内蒙古罕山自然保护区山杨林更新苗特征研究

Characteristics of Regenerated Seedlings of Poplar Forest in Hanshan Nature Reserve,Inner Mongolia

以内蒙古罕山国家级自然保护区山杨次生林为研究区,研究区内近些年出现大面积非正常死亡的山杨林,在山杨林中分别设置倒木、枯立木与对照3类样地进行死亡后更新调查。研究发现,罕山自然保护区山杨林倒木样地、枯立木样地、对照样地更新树种主要以山杨为主,并且均为萌生更新,更新密度总体呈枯立木样地>对照样地>倒木样地,平均更新苗密度分别为3158.33、2466.66、2308.33株/hm 2,郁闭度、林分密度、年均温度和海拔与山杨更新密度呈负相关(P<0.05),枯落物厚度与山杨更新密度呈正相关(P<0.05),年累计降水量未达到显著水平。并且发现山杨林非正常大面积死亡后根系仍然具有萌蘖的活力,在死亡后萌蘖更新得到快速释放,且具有形成新一代森林的潜力。

In this paper,Populus secondary forests occurring in the Hanshan National Nature Reserve in Inner Mongolia was taken as the study area where massive tree mortality has been occurred abnormally in recent years.Three types of sample plots,namely,fallen wood(FW),dead standing wood(DSW)and control(Ctrl)plots,were set up in the poplar forest for post-death update investigation.The study found that the dominant regenerated tree species was Populus in three plots.The regeneration density was generally in the order of DSW>Ctrl>FW with an average of 3158.33,2466.66,and 2308.33 plants/hm 2,respectively.Canopy density,stand density,annual average temperature and altitude were negatively correlated with the regeneration density of Populus(P<0.05),and the thickness of litter was positively correlated with the regeneration density(P<0.05).It was also found that after the occurrence of the massive mortality,the root system of the poplar dead trees still had the vitality of tillering,and the regeneration of the tillering was quickly released after death,and it had the potential to form a new generation of forest.