Multispecies grazing research was conducted using meat-type goats (Capra hircus L.) and Jersey heifers (Bos taurus L.) to determine the relationships between multiple grazing treatments and pasture utilization. The study was conducted for 60 days on the Western Kentucky University Farm in Bowling Green, KY. Cattle and goats have shown to differ in grazing preferences and to be economically important to the area. Grazing treatments included goats and cattle grazing simultaneously, sequentially, and goats grazing alone. A typical established Kentucky pasture was utilized with no weed management practices employed. Predominant forage species included tall fescue (Festuca arundinacea Schreb.), orchardgrass (Dactylis glomerata L.), Kentucky bluegrass (Poa pratensis L.), and white clover (Trifolium repens L.). Exclosures were utilized as controls. Data included forage quality, composition, availability, height, visual weed cover and live ground cover, and thistle consumption, collected every 15 days. Results indicated a significant difference in sample dry weights between grazing treatments and ungrazed controls in every treatment except when goats followed cattle. At day 60, grazed areas had significantly lower forage heights than the control when goats grazed with and before cattle. Instances where goats followed cattle resulted in significantly higher NDF compared to the control. All treatments containing goats had significantly lower leaf numbers per thistle plant (Carduus nutans L.) than cattle only treatment. Based on this study, sequential and simultaneous grazing of cattle and goats may be an effective nodding thistle control strategy, but future experimentation is needed for determination of forage utilization and quality relationships.

A 4-year study was conducted on the Missouri Coteau in the Mixed Grassland Ecoregion of Saskatchewan to determine the effects of mowing to a 7.5 cm stubble height on the growth of <i>Festuca hallii</i> (Vasey) Piper and <i>Stipa curtiseta</i> (A.S. Hitch.) Barkworth. Green standing crop (GSC), dead standing crop (DSC) and above ground net primary production (ANPP) were compared to an unmowed control after a single mowing in April, May, June, July, August, September, October or November on 5 landforms including north aspect-concave-slope, north aspect-convex-slope, south aspect-concave-slope, south aspect-convex-slope and level upland. Mowing reduced GSC, DSC and ANPP with reductions varying among months of mowing and among landforms. Green standing crop, DSC and ANPP of <i>F. hallii</i> were greatest on the north aspects and least on south aspect-convex slope and ranged from 2 to 122 g m-2, 3 to 121 g m-2, and 8 to 122 g m-2, respectively. Mowing reduced GSC of <i>F. hallii</i> for 1 to 11 growing season months and DSC for 1 to >11 growing season months. Mowing in May or November reduced ANPP of <i>F. hallii</i> for 1 growing season, while mowing in other months reduced ANPP for 2 growing seasons. Green standing crop of <i>S. curtiseta</i>, ranging from 3 g m-2 to 55 g m-2, was least on the north aspects and greatest on the south aspect-convex slope and was reduced 1 to 5 growing season months following mowing. Mowing after June reduced DSC of <i>S. curtiseta</i>(5 to 58 g m-2) for 1 to 10 growing season months, and ANPP (6 to 64 g m-2) for 1 growing season. Generally, mowing reduced GSC, DSC and ANPP of <i>F. hallii</i> longer than <i>S. curtiseta</i>. Production of <i>F. hallii</i>- and <i>S. curtiseta</i>-dominated plant communities in the Northern Mixed Prairie will be maintained by providing rest periods between defoliation events based on the number of growing season months for <i>F. hallii</i> to recover production.

Thesis (MS)--University of Montana, 2009. / Contents viewed on December 7, 2009. Title from author supplied metadata. Includes bibliographical references.

In desert grasslands of the southwestern United States, Prosopis velutina (mesquite), an N-fixing legume, has proliferated from historic drainage locations into more xeric grassland plains. This expansion is forming a more heterogenous soil nutrient topography in grasslands, N-pools are becoming localized under mesquite canopies, yet the rate and extent of this sequestration remains relatively unknown. Repeated prescribed burning has been used to control Prosopis distribution, but effects of fires on grassland soil nutrient distribution and aboveground plant biomass are also largely unknown. I examined recent research concerning P. velutina natural history, emphasizing characteristics that contribute to range expansion. I also evaluated Prosopis management practices---which include herbicide treatment, prescribed burning, grazing reduction, and mechanical removal---and management goals---which involve complete removal, no removal, and limited removal. Of these, limited removal is the most beneficial, using an herbicide application followed by periodic prescribed burning. In 1997 I established a study area at Fort Huachuca Military Reservation in southeastern Arizona, selecting two adjacent sites with similar soil composition and topography but different fire histories. I examined spatial and seasonal changes in composition and distribution of available soil N and litterfall. My results indicated these were more spatially and temporally heterogenous on sites with low fire frequency and high P. velutina stand development. In 1998 I selected nine sites at Fort Huachuca on two upland surfaces located < 1 km apart, with similar soil physical characteristics and fire frequencies ranging from 0 to 5 fires/decade. I evaluated relationships between fire frequency, soil nutrient status (pH, available P, organic C, total N, and available N), and aboveground plant biomass, including that of the non-native Eragrostis lehmanniana (Lehmann lovegrass). Soil pH and ammonium significantly decreased with increased fire frequency on one surface, and available P significantly decreased with increased fire frequency on the other surface. Available P and pH were significantly different between the 2 surfaces, but aboveground biomass was similar. Soil nutrient status and biomass were not related, suggesting plant-available soil nutrients may not control plant distribution or recovery following fire. E. lehmanniana biomass was negatively correlated with native grass and forb biomass, and tended to increase with increasing fire frequency. Surface litter and E. lehmanniana biomass were correlated, and may increase fire frequency, an important consideration when implementing grassland fire management practices.

Who uses the forage resources under a communal land tenure system? Using data from a Mexican Indian community with a history of communal land tenure extending prior to the Conquest, the research explores and attempts to answer this question. The analysis is based on 1970 socio-economic data for 533 households, secondary sources, and 1987 field observations in a community of Zapotec farmers in the State of Oaxaca, Mexico. The factors influencing who uses the communal resources include livestock ownership, wealth ranking, migration history, and participation in the local labor market. Although all members of the community have the right to graze animals on the commons, only a fraction of the wealthier households exercise this right. Consequently grazing pressure is minimized (reduced) compared to the potential grazing pressure that otherwise would be exerted if all the members of the community were to exercise their rights to use the forage resources at the same time.

The effects of land-use history in the Animas Mountains, New Mexico (AM) and the Sierra los Ajos, Sonora (SLA) were studied in relation to morphological and soil chemical characteristics, radial and basal area growth, and forest structure. Litter depth, organic matter, total nitrogen, CEC, and exchangeable cations were greater in the AM than in the SLA, apparently as a result of differences in fire frequency and other land uses. Seasonal precipitation (October-January) was reconstructed for the AM. Annual precipitation (July-July) was reconstructed for the SLA. July PDSI was reconstructed for both mountain ranges. Fires in the AM were preceded by relatively wet conditions two years before the fire year. No significant climate-fire relationship was found in the SLA. Tree radial and basal area increase differed between mountain ranges, suggesting that annual growth was influenced by differences in land-use history. Fire suppression activities and other land uses in the AM apparently have produced an increase in tree density and dominance of shade-tolerant but less-fire resistant species (i.e. Douglas-fir, southwestern white pine, pinyon pine). More frequent fires and logging activities in the SLA apparently have produced lower tree densities and dominance by shade-intolerant ponderosa pine.

No description available.

Open grassland productivity was measured within adjacent East Kootenay range units to evaluate forage availability and calculate elk (Cervus canadensis nelsoni) and cattle (Bos taurus) sustainable carrying capacity targets. This research extends rangeland monitoring with an analysis of site differentiation and comparative grazing pressure to 2008 population estimates. Significant productivity differences were found between grass and shrubs for range units (p=0.024 and p<0.0001) and different biogeoclimatic zones (p=0.042 and p<0.0001). Notable grazing pressure distinctions occurred: cattle exceeded the Rampart Mayook carrying capacity, elk exceeded the Pickering Hills carrying capacity, and both species had sustainable populations within the Power Plant range unit. These results provide clear direction for stock management and offer valuable rangeland insight. Furthermore, the study introduces cover-percentage productivity estimation (CPPE), a simple grassland productivity assessment method. Pearson correlation coefficients were significant and high between productivity results and cover estimates, indicating that CPPE will be a useful field tool.

This study illustrates a utilization-focused program evaluation approach newly applied to resource management. The Alberta Riparian Habitat Management (Cows and Fish) Program provides awareness programming to cattle producers to facilitate community-based action on riparian issues. The rationale is to develop producers' ecological literacy by increasing riparian knowledge and use of sustainable grazing management strategies by sharing appropriate ecological and management information. Attitude change is presumed to underlie the new behaviour(s). Programming contributed to ecological literacy when it was community-based, producer-positive and partnership-oriented, and when opportunities existed for personal interaction among peers. Effectiveness declined when resources were insufficient and when programming seemed unrelated to local landscape or operational features. The attitude-behaviour relationship was weakly associated with ecological literacy; its complexity and relevance to ecological behaviours merits further investigation. Program evaluation is of utility in resource management. Its potential will be fully realized by ensuring that research designs appropriately parallel programming rationale and evaluation requirements. / ix, 316 leaves : ill. ; 28 cm.

Observations by local people in the Mier area, southern Kalahari, South Africa, indicated that degraded rangeland does not recover within a time frame acceptable to landowners. Pristine vegetation in this linear dune system consists largely of a herbaceous layer dominated by perennial grasses. Woody vegetation is sparse on dunes and interdunes in good condition. The dunes and interdunes react differently to disturbance, probably because of differences in substrate stability, soil particle size distribution and consequent differences in soil nutrient distribution and moisture content. Degraded dunes are devoid of any vegetation, except for Stipagrostis amabilis, a rhizomatous grass which remain in small clumps, and the tree Acacia haematoxylon. The latter increases in numbers probably due to the high moisture content in degraded dunes. Moisture content in degraded dunes remain high even during prolonged dry periods. Interdunes are more susceptible to degradation and are invaded by the long-lived shrub Rhigozum trichotomum and the annual grass Schmidtia kalahariensis. Both these species compete with perennial grasses for moisture. Additionally, depleted seed banks and increased seed predation by ants (Messor capensis) may also affect the re-establishment of perennial grasses in the interdunes. The main conclusion from this study is that degraded southern Kalahari rangeland cannot recover spontaneously at the landscape scale because of a negative feedback mechanism that prevents establishment and growth of seedlings. The hypothesis put forward is that rangeland ceases to react to rainfall as an ecosystem driver as it becomes degraded. Once degraded, wind controls the dynamics of the system and recovery, irrespective of rainfall, is almost impossible. In contrast, detailed studies at the level of small isolated populations of S. amabilis and S. ciliata on degraded dunes indicate high rates of population growth. The scales at which these processes exist are contradictory and may not be contradicting. Rangeland managers should take cognisance of the influence of the spatial and temporal scale at which they operate, and on which they base their decisions. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2000.