Community characteristics in Hongchiba area of Wuxi County during ecological restoration after controlled burning Study on the Change of Soil Nutrient Before and After Burning Secondary Forest in Xishuangbanna EFFECT OF RANGE FIRE ON NITROGEN FIXATION OF COLLEMA TENAX IN A SEMIARID GRASSLAND OF INNER MONGOLIA, CHINA Variation of soil fertility in Eucalyptus robusta plantations after controlled burning in the red soil region and its ecological evaluation