大兴安岭火烧迹地土壤动物生态地理分析

不同恢复年份森林火烧迹地的土壤动物群落特征明显不同。火烧过后的前1³年,大型土壤动物的种类和数量很少,特别是常见类群中的线蚓所占的比例很小,但运动能力较强的蜈蚣、蜘蛛等所占比例较高。火烧3⁵年后,土壤中线蚓数量才逐渐增多并趋于稳定。中小型土壤动物中的原尾虫只出现在16年迹地和对比样地中,表明原尾虫确是稳定生境的指示动物。火烧过后,土壤环境中最先侵入的是运动能力较强的大型土壤动物,之后中小型土壤动物才逐渐得到恢复。火烧后6⁷年是中小型土壤动物发展的盛期,随后土壤动物种类和数量开始减少并趋于稳定。火烧的强度对土壤动物群落的恢复有一定的影响,轻度火烧影响地区的土壤动物恢复较快,经过6⁷年,土壤动物种类和数量能超过未受火烧影响的地区;而中、重度火烧地区,土壤动物恢复到正常水平则需要超过16年的更长的时间。

Eco-geographical analysis of soil animals in burned forest areas in Greater Hinggan Mountains

Based on researches on soil animals in burned forest areas and contrast sample lands around Tahe County in Heilongjiang Province during different years,we analyze the category and quantity of soil animals in order to take them as a biological indicator to reflect the environmental conditions and the restoration after fire.In October,2003,we chose six burned forest areas in different years from 1987 within the study area and a sample land which wasn't destroyed by fire.Separating soil animals by the methods of picking up,Tullgren and Baerman,we obtained 4 phyla,7 classes and 22 orders in all.In addition,soil animals in burned forest areas differ obviously during different years. (1)The category and quantity of macro-soil faunas prove to be very few,especially Enchytraeidae,which takes up a lower proportion in macro-soil faunas the first one to three years after fire,however,some macro-soil faunas which have strong moving abilities,such as centipedes,spiders etc.,account for higher proportions.Furthermore,the number of Enchytraeidae gradually increases and tends to be stable after burning three to five years. (2)Of all the meso-and micro-soil animals,Protura only appears in burned forest areas after burning 16 years and the contrast sample lands,thus,we can conclude that Protura is a fauna which can indicate stable habitat. (3)After burning,the first species which are able to invade and restore are those macro-soil animals possessing strong moving abilities,and then the meso-and micro-soil animals,which are in the prosperous period six to seven years after fire,when the category and quantity begin to decrease and tend to be stable. (4)The intensity of fire influences the restoration of soil animals community to a certain extent,that is,soil animals restore at a higher speed in the areas which suffered from mild burning,after six to seven years,toth the category and the quantity can even surpass those in regions not affected by fire. (5)However,the speed of restoration is relatively low in the moderately and seriously affected areas,which may take longer than 16 years to restore to a normal level.