摘要
贝加尔针茅草原因常年放牧导致不同程度退化,主要体现为植物多样性下降和土壤养分流失等问题,而将流失养分归还后能否提高贝加尔针茅草原植被群落多样性及生产力尚不明确。故于2010年在内蒙古呼伦贝尔市鄂温克旗贝加尔针茅草原设置长期N、P、K添加(100 kg·hm^(-2)∙a^(-1))及其交互处理试验。连续3年(2017-2019年)试验结果表明:1)长期N、NK、NP和NPK添加显著提高草原禾本科相对重要值(P<0.05),降低杂类草相对重要值,使群落优势种由杂类草转变为禾本科;2)N、NK、NP和NPK添加显著增加群落和禾本科地上生物量(P<0.05),显著降低杂类草地上生物量(P<0.05),P添加显著增加豆科地上生物量(P<0.05),在降水量充足年份植物生物量对养分添加的响应更为敏感;3)Simpson指数、Shannon-Wiener指数、Pielou指数和物种丰富度均在NK、NP和NPK添加下显著降低(P<0.05)。综上所述,N是贝加尔针茅草原群落和功能群地上生物量以及物种多样性的主要限制因子,P的限制作用仅次于N,K的作用最弱。N与P、K的组合添加在降水量充足年份对贝加尔针茅草原植被群落的影响大于干旱年份。
The symptoms of Stipa baicalensis steppe degradation are decreases in plant diversity and soil nutrient loss caused by long-term overgrazing.However,it remains unclear whether returning lost nutrients could improve the community diversity and productivity of S.baicalensis steppe and restore the original vegetation.Therefore,in a long-term experiment,effects of N,P and K additions(100 kg·ha^(-1)·yr^(-1))and various nutrient combination treatments were evaluated in 2010 in an S.baicalensis steppe located at Ewenki Banner,Hulunbuir City,Inner Mongolia.The results for three consecutive years(2017-2019)showed that:1)Long-term addition of N,NK,NP and NPK significantly increased the relative importance value of Gramineae species(P<0.05),decreased the relative importance value of forbs,and changed the dominant species from forbs to grasses.2)N,NK,NP and NPK additions significantly increased the aboveground biomass of the community and of Gramineae(P<0.05),and decreased the aboveground biomass of forbs(P<0.05),while P enhanced the aboveground biomass of Leguminosae(P<0.05).Plant biomass was more sensitive to nutrient addition in years with adequate precipitation.3)Simpson index,Shannon-Wiener index,Pielou index and species richness decreased with the addition of NK,NP and NPK(P<0.05).In conclusion,N is the most important limiting factor for aboveground biomass and species diversity in a S.baicalensis steppe community,P is the second most limiting factor after N,and K is the least limiting of the three.The effects of N,P and K combinations on the S.baicalensis steppe primary vegetation community were greater in years with adequate precipitation than in years with drought.
作者
卢俊艳
红梅
赵巴音那木拉
赵乌英嘎
王文东
马尚飞
杨殿林
LU Jun-yan;HONG Mei;ZHAO Bayinnamula;ZHAO Wuyingga;WANG Wen-dong;MA Shang-fei;YANG Dian-lin(College of Grassland,Resources and Environment,Inner Mongolia Agricultural University,Hohhot 010018,China;Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources,Hohhot 010018,China;Agro-Environmental Protection Institute,Ministry of Agriculture and Rural Affairs,Tianjin 300191,China)
出处
《草业学报》
CSCD
北大核心
2022年第4期22-31,共10页
Acta Prataculturae Sinica
基金
国家自然科学基金(31170435)资助。
关键词
群落结构
物种多样性
功能群
养分添加
贝加尔针茅草原
community structure
species diversity
plant functional groups
nutrient addition
Stipa baicalensis steppe