果洛地区“黑土滩”中秃斑地测定

Determination of Barren Patch(BP)of HEI TU TAN grassland in Gulouo Region

“黑土滩”中的秃斑地和原草地相比，毒草量增加６４．８％，优良牧草明显减少；地下根量（０—１０ｃｍ）减少２３７６．６ｇ／ｍ￣２；土壤趋于碱性、旱化，肥力下降，蓄水能力下降。以上差异均达到显著水平（Ｐ＜０．０５）。

Comparing with original grassland,BP of HEITUTAN grassland was studied.The results showed that,in BP of HETUTAN,the poisonous weeds increased by 64.8%,andthe herbages of quality reduced significantly.The underground phytomass(dry matter)with1n 0-10cm,reduced by 2376.6g/m￣2. The soil was gradually changing into alkalinity and arid-ity the fertility and the capacity of holding water decreased.All the differences above be-tween the BP and the original grassland were significant (P<0.05)。