• Karoobush defoliation in the arid Karoo

      Du Toit, P. C. V. (Society for Range Management, 1996-03-01)
      The relation was studied between the applied stocking rates and the degree to which sheep grazed stems of various karoobush species. A rule of thumb exists amongst farmers and research workers in the Karoo, that sheep graze stems of karoobushes with a diameter of 2 mm or less. This hypothesis was examined over a period of 3 years. The meetly grazed off stems of Pentzia spinescens Less. (doringkaroo) and Rosenia humilis (Less.) Bremer (blou perdekaroo), the most abundant forage species, were measured by sliding Vernier callipers. Estimates of grazeable dry matter, as used in the estimate of the current grazing capacity, is based on the separation of clipped dry matter into grazeable and non-grazeable material. This separation is based on the 2 mm criterion. The hypothesis that sheep voluntarily graze stems with a diameter of up to 2 mm was rejected. The stems of less palatable species are seldom grazed at 2 mm diameter, while grazed stems of paintable species are often thicker than 5 mm. It was established that sheep graze stems of the less palatable karoo bushes to a mean diameter of 1.4 to 1.6 mm. This impacts directly on the method in which dry matter production is estimated for the purposes of determining grazing capacity. The long term grazing capacity norm for this area is 30 ha large stock unit-1. Based on gain ha-1 data obtained from stocking rate trials, the grazing capacity is 33.4 ha large stock unit-1. The stocking rate: grazed stem relation yields an optimum grazing capacity figure of 32.5 ha large stock unit-1. This indicates that monitoring the grazed stems of appropriate species can be used to set grazing capacity limits or adjust stocking rates.
    • Key Attributes Influence the Performance of Local Weed Management Programs in the Southwest United States

      Hershdorfer, Mary E.; Fernandez-Giminez, Maria; Howery, Larry D. (Society for Range Management, 2007-05-01)
      In the southwestern United States, local weed management programs are increasingly important in weed prevention and control; however, little is known about the effectiveness of different local approaches to weed management. We surveyed coordinators of 53 local weed management programs in Arizona, Colorado, New Mexico, and Utah to determine how 4 key program attributes (interagency coordination, volunteer participation, regulatory authority and enforcement, and the state in which the program was located) were related with 4 performance measures: weed control, public education and outreach, weed monitoring, and integrated weed management. Based on the responses of 42 program coordinators (79%) we found that 1) weed programs that coordinated their activities with other organizations and those with citizen volunteers conducted more monitoring, but programs that did not coordinate or use volunteers treated more of their infested acreage; 2) programs that used a light-handed regulatory approach conducted more weed control than those with more punitive enforcement regimes or no enforcement authority; and 3) Colorado programs conducted more outreach and education than did programs in the other 3 states. Thus, although volunteer involvement and interagency coordination contributed to the performance of the local weed programs studied, particularly in monitoring, they have not compensated for the lack of locally enforceable weed regulations or adequate funding. Successful weed management in southwestern United States will require adequately funded, locally adapted approaches supported by locally enforceable weed regulations. 
    • Killing Ribes with 2,4-D and 2,4,5-T

      Offord, H. R. (Society for Range Management, 1949-10-01)
    • Knapweed hay as a nutritional supplement for beef cows fed low-quality forage

      Bohnert, D. W.; Sheley, R. L.; Falck, S. J.; Nyman, A. A. (Society for Range Management, 2014-03)
      Advancing our ability to use invasive plants for producing commodities is central to the agricultural industry. Our objective was to evaluate Russian knapweed (Acroptilon repens "L." DC.) as a winter feed supplement for ruminant livestock. In Experiment 1, we utilized three ruminally cannulated steers in a completely randomized design to compare the ruminal degradation characteristics of alfalfa and Russian knapweed. In the second experiment, Russian knapweed and alfalfa were compared as protein supplements using 48 midgestation, beef cows (530-±-5 kg) offered ad libitum hard fescue (Festuca brevipila Tracey) straw in an 84-d study. Treatments included an unsupplemented control and alfalfa or Russian knapweed provided on an iso-nitrogenous basis. In Experiment 1, the rate and effective degradability of neutral detergent fiber was greater for alfalfa compared with Russian knapweed (P-≤-0.02). Ruminal lag time for NDF (period before measurable disappearance began) was greater for knapweed (P-=-0.03). Soluble nitrogen, rate of N degradation, rumen degradable N, and effective degradability of N were all greater for alfalfa compared with Russian knapweed (P-<-0.01). In Experiment 2, supplementation increased (P-<-0.01) cow weight gain and BCS compared to the unsupplemented control with no difference between alfalfa and Russian knapweed (P-=-0.47). There was no difference (P-=-0.60) in the quantity of straw offered between the unsupplemented cows and supplemented groups, but alfalfa fed cows were offered approximately 11% more (P-=-0.03) than Russian knapweed-fed cows. Total DM offered to cows was greater (P-<-0.01) for supplemented compared with unsupplemented cows with no difference noted between alfalfa and Russian knapweed (P-=-0.79). Russian knapweed is comparable to alfalfa as a protein supplement for beef cows consuming low-quality forage. Using Russian knapweed as a nutritional supplement can help solve two major production problems; managing an invasive weed, and providing a feedstuff that reduces an impediment in livestock production systems. © 2014 The Society for Range Management.
    • Knowing the Land: A Review of Local Knowledge Revealed in Ranch Memoirs

      Knapp, Corrine Noel; Fernandez-Giminez, Maria (Society for Range Management, 2008-03-01)
      Lack of long-term ecological monitoring presents a challenge for sustainable rangeland management in many areas of the western United States. Ranchers and other land managers have local knowledge gained from ongoing experience in specific places that could be useful for understanding ecological change and best management practices. Local knowledge is defined as knowledge gained by daily contact with the natural world and ecological processes. Unfortunately, little is known about ranchers’ local knowledge, and few studies have systematically examined the types, depth, and validity of this knowledge. Ranch memoirs offer an unexplored entry into rancher knowledge acquisition, categories, and context. In this study, we coded and analyzed eighteen ranch memoirs from the western United States to investigate the specific types, depth, and quality of local land knowledge. We found that ranchers possess knowledge of both management and ecology, and that these knowledge realms are intertwined and often inseparable. In addition to learning from experience, social interactions are an important part of rancher education and create a shared knowledge culture. In most of the memoirs, ranchers revealed very little knowledge of long-term patterns of vegetation change. In all the memoirs reviewed, ranchers articulated a deep sense of responsibility and connectedness to the landscapes they manage and steward. This review of ranch memoirs provides a framework for future studies of local knowledge by identifying how ranchers gain their knowledge of the landscapes they manage, describing some of the distinctive types of knowledge that ranchers possess, and challenging conventional classifications of rancher knowledge. 
    • Knowledge in Practice: Documenting Rancher Local Knowledge in Northwest Colorado

      Knapp, Corrine Noel; Fernandez-Gimenez, Maria E. (Society for Range Management, 2009-11-01)
      For more than 150 years, ranchers in the West have gained insight about natural systems through daily interaction and management of landscapes, but this knowledge has never been systematically documented and analyzed. We interviewed 26 ranchers from a single watershed to understand how ranchers acquire their knowledge, document what they know about rangeland ecosystems, and explore how this knowledge varies within the ranching community. This exploratory study offers insight into the types of knowledge ranchers possess without attempting to survey all rancher knowledge or ascribe this set of knowledge to all ranchers. We identified three major knowledge categories in interviews: active knowledge applied to management decisions, embedded knowledge from living in place, and integrative knowledge that links ecological, economic, and social aspects of rangeland systems. We found rancher knowledge complemented scientific knowledge in its ability to provide site-specific information on management practices and ecological responses, and insight regarding potential indicators of rangeland health. Knowledge varies widely within the ranching community, and knowledgeable ranchers are readily identified through community referrals. Ranchers gained their knowledge primarily through experience and social interactions, and this knowledge is an untapped source of context-specific information. We did find that economic constraints, social norms, and proximity to the system might limit application of knowledge to practice. There is also a danger that this accumulated and dynamic knowledge base will be lost over the next generation, as many family ranches are sold to new ranchers or for nonranching uses. Based on our findings, we propose that more dialogue within ranching communities and between ranchers and scientists may lead to more sustainable land management practices and effective outreach efforts, and could expand and strengthen the informal social networks through which much rancher knowledge is shared and on which the social sustainability of ranching communities depends. 
    • Kochia scoparia emergence from saline soil under various water regimes

      Steppuhn, H.; Wall, K. (Society for Range Management, 1993-11-01)
      Kochia scoparia (L.) Schrad. invades disturbed soils and serves as a pioneer species on saline rangelands and sodic mine spoils. The percent germination of kochia seeds declined with increasing salinity, averaging -3.3%/dS/m between 12 and 30 dS/m. The emergence and early survival of kochia seeded into 2 media whose respective saturated-paste extracts averaged 1 and 18 dS/m in electrical conductivity (ECe) were investigated in a greenhouse under simulated rainfall regimes. Water was applied according to 3 average rates: 0.6 mm/day (low); 1.2 mm/day (medium); 2.5 mm/day (high). These rates were administered in 2 phases. Phase I (14 days) involved low and medium on the nonsaline seedbeds, and medium and high on the saline seedbeds. Phase II (42 days) followed sequentially on only the saline soil in Phase-I:II combinations of high-high, high-medium, medium-medium, and medium-high. Kochia seedlings did not emerge under the low rate. Seedlings did emerge from the nonsaline seedbeds when watered at the medium rate, but failed to emerge from the saline seedbeds treated only at this rate. Seedlings emerged from the saline soil under all regimes that included the high rainfall rate. About 30 plants successfully emerged from every 100 seeds sown in the seedbeds where ECe decreased to 15.7 dS/m or less. Despite the severely saline seedbed, kochia emerged within 3 days at a rate of 8 plants/day under the Phase I high regime because the water apparently diluted saline seedbed-solutions sufficiently for germination to occur. Phase II of the medium-high regime stimulated a similar response but only after 13 days under the wetter rate. Kochia's germination and emergence favor its addition to seed mixtures designed to establish forages in saline soils.
    • Komondor Guard Dogs Reduce Sheep Losses to Coyotes: A Preliminary Evaluation

      Linhart, S. B.; Sterner, R. T.; Carrigan, T. C.; Henne, D. R. (Society for Range Management, 1979-05-01)
      Four Komondor dogs were trained to attack captive coyotes and to stay within fenced sheep pastures. The dogs, used in pairs, were then evaluated on three ranches (65 to 330-ha pastures) to determine their potential in protecting sheep from coyote predation. Daily checks of sheep losses were made on each ranch for three consecutive 20-day periods: preceding placement of the dogs, during their time in pastures, and after their removal. Sheep kills by coyotes decreased significantly during and following use of the dogs, suggesting some potential for the deterrence of coyote predation-at least under fenced-grazing conditions.
    • Laboratory germination responses of 3 love-grasses to temperature in relation to seedbed temperature

      Roundy, B. A.; Young, J. A.; Sumrall, L. B.; Livingston, M. (Society for Range Management, 1992-05-01)
      Laboratory tests are often conducted to determine seed germination responses to temperatures for seedbed ecology interpretations and revegetation seeding rate calculations. To determine the utility of laboratory germination tests for indicating seedbank germinability of lovegrasses we measured seedbed temperatures and soil water on 2 semidesert grassland sites in the Southwest. We also tested germination of Lehmann lovegrass (Eragrostis lehmanniana Nees), 'Cochise' lovegrass (E. lehmanniana Nees X E. trichophora Coss & Dur.), and plains lovegrass (E. intermedia Hitch.) seed collections associated with natural or artificial revegetation studies on these 2 sites in relation to an array of constant and alternating temperatures. Germination responses to different temperatures varied with the year and source of collection and seed age and differed compared to those reported in the literature. Lehmann and Cochise lovegrass had high germination at temperature alternations similar to wet seedbed temperature extremes in December (0,2/15 degrees C) and these species and plains lovegrass were germinable at moderate temperature alternations representative of wet seedbeds in April (10/30 degrees C). Ability to germinate in laboratory tests at these temperatures is not necessarily indicative of germinability in the field for Lehmann lovegrass, which has been observed to germinate in April, not December, in wet seedbeds. All species had maximum or near maximum germination at a temperature alternation of 20/40 degrees C, which is similar to wet seedbed temperature extremes during the summer rainy period when these species usually emerge. Because of the variability in germinability of different seed collections of lovegrass over time, specific collections should be tested at specific ages relevant to seedbed ecology and revegetation studies or projects. Laboratory germination tests which mimic actual wet seedbed temperature curves might be more predictive of seedbed germinability than the usual tests which expose the seeds to abrupt temperature alternations.
    • Lack of Native Vegetation Recovery Following Biological Control of Leafy Spurge

      Butler, Jack L.; Wacker, Stefanie D. (Society for Range Management, 2010-09-01)
      Leafy spurge (Euphorbia esula L.) is an aggressive exotic species that has been successfully suppressed in a variety of situations using classical biological control (flea beetles; Aphthona spp.). This 9-yr study investigated patterns of vegetation responses following significant reductions in leafy spurge cover and density by flea beetles in southeastern Montana. We hypothesized that the vegetation following leafy spurge suppression would be dominated by species and plant functional groups able to persist through heavy infestations. Flea beetles were first released in 1998, and by 2006 leafy spurge foliar cover was reduced 80% to 90% compared to 1998 values on both release and nonrelease plots. Although total cover of the resident vegetation, excluding leafy spurge, increased 72% to 88%, relative cover of the functional groups (native forbs, native sedges, native grasses, and non- native species) was similar among years and between release and nonrelease plots. Mean diversity and mean species richness values did not differ among years or between release and nonrelease plots (P < 0.05), but mean diversity on both release and nonrelease plots was significantly less than noninfested plots, although richness was similar (P<0.05). Indicator species analysis revealed that non-native Poa spp. replaced leafy spurge as the dominant species on release and nonrelease plots. Conversely, noninfested plots contained a variety of native species with high indicator values. Although total abundance of the resident vegetation in 2006 was significantly greater than 1998, plant species composition and relative cover showed little change for the duration of the study. Failure of the native vegetation to recover to a community that approached nearby noninfested conditions may be attributed to a variety of interacting scenarios, some of which may be ameliorated by treating infestations as soon as possible to avoid long-term residual effects. 
    • Lana Vetch for Medusahead Control

      Mac Laughlan, R. S.; Miller, H. W.; Hoglund, O. K. (Society for Range Management, 1970-09-01)
      Medusahead is invading California and western Oregon rangeland at an alarming rate. Overseeding with Lana vetch, a self-perpetuating annual legume, appears to be one of the most practical controls. Because Lana vetch can be successfully established without seedbed preparation it offers a practical method of controlling medusahead on rough terrain. Increased production and improved quality of forage from infested annual grass range are the result.
    • Land management history of Canadian grasslands and the impact on soil carbon storage

      Wang, X.; Vandenbygaart, A. J.; McConkey, B. C. (Society for Range Management, 2014-07)
      Grasslands represent a large potential reservoir in storing carbon (C) in plant biomass and soil organic matter via C sequestration, but the potential greatly depends on how grasslands are managed, especially for livestock and wild animal grazing. Positive and negative grazing effects on soil organic carbon have been reported by various studies globally, but it is not known if Canadian grasslands function as a source or a sink for atmospheric C under current management practices. This article examines the effect of grassland management on carbon storage by compiling historical range management facts and measurements from multiple experiments. Results indicate that grazing on grasslands has contributed to a net C sink in the top 15-cm depth under current utilization regimes with a removal rate of CO2 at 0.19 ± 0.02 Mg · C · ha-1 · yr-1 from the atmosphere during recent decades, and net C sequestration was estimated at 5.64 ± 0.97 Mg · C · ha-1 on average. Naturalization of 2.3 M ha of previously cultivated grasslands in the 1930s has also led to C sequestration in the Canadian prairies but has likely abated as the pool has saturated. Efforts made by researchers, policymakers, and the public has successfully led to the restoration of the Canadian prairies to a healthier state and to achieve considerable C sequestration in soils since their severe deterioration in the 1930s. In-depth analysis of management, legislation, and agricultural programs is urgently needed to place the focus on maintaining range health and achieving more C storage in soils, particularly when facing the reduced potential for further C sequestration. © 2014 The Society for Range Management.
    • Land Management Policy and Development of Ecological Concepts

      Jameson, D. A. (Society for Range Management, 1970-09-01)
      As ecological concepts become incorporated into the training and background information of professional land managers, they also become incorporated into land management policies. Recent developments in ecology, such as nutrient cycling studies and computer simulation of complex processes, have a favorable climate for acceptance. Possible applications should be carefully studied by land managers.
    • Land use change effects on breeding bird community composition

      Boren, J. C.; Engle, D. M.; Palmer, M. W.; Masters, R. E.; Criner, T. (Society for Range Management, 1999-09-01)
      We identified land uses, vegetation cover types, and landscape patterns associated with avian community diversity in 2 rural landscapes in a hardwood forest-tallgrass prairie ecotone that differ with regard to human population density. We obtained long-term (24 years) changes in avian community composition through records from the North American Breeding Bird Survey. We obtained historical and present land use, vegetation cover types, and landscape structure of both landscapes from high-resolution aerial photography. Avian community composition in the low density rural population landscape was primarily related to the amount of land in deciduous forest and land treated with fire or herbicides. In contrast, avian community composition in the high density rural population landscape was primarily related to the amount of land in deciduous forest, native grassland, and roads. Changes in vegetation cover type were related to changes in the avian community composition by increasing prairie habitat associated species in the low density rural population and generalist habitat associated species in the high density rural population landscapes. Loss of neotropical migrants and increased number of generalist species in the high density rural population landscape was related to decreased native vegetation, road development, and increased landscape fragmentation. Biologists and conservationists in this region should focus attention on preserving biological diversity of rural ecosystems by maintaining native plant communities.
    • Land Use Influences Carbon Fluxes in Northern Kazakhstan

      Perez-Quezada, Jorge F.; Saliendra, Nicanor Z.; Akshalov, Kanat; Johnson, Douglas A.; Laca, Emilio (Society for Range Management, 2010-01-01)
      A mobile, closed-chamber system (CC) was used to measure carbon and water fluxes on four land-use types common in the Kazakh steppe ecoregion. Land uses represented crop (wheat or barley, WB), abandoned land (AL), crested wheatgrass (CW), and virgin land (VL). Measurements were conducted during the growing season of 2002 in northern Kazakhstan at three locations (blocks) 15-20 km apart. The CC allowed the measurement of the carbon flux components of net ecosystem exchange (NEE), ecosystem respiration (RE) and soil respiration (RS), together with evapotranspiration (ET). Nonlinear regression analyses were used to model gross primary production (GPP) and ET as a function of photosynthetically active radiation (Q); RE and RS were modeled based on air (Tair) and soil (Ts) temperature, respectively. GPP, RE, RS, and ET were estimated for the entire year with the use of continuous 20-min means of Q, Tair, and Ts. Annual NEE indicated that AL gained 536 g CO2 m-2, WB lost – 191 g CO2 m-2, CW was near equilibrium (–14g CO2 m-2), and VL exhibited considerable carbon accumulation (153g CO2 m-2). The lower GPP values of the land-use types dominated by native species (CW and VL) compared to WB and AL were compensated by positive NEE values that were maintained during a longer growing season. As expected, VL and CW allocated a larger proportion of their carbon assimilates belowground. Non-growing-season RE accounted for about 19% of annual RE in all land-use types. The results of this landscape-level study suggest that carbon lost by cultivation of VLs is partially being restored when fields are left uncultivated, and that VLs are net sinks of carbon. Estimations of carbon balances have important management implications, such as estimation of ecosystem productivity and carbon credit certification. 
    • Land Use, Ethics, and Property Rights—a Western View from the East

      Burch, W. R. (Society for Range Management, 1975-01-01)
      Changes in the nature of property rights regulate the survival potential of social systems. In our era the traditional market system no longer manages the property realities where former scarcities become abundant and former abundance becomes scarce. The experience of land-use in the arid West and John Wesley Powell's vision of the future provide essential lessons for both the dry and humid zones of modern America.
    • Land Use, Soil Erosion, and Livestock Problems in Ceylon

      Gorrie, R. M. (Society for Range Management, 1952-07-01)
    • Land-Use Legacies and Vegetation Recovery 90 Years After Cultivation in Great Basin Sagebrush Ecosystems

      Morris, L. R.; Monaco, T. A.; Sheley, R. L. (Society for Range Management, 2011-09-01)
       Agricultural land use is known to alter ecological processes, and native plant communities can require decades to centuries to recover from the disturbance of cultivation. ‘‘Recovery’’ is typically measured by comparison to undisturbed adjacent sites as a control. Recovery following cultivation in sagebrush ecosystems of the Great Basin remains largely unexamined even though nearly a half million hectares of land were dry-farmed and abandoned in the early 1900s. We tested the hypothesis that the native vegetation has not recovered from this exotic disturbance by evaluating differences in canopy cover of shrubs, grasses, and forbs between paired sets of historically dry-farmed land and adjacent never-cultivated areas. Paired sites were located in three ecological sites in northwestern Utah. We found that vegetation recovery from cultivation is variable by growth form, species, and ecological site. Shrub recovery was different among sagebrush (Artemisia) species. Yellow rabbitbrush (Chrysothamnus viscidiflorus [Hook.] Nutt.) and black greasewood (Sarcobatus vermiculatus [Hook.] Torr.), which often increase following disturbance, maintained higher cover inside old fields. At one of the paired sets, shrub composition was altered from a mix of four species to dominance of mainly Wyoming big sagebrush (Artemisia tridentata Nutt. subsp. wyomingensis Beetle Young). Total forb cover was generally lower in cultivated areas and some species, such as spiny phlox (Phlox hoodii Richardson), had not recovered. The most common grass species encountered across all ecological sites, bottlebrush squirreltail (Elymus elymoides [Raf.] Swezey), had higher cover in cultivated areas. Surprisingly, exotic annual species, such as cheatgrass (Bromus tectorum L.), did not dominate these sites as they have for decades after cultivation in other areas of the Great Basin. This study demonstrates that the land-use legacy of dry farming on vegetation remains nearly a century after cultivation has ceased, and has direct implications for describing ecological site conditions. Resumen Es sabido que la actividad agr ́ıcola altera los procesos ecolo ́gicos y las comunidades de plantas nativas pueden requerir de ́cadas o siglos para recuperarse del disturbio provocado por el cultivo. La ‘‘Recuperacio ́n’’ es mide normalmente, comparando un sitio con disturbio con otro sin disturbio como control. La recuperacio ́n de los ecosistemas de artemisa del Great Basin, en los Estados Unidos de Norteame ́rica permanece sin investigar aun cuando cerca de medio millo ́n de hecta ́reas de tierra fueron abiertas al cultivo y despue ́s abandonadas a principios del 1900. Probamos la hipo ́tesis de que la vegetacio ́n nativa no se ha recuperado de ese disturbio, evaluando diferencias en la cubierta del dosel de arbustos, pastos y hierbas entre parcelas pares; una histo ́ricamente cultivada en condiciones de temporal y otra parcela adyacente nunca cultivada. Las parcelas apareadas fueron ubicadas en tres sitios ecolo ́gicos en la parte noroeste de Utah. Encontramos que la recuperacio ́n de la vegetacio ́n por efecto del cultivo es variable por formas de crecimiento, especies y sitio ecolo ́gico. La recuperacio ́n de los arbustos fue diferente entre las especies de artemisas. Las especies Chrysothamnus viscidiflorus (Hook.) Nutt. y Sarcobatus vermiculatus (Hook.) Torr. que normalmente incrementan despue ́s del disturbio mantuvieron alta cobertura en las tierras de cultivo abandonadas. En uno de los grupos de parcelas, la composicio ́n de arbustos fue dominada principalmente, por cuatro especies Artemisia tridentata Nutt. subsp. wyomingensis Beetle Young. La cubierta de hierbas fue generalmente baja en a ́reas cultivadas y algunas especies como Phlox hoodii Richardson no tuvieron recuperacio ́n. La especie de pasto comu ́nmente encontrada en todos los sitios ecolo ́gicos fue, Elymus elymoides (Raf.) Swezey que mostro alta cobertura en areas cultivadas. Sorpresivamente, especies exo ́ticas anuales como Bromus tectorum L no dominaron esos sitios como lo han hecho por de ́cadas en tierras abiertas al cultivo en otras partes de la Great Basin. Este estudio demuestra que la herencia dejada por la agricultura en condiciones de temporal se mantiene despue ́s de casi un siglo que la actividad agrı ́cola haya terminado y tiene implicaciones directas para describir la condicio ́n de sitio ecolo ́gico.
    • Landowner willingness to participate in a Texas brush reduction program

      Kreuter, Urs P.; Tays, Mark R.; Conner, J. Richard (Society for Range Management, 2004-05-01)
      Because most of Texas consists of privately owned land and the amount of brush cover on rangelands may affect off-site water yields, there has been increasing interest in publicly funded brush clearing programs aimed at increasing water yield. The Pedernales River was selected as 1 of 8 watersheds to determine the feasibility of implementing such a program. A survey questionnaire was mailed to 720 landowners in Blanco and Gillespie County (containing most of the Pedernales watershed) in June 2000 to identify factors that influence their interest in participating in a brush reduction program. The sample consisted of equal numbers of landowners with 4-20, 21-202, and > 202 ha of land. Fifty eight percent of the survey participants responded, 82% of whom answered questions about their willingness to enroll at least part of their land in a brush reduction program. Property size and income from wildlife were found to be significant positive determinants and level of satisfaction with brush a significant negative determinant of respondents' willingness to enroll. To optimize public investments, it may be preferable to maximize the area enrolled in a brush removal program by targeting larger landowners who appear to be willing to enroll larger portions of their land without requiring compensation that exceeds their net cost of enrollment. Because land in the Edwards Plateau is being subdivided and purchased by people who do not depend on land-based income and who may be more tolerant of brush, public funds required to encourage landowner participation may increase over time.
    • Landsat Computer-aided Analysis Techniques for Range Vegetation Mapping

      McGraw, J. F.; Tueller, P. T. (Society for Range Management, 1983-09-01)
      Landsat computer-aided analysis techniques were used to map the sagebrush-grass vegetation of northern Nevada. A final Landsat digital classification resulted in 14 spectral classes representing 8 range plant communities. Classification accuracy for all sample plots was 86.4%, with individual class accuracies ranging from 77.8 to 95.4%. Classification methods included supervised, unsupervised, and guided clustering techniques using a maximum likelihood classifier.