• 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.
    • Landscape Attributes Of Subdivided Ranches

      Mitchell, John E.; Knight, Richard L.; Camp, Richard J. (Society for Range Management, 2002-02-01)
    • Landscape Factors Influencing the Abundance and Dominance of the Invasive Plant Potentilla recta

      Endress, Bryan A.; Naylor, Bridgett J.; Parks, Catherine; Radosevich, Steven R. (Society for Range Management, 2007-05-01)
      Little is known about the relative importance of environmental, biotic, historical, and spatial factors that influence invasive plant abundance, dominance, and distribution across landscapes. We identified factors that influence the abundance and dominance of Potentilla recta L. (sulfur cinquefoil) in bunchgrass grasslands of northeastern Oregon to better understand the conditions under which it becomes a major component of plant communities. We estimated P. recta stem density and dominance from field measurements across the landscape and used classification and regression tree analyses to assess the importance of environmental, biotic, spatial, and historical factors in explaining P. recta presence, stem density, and dominance. Plots were sampled within a systematic grid with 250-m spacing within our 6.5-km2 study landscape. At each sample point we recorded P. recta presence, stem density, and dominance as well as 11 biological, environmental, spatial, and historical variables. P. recta was widely distributed, with stem densities in occupied plots averaging 5.8 stems N m-2 and dominance values ranging from 1% to 52%. Percent cover of bare ground was the most important variable to predict the presence of P. recta, though the model fit was poor, likely because the entire study area is suitable for P. recta establishment. A strong relationship between P. recta dominance and habitat type (r2 = 67.5%) was found, with dominance greatest in old fields on relatively flat slopes (mean dominance of 34.1%). Dominance estimates were < 1% in plots located in forest, shrub, and grassland habitats. Factors that make old fields susceptible to dominance remain unknown, though microsite conditions that increase P. recta seedling survival rates and limited native propagule availability due to previous cultivation may be involved. Since old fields are found throughout the region, are highly susceptible to P. recta invasion, and represent a source of seeds, containment and restoration activities should focus on these areas. 
    • Landscape heterogeneity and long-term animal production in Tierra del Fuego

      Cingolani, A. M.; Anchorena, J.; Collantes, M. B. (Society for Range Management, 1998-01-01)
      Grasslands of northern Tierra del Fuego sustain 1 sheep/ha and are very extensively managed, with flocks roaming freely in large paddocks (2,000-4,000 ha). This system requires knowledge of landscape-level constraints and influences upon production for decision making. On a typical sheep ranch we checked upland floristic gradients against 30-years records of animal production. Community types and landscape units were surveyed and mapped. Using gradient analysis techniques we obtained animal production differences at the landscape scale that were strongly related to a vegetation gradient associated with soil fertility. Extensive and strongly variable lithological mantles allowed expression of the fertility gradient at that scale. Landscapes with fertile soils and neutrophilous community types were best for sheep breeding. These landscapes produced a mean of 37% more lambs ha-1 yr-1 than lands with soils of intermediate fertility and slightly acidophilous community types, and 116% more lambs ha-1 yr-1 than lands with highly infertile soils and highly acidophilous vegetation. Contrarily, the soil moisture gradient, being mainly expressed at the topographic scale, was not related with sheep production records. A forage gradient which was identified behind the fertility gradient supported our findings. Poa spp., the main item in sheep diets, and other important forage species attained the highest covers in neutrophilous community types. With the range in proportion of lowlands present in this ranch (12 to 30%), no relationship was found between the percentage of hygrophitic vegetation in the landscape and animal production.
    • Landscape structure and change in a hardwood forest-tall-grass prairie ecotone

      Boren, J. C.; Engle, D. M.; Gregory, M. S.; Masters, R. E.; Bidwell, T. G.; Mast, V. A. (Society for Range Management, 1997-05-01)
      Temporal changes in land use, vegetation cover types, and landscape structure were examined in a hardwood forest-tallgrass prairie ecotone in northern Oklahoma using a Geographic Information System. Our objective was to examine relationships between human activity, changes in land use and vegetation cover type, and landscape structure in rural landscapes between 1966 and 1990. Cover types in most of the high density rural population landscape in this study require more intensive inputs and management, which resulted in a landscape with lower diversity, higher homogeneity, and greater patch fragmentation compared to the low density rural population landscape. Both native grasslands and forests were less fragmented in the low density rural population landscape whereas forests were increasingly fragmented in the high density rural population landscape. Native grasslands were less fragmented than forests for all years in both the low density rural population and high density rural population landscapes. Our study suggests conservationists should focus their concerns on fragmentation and losses in biological diversity that accompany increased human activity in densely populated rural landscapes that surround urban centers. Extensively managed landscapes dominated by native vegetation that are under less pressure from expanding human influence are in less peril.
    • Landscape use by cattle affected by pasture developments and season

      Zuo, Haitao; Miller-Goodman, Mary S. (Society for Range Management, 2004-09-01)
      Allowing cattle (Bos taurus L.) unrestricted access to streams can contribute to degradation of riparian and aquatic habitats. The objectives of this study were (1) to quantify the amount of time cattle spend using streams and associated riparian habitats when off-stream water and shade sources are offered and (2) to relate these patterns of habitat use to diurnal and seasonal changes in environmental conditions characteristic of the lower southeast. Diurnal (dawn-to-dusk) patterns of cattle location and behaviors were monitored between March 2000 and October 2001 in north-central Alabama at farms with pastures in which wooded streams were present. No significant decrease was detected in the length of diurnal periods cattle spent in riparian habitats after water and shade developments were in place. Grazing (7.8 hours) dominated daytime behaviors of cattle during the cool season when preference was for grassland habitat (7.6 hours). During the warm season, time spent lying increased to 4.7 hours versus 2.7 hours during the cool season; cattle consistently sought either riparian or other wooded habitat at midday and afternoon in comparison to morning and evening periods. Overall, grazing behaviors occurred predominantly (80%) in grassland habitat and lying behaviors occurred mainly (60%) in wooded habitat. Results suggested that comfort (relief from heat stress) appeared to be a major criterion in habitat use decisions by cattle during the warm season for the relatively small spatial scales (3.3 and 6.9 ha) studied. Therefore, dependence only on water and shade developments for alterations in livestock distribution may not be the most effective strategy for reduced degradation of many riparian habitats found in this region.
    • Landscape-Level Conservation: Modern management of traditional lands: A case study of common rangelands in Germany’s Southern Black Forester

      Plieninger, Tobias; Reinbolz, Andreas (Society for Range Management, 2004-12-01)
      Modern management of traditional lands: A case study of common rangelands in Germany's Southern Black Forest.
    • Landscape-level dynamics of grassland-forest transitions in British Columbia

      Bai, Yuguang; Broersma, Klaas; Thompson, Don; Ross, Timothy J. (Society for Range Management, 2004-01-01)
      Grasslands in the interior British Columbia of Canada are adjacent to forests and are susceptible to tree encroachment. Grazing, fire suppression, and climate variability are among factors affecting vegetation dynamics in the ecotone between grassland and forest, but topographic factors such as slope aspect, slope degree and elevation may interact with these factors and result in uneven changes in vegetation among landscape elements. Nine sites with a total of approximately 50,000 ha of grasslands and forests in the Cariboo/Chilcotin forest region of British Columbia were selected to study the effect of slope aspect, slope degree and elevation on vegetation distribution, dynamics and forest expansion from the 1960's to 1990's. Vegetation maps of the 1960's and 1990's were generated using aerial photos and overlaid with GIS layers including aspect, slope and elevation. The classification of open grassland, treed grassland, open forest and closed forest was based on the percent coverage of coniferous species, ranging from 0-5%, 5-15%, 15-35%, and ≥ 35%, respectively. A probability index (P-value) was developed to test the effect of aspect, slope, and elevation on vegetation distribution, dynamics, and forest expansion based on the distribution and changed areas. Results show that open grasslands occurred on southerly aspects and the shift to treed grassland occurred mostly on these aspects. The probability of vegetation shift from open to treed grasslands decreased with increasing slope degree, probably due to the less favorable moisture regime on steep slopes. Treed grassland also shifted to open forest on south facing slopes and more level sites. In contrast, closed forest most often occurred on northerly facing slopes and the shift from open to closed forests was most likely to occur there. The greatest changes in vegetation cover types occurred at mid-elevations between 700 and 1,000 m. Management plans aimed at the control of tree encroachment and forest ingrowth should take these topographic factors into consideration.
    • Large Alligator Junipers Benefit Early-Spring Forage

      Clary, W. P.; Morrison, D. C. (Society for Range Management, 1973-01-01)
      The production of early-spring grasses in central Arizona was four to five times higher under crowns of large alligator juniper than for similar sized areas away from the trees. Virtually all utilization of green forage by grazing animals at this time of the year occurred under the juniper crowns. These large alligator junipers should be protected during pinyon-juniper control operations.
    • Large Scale Farming of Native Plant and Animal Species

      Henshaw, Rebecca L. (Society for Range Management, 1986-04-01)
    • Large Seeds Produce More, Better Alkali Sacaton Plants

      Knipe, O. D. (Society for Range Management, 1970-09-01)
      Larger seeds of alkali sacaton germinated better and faster than the smaller sizes. Seedlings from larger seeds emerged from deeper depths and had a higher growth rate.
    • Large ungulate habitat preference in Chobe National Park, Botswana

      Omphile, U. J.; Powell, J. (Society for Range Management, 2002-07-01)
      Both large ungulates and wildlife tourists tend to concentrate along the Chobe River in Chobe National Park, Botswana, during the dry season causing concern for wildlife habitat and the recreational experience for wildlife viewers. Therefore, ground reconnaissance inventory data of 5 most common large ungulates were collected during the early morning and late afternoon hours along tourist routes in 5 different habitat types every second month for a period of 24 months in Chobe National Park to determine their relative, seasonal habitat preference and availability for viewing by vehicular tourists. A total of 909 herds: greater kudu (Tragelaphus strepsiceros), 285; impala (Aepyceros melampus), 209; elephant (Loxodonta africana), 200; giraffe (Giraffa camelopardalis), 138; and buffalo (Syncerus caffra), 77 were observed during the 760 observation periods. The average frequency of observation of a herd of 1 or more of these 5 ungulates per habitat type was alkali flats, 3.42; floodplain grassland, 2.67; shrub savanna, 2.29; tree savanna, 1.04; and woodland, 0.30. This order of frequency of observation is highly correlated with nearness to the Chobe River, the major water source during the dry season. Elephant and giraffe were more wide-ranging than buffalo, impala, and kudu. During the dry season, all animals were seen more often on the floodplain grassland in the afternoon than in the morning. Giraffe were never seen in any habitat type in December, and impala were never seen in the woodland in any month. Our data confirm that tour operators interested primarily in providing their guests with a view of the greatest numbers of animals in a limited period of time are justified in congregating along the Chobe River during the dry season. However, as in most public wildlife reserves, Chobe National Park management is faced with the decision of how best to optimize the biological needs of Park animals and their habitat with the economic and recreational desires of Park users.
    • Large-Scale Aerial Images Capture Details of Invasive Plant Populations

      Blumenthal, Dana; Booth, D. Terrence; Cox, Samuel E.; Ferrier, Cara E. (Society for Range Management, 2007-09-01)
      Satellite and high-altitude aerial remote sensing have been used to measure dense infestations of invasive weeds over very large areas but have limited resolution and cannot be used to detect sparsely distributed weeds. Ground-based methods have provided detailed measurements of invasive weeds but can measure only limited areas. Here we test a novel approach that uses a lightweight airplane, flying at 72 km h-1 and 100-m altitude, to rapidly collect high-resolution images over relatively large areas. We obtained 1 987 images, each representing 48.5 m2 of mixed-grass prairie with 2-mm resolution (ground sample distance). From these images we were able to reliably measure small patches and even individual plants of the invasive forb Dalmatian toadflax (Linaria dalmatica [L.] P. Mill.). Ground-based measurements of aboveground toadflax biomass were highly correlated (R2>0.93) with point-intercept and visual-estimate cover measurements from aerial images. The time required to analyze images ranged from 4 to 45 seconds for presence/absence data and from 1 to 6 minutes for cover data. Toadflax was present in 795 of 1 987 images but exceeded 1% cover in only 99 images. Given the observed variation among images in toadflax cover, at least 400 images were needed to precisely estimate the mean toadflax cover of 0.2%. These results suggest that such high-resolution aerial imagery could be used to obtain detailed measurements of many invasive weed populations. It may be most useful for identifying incipient weed infestations and expanding the scale at which population-level attributes of weed populations can be effectively measured. 
    • Large-scale downy brome treatments alter plant-soil relationships and promote perennial grasses in salt desert shrublands

      Hirsch-Schantz, M. C.; Monaco, T. A.; Call, C. A.; Sheley, R. L. (Society for Range Management, 2014-05)
      Because invasive annual grasses can strongly influence soil resource availability and disturbance regimes to favor their own persistence, there is a great need to understand the interrelationships among invasive plant abundance, resource availability, and desirable species prominence. These interrelationships were studied in two salt desert sites where the local abundance of downy brome (Bromus tectorum L.) varied spatially and increased more than 12-fold over a 3-yr period. We measured downy brome percentage cover, resource availability, and soil chemical and physical properties within 112 plots per site and found significant negative associations between downy brome abundance and both soil water content (P&lt;0.05; r=-0.27 to -0.49) and nitrate accumulation (P&lt;0.05; r=-0.34 to -0.45), which corroborated with the direction and strength of multivariate factor loadings assessed with principal component analysis. We then applied factorial combinations of prescribed burning and preemergence herbicide at management-relevant scales (i.e., 6 to 46 ha) as well as biomass removal to smaller plots (12.25 m2) at both sites to determine their impact on downy brome, soil resources, and resident plant species. Burning and herbicide applications, especially when combined, significantly reduced downy brome cover (P=0.069 to 0.015), which in turn increased soil nitrate accumulation and water content in the spring. Furthermore, for one shrubland site that was seeded 6 yr previously, the combination of burning and herbicide treatments significantly increased perennial grass percentage cover in the 2 yr posttreatment (P&lt;0.05). Results not only demonstrate the strong relationships between downy brome abundance, soil resources, and residence species for impoverished salt desert shrub ecosystems, but also suggest that restoration and management efforts must include tactics that facilitate resource use by the residual plant community or establish a greater abundance of species capable of high resource acquisition in the spring.
    • Larger Pits Aid Reseeding of Semidesert Rangeland

      Slayback, R. D.; Cable, D. R. (Society for Range Management, 1970-09-01)
      Broad, shallow intermediate pits have proved to be longer lasting than conventional pits on semidesert range in the 6- to 8-inch summer rainfall zone in southern Arizona. Rainfall penetration averaged twice as deep in the pits as on adjacent flats. Herbage production of buffelgrass averaged 2 1/2 times as high, over a 4-year period, on the intermediate pits as on conventional pits, and five times as much as on similar adjacent untreated range.
    • Larger Seeds of Winterfat Germinate Better

      Springfield, H. W. (Society for Range Management, 1973-03-01)
      Seeds of winterfat (Eurotia lanata) were separated into three size classes and germinated under four temperature regimes. Large- and medium-size seeds germinated better and faster than small-size seeds.
    • Larkspur chemistry: Toxic alkaloids in tall larkspurs

      Manners, G. D.; Pfister, J. A.; Ralphs, M. H.; Panter, K. E.; Olsen, J. D. (Society for Range Management, 1992-01-01)
      Three species of tall larkspur (Delphinium barbeyi (Huth), Delphinium occidentale (Wats.) Wats, and Delphinium glaucescens) that are toxic to cattle were chemically analyzed to determine “total alkaloid” content. D. barbeyi and D. occidentale contained more “total alkaloids” than D. glaucescens. The “total alkaloid” content of all plant tissues in the 3 species declined as the growing season progressed. Variation in the occurrence of specific diterpenoid alkaloids was established by gas chromatographic analysis of D. barbeyi plant tissues at different phenological growth stages. Highest yields of specific alkaloids were found in early growth stage plant tissues. Deltaline was the most prominent diterpenoid alkaloid in D. barbeyi and 14-0-acetyldictyocarpine is a new diterpenoid alkaloid with high occurrence in this plant. The toxicity of specific diterpenoid alkaloids obtained from the tall larkspurs evaluated in a mouse bioassay showed methyllcaconitine to be highly toxic. Other diterpenoid alkaloids isolated from the 3 Iarkspurs showed much lower levels of toxicity compared to methyllycaconitine