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Range Condition Scoring was developed as a way to quantify biodiversity in a given rangeland system. This practice is widely used in the Sand Hills region of Nebraska, as well as the tallgrass prairie regions, as evidenced by the authoritative book on the subject, "Range Judging Handbook and Contest Guide for Nebraska." This book outlines the steps required to evaluate, or score, a particular region of rangeland; and it serves as a baseline for the understanding of this method of judging rangeland health. ==Completing a survey== A certain area of land is chosen for a survey and random selections are made to determine where species composition measurements must be taken. Once these areas are selected, plant species composition measurements are taken by clipping the plants in a cordoned off area and measuring the mass of each type of plant species. This can then be compared to the entire plant mass in the area to determine the percent of each species located within the area. Once these percentages are determined, they can be compared with the "Guides for determining range condition" located in the Range Judging Handbook. These tables show the amount of each species that is allowed in each area of rangeland. The tables differ depending upon average rainfall as well as soil type. These differences occur because the climax plant community would differ as the variables of rainfall and soil type change. The score that is computed will fall in the range of 0-25% if the range is in "Poor" Condition, 26-50% if the range is in "Fair" Condition, 51-75% if the range is in "Good" Condition, and 76-100% if the range is in "Excellent" Condition. By taking the range condition score that is determined, the researcher then can use Table 4 in the Nebraska Cooperative Extension Circular EC 86-113-C to determine an "Adjustment Factor for Initial Stocking Rate." This adjustment factor is then multiplied with the correct number found in Table 3 of the same Extension Circular to determine an initial stocking rate value for livestock. This stocking rate is expressed in units called AUM/acre (Animal Unit Months per acre). AUMs are based on the amount of forage that a 1000 pound animal will graze in one month's time, which is roughly 780 pounds of air-dry forage. This information is further detailed in the "Nebraska Handbook of Range Management" (EC 92-124-E by Reece and Stubbendieck). By connecting the research completed involving quantifying rangeland health to the research completed involving livestock grazing and distribution, we now have a system in place to more properly manage stocking rates of grazing livestock. In addition, we have a system that determines the amount of forage that should not be grazed to provide adequate support for wildlife biodiversity. This use, as well as others, is detailed below. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Range condition scoring」の詳細全文を読む スポンサード リンク
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