Pub Date : 2003-11-01DOI: 10.2458/AZU_JRM_V56I6_WHALEN
J. Whalen, W. Willms, J. F. Dormaar
Rangelands contain between 10 and 30% of global soil organic C reserves and may be an important sink for atmospheric CO2, but less C tends to be stored in rangelands cultivated for agricultural use than undisturbed rangelands. Establishing perennial plant communities on formerly cultivated rangelands is expected to stabilize soil properties and increase the amount of C stored in rangeland soils, but there is little information on what plant communities are most effective at building soil C reserves. The purpose of this study was to compare soil C, N, and P pools in ungrazed native rangelands with ungrazed, unfertilized rangelands that were cultivated and then 1) abandoned, 2) seeded with non-native perennial grasses or legumes, or 3) cropped annually for 5 to 6 years. Three study sites in southern Alberta, Canada with native Stipa-Bouteloua, Stipa-Bouteloua-Agropyron and Festuca campestris plant communities represented the major ecotypes of the Northern Great Plains. The total C, N, and P content of rangeland soils were greatest at the Festuca campestris site, followed by the Stipa-Bouteloua-Agropyron and Stipa-Bouteloua sites, probably due to climatic conditions (precipitation and temperature). Generally, soils under modified plant communities contained less total C and N than soils under native rangeland, but the total P content was related more to site preparation than experimental treatments. Soils under alfalfa, orchardgrass and bromegrass tended to have more total C and N than soils cultivated annually in continuous wheat or wheat-fallow systems. The accumulation of C and N in soils under permanent cover was not related to net primary productivity and may be influenced more by the chemical composition and rate of decomposition of plant residues. DOI:10.2458/azu_jrm_v56i6_whalen
{"title":"Soil carbon, nitrogen and phosphorus in modified rangeland communities","authors":"J. Whalen, W. Willms, J. F. Dormaar","doi":"10.2458/AZU_JRM_V56I6_WHALEN","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V56I6_WHALEN","url":null,"abstract":"Rangelands contain between 10 and 30% of global soil organic C reserves and may be an important sink for atmospheric CO2, but less C tends to be stored in rangelands cultivated for agricultural use than undisturbed rangelands. Establishing perennial plant communities on formerly cultivated rangelands is expected to stabilize soil properties and increase the amount of C stored in rangeland soils, but there is little information on what plant communities are most effective at building soil C reserves. The purpose of this study was to compare soil C, N, and P pools in ungrazed native rangelands with ungrazed, unfertilized rangelands that were cultivated and then 1) abandoned, 2) seeded with non-native perennial grasses or legumes, or 3) cropped annually for 5 to 6 years. Three study sites in southern Alberta, Canada with native Stipa-Bouteloua, Stipa-Bouteloua-Agropyron and Festuca campestris plant communities represented the major ecotypes of the Northern Great Plains. The total C, N, and P content of rangeland soils were greatest at the Festuca campestris site, followed by the Stipa-Bouteloua-Agropyron and Stipa-Bouteloua sites, probably due to climatic conditions (precipitation and temperature). Generally, soils under modified plant communities contained less total C and N than soils under native rangeland, but the total P content was related more to site preparation than experimental treatments. Soils under alfalfa, orchardgrass and bromegrass tended to have more total C and N than soils cultivated annually in continuous wheat or wheat-fallow systems. The accumulation of C and N in soils under permanent cover was not related to net primary productivity and may be influenced more by the chemical composition and rate of decomposition of plant residues. DOI:10.2458/azu_jrm_v56i6_whalen","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90470045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-11-01DOI: 10.2458/AZU_JRM_V56I6_TURLEY
D. Turley, B. Roundy, S. Walker
True mountain mahogany (Cercocarpus montanus Raf.) compensates for annual growth lost to browsing under conditions of high resource availability. To develop better guidelines for its management for big game winter forage, twig demography was studied under natural herbivory and resource availability inside and outside exclosures at 1 site in the Wasatch Mountains and on 4 sites on the North Slope of the Uinta Mountains, Utah. Annual and previous years' twig lengths, as well as location and numbers of flowers and seeds were diagrammed on branches of browsed and unbrowsed shrubs in the spring or summer and fall between 1996 and 1999. Annual twig growth and flower and seed numbers of both browsed and unbrowsed shrubs were greatest in 1997 or 1998 when precipitation was highest. Utilization of annual growth varied among sites within a year and among years within a site and ranged from 300 % when previous years' growth was browsed. Despite differences in utilization, browsed twigs compensated similarly for length lost to herbivory, so that total twig lengths remained the same over the course of the study. Although twigs on unbrowsed shrubs had less annual growth per unit branch length than those on browsed shrubs, lack of length lost to herbivory resulted in an increase in total twig length over time. Years of high resource availability are important in allowing grazing tolerant shrubs such as true mountain mahogany to compensate for years of heavy utilization. Flower and seed numbers were much higher (P 100 %) even on years of high resource availability. DOI:10.2458/azu_jrm_v56i6_turley
{"title":"Growth and reproductive responses of true mountain mahogany to browsing","authors":"D. Turley, B. Roundy, S. Walker","doi":"10.2458/AZU_JRM_V56I6_TURLEY","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V56I6_TURLEY","url":null,"abstract":"True mountain mahogany (Cercocarpus montanus Raf.) compensates for annual growth lost to browsing under conditions of high resource availability. To develop better guidelines for its management for big game winter forage, twig demography was studied under natural herbivory and resource availability inside and outside exclosures at 1 site in the Wasatch Mountains and on 4 sites on the North Slope of the Uinta Mountains, Utah. Annual and previous years' twig lengths, as well as location and numbers of flowers and seeds were diagrammed on branches of browsed and unbrowsed shrubs in the spring or summer and fall between 1996 and 1999. Annual twig growth and flower and seed numbers of both browsed and unbrowsed shrubs were greatest in 1997 or 1998 when precipitation was highest. Utilization of annual growth varied among sites within a year and among years within a site and ranged from 300 % when previous years' growth was browsed. Despite differences in utilization, browsed twigs compensated similarly for length lost to herbivory, so that total twig lengths remained the same over the course of the study. Although twigs on unbrowsed shrubs had less annual growth per unit branch length than those on browsed shrubs, lack of length lost to herbivory resulted in an increase in total twig length over time. Years of high resource availability are important in allowing grazing tolerant shrubs such as true mountain mahogany to compensate for years of heavy utilization. Flower and seed numbers were much higher (P 100 %) even on years of high resource availability. DOI:10.2458/azu_jrm_v56i6_turley","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81420827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fremont cottonwood (Populus fremontii S. Watson) is the most important cottonwood species of the southwestern United States. It is usually found in riparian areas of desert riverine systems. Often it is the only tree species in such environments. Lack of Fremont cottonwood seedling recruitment is of concern in many areas. This is especially an issue in river systems infested with the exotic saltceder (Tamarix ramosissima Ledeb.). The proposed suppression of saltceder with a biological control agent, raises the question of the spontaneous recruitment of Fremont cottonwood seedlings if competition is reduced from exotic woody species. Several studies have stressed that geomorphologic-hydrologic conditions in riparian habitats control safesites for Fremont and other cottonwood species seed germination and seedling establishment. Our purpose was to investigate the physiological amplitude for Fremont cottonwood seeds to germinate under a wide range of constant or alternating temperatures. Immediately after dispersal the seeds of Fremont cottonwood are highly germinable. In each of the 3 years that seeds were collected multiple temperature regimes supported 100% germination. Optimum germination averaged over 90%. At moderate to high warm period temperatures, most germination that will occur does so during the first week after imbibition of moisture. Temperature regimes that supported optimum germination at least once ranged from 0/5 C to 25/40 C. The regimes that always supported optimum germination were in 2 distinct group: 2/25 and 2/30 C; and a wider dispersed group with 15, 25, or 25 C cold period temperatures and 25, 30, or 35 C warm period temperatures. There was one outlier at 10/15 C. Fremont cottonwood seeds are highly and rapidly germinable at a wide range of temperatures. DOI:10.2458/azu_jrm_v56i6_young2
白杨(Populus fremontii S. Watson)是美国西南部最重要的白杨树种。它通常出现在沙漠河流系统的河岸地区。通常它是这种环境中唯一的树种。棉杨苗木缺乏是许多地区关注的问题。这在被外来的柽柳(Tamarix ramosissima Ledeb.)侵染的河流系统中尤其是个问题。提出了用生物防治剂抑制盐碱病的建议，提出了如果外来木本物种的竞争减少，白杨幼苗的自发招募问题。一些研究强调，河岸生境的地貌水文条件控制着白杨和其他白杨种子萌发和幼苗建立的安全场所。我们的目的是研究在恒定或交变温度的大范围内，棉杨种子发芽的生理振幅。立即散布后，孟山杨的种子是高度发芽。在收集种子的3年中，每一年都有多种温度制度支持100%的发芽。最佳发芽率平均在90%以上。在中等到较高的温暖期温度下，大多数发芽发生在吸湿后的第一周。在0/5℃至25/40℃的温度范围内，至少有一次能使种子萌发达到最佳状态;在2/25℃和2/30℃的温度范围内，总能使种子萌发达到最佳状态;以及具有15、25或25℃冷期温度和25、30或35℃暖期温度的更广泛的分散组。在10/15℃有一个异常值，白杨种子在很宽的温度范围内都能迅速萌发。DOI: 10.2458 / azu_jrm_v56i6_young2
{"title":"Germination of seeds of Fremont cottonwood.","authors":"James A. Young, C. Clements","doi":"10.2307/4003943","DOIUrl":"https://doi.org/10.2307/4003943","url":null,"abstract":"Fremont cottonwood (Populus fremontii S. Watson) is the most important cottonwood species of the southwestern United States. It is usually found in riparian areas of desert riverine systems. Often it is the only tree species in such environments. Lack of Fremont cottonwood seedling recruitment is of concern in many areas. This is especially an issue in river systems infested with the exotic saltceder (Tamarix ramosissima Ledeb.). The proposed suppression of saltceder with a biological control agent, raises the question of the spontaneous recruitment of Fremont cottonwood seedlings if competition is reduced from exotic woody species. Several studies have stressed that geomorphologic-hydrologic conditions in riparian habitats control safesites for Fremont and other cottonwood species seed germination and seedling establishment. Our purpose was to investigate the physiological amplitude for Fremont cottonwood seeds to germinate under a wide range of constant or alternating temperatures. Immediately after dispersal the seeds of Fremont cottonwood are highly germinable. In each of the 3 years that seeds were collected multiple temperature regimes supported 100% germination. Optimum germination averaged over 90%. At moderate to high warm period temperatures, most germination that will occur does so during the first week after imbibition of moisture. Temperature regimes that supported optimum germination at least once ranged from 0/5 C to 25/40 C. The regimes that always supported optimum germination were in 2 distinct group: 2/25 and 2/30 C; and a wider dispersed group with 15, 25, or 25 C cold period temperatures and 25, 30, or 35 C warm period temperatures. There was one outlier at 10/15 C. Fremont cottonwood seeds are highly and rapidly germinable at a wide range of temperatures. DOI:10.2458/azu_jrm_v56i6_young2","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80105204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Several U.S. rangeland areas recently have been designated as national monuments to protect scientifically or culturally important resources. Typically recreation and livestock uses have been retained in these areas. Because some people believe protection and use are incompatible, and because monument designation can increase public scrutiny of management while attracting new visitors to the area, we surveyed hunters and hikers in the Grand Staircase-Escalante National Monument, Utah, about their perceptions of livestock grazing in the monument. We examined associations between visitors' personal characteristics and their reports of how livestock grazing and multiple-use management affect recreation experiences. Recreation activity type was a significant predictor of experience effects, but we found no evidence that the act of designating a national monument itself affected experiences. Locations of current and childhood residence also were significantly associated with experience effects. Because designation tends to attract certain types of visitors more than others, creating rangeland national monuments may foster increased conflict between recreation and livestock grazing uses in those areas. DOI:10.2458/azu_jrm_v56i6_brunson
{"title":"Recreationist responses to livestock grazing in a new national monument.","authors":"M. Brunson, L. Gilbert","doi":"10.2307/4003930","DOIUrl":"https://doi.org/10.2307/4003930","url":null,"abstract":"Several U.S. rangeland areas recently have been designated as national monuments to protect scientifically or culturally important resources. Typically recreation and livestock uses have been retained in these areas. Because some people believe protection and use are incompatible, and because monument designation can increase public scrutiny of management while attracting new visitors to the area, we surveyed hunters and hikers in the Grand Staircase-Escalante National Monument, Utah, about their perceptions of livestock grazing in the monument. We examined associations between visitors' personal characteristics and their reports of how livestock grazing and multiple-use management affect recreation experiences. Recreation activity type was a significant predictor of experience effects, but we found no evidence that the act of designating a national monument itself affected experiences. Locations of current and childhood residence also were significantly associated with experience effects. Because designation tends to attract certain types of visitors more than others, creating rangeland national monuments may foster increased conflict between recreation and livestock grazing uses in those areas. DOI:10.2458/azu_jrm_v56i6_brunson","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75060601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-11-01DOI: 10.2458/AZU_JRM_V56I6_SCHINDLER
J. R. Schindler, T. Fulbright
Palatability of shrub sprouts to white-tailed deer (Odocoileus virginianus Raf.) differs among species, which causes selective browsing and can shift shrub species composition to dominance by less palatable species. The hypothesis was tested that differences in palatability of new sprouts among shrub species following roller chopping small (4 ha) patches within a shrubland matrix would result in a shift in shrub species composition within the patches toward less palatable species. Relative density and relative canopy cover of all woody species in plots 9 years after 1 roller chopping treatment, in plots 3 years after 2 roller chopping treatments, and in untreated plots were estimated. Relative density of blackbrush acacia (Acacia rigidula Benth.) was 3 times greater and relative canopy cover was 12 times greater 9 years after the first roller chopping treatment compared to untreated plots, but relative density and relative canopy cover of blackbrush acacia in roller chopped plots were similar to relative density and relative canopy cover in untreated plots 3 years after the second roller chopping treatment. Relative canopy cover of spiny hackberry (Celtis pallida Torr.) in plots roller chopped in 1989 and 1995 was higher than in untreated plots. Relative density and canopy cover of all other species were similar between roller chopped and untreated plots. Shrub community composition 9 years after 1 roller chopping treatment or 3 years after 2 roller chopping treatments in the subtropical thornscrub communities in southern Texas did not shift toward greater dominance of less palatable species. DOI:10.2458/azu_jrm_v56i6_schindler
{"title":"Roller chopping effects on tamaulipan scrub community composition","authors":"J. R. Schindler, T. Fulbright","doi":"10.2458/AZU_JRM_V56I6_SCHINDLER","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V56I6_SCHINDLER","url":null,"abstract":"Palatability of shrub sprouts to white-tailed deer (Odocoileus virginianus Raf.) differs among species, which causes selective browsing and can shift shrub species composition to dominance by less palatable species. The hypothesis was tested that differences in palatability of new sprouts among shrub species following roller chopping small (4 ha) patches within a shrubland matrix would result in a shift in shrub species composition within the patches toward less palatable species. Relative density and relative canopy cover of all woody species in plots 9 years after 1 roller chopping treatment, in plots 3 years after 2 roller chopping treatments, and in untreated plots were estimated. Relative density of blackbrush acacia (Acacia rigidula Benth.) was 3 times greater and relative canopy cover was 12 times greater 9 years after the first roller chopping treatment compared to untreated plots, but relative density and relative canopy cover of blackbrush acacia in roller chopped plots were similar to relative density and relative canopy cover in untreated plots 3 years after the second roller chopping treatment. Relative canopy cover of spiny hackberry (Celtis pallida Torr.) in plots roller chopped in 1989 and 1995 was higher than in untreated plots. Relative density and canopy cover of all other species were similar between roller chopped and untreated plots. Shrub community composition 9 years after 1 roller chopping treatment or 3 years after 2 roller chopping treatments in the subtropical thornscrub communities in southern Texas did not shift toward greater dominance of less palatable species. DOI:10.2458/azu_jrm_v56i6_schindler","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74057391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-11-01DOI: 10.2458/AZU_JRM_V56I6_MONACO
T. Monaco, C. T. Mackown, Douglas A. Johnson, T. Jones, J. Norton, J. Norton, M. Redinbaugh
Recent evidence associates the persistence of invasive plant species with disturbance and fluctuations in distinct forms of mineral N in soils. We conducted soil and hydroponic experiments to investigate the influence of N form and availability on germination and seedling development of 2 invasive annual grasses, cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae) and 6 perennial grasses, bluebunch wheatgrass (Pseudoroegneria spicata), crested wheatgrass (Agropyron cristatum x A. desertorum), Sand Hollow and Seaman's Gulch big squirreltail (Elymus multisetus), and Little Camas and Little Wood bottlebrush squirreltail (E. elymoides ssp. brevifolius and E. elymoides ssp. elymoides, respectively). Seeds were sown in soils with no soil additions, barley straw (1 mg kg-1), NH4+ = 10 mg N kg-1, NH4+ + I (nitrification inhibitor) = 10 mg N kg-1 + 37 ml nitrapyrin, or NO3- = 10 mg N kg-1 to evaluate cumulative germination percentage for 20 days in an incubator. For the hydroponic experiment, grass seedlings were exposed to distinct forms and uniform concentrations of mineral N to monitor root and shoot growth for 21 days. Treatments were no N added, NH4+ (1 mM), NO3- (1 mM), and NH4NO3 (0.5 mM). Treatments did not alter germination in the soil experiment. Lack of soil N effect on seed germination is attributed to the absence of seed dormancy in the populations of grasses we evaluated. Initial root length and overall shoot growth of grasses were greater in the NO3- than in the NH4+ treatment more frequently for perennial grasses. Root and shoot growth of medusahead and cheatgrass generally exceeded that of the other grasses except crested wheatgrass. However, relative decreases in root dry mass for the no N treatment were greater for the invasive annual grasses than the perennial grasses when compared to the N-addition treatments. DOI:10.2458/azu_jrm_v56i6_monaco
最近的证据表明，入侵植物物种的持续存在与土壤中不同形式的矿物氮的干扰和波动有关。通过土壤和水培试验，研究了N形态和有效性对2种入侵一年生禾草(Bromus tectorum)和medusae (Taeniatherum capt -medusae)和6种多年生禾草(pseudooroegneria spicata)、冠状麦草(Agropyron cristatum x A. desertorum)、沙穴草和海门沟大鼠尾草(Elymus multisetus)萌发和幼苗发育的影响。小卡玛斯和小伍德瓶刷松鼠尾巴(E. elymoides ssp)。短曲属和鞘翅属。分别为elymoides)。将种子播种在不添加土壤、大麦秸秆(1 mg kg-1)、NH4+ = 10 mg N kg-1、NH4+ + I(硝化抑制剂)= 10 mg N kg-1、NO3- = 10 mg N kg-1的土壤中，在培养箱中观察20天的累积发芽率。在水培试验中，草苗暴露于不同形态、均匀浓度的矿质氮中21 d，监测根和茎的生长情况。处理为不添加N、NH4+ (1 mM)、NO3- (1 mM)和NH4NO3 (0.5 mM)。在土壤试验中，处理没有改变种子的萌发。土壤氮的缺乏对种子萌发的影响是由于我们评价的禾本科群体中没有种子休眠。多年生草在NO3-处理下的初始根长和总梢长均大于NH4+处理。除麦穗草外，麦穗草的根、芽生长均优于其他禾本科植物。然而，与施氮处理相比，无氮处理对入侵一年生禾草根系干质量的相对减少更大。DOI: 10.2458 / azu_jrm_v56i6_monaco
{"title":"Nitrogen effects on seed germination and seedling growth","authors":"T. Monaco, C. T. Mackown, Douglas A. Johnson, T. Jones, J. Norton, J. Norton, M. Redinbaugh","doi":"10.2458/AZU_JRM_V56I6_MONACO","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V56I6_MONACO","url":null,"abstract":"Recent evidence associates the persistence of invasive plant species with disturbance and fluctuations in distinct forms of mineral N in soils. We conducted soil and hydroponic experiments to investigate the influence of N form and availability on germination and seedling development of 2 invasive annual grasses, cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae) and 6 perennial grasses, bluebunch wheatgrass (Pseudoroegneria spicata), crested wheatgrass (Agropyron cristatum x A. desertorum), Sand Hollow and Seaman's Gulch big squirreltail (Elymus multisetus), and Little Camas and Little Wood bottlebrush squirreltail (E. elymoides ssp. brevifolius and E. elymoides ssp. elymoides, respectively). Seeds were sown in soils with no soil additions, barley straw (1 mg kg-1), NH4+ = 10 mg N kg-1, NH4+ + I (nitrification inhibitor) = 10 mg N kg-1 + 37 ml nitrapyrin, or NO3- = 10 mg N kg-1 to evaluate cumulative germination percentage for 20 days in an incubator. For the hydroponic experiment, grass seedlings were exposed to distinct forms and uniform concentrations of mineral N to monitor root and shoot growth for 21 days. Treatments were no N added, NH4+ (1 mM), NO3- (1 mM), and NH4NO3 (0.5 mM). Treatments did not alter germination in the soil experiment. Lack of soil N effect on seed germination is attributed to the absence of seed dormancy in the populations of grasses we evaluated. Initial root length and overall shoot growth of grasses were greater in the NO3- than in the NH4+ treatment more frequently for perennial grasses. Root and shoot growth of medusahead and cheatgrass generally exceeded that of the other grasses except crested wheatgrass. However, relative decreases in root dry mass for the no N treatment were greater for the invasive annual grasses than the perennial grasses when compared to the N-addition treatments. DOI:10.2458/azu_jrm_v56i6_monaco","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84205824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-11-01DOI: 10.2458/AZU_JRM_V56I6_TORELL
L. A. Torell, N. Rimbey, L. V. Tassell, J. Tanaka, E. Bartlett
The federal grazing fee is currently set using the Public Rangeland Improvement Act (PRIA) fee formula established in 1978 and modified in 1986. The formula is adjusted annually using indices of private land grazing lease rates (Forage Value Index, FVI), prices received for beef cattle (Beef Cattle Price Index, BCPI), and costs of beef production (Prices Paid Index, PPI). The FVI tracks price movement in the private forage market and was the only index originally proposed to be included in the fee formula. Public land ranchers and the Interdepartmental Grazing Fee Technical Committee assigned to study grazing fee alternatives in the 1960s questioned the ability of the FVI to account for short-term demand, supply, and price equilibrium, and, for this reason, the BCPI and PPI were added to the fee formula. Nearly 40 years of data are now available to evaluate whether adding the BCPI and PPI did, in fact, help explain short-term market fluctuations. Analysis shows that if tracking the private forage market is the primary objective, the fee formula should have included only the FVI. Including the BCPI and the PPI has caused calculated grazing fees to fall further and further behind private land lease rates. Had the $1.23 base fee in the PRIA formula been indexed by only the FVI, the federal grazing fee would have been $4.36 AUM-1 instead of $1.43 AUM-1 in 2002. It is time to consider the feasibility of a competitive bid system for public lands, or, at the very least, drop the BCPI and PPI indices and adopt a new fee formula that generates more equitable grazing fees. DOI:10.2458/azu_jrm_v56i6_torell
{"title":"An evaluation of the federal grazing fee formula.","authors":"L. A. Torell, N. Rimbey, L. V. Tassell, J. Tanaka, E. Bartlett","doi":"10.2458/AZU_JRM_V56I6_TORELL","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V56I6_TORELL","url":null,"abstract":"The federal grazing fee is currently set using the Public Rangeland Improvement Act (PRIA) fee formula established in 1978 and modified in 1986. The formula is adjusted annually using indices of private land grazing lease rates (Forage Value Index, FVI), prices received for beef cattle (Beef Cattle Price Index, BCPI), and costs of beef production (Prices Paid Index, PPI). The FVI tracks price movement in the private forage market and was the only index originally proposed to be included in the fee formula. Public land ranchers and the Interdepartmental Grazing Fee Technical Committee assigned to study grazing fee alternatives in the 1960s questioned the ability of the FVI to account for short-term demand, supply, and price equilibrium, and, for this reason, the BCPI and PPI were added to the fee formula. Nearly 40 years of data are now available to evaluate whether adding the BCPI and PPI did, in fact, help explain short-term market fluctuations. Analysis shows that if tracking the private forage market is the primary objective, the fee formula should have included only the FVI. Including the BCPI and the PPI has caused calculated grazing fees to fall further and further behind private land lease rates. Had the $1.23 base fee in the PRIA formula been indexed by only the FVI, the federal grazing fee would have been $4.36 AUM-1 instead of $1.43 AUM-1 in 2002. It is time to consider the feasibility of a competitive bid system for public lands, or, at the very least, drop the BCPI and PPI indices and adopt a new fee formula that generates more equitable grazing fees. DOI:10.2458/azu_jrm_v56i6_torell","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78532952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
True mountain mahogany (Cercocarpus montanus Raf.) provides nutritional winter forage for big game species in the mountain brush zone. To determine browsing effects, animal use, percent vegetation cover, and shrub dimensions were measured inside and outside exclosures up to 7 years old on 4 sites on the North Slope of the Unita Mountains, and at an exclosure > 50 years old in the Wasatch Mountains, Utah. Utilization was measured in an associated twig demography study. Winter big game use increased from 1997 to 1999 at the North Slope. Utilization of annual growth ranged from 21 to over 300%, depending on the site and year and did not necessarily parallel animal use. Greater than 100% utilization of annual growth resulted when previous years' wood was browsed. There was little difference in vegetation cover, species richness, and diversity inside and outside the exclosures, but mountain mahogany had lower cover and smaller size outside than inside the exclosures at 3 North Slope sites. Mahogany cover was similar, but width and breadth of shrubs were smaller outside than inside the > 50-year old exclosure in the Wasatch Mountains. Browsed shrubs maintained their size from 1995 to 1999 at the North Slope, despite over 100 % utilization of annual growth at 3 of the sites in at least 1 year. True mountain mahogany is highly tolerant of winter browsing, and can compensate for > 100% utilization of annual growth by increased growth during wet years. However, continued use of over 100 % of annual growth could reduce cover, shrub size, and forage production during years of lower resource availability. A practical management approach is to monitor cover and size of shrubs inside and outside well-placed exclosures across the winter range over time, and reduce herd numbers as appropriate to allow browsed shrubs to maintain or reach the size of unbrowsed shrubs when their growth has leveled off after a few years of exclusion. DOI:10.2458/azu_jrm_v56i6_turley2
{"title":"True mountain mahogany community and shrub size responses to browsing.","authors":"D. Turley, B. Roundy, S. Walker","doi":"10.2307/4003934","DOIUrl":"https://doi.org/10.2307/4003934","url":null,"abstract":"True mountain mahogany (Cercocarpus montanus Raf.) provides nutritional winter forage for big game species in the mountain brush zone. To determine browsing effects, animal use, percent vegetation cover, and shrub dimensions were measured inside and outside exclosures up to 7 years old on 4 sites on the North Slope of the Unita Mountains, and at an exclosure > 50 years old in the Wasatch Mountains, Utah. Utilization was measured in an associated twig demography study. Winter big game use increased from 1997 to 1999 at the North Slope. Utilization of annual growth ranged from 21 to over 300%, depending on the site and year and did not necessarily parallel animal use. Greater than 100% utilization of annual growth resulted when previous years' wood was browsed. There was little difference in vegetation cover, species richness, and diversity inside and outside the exclosures, but mountain mahogany had lower cover and smaller size outside than inside the exclosures at 3 North Slope sites. Mahogany cover was similar, but width and breadth of shrubs were smaller outside than inside the > 50-year old exclosure in the Wasatch Mountains. Browsed shrubs maintained their size from 1995 to 1999 at the North Slope, despite over 100 % utilization of annual growth at 3 of the sites in at least 1 year. True mountain mahogany is highly tolerant of winter browsing, and can compensate for > 100% utilization of annual growth by increased growth during wet years. However, continued use of over 100 % of annual growth could reduce cover, shrub size, and forage production during years of lower resource availability. A practical management approach is to monitor cover and size of shrubs inside and outside well-placed exclosures across the winter range over time, and reduce herd numbers as appropriate to allow browsed shrubs to maintain or reach the size of unbrowsed shrubs when their growth has leveled off after a few years of exclusion. DOI:10.2458/azu_jrm_v56i6_turley2","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87596821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.2458/AZU_JRM_V56I5_KARN
J. Karn, A. Frank, J. Berdahl, W. Poland
High quality forage for spring and autumn grazing can be obtained from Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], a cool-season bunchgrass. However, little is known about mineral concentrations critical to livestock production, especially in the relatively new tetraploid plants. A knowledge of plant mineral concentrations and how they can be manipulated to more nearly meet animal requirements is necessary to optimize animal production. A study was undertaken to determine the extent that concentrations of critical minerals in leaf and stem tissue of Russian wildrye were affected by ploidy level, growing-season water (50 and 150% of average), and N fertilizer (10 and 134 kg N ha-1). Plants were sampled at vegetative, boot, anthesis, and anthesis plus 10-day stages of maturity in 1994, 1995, and 1996. Ploidy level resulted in small but significant differences in some mineral concentrations, with diploid plants usually having higher levels. An exception was P in stem tissue. This finding indicates that in breeding and selection for other traits, forage quality was not adversely affected. Growing-season water level also had minimal effects on mineral concentrations, except for P which was enhanced (P < 0.05) by greater amounts of soil water. Fertilizer N increased forage levels of Ca, K, Cu, and Zn, and decreased levels of P. Higher concentrations of K are not desirable, because they increase the possibility of a grass tetany problem. Advancing plant maturity caused a decrease in P and Zn concentrations, but Ca and Mg in leaf tissue increased as plants matured. These results suggest that concentrations of P, Ca, Mg, and Cu were marginal for high producing cattle at some stages of maturity, but we found the effects of nitrogen and growing-season water did not result in leaf and stem mineral concentration changes that would adversely affect the safety and nutritive quality of Russian wildrye. DOI:10.2458/azu_jrm_v56i5_karn
从俄罗斯野生牧草(Psathyrostachys juncea (Fisch.))中可以获得高品质的春秋季牧草。一种凉爽季节的束草。然而，对牲畜生产至关重要的矿物质浓度知之甚少，特别是在相对较新的四倍体植物中。了解植物矿物质浓度以及如何使其更接近于满足动物需求是优化动物生产所必需的。本研究确定了倍性水平、生长季节水分(平均水平的50%和150%)和氮肥(10和134 kg N ha-1)对俄罗斯野生牧草叶片和茎组织中关键矿物质浓度的影响程度。分别于1994年、1995年和1996年在营养期、靴期、开花期和开花期加10天成熟期取样。倍性水平导致某些矿物质含量差异不大，但差异显著，二倍体植株的矿物质含量通常较高。茎组织中的P是一个例外。这表明在其他性状的育种和选择中，饲草质量没有受到不利影响。生长季节水位对矿质元素含量的影响也很小，但磷元素含量随土壤水量的增加而增加(P < 0.05)。施氮肥增加了草料中Ca、K、Cu和Zn的含量，降低了p的含量。钾浓度过高是不可取的，因为它们增加了草料出现肌肉痉挛问题的可能性。随着植株成熟的推进，叶片组织中磷、锌含量降低，钙、镁含量增加。这些结果表明，在某些成熟阶段，P、Ca、Mg和Cu的浓度对高产牛来说是边际的，但我们发现氮和生长季节水分的影响不会导致叶和茎矿物质浓度的变化，从而对俄罗斯野生牧草的安全和营养质量产生不利影响。DOI: 10.2458 / azu_jrm_v56i5_karn
{"title":"Water, nitrogen and ploidy effects on Russian wildrye mineral concentrations","authors":"J. Karn, A. Frank, J. Berdahl, W. Poland","doi":"10.2458/AZU_JRM_V56I5_KARN","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V56I5_KARN","url":null,"abstract":"High quality forage for spring and autumn grazing can be obtained from Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], a cool-season bunchgrass. However, little is known about mineral concentrations critical to livestock production, especially in the relatively new tetraploid plants. A knowledge of plant mineral concentrations and how they can be manipulated to more nearly meet animal requirements is necessary to optimize animal production. A study was undertaken to determine the extent that concentrations of critical minerals in leaf and stem tissue of Russian wildrye were affected by ploidy level, growing-season water (50 and 150% of average), and N fertilizer (10 and 134 kg N ha-1). Plants were sampled at vegetative, boot, anthesis, and anthesis plus 10-day stages of maturity in 1994, 1995, and 1996. Ploidy level resulted in small but significant differences in some mineral concentrations, with diploid plants usually having higher levels. An exception was P in stem tissue. This finding indicates that in breeding and selection for other traits, forage quality was not adversely affected. Growing-season water level also had minimal effects on mineral concentrations, except for P which was enhanced (P < 0.05) by greater amounts of soil water. Fertilizer N increased forage levels of Ca, K, Cu, and Zn, and decreased levels of P. Higher concentrations of K are not desirable, because they increase the possibility of a grass tetany problem. Advancing plant maturity caused a decrease in P and Zn concentrations, but Ca and Mg in leaf tissue increased as plants matured. These results suggest that concentrations of P, Ca, Mg, and Cu were marginal for high producing cattle at some stages of maturity, but we found the effects of nitrogen and growing-season water did not result in leaf and stem mineral concentration changes that would adversely affect the safety and nutritive quality of Russian wildrye. DOI:10.2458/azu_jrm_v56i5_karn","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75491958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2003-09-01DOI: 10.2458/AZU_JRM_V56I5_BEST
Jody N. Best, E. Bork, N. Cool
Beaked hazel (Corylus cornuta Marsh) dominates the understory of many Boreal Mixedwood forests in central Alberta including those in Elk Island National Park, where this species demonstrates a high tolerance to browsing. This research quantified changes in beaked hazel stem morphology (total twig length and number) and leaf and twig biomass of current annual growth, both inside and outside 4 newly established exclosures during the growing seasons of 1999 and 2000. At 2 sites, leaf and twig current annual growth of beaked hazel shrubs recently protected from herbivory increased significantly (P 0.05) changes in current annual growth at the individual shrub stem level, potentially due to intense intra-specific competition. These results indicate that at several locations in the Park, the recent history of intense browsing appears to be limiting the annual growth of beaked hazel, including browse production. Despite the general increase in growth of individual beaked hazel stems, however, no changes in production were evident at the community level (P > 0.05) with the removal of browsing after 2 years. Protection from browsing did increase average beaked hazel height by 40% over the same period. DOI:10.2458/azu_jrm_v56i5_best
{"title":"Initial beaked hazel growth responses following protection from ungulate browsing.","authors":"Jody N. Best, E. Bork, N. Cool","doi":"10.2458/AZU_JRM_V56I5_BEST","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V56I5_BEST","url":null,"abstract":"Beaked hazel (Corylus cornuta Marsh) dominates the understory of many Boreal Mixedwood forests in central Alberta including those in Elk Island National Park, where this species demonstrates a high tolerance to browsing. This research quantified changes in beaked hazel stem morphology (total twig length and number) and leaf and twig biomass of current annual growth, both inside and outside 4 newly established exclosures during the growing seasons of 1999 and 2000. At 2 sites, leaf and twig current annual growth of beaked hazel shrubs recently protected from herbivory increased significantly (P 0.05) changes in current annual growth at the individual shrub stem level, potentially due to intense intra-specific competition. These results indicate that at several locations in the Park, the recent history of intense browsing appears to be limiting the annual growth of beaked hazel, including browse production. Despite the general increase in growth of individual beaked hazel stems, however, no changes in production were evident at the community level (P > 0.05) with the removal of browsing after 2 years. Protection from browsing did increase average beaked hazel height by 40% over the same period. DOI:10.2458/azu_jrm_v56i5_best","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83376540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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