比较目测法和刈割测产法对草地地上干物质现存量的测定

THE MEASUREMENT OF THE ABOVEGROUND DRY MATTER YEILD OF GRASSLAND BY THE VISUAL ASSESSMENT AND THE MOWING

通过对呼仑贝尔市鄂温克草甸草原地上干物质现存量进行目测法和刈割法比较试验,表明:目测样方数与地上干物质现存量呈显著正相关关系(P<0.05)。且测得的地上现存量大小:A>B>C>D。受过训练的人员通过比较目测法测得草地地上干物质现存量(SDM)与刈割测得的地上现存量SDM最接近,其余首次进行该试验的工作人员测得的SDM与刈割测得的SDM差异很大。分别对目测样方数量、取样距离对SDM影响进行分析得出:随目测样方数量增加,目测SDM逐渐接近刈割测得的SDM;增加取样距离,4条曲线波动性增加,测得的SDM变化增大。

A comparative study of the visual assessment and the assessment by harvesting of aboveground dry standing crop was performed on Ewenke Grassland in Hulunbuir. The results showed that the number of quart performed can positively affect the accuracy of assessment of the aboveground standing crop （SDM） （p 〈 0.05）. The resulted aboveground standing crop： A 〉 B 〉 C 〉 D. The trained observers or A who used the visual assessment gave the much more similar result with that of harvesting. Those fresh observers who first participated in the experiment gave more deflected results from that of harvesting. The effects of quantities of quart performed and distances of the visual assessment on the accurate assessment of aboveground standing crop of grassland were analyzed. It indicates that as the quantity of quart performed increased, SDM of the visual assessment was closer to that of harvesting; as the distance of sampiing increased, the fluctuation of four curves increased, resulting in a more varied SDM.