Systems Biology Commons^™

Synthesis Of Satellite Microwave Observations For Monitoring Global Land-Atmosphere Co2 Exchange, Lucas Alan Jones

Graduate Student Theses, Dissertations, & Professional Papers

This dissertation describes the estimation, error quantification, and incorporation of land surface information from microwave satellite remote sensing for modeling global ecosystem land-atmosphere net CO₂ exchange. Retrieval algorithms were developed for estimating soil moisture, surface water, surface temperature, and vegetation phenology from microwave imagery timeseries. Soil moisture retrievals were merged with model-based soil moisture estimates and incorporated into a light-use efficiency model for vegetation productivity coupled to a soil decomposition model. Results, including state and uncertainty estimates, were evaluated with a global eddy covariance flux tower network and other independent global model- and remote-sensing based products.

Inter- And Intra-Specific Interactions In Germination And Seedling Establishment Of Cheatgrass And Russian Wildrye, Erin K. Espeland

The Prairie Naturalist

Cheatgrass (Bromus tectorum) is an invasive species in the arid and semi-arid west of the USA, and is weedy in disturbed prairie landscapes. Perennial Russian wildrye (Psathyrostachys juncea) limits population growth of cheatgrass, but the mechanism is unclear. I conducted glasshouse and greenhouse experiments to test if intra- and interspecific competitive interactions of seeds and seedlings of cheatgrass and Russian wildrye were different across a geographic soil gradient with different cultivation legacies in eastern Montana, USA. Seed-seed interactions occurred in both species. Cheatgrass and Russian wildrye inhibited one another’s emergence in one edaphic condition in one experiment. Cheatgrass growth was …

Association Of Soil Conditions And Grass Species With Variable Cover Of Leafy Spurge, Terence P. Mcgonigle, Jeremy L. Timmer

The Prairie Naturalist

Variation in soil conditions and grass cover was assessed across a range of leafy spurge (Euphorbia esula L.) cover values on a sandy rangeland in Manitoba, Canada. Soil conditions varied by site but not in relation to cover of leafy spurge. We observed a significant negative relationship between total grass cover and increasing cover of leafy spurge. Only porcupine grass (Hesperostipa spartea [Trin.] Barkworth) had a negative relationship with leafy spurge, falling from high cover at low weed occurrence to only trace levels at the highest leafy spurge abundance. Neither prairie Junegrass (Koeleria macrantha [Ledeb.] Schult.), rough …

Of Gardens, Microorganisms, And Long Island Sound, Judy Preston

Wrack Lines

How healthy soil can make an environmental difference.

"I happened to turn over a large rounded stone in my garden to find a mesmerizing world of organisms that had, just moments earlier, been going about their business before being exposed to the sunlit world, and me."

Sheep Grazing Wheat Summer Fallow And The Impact On Soil Nitrogen, Moisture, And Crop Yield, Andrew W. Lenssen, E. E. Snyder, H. B. Goosey, P. G. Hatfield

Andrew W. Lenssen

In typical dryland farming areas of Montana, annual precipitation is not sufficient for annual harvest of small grains. Summer fallow in alternate years, is a common method of conserving soil moisture to produce a crop in the following season. Current methods of fallow management are primarily mechanical tillage and spraying with herbicides. Although these methods are effective, they are expensive, making fallow management the highest variable cost associated with dryland grain production. The objectives of this study were to compare the impact of grazing small grains stubble with sheep, as a fallow management tactic, against traditional management practices of chemical …

An Inventory Of Rangelands In Part Of The Broome Shire, Western Australia, W E. Cotching

Technical Bulletins

The inventory of rangelands in part of the Broome Shire in Western Australia was undertaken by DAFWA between 1989 and 1990. It describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the natural area’s resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The survey of part of the Broome Shire …

An Inventory And Condition Survey Of The Pilbara Region, Western Australia, A M E Van Vreeswyk, K A. Leighton, A L. Payne, P Hennig

Technical Bulletins

The inventory and condition survey of the Pilbara region, undertaken by the Department of Agriculture, Western Australia between 1995 and 1999, describes and maps the natural resources of the region’s pastoral leasehold land. This survey report provides a baseline record of the existence and condition of the natural area’s resources, to assist with the planning and implementation of land management practices. The report identified and described the condition of soils, landforms, vegetation, habitat, ecosystems, and declared plants and animals. It also assessed the impact of pastoralism and made land management recommendations. The area surveyed covers about 181 723 km². Seven …