Rangeland Ecology & Management, Volume 59, Number 5 (September 2006)http://hdl.handle.net/10150/6354252024-03-28T08:17:05Z2024-03-28T08:17:05ZUse of Fluorometry to Differentiate Among Clipped Species in the Genera Astragalus, Oxytropis, and PleuraphisAnderson, Dean M.Rayson, Gary D.Obeidat, Safwan M.Ralphs, MichaelEstell, RickFredrickson, Ed L.Parker, EricGray, Perryhttp://hdl.handle.net/10150/6431072020-09-06T01:52:16Z2006-09-01T00:00:00ZUse of Fluorometry to Differentiate Among Clipped Species in the Genera Astragalus, Oxytropis, and Pleuraphis
Anderson, Dean M.; Rayson, Gary D.; Obeidat, Safwan M.; Ralphs, Michael; Estell, Rick; Fredrickson, Ed L.; Parker, Eric; Gray, Perry
A rapid and reproducible method to determine botanical composition of forage is an ecological and economic goal for range animal ecologists. Multidimensional fluorometry previously demonstrated the possibility of a unique optical approach for accurately determining species composition of clipped and digested plant materials. Fluorometry may be used to detect toxic plants in standing crop as well as diets by using electronic transitions in chemical structures at wavelengths between 370 and 580 nm. Grass hay (genus Pleuraphis) and 6 clipped forbs (4 species of Astragalus and 2 species of Oxytropis) were examined. The resulting spectral signatures were evaluated for differences in the blue and green regions of the visible spectrum using Principal Component Analysis (PCA). This represents the first published data using chemometrics to differentiate among fluorophores from these plant extracts. It was possible to distinguish between the grass and forbs and among forbs. Further research will be required to evaluate these same plant species in mixed diets and fecal samples.
2006-09-01T00:00:00ZEstablishing Vegetation on Migrating Inland Sand Dunes in TexasFulbright, Timothy E.Ortega-Santos, Alfonso J.Lozano-Cavazos, AlejandroRamírez-Yanez, Luis Enriquehttp://hdl.handle.net/10150/6431062020-09-06T01:52:04Z2006-09-01T00:00:00ZEstablishing Vegetation on Migrating Inland Sand Dunes in Texas
Fulbright, Timothy E.; Ortega-Santos, Alfonso J.; Lozano-Cavazos, Alejandro; Ramírez-Yanez, Luis Enrique
Migration of sand dunes damages range improvements in the Texas Coastal Sand Plain. We determined effects of mulching with native prairie hay and an open weave geotextile fabric, seeding, fertilization, and transplanting on plant species canopy cover on inland sand dunes. We compared applying native hay vs. a synthetic geotextile material to inhibit wind erosion, seeding ‘Alamo’ switchgrass (Panicum virgatum L.), ‘Mason’ sandhill lovegrass (Eragrostis trichodes [Nutt.] Wood), and partridge pea (Chamaecrista fasciculata [Michx.] Greene) vs. no seeding, and fertilization with 468 kg ha-1 of 45:45:90 (N:P:K) vs. no fertilization. The same treatments were compared in a second experiment except that switchgrass, sandhill lovegrass, vetiver (Vetiveria zizanoides [L.] Nash ex Small), and giant reed (Arundo donax L.) were transplanted rather than seeded. Treatments were applied during March and April 1994 and canopy cover of vegetation in each experimental unit was estimated in October 1994, 1995, and 2004. Livestock were excluded from the study sites. The geotextile fabric degraded within 4 months and was replaced with coastal Bermuda (Cynodon dactylon [L.] Pers.) hay. Fertilization plus native hay mulch resulted in greater (P < 0.05) canopy cover of purple sandgrass (Triplasis purpurea [Walt.] Chapm.), sandbur (Cenchrus incertus M. A. Curtis and C. echinatus L.), and snakecotton (Froelichia spp.) than other treatments in 1994. In 1994 and 1995, canopy cover of switchgrass and sandhill lovegrass was greater (P < 0.05) with a combination of geotextile fabric and commercial hay, seeding, and fertilization than in other treatments. Vegetation composition and canopy cover were similar (P > 0.05) across treatments in 2004 in both experiments. Fertilization, seeding, and transplanting appear unnecessary to establish vegetation on dunes protected from livestock grazing when mulch is applied to inhibit sand movement.
2006-09-01T00:00:00ZExperimental Use of Remote Sensing by Private Range Managers and Its Influence on Management DecisionsBetterfield, Scott H.Malmstrom, Carolyn M.http://hdl.handle.net/10150/6431052020-09-06T01:51:51Z2006-09-01T00:00:00ZExperimental Use of Remote Sensing by Private Range Managers and Its Influence on Management Decisions
Betterfield, Scott H.; Malmstrom, Carolyn M.
Although remote sensing has many potential applications for range management, its use by range managers thus far has been limited. To investigate the factors that encourage use of remote sensing and to examine its influence on decision making by individuals who manage privately owned rangeland, we evaluated the decision-making processes of 3 ranch owners and 1 professional ranch manager who were introduced to remote sensing while collaborating with us in a rangeland stewardship program in California. Two of the participants had extensive ranching experience (11 to > 20 years) and managed large cattle ranches (1 000 to > 2 000 ha), and 2 had less experience and managed smaller sheep ranches (< 200 ha). During the 5-year program, the participants implemented a series of new management practices, including prescribed burning, rotational grazing, and seeding of native grasses, with the aim of reducing noxious weeds and increasing productivity. We used remote sensing to quantify the effect of these practices and provided ranch-wide remote sensing analyses to each manager on a password-protected Web site. Using case study methodologies, we found that managers of larger, commercially active ranches found the experimental use of remote sensing to be a highly positive experience that convinced them that this technology could help address difficult management situations and increase ranch profitability. This suggests that the broad use of remote sensing by managers of privately held, commercial rangelands may be limited in part by the simple lack of opportunity to test these technologies. Programs that assist ranchers in obtaining appropriate remote sensing products thus may be a cost-effective way to enhance conservation on private rangelands. Our findings suggest that voluntary self-analysis by ranchers of the landscape dynamics of their own properties is likely to lead to more engaged conservation efforts than will top- down prescriptions.
2006-09-01T00:00:00ZRemote Sensing for Grassland Management in the Arid SouthwestMarsett, Robert C.Qi, JiaguoHeilman, PhilipBiedenbender, Sharon H.Watson, Carolyn M.Amer, SandWeltz, MarkGoodrich, DavidMarsett, Roseannhttp://hdl.handle.net/10150/6431042020-09-06T01:51:39Z2006-09-01T00:00:00ZRemote Sensing for Grassland Management in the Arid Southwest
Marsett, Robert C.; Qi, Jiaguo; Heilman, Philip; Biedenbender, Sharon H.; Watson, Carolyn M.; Amer, Sand; Weltz, Mark; Goodrich, David; Marsett, Roseann
We surveyed a group of rangeland managers in the Southwest about vegetation monitoring needs on grassland. Based on their responses, the objective of the RANGES (Rangeland Analysis Utilizing Geospatial Information Science) project was defined to be the accurate conversion of remotely sensed data (satellite imagery) to quantitative estimates of total (green and senescent) standing cover and biomass on grasslands and semidesert grasslands. Although remote sensing has been used to estimate green vegetation cover, in arid grasslands herbaceous vegetation is senescent much of the year and is not detected by current remote sensing techniques. We developed a ground truth protocol compatible with both range management requirements and Landsat’s 30 m resolution imagery. The resulting ground-truth data were then used to develop image processing algorithms that quantified total herbaceous vegetation cover, height, and biomass. Cover was calculated based on a newly developed Soil Adjusted Total Vegetation Index (SATVI), and height and biomass were estimated based on reflectance in the near infrared (NIR) band. Comparison of the remotely sensed estimates with independent ground measurements produced r2 values of 0.80, 0.85, and 0.77 and Nash Sutcliffe values of 0.78, 0.70, and 0.77 for the cover, plant height, and biomass, respectively. The approach for estimating plant height and biomass did not work for sites where forbs comprised more than 30% of total vegetative cover. The ground reconnaissance protocol and image processing techniques together offer land managers accurate and timely methods for monitoring extensive grasslands. The time-consuming requirement to collect concurrent data in the field for each image implies a need to share the high fixed costs of processing an image across multiple users to reduce the costs for individual rangeland managers.
2006-09-01T00:00:00Z