The location, quantity, and germinability of seed (caryopses) reserves of Oryzopsis hymenoides (R. & S.) Ricker in the soil were investigated at 4 locations in the Carson Desert of western Nevada. Numerous germinable seeds were recovered from the surface 15 cm of Lahontan sands. There was no clear relation between the number of seeds and depth of burial. On sites with pronounced dunes more seeds were found in the dune sands than in the interspaces. Seeds were recovered with and without evidence of sand abrasion of the indurate lemma and paleas. Seeds without wear marks were much more highly germinable (80%) than the more numerous seeds with wear marks (6%). The germhmble seed reserve consisted of seeds that germinated without pretreatment when incubated at 20°C; a much larger portion that required dissection to remove the indurate lemma and palea; and a fnction with embryo dormancy that had to be overcome with gibberellin enrichment of the germination substrate. Large numbers of opened, empty lemma and paler were found in the sands. Rodent enhancement of the germination of Oryzopsis hymenoides seeds appears to be a more valid hypothesis than mechanical abrasion from saltation. Oryzopsis hymenoides (R. & S.) Ricker is the predominant herbaceous species in many plant communities at lower elevations of pluvial lake basins of the Great Basin. This perennial bunchgrass reaches its greatest abundance on sandy soils or on active dune areas. In the northern Carson Desert large areas of relatively pure stands of Oryzopsis hymenoides grow on Lahontan sands (Billings 1945, 1949). This geologic formation is derived from sand-textured sediments that were dumped by rivers into the pluvial Lake Lahontan during the Pleistocene and since have been transported by winds across what is now a desert landscape (Morrison 1964). Oryzopsis hymenoides seeds (caryopses) are highly polymorphic, but all forms are generally dormant (Huntamer 1934). The nature of the dormancy has been attributed to the persistent lemma and palea and pericarp that inhibit oxygen transfer to the embryo (Huntamer 1934, Fendall 1964, Clark and Bass 1970, Shaw 1976, and McDonald and Khan 1977). The lemma and palea have to be removed and the pericarp pricked in order for the seeds to germinate (Plummerand Frischknecht 1952). Considering the nature of thedormancy, 3 hypotheses have been offered to explain how dormancy is broken in the natural environment. The first hypothesis postulates that temperature fluctuations and microbial degradation cause the lemma and palea to split and allow germination (Stoddart and Wilkinson 1938). The second hypothesis takes into account the affinity of this grass for sandy soils and suggests that the relatively small and dense seeds of this species move along the surface of the sands by saltation until the lemma and palea are broken by the abrasive action of the sand grains (e.g. Robertson 1977). The third hypothesis, as recently proposed by McAdoo et al. (1983), is th
沙丘高出间距不到0.5米。我们根据这种微地形对采样进行分层。1977年9月，在每个地点，我们选择了一个相对均匀的区域，并以随机设计的方式布置了4,50米乘50米的街区。在每个区块中，32 × 32厘米的开底金属盒被打入15厘米深的沙子中。每个箱体内表面以每2.5 cm的水平线为段，方便采样。沙子被小心地移走，每2.5厘米深，装在袋子里运往实验室。在每个重复的空间和沙丘中随机放置一个盒子，每个采样日期每个位置共8个样本。将样品铺在纸上晾干后，用0.99 mm筛网筛分，回收全部稻穗种子和部分种子。在最浅的空间土壤中，15 cm的最大采样深度以土壤深度为基础。拉洪滩的沙子深度从15厘米到100厘米不等，但沙丘上的沙子更深。质地相当均匀，94% ~ 96%为砂，4% ~ 6%为粉砂和粘土。土壤剖面pH值在8.0 ~ 8.9之间。由于淤泥和粘土含量低，土壤结构几乎完全缺失，种子很容易通过筛分恢复。将回收的种子材料分为:(a)完整种子;(b)外稃和旧皮有磨损痕迹或孔洞的种子;(c)空外稃和旧皮。整个种子和磨损的区域被拇指和食指挤压，看看它们是否空的。空的外稃和原稃崩解，而填满的种子太硬而无法碾碎。通过试验的种子见JOURNAL OF RANGE MANAGEMENT, 1983年1月36期(1期)。实验地点的特点。
{"title":"Quantity and Germinability of Oryzopsis hymenoides Seed in Lahontan Sands","authors":"J. A. Young, R. A. Evans, B. Roundy","doi":"10.2307/3897989","DOIUrl":"https://doi.org/10.2307/3897989","url":null,"abstract":"The location, quantity, and germinability of seed (caryopses) reserves of Oryzopsis hymenoides (R. & S.) Ricker in the soil were investigated at 4 locations in the Carson Desert of western Nevada. Numerous germinable seeds were recovered from the surface 15 cm of Lahontan sands. There was no clear relation between the number of seeds and depth of burial. On sites with pronounced dunes more seeds were found in the dune sands than in the interspaces. Seeds were recovered with and without evidence of sand abrasion of the indurate lemma and paleas. Seeds without wear marks were much more highly germinable (80%) than the more numerous seeds with wear marks (6%). The germhmble seed reserve consisted of seeds that germinated without pretreatment when incubated at 20°C; a much larger portion that required dissection to remove the indurate lemma and palea; and a fnction with embryo dormancy that had to be overcome with gibberellin enrichment of the germination substrate. Large numbers of opened, empty lemma and paler were found in the sands. Rodent enhancement of the germination of Oryzopsis hymenoides seeds appears to be a more valid hypothesis than mechanical abrasion from saltation. Oryzopsis hymenoides (R. & S.) Ricker is the predominant herbaceous species in many plant communities at lower elevations of pluvial lake basins of the Great Basin. This perennial bunchgrass reaches its greatest abundance on sandy soils or on active dune areas. In the northern Carson Desert large areas of relatively pure stands of Oryzopsis hymenoides grow on Lahontan sands (Billings 1945, 1949). This geologic formation is derived from sand-textured sediments that were dumped by rivers into the pluvial Lake Lahontan during the Pleistocene and since have been transported by winds across what is now a desert landscape (Morrison 1964). Oryzopsis hymenoides seeds (caryopses) are highly polymorphic, but all forms are generally dormant (Huntamer 1934). The nature of the dormancy has been attributed to the persistent lemma and palea and pericarp that inhibit oxygen transfer to the embryo (Huntamer 1934, Fendall 1964, Clark and Bass 1970, Shaw 1976, and McDonald and Khan 1977). The lemma and palea have to be removed and the pericarp pricked in order for the seeds to germinate (Plummerand Frischknecht 1952). Considering the nature of thedormancy, 3 hypotheses have been offered to explain how dormancy is broken in the natural environment. The first hypothesis postulates that temperature fluctuations and microbial degradation cause the lemma and palea to split and allow germination (Stoddart and Wilkinson 1938). The second hypothesis takes into account the affinity of this grass for sandy soils and suggests that the relatively small and dense seeds of this species move along the surface of the sands by saltation until the lemma and palea are broken by the abrasive action of the sand grains (e.g. Robertson 1977). The third hypothesis, as recently proposed by McAdoo et al. (1983), is th","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77131480","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}
H. D. Galt, B. Theurer, J. Ehrenreich, W. Hale, S. Martín
In conclusion, it should not be inferred from the two changes in land use investigated here that they necessarily represent the expected future trend in Grant County. The reduction in federal grazing was utilized because of available information on reductions in gross ranch incomes from such action. The increase in receipts in the Lumber sector was purely arbitrary; a reduction could also have been discussed. Recent research in northeastern Oregon indicates that improved timber management practices are generally conducive to greater forage production. Thus increased timber harvests could occur simultaneously with increased carrying capacity for livestock (Hedrick et al., 1968). The model used here did not permit the isolation of recreation expenditures but it should be recognized that this is another use of federal lands which can be significant to the rural economy. The expenditures of these users are usually well publicized while much less attention is paid to expenditures by ranchers, loggers, or mining interests. If administrators are made aware of the relative importance to the local economy of all uses of federal lands, policy decisions could be made in the light of more complete knowledge than is now the case.
总之，不应该从这里调查的两种土地利用变化中推断出它们一定代表了格兰特县预期的未来趋势。之所以利用减少联邦放牧的办法，是因为已有资料表明这种行动减少了牧场总收入。木材部门收入的增加完全是武断的;还可以讨论削减的问题。最近在俄勒冈州东北部进行的研究表明，改善木材管理做法通常有助于提高饲料产量。因此，木材采伐的增加可能与牲畜承载能力的增加同时发生(Hedrick et al.， 1968)。这里使用的模型不允许将娱乐支出隔离开来，但应该认识到，这是对联邦土地的另一种使用，对农村经济可能具有重要意义。这些用户的支出通常被广为宣传，而对牧场主、伐木者或采矿利益集团的支出的关注要少得多。如果让行政人员意识到联邦土地的所有用途对地方经济的相对重要性，就可以在比现在更全面的知识基础上做出政策决定。
{"title":"Botanical Composition of Diet of Steers Grazing a Desert Grassland Range (Composicion Botanica de la Dieta de Novillos Pastoreando en un Pastizal Desertico de Gramineas)","authors":"H. D. Galt, B. Theurer, J. Ehrenreich, W. Hale, S. Martín","doi":"10.2307/3896025","DOIUrl":"https://doi.org/10.2307/3896025","url":null,"abstract":"In conclusion, it should not be inferred from the two changes in land use investigated here that they necessarily represent the expected future trend in Grant County. The reduction in federal grazing was utilized because of available information on reductions in gross ranch incomes from such action. The increase in receipts in the Lumber sector was purely arbitrary; a reduction could also have been discussed. Recent research in northeastern Oregon indicates that improved timber management practices are generally conducive to greater forage production. Thus increased timber harvests could occur simultaneously with increased carrying capacity for livestock (Hedrick et al., 1968). The model used here did not permit the isolation of recreation expenditures but it should be recognized that this is another use of federal lands which can be significant to the rural economy. The expenditures of these users are usually well publicized while much less attention is paid to expenditures by ranchers, loggers, or mining interests. If administrators are made aware of the relative importance to the local economy of all uses of federal lands, policy decisions could be made in the light of more complete knowledge than is now the case.","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82314979","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}
A point frame has been modified to allow for plant cover estimates to a 152 cm height. Construction ofa third crossmember that can be added to a 76.cm tall point frame allows sampling pins to be projected both upward and downward. Spacings between pins were changed to produce equal sampling areas while sampling circular plots. This design was tested with a miniature point frame on artificial plant populations and was shown to measure within 3~5% of actual cover values. The point frame, widely used in range ecological work, is normally placed at selected field points or moved along a transect. Point frames have been used to measure plant height (Heady 1957) insect damage (Nerney 1960) leaf area (Warren-Wilson 1963) basal cover (Fisser and Van Dyne 1966), foliar cover, frequency, herbage production and species composition (Hughes 1962), and to determine plant density in rectangular quadrats (Ellison 1942). The basic point frame with its sampling precision (Schultz et al. 1961, Hutchings and Pase 1963, Fisser and Van Dyne 1966) is easily modified and retains its accuracy and usefulness with design modifications. Point frames have been constructed of wood, steel, and aluminum. Modifications are normally made for specific purposes such as the sampling of a vegetation type, the increase of accuracy, or the ease of sampling (Nerney 1960, Long et al. 1972, Sharrow and Tober 1979). Foliar cover of herbaceous and woody vegetation is important in determining understory vegetation production and composition in southern forests (Pearson and Sternitzke 1974). The point frame can be used to determine foliar cover and botanical composition accurately; therefore, it was selected for use in training and checking ocular estimates of plant cover on I-m* circular plots by Forest Service Renewable Resource Evaluation field personnel during extensive forest resource surveys in midsouth forests. (Foliar cover of herbage can be used to estimate herbage production from established foliar cover-herbage production relationships). We will discuss how modifications in frame height and pin spacing can allow the point frame to be used in small, circular plot sampling.
一个点框架已被修改，以允许植物覆盖估计到152厘米的高度。可以添加到76的第三个横梁的构造。厘米高的点框架允许采样针向上和向下投影。在采样圆形地块时，改变针之间的间距以产生相等的采样区域。该设计在人工植物种群上进行了微型点架试验，结果表明其测量值在实际覆盖值的3~5%范围内。点架在牧场生态工作中广泛使用，通常放置在选定的野外点或沿着样带移动。点框架已被用于测量植物高度(Heady 1957)、虫害(Nerney 1960)、叶面积(Warren-Wilson 1963)、基盖(Fisser和Van Dyne 1966)、叶盖、频率、牧草产量和物种组成(Hughes 1962)，并确定矩形样方的植物密度(Ellison 1942)。具有采样精度的基本点框架(Schultz et al. 1961, Hutchings and Pase 1963, Fisser and Van Dyne 1966)很容易修改，并在设计修改时保持其准确性和实用性。点框架已建成的木材，钢和铝。修改通常是为了特定的目的，如对植被类型进行采样，提高精度，或便于采样(Nerney 1960, Long et al. 1972, Sharrow and Tober 1979)。草本和木本植被的叶面覆盖度对确定南方森林林下植被的生产和组成具有重要意义(Pearson and Sternitzke 1974)。该点框架可以准确地确定叶面覆盖度和植物组成;因此，在中南部森林进行广泛的森林资源调查时，林业局可再生资源评价现场人员选择使用它来培训和检查1 -m*圆形样地植物覆盖的目测估计。(牧草叶面盖度可以根据已建立的叶面盖度-牧草产量关系来估计牧草产量)。我们将讨论如何修改帧高度和引脚间距，使点帧能够用于小的圆形地块采样。
{"title":"A Point Frame for Circular Plots in Southern Forest-Ranges","authors":"R. Baker, C. E. Thomas","doi":"10.2307/3897998","DOIUrl":"https://doi.org/10.2307/3897998","url":null,"abstract":"A point frame has been modified to allow for plant cover estimates to a 152 cm height. Construction ofa third crossmember that can be added to a 76.cm tall point frame allows sampling pins to be projected both upward and downward. Spacings between pins were changed to produce equal sampling areas while sampling circular plots. This design was tested with a miniature point frame on artificial plant populations and was shown to measure within 3~5% of actual cover values. The point frame, widely used in range ecological work, is normally placed at selected field points or moved along a transect. Point frames have been used to measure plant height (Heady 1957) insect damage (Nerney 1960) leaf area (Warren-Wilson 1963) basal cover (Fisser and Van Dyne 1966), foliar cover, frequency, herbage production and species composition (Hughes 1962), and to determine plant density in rectangular quadrats (Ellison 1942). The basic point frame with its sampling precision (Schultz et al. 1961, Hutchings and Pase 1963, Fisser and Van Dyne 1966) is easily modified and retains its accuracy and usefulness with design modifications. Point frames have been constructed of wood, steel, and aluminum. Modifications are normally made for specific purposes such as the sampling of a vegetation type, the increase of accuracy, or the ease of sampling (Nerney 1960, Long et al. 1972, Sharrow and Tober 1979). Foliar cover of herbaceous and woody vegetation is important in determining understory vegetation production and composition in southern forests (Pearson and Sternitzke 1974). The point frame can be used to determine foliar cover and botanical composition accurately; therefore, it was selected for use in training and checking ocular estimates of plant cover on I-m* circular plots by Forest Service Renewable Resource Evaluation field personnel during extensive forest resource surveys in midsouth forests. (Foliar cover of herbage can be used to estimate herbage production from established foliar cover-herbage production relationships). We will discuss how modifications in frame height and pin spacing can allow the point frame to be used in small, circular plot sampling.","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86551694","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}
Resume& Este estudio se llev6 a cabo en la Subestacion de ARCHER cerca de Cheyenne, Wyoming, EUA. El contenido de proteina de cada especie decline generalmente con el desarrollo. Sin embargo, el navajita azul mostrci variaciones en el contenido de proteina por el crecimiento nuevo despues de las lluvias a6n durante el otono y despues de algunos dias con heladas. Se observe un aumento ripido en el contenido de proteina con el crecimiento nuevo per0 este no ocurrio para el Western Wheatgrass. A mediados de agosto el contenido de fosforo en ambas especies decline por abajo de 10s requisitos alimenticios dados por el National Research Council (NRC). Esto sugiere la necesidad de
{"title":"Mineral and Protein Contents of Blue Grama and Western Wheatgrass (Contenido de Minerales y Proteinas en el Navajita Azul (Bouteloua gracilis) y Western Wheatgrass (Agropyron smithii))","authors":"F. Rauzi, L. Painter, A. Dobrenz","doi":"10.2307/3896033","DOIUrl":"https://doi.org/10.2307/3896033","url":null,"abstract":"Resume& Este estudio se llev6 a cabo en la Subestacion de ARCHER cerca de Cheyenne, Wyoming, EUA. El contenido de proteina de cada especie decline generalmente con el desarrollo. Sin embargo, el navajita azul mostrci variaciones en el contenido de proteina por el crecimiento nuevo despues de las lluvias a6n durante el otono y despues de algunos dias con heladas. Se observe un aumento ripido en el contenido de proteina con el crecimiento nuevo per0 este no ocurrio para el Western Wheatgrass. A mediados de agosto el contenido de fosforo en ambas especies decline por abajo de 10s requisitos alimenticios dados por el National Research Council (NRC). Esto sugiere la necesidad de","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81153050","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}
{"title":"Proceedings of the Inter-American Conference on Conservation of Renewable Natural Resources","authors":"A. W. Sampson","doi":"10.2307/3894712","DOIUrl":"https://doi.org/10.2307/3894712","url":null,"abstract":"","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78803994","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}
On the flatwoods of the southeastern United States control of saw-palmetto (Serenoa repetrs (Bartr.) Small) is an important step in the improvement of native pastures. This study, conducted at the Ona Agricultural Research Center in south Florida, measured fluctuations in total available carbohydrates (TAC) in rhizomes of burned and unburned saw-palmetto which received a June or October application of 8.9 kg/ha (acid equiv.) of 2,4,5-T. Palmetto kill, change in palmetto cover, and grass canopy cover were evaluated. Burning reduced TAC concentration in rhizomes from 48.8% in March to 14.3% in July as compared to a drop from 47.2% to 37.4% for unburned plants. Applying 2,4,5-T caused a further significant decline in TAC concentration. Both burning and 2,4,5T resulted in lower rhizome percent dry matter indicating that treatment stress caused metabolism of carbohydrate which was replaced by water. After 1 year there was higher mortality on palmetto receiving 2,4,5-T in June, but after 2 years there was no difference in mortality between June (48%) and October sprayed (39%) plants. Burning was not found to have a significant effect on mortality of sprayed plants. Burning and 2,4,5-T decreased palmetto cover, and burned plants treated with 2,4,5-T in June had less cover than burned plants treated in October with 2,4,5-T. Burning followed by 2,4,5-T application in June increased grass cover from 29.4% at the beginning of the study to 67.5% at the end. Saw-palmetto (Serenou repens (Bartr. Small)) is one of the most abundant shrubs on the sandy flatwoods from southern South Carolina to southern Mississippi and throughout all of Florida. The primary method of reproduction is by sprouting from partially buried stems or rhizomes which are capable of elongation. However, palmettos flower in late April and produce some fruit in September or October. In Florida palmettos are relatively dormant in the winter and produce 80% of their annual growth during the rainy May to October period (Hilmon 1968). Carbohydrate reserves of saw palmetto are principally starch which is stored in the rhizomes (Hough 1968). These reserves follow seasonal cycles which are influenced by periods of dormancy, frond growth, and flowering. In rhizomes of unburned plants grown in Georgia, starch was highest in winter (37%) and lowest in summer (27%). Florida cattlemen burn range every 3 to 4 years after winter grazing in order to remove old forage and litter, but palmettos regain 80% of their crown coverage the first year after burning (Hilmon 1968). Burning significantly lowered plant reserves, and three repeated summer burnings after a winter burn lowered starch to 12% (Hough 1968). Interest in reducing palmetto cover has increased with demands for forage production. McCaleb et al. (1960) tested 25 chemicals Authors are associate agronomist, Ona Agricultural Research Center. Ona, Florida 33865; and associate plant physiologist and associate statistician, University of Florida, Gainesvi
在美国东南部平坦的树林里锯棕榈的控制(Serenoa repetrs (Bartr.)小)是改善原生牧场的重要一步。这项研究是在南佛罗里达的奥纳农业研究中心进行的，测量了6月或10月施用8.9公斤/公顷(酸当量)2,4,5- t的燃烧和未燃烧锯棕榈根茎中总有效碳水化合物(TAC)的波动。评价了棕榈死亡、棕榈盖度变化和草冠层盖度变化。燃烧使根状茎中TAC浓度从3月的48.8%下降到7月的14.3%，而未燃烧的根状茎中TAC浓度从47.2%下降到37.4%。施用2,4,5- t引起TAC浓度进一步显著下降。燃烧和2、4、5T处理均导致根茎干物质含量降低，说明处理胁迫导致碳水化合物代谢被水取代。2年后6月喷2、4、5-T的棕榈死亡率较高，但2年后6月(48%)与10月(39%)的死亡率无显著差异。未发现燃烧对喷施植株的死亡率有显著影响。2、4、5-T和2、4、5-T使棕榈盖度降低，6月2、4、5-T处理的烧伤植株盖度低于10月2、4、5-T处理的烧伤植株。6月份焚烧后再施用2,4,5- t，使草盖度从研究开始时的29.4%增加到研究结束时的67.5%。锯棕榈(Serenou repens)。从南卡罗莱纳南部到密西西比南部和整个佛罗里达的沙质平原森林中最丰富的灌木之一。繁殖的主要方法是从部分埋藏的茎或根茎中萌发，这些茎或根茎能够伸长。然而，棕榈在4月下旬开花，在9月或10月结出一些果实。在佛罗里达，棕榈在冬季相对休眠，在多雨的5月至10月期间产生80%的年生长量(Hilmon 1968)。锯棕榈的碳水化合物储备主要是淀粉，储存在根茎中(Hough 1968)。这些储备遵循季节周期，受休眠，叶片生长和开花时期的影响。在格鲁吉亚种植的未燃烧植物的根茎中，淀粉含量在冬季最高(37%)，在夏季最低(27%)。佛罗里达的牧场主在冬季放牧后每3到4年就会烧掉一次，以清除旧的草料和垃圾，但棕榈在燃烧后的第一年就会恢复80%的树冠覆盖率(Hilmon 1968)。燃烧显著降低了植物储量，冬季燃烧后三次重复的夏季燃烧将淀粉降低到12% (Hough 1968)。减少棕榈覆盖的兴趣随着饲料生产需求的增加而增加。McCaleb等人(1960)测试了25种化学物质。作者是奥纳农业研究中心的副农学家。奥纳，佛罗里达州33865;和佛罗里达大学植物生理学家和统计学家助理，盖恩斯维尔326 I.本文是佛罗里达农业实验站论文编号3042。论文发表于1981年4月30日，JOURNAL OF RANGE MANAGEMENT 36(l)， 1983年1月，报道2,4,5- t是杀死锯棕榈的最佳药剂之一。最近在奥纳农业研究中心(ARC)进行的初步实验(未发表)支持2,4,5-t(2,4,5-三氯-苯氧乙酸)是10种化合物中最好的。McCaleb等人(1961)在9月和10月对未燃烧的棕榈施用除草剂，报告死亡率较低(75%)，为4.48千克酸当量/公顷(AE/公顷)。Burton和Hughes(1961)对燃烧和未燃烧的棕榈分别在3个日期施用3种2、4、5-T和2载体后20个月的死亡率进行了评估。他们报告说，由于烧伤和发病率造成的主要影响并不显著，施用日期仅对烧伤的棕榈有显著影响，其中最佳处理(3月7日烧伤，8月26日用2,4,5- t和水喷洒)导致76%的死亡率。Altobellis和Hough(1968)用2,4,5- t两种速率的7种燃烧和喷洒组合进行了实验。1963年7月施用6.16 kg/ hm2 AE, 7个月后燃烧，1964年7月再喷，1965年7月再燃烧，防治效果最佳(61%)。尽管本研究中没有淀粉分析的报道，但参考Hough(1968)的碳水化合物储备工作对该处理的成功进行了评估。由于燃烧后的棕榈比未燃烧的棕榈具有更弱的能量状态(Hough 1968)，当喷洒2,4,5- t (McCaleb et al. 1960, McCaleb 1961, green 1960, Burton and Hughes 1961, Altobellis and Hough 1968)时，燃烧可能使植物死亡率更高(Burton and Hughes 1961, Altobellis and Hough 1968)。2,4,5- t可有效杀死棕榈(McCaleb et al. 1960, McCaleb 1961, green 1960, Burton and Hughes 1961, Altobellis and Hough 1968)。然而，烧伤后的应用时间仍然停留在试验和错误的基础上。 Hough(1968)认为，基于这种碳水化合物储备工作，10月施用除草剂可能对冬烧棕榈的杀灭效果最好。然而，由于未燃烧棕榈中的碳水化合物在6月下旬和7月处于最低水平(Hough 1968)，这将是施用除草剂的适当时间，这可能会最大限度地控制未燃烧棕榈。本研究的目的是测量总有效碳水化合物，并将其与6月和10月喷施2,4,5- t的冬季燃烧和未燃烧棕榈的死亡率联系起来。材料和方法研究在佛罗里达州中南部的佛罗里达大学Ona ARC (27 ' 26'N, 8 ' 55'W)进行。年平均降雨量约140厘米，其中75%集中在5月至10月。5月至10月的平均气温最高/最低为31.6/ 17.8”C，其余月份的平均气温为25.311 I .6”C。实验场地的土壤是一种Eau Gallie细沙(Arenic haplquod)，它支撑着一大片均匀的锯棕榈，这些锯棕榈在过去的10年里没有被烧毁。治疗方法:(1)烧伤(1977年3月1日)和不烧伤;(2) 1977年6月30日或1977年10月20日，2,4,5- t(丙二醇，丁基醚酯)以8.9 kg AE/ha施用的时间
{"title":"Burning and 2, 4, 5-T Application on Mortality and Carbohydrate Reserves in Saw-Palmetto","authors":"R. Kalmbacher, K. Boote, F. Martin","doi":"10.2307/3897970","DOIUrl":"https://doi.org/10.2307/3897970","url":null,"abstract":"On the flatwoods of the southeastern United States control of saw-palmetto (Serenoa repetrs (Bartr.) Small) is an important step in the improvement of native pastures. This study, conducted at the Ona Agricultural Research Center in south Florida, measured fluctuations in total available carbohydrates (TAC) in rhizomes of burned and unburned saw-palmetto which received a June or October application of 8.9 kg/ha (acid equiv.) of 2,4,5-T. Palmetto kill, change in palmetto cover, and grass canopy cover were evaluated. Burning reduced TAC concentration in rhizomes from 48.8% in March to 14.3% in July as compared to a drop from 47.2% to 37.4% for unburned plants. Applying 2,4,5-T caused a further significant decline in TAC concentration. Both burning and 2,4,5T resulted in lower rhizome percent dry matter indicating that treatment stress caused metabolism of carbohydrate which was replaced by water. After 1 year there was higher mortality on palmetto receiving 2,4,5-T in June, but after 2 years there was no difference in mortality between June (48%) and October sprayed (39%) plants. Burning was not found to have a significant effect on mortality of sprayed plants. Burning and 2,4,5-T decreased palmetto cover, and burned plants treated with 2,4,5-T in June had less cover than burned plants treated in October with 2,4,5-T. Burning followed by 2,4,5-T application in June increased grass cover from 29.4% at the beginning of the study to 67.5% at the end. Saw-palmetto (Serenou repens (Bartr. Small)) is one of the most abundant shrubs on the sandy flatwoods from southern South Carolina to southern Mississippi and throughout all of Florida. The primary method of reproduction is by sprouting from partially buried stems or rhizomes which are capable of elongation. However, palmettos flower in late April and produce some fruit in September or October. In Florida palmettos are relatively dormant in the winter and produce 80% of their annual growth during the rainy May to October period (Hilmon 1968). Carbohydrate reserves of saw palmetto are principally starch which is stored in the rhizomes (Hough 1968). These reserves follow seasonal cycles which are influenced by periods of dormancy, frond growth, and flowering. In rhizomes of unburned plants grown in Georgia, starch was highest in winter (37%) and lowest in summer (27%). Florida cattlemen burn range every 3 to 4 years after winter grazing in order to remove old forage and litter, but palmettos regain 80% of their crown coverage the first year after burning (Hilmon 1968). Burning significantly lowered plant reserves, and three repeated summer burnings after a winter burn lowered starch to 12% (Hough 1968). Interest in reducing palmetto cover has increased with demands for forage production. McCaleb et al. (1960) tested 25 chemicals Authors are associate agronomist, Ona Agricultural Research Center. Ona, Florida 33865; and associate plant physiologist and associate statistician, University of Florida, Gainesvi","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77677006","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}
Mean infiltration rates differed among several natural vegetation communities with ponderosa pine (Pinusponderosa) exhibiting the lowest mean infiltration rate of 6.0 cm/hr and larch (Larix occidentalis) demonstrating the highest at 8.8 cm/hr. A trend toward increasing infiitration rates corresponded to increasingly mesic sites. Alpine, Douglas fir (Psuedotsuga me&e@), mountain meadow, and larch types demonstrated the greatest vegetative cover, occupied the most mesic sites, and exhibited the highest infiltration rates. Infiltration differences within vegetative communities,based upon changes in condition and productivity were also noted. The forested sites were more dependent upon condition class than productivity class, with higher infiltration rates being exhibited on pole sites than on timbered sites, apparently in response to higher plant densities associated with the pole thickets. Nonforested sites were responsive to both productivity and condition class with higher infiltration rates being exhibited on these sites with the more productive or better condition classifications. Water is a primary factor limiting production on many western rangelands. Many of these areas are subject to low annual precipitation and high potential evaporational losses. Activities which disturb the soil surface or vegetative composition and cover have the potential for reducing soil water intake, thereby reducing productivity which in some instances may be minimal at best. A prime concern of land managers is to maintain or enhance those factors within managerial capabilities which affect soil water intakeand to identify those areas most susceptible to disturbance. Blackburn and Skau (1974) studied infiltration rates and sediment production fo 29 plant communities and soils in central and eastern Nevada. The highest infiltration rates occurred on sites with weliaggregated surface soils free of vesicular porosity. Williams et al. (1972) used multiple regression analysis to determine relationships between vegetative and soil factors and infiltration rates and erosion from 550 infiltrometer plots at chained pinyon-juniper sites in Utah. Factors found to be most important in predicting infiltration rates were: (1) total porosity in the O-8 cm layer of soil, (2) percent bare soil surface, (3) soil texture in the O-8 cm layer of soil, and (4) crown cover. Raindrop impact on bare soil tends to rapidly close the natural channels of percolation by degrading soil structure. Studies at the Manti County watershed in Utah showed that runoff varied inversely with the total amount of ground cover (Orr 1957). Vegetative cover tends to reduce the energy of rainfall by reducing velocity and by breaking the large drops into a fine spray which can then enter the soil without damage to the soil surface. Gifford (1972) reported that the ability to predict infiltration rates, using cover characteristics alone varies with time, both within a given storm The authors are teacher, Monument
{"title":"Infiltration Rates of Various Vegetative Communities within the Blue Mountains of Oregon","authors":"R. E. Gaither, J. Buckhouse","doi":"10.2307/3897983","DOIUrl":"https://doi.org/10.2307/3897983","url":null,"abstract":"Mean infiltration rates differed among several natural vegetation communities with ponderosa pine (Pinusponderosa) exhibiting the lowest mean infiltration rate of 6.0 cm/hr and larch (Larix occidentalis) demonstrating the highest at 8.8 cm/hr. A trend toward increasing infiitration rates corresponded to increasingly mesic sites. Alpine, Douglas fir (Psuedotsuga me&e@), mountain meadow, and larch types demonstrated the greatest vegetative cover, occupied the most mesic sites, and exhibited the highest infiltration rates. Infiltration differences within vegetative communities,based upon changes in condition and productivity were also noted. The forested sites were more dependent upon condition class than productivity class, with higher infiltration rates being exhibited on pole sites than on timbered sites, apparently in response to higher plant densities associated with the pole thickets. Nonforested sites were responsive to both productivity and condition class with higher infiltration rates being exhibited on these sites with the more productive or better condition classifications. Water is a primary factor limiting production on many western rangelands. Many of these areas are subject to low annual precipitation and high potential evaporational losses. Activities which disturb the soil surface or vegetative composition and cover have the potential for reducing soil water intake, thereby reducing productivity which in some instances may be minimal at best. A prime concern of land managers is to maintain or enhance those factors within managerial capabilities which affect soil water intakeand to identify those areas most susceptible to disturbance. Blackburn and Skau (1974) studied infiltration rates and sediment production fo 29 plant communities and soils in central and eastern Nevada. The highest infiltration rates occurred on sites with weliaggregated surface soils free of vesicular porosity. Williams et al. (1972) used multiple regression analysis to determine relationships between vegetative and soil factors and infiltration rates and erosion from 550 infiltrometer plots at chained pinyon-juniper sites in Utah. Factors found to be most important in predicting infiltration rates were: (1) total porosity in the O-8 cm layer of soil, (2) percent bare soil surface, (3) soil texture in the O-8 cm layer of soil, and (4) crown cover. Raindrop impact on bare soil tends to rapidly close the natural channels of percolation by degrading soil structure. Studies at the Manti County watershed in Utah showed that runoff varied inversely with the total amount of ground cover (Orr 1957). Vegetative cover tends to reduce the energy of rainfall by reducing velocity and by breaking the large drops into a fine spray which can then enter the soil without damage to the soil surface. Gifford (1972) reported that the ability to predict infiltration rates, using cover characteristics alone varies with time, both within a given storm The authors are teacher, Monument","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90276758","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 : 2006-01-01DOI: 10.2458/azu_jrm_v54i2_blank
R. Blank, F. Allen, James A. Young
In arid and semi-arid climates, the physical and chemical nature of the soil seedbed greatly effects success or failure of plant recruitment. We hypothesized that the presence or absence of microphytic soil crusts may influence the character of soil seedbeds. To test this hypothesis, we compared chemical and physical attributes of the soil seedbed (0-6 cm) between adjacent areas of well-expressed microphytic soil crusts and non-microphytic soil surfaces for 2 sites on granitic alluvial fans in north-western Nevada. As compared with non-microphytic areas, microphytic soil seedbeds were finer-textured and contained more DTPA-extractable Mn, Cu, and Zn. Further research should examine in greater detail the role of microphytic soil surfaces in eolian dust entrapment, its relationship to nutrient deposition, and the interaction with seed recruitment. DOI:10.2458/azu_jrm_v54i2_blank
{"title":"Technical note: Physical and chemical comparisons between microphytic and non-microphytic soil seedbeds.","authors":"R. Blank, F. Allen, James A. Young","doi":"10.2458/azu_jrm_v54i2_blank","DOIUrl":"https://doi.org/10.2458/azu_jrm_v54i2_blank","url":null,"abstract":"In arid and semi-arid climates, the physical and chemical nature of the soil seedbed greatly effects success or failure of plant recruitment. We hypothesized that the presence or absence of microphytic soil crusts may influence the character of soil seedbeds. To test this hypothesis, we compared chemical and physical attributes of the soil seedbed (0-6 cm) between adjacent areas of well-expressed microphytic soil crusts and non-microphytic soil surfaces for 2 sites on granitic alluvial fans in north-western Nevada. As compared with non-microphytic areas, microphytic soil seedbeds were finer-textured and contained more DTPA-extractable Mn, Cu, and Zn. Further research should examine in greater detail the role of microphytic soil surfaces in eolian dust entrapment, its relationship to nutrient deposition, and the interaction with seed recruitment. DOI:10.2458/azu_jrm_v54i2_blank","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73432588","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 : 2006-01-01DOI: 10.2458/AZU_JRM_V56I6_SCARNECCHIA
D. L. Scarnecchia
The fragmented, weak identity of range science has been disadvantageous to the institutions and individuals involved with it. This paper addresses a complex, interrelated group of issues related to range science, the Journal of Range Management, and the Society for Range Management. Beginning with the long-standing conception of the art of range management, it presents a concept of range management science that has multiple implications for the Society for Range Management and its flagship publication, the Journal of Range Management. The paper presents a strategically designed identity for range management science as a synthetic science, i.e., a science of synthesis, and examines the elements of diversity, synthesis, and communication that are the essence of that identity. It encourages a diverse, inclusive, synergistic character for, and offers many suggestions related to the philosophy and conduct of, the science, the Journal, and the Society. The harmonious vision of range management science that it presents is designed to give the science a strong, coherent, marketable identity. The vision is dynamic in that it can readily accommodate evolving changes. That vision is designed to make the diversity of the science and the Society work for us, rather than against us, by establishing a philosophical environment where the kind of scientific, institutional, informational, and professional synergies we need can flourish. DOI:10.2458/azu_jrm_v56i6_scarnecchia
{"title":"Empowering diversity: envisioning, designing, and developing range management science.","authors":"D. L. Scarnecchia","doi":"10.2458/AZU_JRM_V56I6_SCARNECCHIA","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V56I6_SCARNECCHIA","url":null,"abstract":"The fragmented, weak identity of range science has been disadvantageous to the institutions and individuals involved with it. This paper addresses a complex, interrelated group of issues related to range science, the Journal of Range Management, and the Society for Range Management. Beginning with the long-standing conception of the art of range management, it presents a concept of range management science that has multiple implications for the Society for Range Management and its flagship publication, the Journal of Range Management. The paper presents a strategically designed identity for range management science as a synthetic science, i.e., a science of synthesis, and examines the elements of diversity, synthesis, and communication that are the essence of that identity. It encourages a diverse, inclusive, synergistic character for, and offers many suggestions related to the philosophy and conduct of, the science, the Journal, and the Society. The harmonious vision of range management science that it presents is designed to give the science a strong, coherent, marketable identity. The vision is dynamic in that it can readily accommodate evolving changes. That vision is designed to make the diversity of the science and the Society work for us, rather than against us, by establishing a philosophical environment where the kind of scientific, institutional, informational, and professional synergies we need can flourish. DOI:10.2458/azu_jrm_v56i6_scarnecchia","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91412243","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 : 2006-01-01DOI: 10.2458/AZU_JRM_V53I6_GONG
P. Gong, G. Biging, R. Standiford
{"title":"Use of digital surface model for hardwood rangeland monitoring.","authors":"P. Gong, G. Biging, R. Standiford","doi":"10.2458/AZU_JRM_V53I6_GONG","DOIUrl":"https://doi.org/10.2458/AZU_JRM_V53I6_GONG","url":null,"abstract":"","PeriodicalId":16918,"journal":{"name":"Journal of Range Management","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83351746","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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