摘要
采用空间替代时间的方法,对大兴安岭不同发育阶段兴安落叶松3种林型林下植被物种多样性进行研究。结果表明:林下植被物种多样性随兴安落叶松林的发育年龄而改变。草类-兴安落叶松林灌草层多样性从幼龄林开始,增加到中龄林(或近熟林)达到最大值(中龄林灌木层D、H为0.34和0.55,草本层H为1.07;近熟林草本层D为0.54),然后随郁闭度的增加在成熟林(灌草层D、H分别为0.20,0.38和0.32,0.63)降到最低,到过熟林由于林冠疏开和自然整枝增强了林地光照强度,多样性又升高。杜香-兴安落叶松林灌草层多样性从幼龄林开始,增加到近熟林达到最高(灌草层D和H分别为0.39,0.76和0.57,1.06),灌木层在过熟林最低(D和H为0.37和0.64),草本层在成熟林最低(D和H为0.42,0.77)。藓类-兴安落叶松林灌木层多样性近熟林最低(D、H为0.41和0.76),H在中龄林最高(0.80),D在过熟林为最高(0.48);草本层中龄林多样性最低(D、H为0.50和0.83),过熟林最高(D、H为0.68和1.32)。林下植被物种多样性的变化与林分密度呈负相关,与植被和灌木总盖度呈正相关。
In order to compare the diversity dynamics of understory vegetation in different developmental stages, three forest type, SPhagnum-Bryum-Larix gmelinii forest, herbage-Larix gmelinii forest and Ledum palustre-Larix gmelinii forest were selected in Daxinganling region using the method of temporal and spatial substitution. The Simpson index （D）, Shannon-Wiener index （H） and Pielou evenness index （J） were all used. The results suggested that the diversity of shrubby and herbaceous in herbage-Larix gmelinii forest had the same dynamics, increased from the early stage of the forest, then decreased with the increase of forest crown density, and increased again with decrease of forest crown density in the overmature forest. The understory vegetation diversity peaked in the nearly mature forest, and reached the lowest in the overmature forest for diversity of shrubby and in the mature forest for diversity of herbaceous in Ledum palustre-Larix gmelinii forest. The diversity of shrubby and herbaceous in SPhagnum-Bryum-Larix gmelinii forest all peaked in the overmature period （the value of D and H was 0.68 and 1.32, respectively） and the lowest diversity in the nearly mature forest for the shrubby （the value of D and H was 0.41 and 0.76. respectively） and in the middle age for the herbage （the value of D and H was 0.50 and 0.83, respectively）. The species diversity variations of understory vegetation had a negative correlation with stand density, while it had a positive correlation with vegetation coverage and shrub coverage.
出处
《沈阳农业大学学报》
CAS
CSCD
北大核心
2013年第6期771-775,共5页
Journal of Shenyang Agricultural University
基金
"十二五"国家科技支撑计划课题团队项目(2012BAD22B00)
关键词
兴安落叶松
林型
林龄
林下植被
物种多样性
Larix gmelinii
forest types
forest age
understory vegetation
diversity index
