摘要
为系统认识荒漠草原中间锦鸡儿人工林草本植被特征及演变趋势对土壤养分的响应,采用空间代替时间的方法,以天然草地为对照,构建3个中间锦鸡儿林龄(16a、25a、37a)研究序列,调查不同中间锦鸡儿林灌丛内外土壤植被并分析二者之间的关系。结果表明:(1)随林龄增加,不同功能群植物重要值呈不同变化趋势,其中禾本科植物显著增加,豆科植物显著降低,杂草类植物先减小后增加。(2)α多样性分析显示,荒漠草原中间锦鸡儿人工林16a灌丛外物种丰富度(S)、香浓维纳指数(H)最高(P<0.01);不同林龄均匀度指数(J)、优势度指数(P)未表现出明显的变化规律。(3)β多样性分析显示,Cody指数(βc)和Morisita-Horn(CMH)相似指数均表现出16a与25a、37a之间的物种差异较大、25a与37a之间物种差异相对较小、37a中间锦鸡儿林与天然草地物种组成相似,βws指数在25a中间锦鸡儿林最大。(4)人工中间锦鸡儿林存在显著的土壤碳氮"肥岛效应",其中土壤有机碳是不同林龄植物群落组成差异的显著性影响因子,土壤速效氮为不同林龄灌丛外植物多样性差异的显著性影响因子,但灌丛内植物多样性对土壤养分的响应并不显著。研究认为,中间锦鸡儿林土壤养分演替正效应提高了植物多样性,增强了植物物种的更替程度,但建植后期(37a)植物群落存在向天然草地演替趋势。
In order to understanding the characteristics and evolution trend of Caragana intermedia plantation herbaceous vegetation systematically and the response of soil nutrients in desert steppe,we used spatiotemporal substitution method,toke natural meadow as control,constructed three C.intermedia age as research sequence,and investigated inside and outside of different soil vegetation and shrubs and analyzed the relationship between them.The results showed that：（1）with the increasing of the planting years of C.intermedia,different groups of plants showed different trends to the overall important values：a significantincrease in grasses,a significantly reduce in legume,and the weed species increase after the first decrease.（2）αdiversity：the biodiversity index including Richness（S）Shannon Wiener index（H）had a highest value in 16 aoutside shrub（P〈0.01）.Evenness index（J）and Dominance index（P）did not showed significant trend in different stand ages.（3）βdiversity：The change of Cody index（βc）and Morisita-Horn（CMH）similarity index indicated that：the species of 16 a,25aand 37 awere quite different,while the differences were relatively small between 25 aand 37a.The composition between 37 aCaraganaforest and natural grassland species were similar.Theβwsindex had the highest value in 25 a.（4）There was a significant＂fertile island effect＂of soil carbon and nitrogen in Caragana intermediaforest.The soil organic carbon had a significantly influence on community group for different artificial Caraganaforest.The effect of soil nitrogen on plant diversity was not significant in shrubs interior while was significant in shrubs external.The study illustrated that：the positive effect of soil nutrient succession could improve the plant diversity in C.intermediaforest and enhance the degree of replacement of plant species.However,plant community succession had a trend from presence to natural meadow on later（37a）.The vegetation succession direction of C.intermediaforest wa
出处
《西北植物学报》
CAS
CSCD
北大核心
2016年第9期1872-1881,共10页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金(41461046)
国家重点基础研究发展计划前期专项(2012CB723206)
宁夏大学211项目
关键词
荒漠草原
中间锦鸡儿
土壤养分
植物群落
土壤养分效应
desert steppe region
Caragana intermedia
soil nutrients
plant community
soil nutrient
