关键词: 特早熟棉区, 棉铃, 施氮量, 种植密度, 生物量, 品质

Abstract: The composition, biomass and nutrient storage of fallen trees and snags are surveyed in major forest types of Korean pine-deciduous mixed forest at Changbai Mountain Natural Reserve. The amount and biomass of fallen trees and snags range from 82 logs穐a^-1,5 snags穐a^-1 and 7.9t穐a^-1, 1.71t穐a^-1 in Korean pine-broadleaved forest to 94 logs穐a^-1,20 snags穐a^-1 and 16.23t穐a^-1, 7.34t穐a^-1 in broadleaved-Korean pine forest. Fallen tree and snag compositions in these two forest types are respectively similar to their stand compositions. Fallen trees and snags are important nutrient pools in Korean pine-deciduous mixed forest, especially for their 28.96 and 43.27 kg穐a^-1 storage of Nitrogen. They are a part of forest detritus that should be included in forest detritus survey and be well reserved in forest land after forest cutting.

Key words: extremely early maturing cotton region, cotton boll, nitrogen fertilization rate, planting density, biomass, quality