://hdl.handle.net/2097/35284.

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Doctor of Philosophy
Division of Biology
Anthony Joern
John Blair
Ecological communities are comprised both of species and their interactions. The importance of species interactions is embraced by ecological network analysis, a framework used to identify non-random patterns in species interactions, and the consequences of these patterns for maintaining species diversity. Here, I investigated environmental drivers of the structure of plant-pollinator and plant-herbivore networks. Specifically, I asked: (1) Do global-scale climate gradients shape mutualistic and antagonistic networks? (2) At a landscape scale (within a 3,487 ha research site), how do contrasting regimes of major grassland disturbances - fire frequency and grazing by bison (Bison bison) - shape plant-pollinator network structure? (3) How do fire and grazing affect plant-grasshopper network structure? And, (4) What is the role of plant species diversity in determining plant-herbivore network structure? At the global scale, variability in temperature was the key climatic factor regulating both antagonistic and mutualistic network structural properties. At the landscape scale, fire and grazing had major consequences for plant-pollinator and plant-herbivore communities. In particular, bison grazing increased network complexity and resistance to species loss for both plant-pollinator and plant-herbivore systems. Results from an experimental grassland restoration that manipulated plant diversity suggest that plant diversity directly affects plant-herbivore structure and increases network stability. Collectively, these results suggest that environmental gradients and plant species diversity regulate the network structure of ecological communities. Determining how the structure of ecological interactions change with environmental conditions and species diversity improves our ability to identify vulnerable communities, and to predict responses of biodiversity to global change.

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Tofts, Richard James. "On the assembly of a grassland plant community." Thesis, n.p, 1998. http://oro.open.ac.uk/19787/.

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Burnside, Niall George. "Ecological management of the Sussex South Downs : applications of GIS and landscape ecology." Thesis, University of Brighton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324395.

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The South Downs Area of Outstanding Natural Beauty is a nationally important conservation area, which contains a significant proportion (28%) of the South East calcareous grassland resource. The traditional calcareous grassland habitats characteristic of the Downland landscape have suffered significant losses since the Second World War, and the remaining sites are small, fragmented and confined to the more marginal areas, often the steeper slopes. The recreation and regeneration of these species-rich grasslands has become an important aim of regional conservation organisations, but the methods and mechanisms by which restoration sites could be identified has not been clarified. The work reported here aims, by the integration of landscape ecology and Geographical Information Systems, to develop a sound methodological approach for the targeting of sites for restoration and regeneration of calcareous grassland on the South Downs. The study examines temporal land use dynamics of the Downland and the predominant land conversion sequences are identified. Land management changes between 1971 and 1991 are assessed, and sites of unimproved grassland and those sites considered more marginal to modem intensive farming approaches are identified. The structure of the Downs landscape is investigated at the landscape, habitat and community level using fine-scale spatial data. Particular emphasis is placed upon the remaining calcareous resource and the extent of habitat loss and fragmentation is quantified. Analysis at the community level shows a clear relationship between community richness and habitat area. The analysis identifies key attributes of calcareous grassland sites and provides a baseline from which to formulate restoration targets and objectives. Finally, using fuzzy logic, a GIS-based Habitat Suitability Model is developed for use as a tool to support strategic landscape evaluation and to provide a method of identifying areas of search and site selection for targeted restoration. The approach models the relationships between specific grassland communities and landscape position, and is applied to the South Downs landscape in order to predict the nature of grassland communities likely to result from restoration efforts at specific sites.

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Lowman, Guy Russell Pollock. "Deposition of nitrogen to grassland versus forested areas in the vicinity of sabie, Mpumalanga, South Africa." Thesis, University of the Witwatersrand, 2003. http://hdl.handle.net/10539/20112.

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Nitrogen deposition to adjacent grassland and forested areas in the vicinity of Sabie, Mpumalanga, South Africa was studied. Total deposition amounts to the forested area are calculated to be 7l.2 kg N ha-1 yr1 and to the grassland area, 25 kg N ha· 1 yr1. The average deposition amounts are similar to or at least approach nitrogen mineralisation amounts at nearby sites of 50-70 kg N ha-1 yr1. The deposition amounts are made up of 21.4 kg N ha-1 yr1 dry deposition, 7.8 kg N ha-1 yr1 wet deposition and 42 kg N ha-1 yr1 cloud droplet deposition for the forest. For the grassland, the amounts are 7 kg N ha-1 yr1 dry deposition, 7.8 kg N ha-1 yr1 wet deposition and 10.5 kg N ha-1 yr1 cloud droplet. deposition. For both wet and cloud droplet deposition, the amount attributable to nitrate was greater than that attributable to ammonium. For wet deposition, nitrate contributed 4.1 kg N ha-1 yr1 and ammonium contributed 3.7 kg N ha-1 yr1 to both forests and grasslands. For cloud droplet deposition to forests, the amounts were 28 kg N ha-1 yr1 attributable to nitrate and 14 kg N ha-1 yr1 attributable to ammonium. For grasslands the amounts were 7 and 3.5 kg N ha-1 yr1. In both forests and grasslands, the component of dry deposition contributing the most to deposition was ammonia gas, the amounts being 14.2 and 4.3 kg N ha-1 yr1 respectively. Nitric acid contributes 3.7 and 1.9 kg N ha-1 yr1 respectively and is followed by the nitrogen dioxide component that contributes 1.6 and 0.5 kg N ha- I yr1. Ammonium and nitrate particles contribute the least to deposition. For the forests the amounts are 1 and 0.9 kg N ha-1 yr1 and for the grasslands they are 0.2 and 0.1 kg N ha-1 yr1. A strong seasonal variance in deposition amounts is apparent with maximum deposition amounts occurring in Summer and minimum amounts in Winter. Intermediate amounts are deposited in Autumn and Spring, with the latter season having slightly larger deposition amounts. The seasonal variance is strongly linked to the seasonal rainfall and cloud droplet deposition patterns. Biomass burning is indicated as a possible important factor in influencing the chemical composition of rainfall during Spring. Of the deposition amounts obtained in this study, the deposition from cloud droplets is high compared to other studies and is probably overestimated. Further research into this area is needed.

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Krutsinger, Roxane. "Evaluation of Grassland Restoration Success in Illinois Using Indicators of Ecosystem Function." Thesis, Southern Illinois University at Edwardsville, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1556741.

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Grasslands are known to have been an important ecosystem in the Illinois landscape prior to European settlement. They have been severely impacted by changes in land use such as the conversion of native grasslands to agricultural land for the production of crops and livestock. Grassland ecosystems are known to provide several essential ecosystem functions that are important for the maintenance of the ecosystem and for human survival. Some of the ecosystem functions associated with grasslands include: nutrient cycling, carbon sequestration, and the cleansing of environmental contaminants from water or soil. As grasslands are converted to agricultural use, their ability to perform these ecosystem functions are greatly impaired or lost completely. Due to their recognized importance, grassland restoration projects have been given high priority by conservationists and governmental agencies around the world. Some grassland restorations aim to restore the native vegetation including the great species richness that grasslands, and prairie ecosystems in particular, are known for. Other projects, like the Conservation Reserve Program (CRP), aim to restore one of the vital ecosystem functions that grasslands provide. The measure of success for a grassland restoration has largely been evaluated using species composition and indices of species richness and evenness. These types of measurements do not directly assess the ability of a restoration site to perform the ecosystem functions of a native grassland. The aim of this study is to determine if ecosystem function is recovered over time since restoration. This will be accomplished using a chronosequence of grassland restorations at the Nature Institute in Godfrey, IL ranging from 1 year to 25 years since restoration. Several indicators of ecosystem functioning will be assesses at each site including: soil bulk density, soil organic matter, and peak standing crop. The differences in these characteristics among the sites were analyzed by one-way ANOVA followd by Tukey’s HSD test if significant. All properties were analyzed using linear regression to assess their fit to a linear model. Soil bulk density was found to moderately but significantly decrease in response to time since restoration (p = 0.0049) indicating a recovery from soil compaction and improved soil structure. Differences were detected in soil organic matter among the sites, but no linear trend in response to time since restoration was detected. Similarly with peak standing crop, differences were detected among the sites, but no linear trend with time since restoration. The lack of a predictable recovery in soil characteristics over time was attributed to differences in historical land use. In order to strengthen this study in the future, analysis of a remnant prairie and older restoration sites should be examined.

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Martinez, Yrizar Angelina. "Above-ground productivity, nutrient dynamics and leaf characteristics in a chalk grassland." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279916.

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Lloyd, John David 1973. "Large-scale vegetation features affecting the distribution and abundance of grassland birds." Thesis, The University of Arizona, 1997. http://hdl.handle.net/10150/278602.

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I predicted the likely effects of fire on the abundance of grassland birds by determining which vegetal features influenced the distribution and abundance of grassland birds at the Buenos Aires National Wildlife Refuge, Arizona. Abundance of pyrrhuloxia (Cardinalis sinuatus) (r² = 0.363), Lucy's warbler (Vermivora luciae) (r² = 0.348), and total abundance of birds (r² = 0.358) was positively correlated with increasing density of mesquite (Prosopis velutina), whereas abundance of cactus wren (Campylorhynchus brunneicappillus) (r² = 0.452) was negatively correlated with increasing mesquite density. Abundance of loggerhead shrikes (Lanius ludovicianus) (r² = 0.693) was positively correlated with increasing environmental patchiness. Fire is likely to reduce the density of mesquite, thus I predict that those species positively correlated with mesquite density will decline following fire whereas species negatively correlated with mesquite density will benefit.

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Kamffer, Dewald. "Community-level effects of fragmentation of the afromontane grassland in the escarpment region of Mpumalanga, South Africa." Connect to this title online, 2004. http://upetd.up.ac.za/thesis/available/etd-11242004-104932.

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Topping, Christopher J. "Pitfall trap sampling and community analysis of grassland spiders." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278815.

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Shiers, Eric Mitchell. "A Study of Measured vs Predicted Soil Loss and Steady State Infiltration Rates on a Semi-Arid Watershed." Thesis, The University of Arizona, 2002. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_etd_hy0013_m_sip1_w.pdf&type=application/pdf.

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Tirado, Quito Lopez. "A simulation model to assess primary production and use of Bouteloua gracilis grasslands." Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253495.

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42

Roy, Gairik. "Methodologies for mapping the spatial extent and fragmentation of grassland using optical remote sensing." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Physics and Astronomy, c2012, 2012. http://hdl.handle.net/10133/3316.

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Grassland is an important part of the ecosystem in the Canadian prairies and its loss and fragmentation affect biodiversity, as well as water and carbon fluxes at local and regional levels. Over the years, native grasslands have been lost to agricultural activities, urban development and oil and gas exploration. This research reports on new methodologies developed for mapping the spatial extent of native grasslands to an unprecedented level of detail and assessing how the grasslands are fragmented. The test site is in the Newell County region of Alberta (NCRA). 72 Landsat and 34 SPOT images from 1985 to 2008 were considered for the analysis. With an airport runway used as a pseudo-invariant feature (PIF), relative radiometric correction was applied to 17 Landsat and 8 SPOT images that included the same airport runway. All the images were classified using the Support Vector Machine (SVM) classification algorithm into grassland, crop, water and road infrastructure classes. The classification results showed an average of 98.2 % overall accuracy for Landsat images and SPOT images. Spatial extents and their temporal change were estimated for all the land cover classes after classifying the images. Fragmentation statistics were obtained using FRAGSTATS 3.3 software that calculated land cover pattern metrics (patch, class and landscape). Based on the available satellite image data, it is found that in Newell County there is almost no significant change found in the grassland and road infrastructure land cover in over two decades. Also, the fragmentation results suggest that fragmentation of grassland was not due to the result of road infrastructure.
x, 105 leaves : ill., ; 29 cm

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Heard, Matthew Spencer. "The role of invertebrate herbivory and plant competition in structuring mesic grassland communities." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390618.

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Booth, Karen Dawn. "A study of the re-establishment of chalk grassland vegetation following arable cultivation." Thesis, University of Sussex, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283530.

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Rincon, Saucedo J. Emmanuel. "Experimental investigations of the ecology of bryophytes in calcareous grassland in northern England." Thesis, University of Sheffield, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338839.

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Judd, Rachel Anne. "The coastal grasslands of the Eastern Cape west of the Kei River." Thesis, Rhodes University, 1999. http://hdl.handle.net/10962/d1003772.

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The grasslands of South Africa are the foundation of commercial and subsistence agriculture yet they are being degraded at an alanning rate. The coastal grasslands of the Eastern Cape are no exception and they suffer added pressure of coastal resort development because of their proximity to an attractive coastline. In order to determine the degree of conservation necessary for any area it is essential to know what species occur there in order to determine if protection from habitat destruction is required. Four aims were defined for this studv. The initial aim was a phytogeographical classification of the grasslands in the coastal region west of the Kei River. This was done by vegetation sampling followed by computer based analysis with TWINSPAN. This analysis defined ten grassland associations. five being located in the area west of the Keiskamma River and five occurring east of it. The associations in the eastern half are termed mesic while those in the western balf are xeric. The second aim was to determine the presence of any underlying ecological gradients affecting the distribution of tbe associations. Indirect gradient analysis was carried out where samples are analysed irrespective of environmental factors. Direct gradient analysis was then carried out using scores per sample of various environmental factors. Environmental factors whicb migbt produce such gradients are both naturally-ocurring and man-induced. Natural factors which were recorded in the field include depth of soil at sample site, soil family, aspect and distance from the shore. An important factor is the land / sea interface. Natural factors analysed in the laboratory include soil pH. conductivity. percent organic matter, calcium, magnesium, phosphate and potassium. Man-induced factors are land use history e.g. Ploughing and grazing. Both direct and indirect gradient analysis were carried out with the computer based programme CANOCO. The third aim of the study was to determine the presence of any successional trends between the ten defined associations. This was done using several characteristics of the associations. Alpha and beta diversity were the first factors compared between associations. The percentage contribution of the Cyperaceae, Fabaceae, Asteraceae and Poaceae to each association was assessed and compared. The presence of various life forms of the species occurring in each association was determined together with the cover abundance of different classes of grass species. These results were then combined and analysed in the light of the results from CANOCO analvsis. They show that the mesic Themeda Iriandra - Anthospermum herhoceum, association which occurs closest to the shore and with the least disturbance is a depauperate form of the mesic climax Themeda triandra association. The mesic Hyparrhenia hirta - Dtheteropogon amplectens association may be a secondary grassland on account of phosphate and potassiun poor soils and land-use. The mesic Hyparrhenia hirta - Themedo triandra association is a slightly degraded form of the climax association due to grazing. The severely disturbed Stenotaphrum secundatum - C'entella coriacea association, which is located close to the shore, is a secondary grassland. Analysis of the xeric associations indicates a clearly defined ordination of associations on the basis of land-use. The Cynodon daclylon - Helictolrichon hirtulum and Sporobolis africanus - Setaria sphacelata associations which occur where ploughed lands have been left to lie fallow are secondary in nature. The Themeda triandra - Ehrharta calycina association is thought to be the closest representati ve of a climax xeric association but the presence of E. calycina indicates that some disturbance has occurred. The vegetation is subject to moderate grazing. The Cynodon dactylon - Ehrharla calycina and Diheleropogon filifolius - Ehrharla calycina associations are subject to varying intensities of trampling and grazing and are degraded forms of the Themeda triandra - Ehrharla calycina association. Because of tbe overriding influence of the land-use gradient separation along gradients of the remaining eight factors was limited. The effect of fire and temporal change in the mesic Themeda triandra and Hyparrhenia hirta - Themeeia trianda associations was assessed via long-term studies at Potter's Pass outside East London. The results show a quick response to burning with a return to 100% cover within six months by both associations. During spring the two associations could not be separated by either TWINSPAN or DECORANA. indicating a temporal shift from the Hyparrhenia hirta - Themeda triandra association to the Themeda triandra association. The fourth and final aim was to identify plants requiring protection from habitat destruction and to make recommendations for further conservation areas and management of the coastal grasslands. Through the collection and identification of as many plants as possible a species checklist was prepared and the status of each was determined through reference to the Red Data Book of threatened and endangered species. Kniphofia rooperi is vulnerable in the Cape and Euphorbia hupleuroides is considered rare in kwazulu-Natal. Ten species are endemic to the Cape and / or South Africa. The richness of the vegetation lies in the presence of species representative of the four major floras which converge in the eastern Cape. i.e. The Cape, NamaKarroo, Tongoland-Pondolaod floras and the Kalahari Highveld Regional Transitional Zone. Suggestions are made for the conservation of the grassland associations at various sites within the study area based on the present area conserved. Less than 2% of the coastline in the study area is conserved and it is felt that the area under conservation should be increased. Management suggestions based on the available literature are given for both farmed and conserved areas. There is a great potential for further studies on grassland dmamics within the areas surveyed. In terms of management, the grasslands require careful examination to determine the most effective season in which to burn if at all. As with most agricultural systems in South Africa. grazing strategies will benefit from further research. Any additional research on the dynamics of these grasslands can only be of benefit to the sustained utilisation of this vital resource.

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Bucklnad, Sarah M. "An investigation into the responses of limestone grassland to climatic manipulation and species introductions." Thesis, University of Sheffield, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284300.

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Ložytė, Aurelija. "The influence of agri-environmental measures based grassland management on grassland plant communities." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140526_082518-10331.

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Grassland is an important component of agrarian landscape, performing wide range of ecological, economic and social functions. Long-term changes of the conditions of habitats, determined by human economic activities, influence the state of grassland plants. Rural Development Programme for Lithuania 2007–2013 sets measure to preserve biological diversity of grassland. The purpose of it is to reduce negative anthropogenic effect on grassland plant communities using the EU funds. Having researched the differences of grassland plant diversity and economic value, influenced by different intensity economic activities, the main objective of this paper is to evaluate the efficiency of EU regulated, agri-environmental measures based, grassland management methods in small farming sector of Lithuania. The research, involving the assessment of the number of plant species, diversity of plant families, distribution of relative plant abundance, and dominance of plant species in plant communities in grassland managed traditionally and according to the requirements of agri-environmental farming, showed that both types of grassland had similar plant communities. Such conclusion was drawn from the analysis of Jaccard and Sörensen similarity coefficients. The difference of plant adaptation to soil dampness, acidity, and nutrition was not statistically significant in grasslands of both types. Most of the plants in grassland researched were mesophytes; soil acidity was not a determining factor to... [to full text]
Pievos yra svarbus agrarinio kraštovaizdžio komponentas, atliekantis įvairias ekologines, ekonomines ir socialines funkcijas. Ilgalaikiai augaviečių sąlygų pokyčiai, kuriuos lemia žmogaus ūkinė veikla, įtakoja pievų augalų būklę. Lietuvos kaimo plėtros 2007–2013 m. programoje numatyta priemonė pievų biologinės įvairovės išsaugojimui, kurios tikslas panaudojant ES lėšas mažinti neigiamą antropogeninį poveikį pievų augalų bendrijoms. Ištyrus pievų augalijos įvairovės ir ūkinės vertės skirtumus, sąlygotus skirtingos ūkinės veiklos intensyvumo, šio darbo tikslas įvertinti reglamentuotų, ES agrarinės aplinkosaugos priemonėmis paremtų, pievų tvarkymo metodų efektyvumą smulkiuose Lietuvos ūkiuose. Atliktas tyrimas parodė, kad įvertinus augalų rūšių skaičių, augalų šeimų įvairovę, augalų rūšių santykinio gausumo pasiskirstymą, dominuojančias augalų rūšis tradiciniais ir agrarinės aplinkosaugos reikalavimus atitinkančiais ūkininkavimo metodais tvarkomose pievose, nustatyta, kad jose augo panašios augalų bendrijos. Tai parodė ir Žakaro bei Sörensen bendrumo koeficientų reikšmės. Abiejų tipų pievose rastų augalų rūšių prisitaikymo prie dirvožemio drėgmės, rūgštingumo, turtingumo maisto medžiagomis rodiklių reikšmės statistiškai reikšmingai nesiskyrė. Pievų augalų bendrijose vyravo mezofitai, daugumai augalų rūšių dirvožemio rūgštingumas buvo neįtakojantis veiksnys, pievoms būdingi mezooligotrofiniai ir mezotrofiniai žolynai. Tyrimas parodė, kad biologinės įvairovės apsaugai palankus... [toliau žr. visą tekstą]

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Hodge, Josh. "Using the plant trait-based approach to study temperate grassland ecology and restoration." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/110962/.

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Grasslands are considered to be the most endangered terrestrial ecosystem in the world. In the United Kingdom, substantial losses in unimproved grasslands and the abandonment of traditional grazing has resulted in the decline of ecosystem services, such as pollination. A plant trait-based approach was conducted to study the community ecology and restoration of temperate grasslands, with a focus on the convergence/divergence patterns in response to environmental and management factors, and how these scale to the provision of ecosystem processes and services –biomass production and livestock. The role of seven plant traits, obtained from the TRY-database, was investigated using the botanical data of the National Vegetation Classification, the Park Grass Experiment and the North Wyke Farm Platform. Trait-based analyses were conducted on the latter two to investigate the provision of biomass production and livestock production. A microcosm experiment was conducted to test the effects of agricultural soil legacies and restoration seed mixture on the reassembly of grassland communities, and their associated functional structure and composition. It was found that the seven traits investigated were independent and countered the conceptualisation of ecological axes of specialisation and ecological strategies. The type of fertiliser used to improve grasslands was found to be a significant factor driving the convergence/divergence patterns of temperate grassland communities, together with grazing. Biomass production was found to be best explained by statistical models incorporating climate and environmental factors, community-weighted means and different facets of functional diversity. In essence, environmental and management pressures resembling intensely managed, especially with nitrate-based fertilisers, temperate grasslands and an exploitative community best supported greater amounts of high quality biomass. Livestock production was found to be best explained by the Functional Diversity Hypothesis: higher yields from cattle and sheep were found from diverged grazing pastures. A trade-off between cattle quantity and quality was also highlighted. Agricultural soil legacies were found to greatly hinder the progression towards vegetation and functional restoration targets, producing ruderal communities dominated by weak competitors and opportunistic weedy plant species. The work has important implication for the management and restoration of grassland communities.

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Enloe, Stephen Frederick. "The ecology and management of yellow starthistle in annual and perennial grassland communities /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.

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Dissertations / Theses on the topic 'Grassland ecology'

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