Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 22 for “"grassland communities"”.
-
Restoration implications of land management on aboveground vegetation and seed bank composition of grassland communities in Illinois
A variety of non-prairie landscapes are restored to prairie on a yearly basis including pastures, croplands, and old fields. Most of these restoration efforts do not take into account the seed bank associated with these non-prairie lands as a potential source of plant diversity or weedy …
-
Monitoring changes in plant community composition and landscape structure as a result of prescribed burning at Big Oaks National Wildlife Refuge
… of fire management within the refuge. These grassland communities are important for managing rare grassland wildlife species, especially Henslow's sparrows. Permanent plots were established in three managed grassland communities. Information on plant community species composition and …
-
Plant community assembly and biodiversity: a spatio-temporal perspective
… functional) were characterized in semi-natural grasslands (in plots of 0.5 × 0.5 and 2 × 2 m, and whole grassland polygons). The extent to which the present-day and historical characteristics of the sites and their surrounding landscape explain the current diversity patterns was quantified. …
-
THE AUTECOLOGY OF THE MEADOW THISTLE (Cirsium dissectum L. Hill) ON DEVON RHoS PASTURES, WITH PARTICULAR REFERENCE TO THE EFFECT OF MAJOR ENVIRONMENTAL VARIABLES ON THE POPULATION DYNAMICS
Semi-natural wet grassland communities are rapidly disappearing from the farmed landscape. Protection of remaining areas and restoration of degraded areas has become a priority with organisations concerned with the conservation of biodiversity in the U.K. The research described in this thesis …
-
The response of grassland carbon cycling to drought events and changes in nutrient availability
In grasslands, climate change has the potential to disrupt a range of ecosystem services, including agricultural production, carbon (C) storage and nutrient cycling. In particular, climate change is likely to increase the frequency and severity of extreme climate events, such as drought and the …
-
Assessing The Biophysical Naturalness Of Grassland In Eastern North Dakota With Hyperspectral Imagery
… the past two decades, non-native species within grassland communities have quickly developed due to human migration and commerce. Invasive species like Smooth Brome grass (Bromus inermis) and Kentucky Blue Grass (Poa pratensis), seriously threaten conservation of native grasslands. This study …
-
Plant Height Dynamics and Competition: From Local Interactions to Global Patterns
… for species within neighbourhoods and communities. My thesis explores this contradiction between theoretical predictions and observed patterns by examining how plant height mediates species interactions across environmental gradients in grassland ecosystems. First, I investigated how …
-
A multi-proxy approach to investigating the latest Holocene (~4,500 yrs. BP) vegetational history of Catahoula Lake, Louisiana
… useful in distinguishing between forest and grassland communities and identifying preservational bias in phytolith types. This analog was then used in conjunction with additional proxies, to interpret downcore data. Three sediment cores (from 3.2 - 4.3 meters in length) were retrieved from …
-
The effects of mammalian herbivores on successional grasslands in central Illinois
… types of herbivorous mammals on mid-western grassland communities at different stages of development, in spite of a substantial literature indicating the potential of mammals to impact the composition of these plant communities. Mice and voles consume large seeds, and rabbits disperse small …
-
Biotic and Abiotic Factors of Picea rubens (Red Spruce) Seedling Regeneration in Disturbed Heathland Barrens of the Central Appalachians
… of Canaan Valley, West Virginia, where heath and grassland communities have both persisted in natural barrens and expanded into formerly forested areas. To understand abiotic and biotic conditions guiding the advance of the red spruce stand, I conducted a broad-scale assessment of thirty-one …
-
Land use and vegetation change on the Long Mynd
The plant communities of the Long Mynd plateau are the culmination of over 3000 years of human intervention that largely deforested the uplands, and subsequently maintained the generally treeless heath and grassland communities now extant. The capacity of these communities to respond to directional …
-
The Influence of Plant Diversity on Soil Physical Properties in Grasslands.
… nutrient cycling and the stability of communities under environmental change. However, virtually nothing is known about the response of soil physical properties to plant biodiversity change, which represents a serious gap in our knowledge given the key role soil physical structure has …
-
Seeing the light: germination, growth and flowering responses in wildflowers under artificial nighttime lighting
… to outdoor lighting technologies on wild plant communities, despite the fact that plant growth and development are under photoperiodic control. The present study evaluated the effects of photoperiod extension that comes from cool white light-emitting diode (LED) street lighting at ground-level …
-
The development of a methodology for the identification of potential wet grassland restoration sites in south west England
… neglect of the floristically diverse wet grasslands in south west England have caused a significant decrease, approximately 92% since 1900. in the total area of this ecologically valuable semi-natural plant community. The plant community, which is locally called Culm grassland, consists of …
-
MODELLING THE INTERACTION BETWEEN WILD AND CULTIVATED SPECIES.
… levels of biodiversity and, in the context of grassland communities, they are crucial for the provision of ecosystem services like those involved with pollination and recreational experiences. A quantitative understanding of the complex and dynamic interactions among species within …
-
Vegetation and flora of the Southern Drakensberg escarpment and adjacent areas
The grasslands of South Africa, and especially the higher altitudinal grasslands, are under increasing human pressure. In this study a floristic-ecological account of the vegetation of the southernmost Drakensberg and its foothills is given. This is the first comprehensive botanical study …
-
Vegetation structure and inferred patterns of functional group attrition in a shrub encroached old field and tallgrass prairie mosaic
… gain insights into patterns of disassembly in grassland communities. The study site is a 65 ha (160 acre) tallgrass prairie and old field mosaic in Lake County, Illinois. The three main objectives in this study are to: (1) analyze and classify plant communities, (2) explore seed bank dynamics …
-
Beyond productivity- Effects of extreme weather events on ecosystem processes and biotic interactions
… In our experiment in artificially planted communities, even an extreme drought of 1000-year recurrence did not have effects on above- or below-ground biomass production from 2005-2010. Thus, the main objectives of this thesis were (1) to investigate if extreme weather events have an effect …
-
Direct Amino Acid Uptake by Plants related to Grassland Diversity - methodological and ecological Investigations
… thus amino acid uptake might explain how plant communities enable higher productive with increasing diversity. However, the ecological importance of organic N uptake has also been questioned due to the high competitive power of microbes in soils of the temperate zone and due to a number of flaws …
-
Climate change in experimental ecology - The impact of warming and drought on key European tree, heath, and grassland species
… (manuscript 3)? 4. Does stress response of plant communities and species (heath and grassland) differ if drought reoccurs (manuscript 4)? Concerning the first of the above stated research questions, the comparison of the two warming techniques "passive warming" and "warming by transplantation" …
Page 1 of 2