Alpine Kobresia meadows are major vegetation types on the Qinghai-Tibetan Plateau. There is growing concern over their relationships among biodiversity, productivity and environments. Despite the im-portance of specie...Alpine Kobresia meadows are major vegetation types on the Qinghai-Tibetan Plateau. There is growing concern over their relationships among biodiversity, productivity and environments. Despite the im-portance of species composition, species richness, the type of different growth forms, and plant bio-mass structure for Kobresia meadow ecosystems, few studies have been focused on the relationship between biomass and environmental gradient in the Kobresia meadow plant communities, particularly in relation to soil moisture and edaphic gradients. We measured the plant species composition, her-baceous litter, aboveground and belowground biomass in three Kobresia meadow plant communities in Haibei Alpine Meadow Ecosystem Research Station from 2001 to 2004. Community differences in plant species composition were reflected in biomass distribution. The total biomass showed a de-crease from 13196.96±719.69 g/m2 in the sedge-dominated K. tibetica swamp to 2869.58±147.52 g/m2 in the forb and sedge dominated K. pygmaea meadow, and to 2153.08±141.95 g/m2 in the forbs and grasses dominated K. humilis along with the increase of altitude. The vertical distribution of below-ground biomass is distinct in the three meadow communities, and the belowground biomass at the depth of 0-10 cm in K. tibetica swamp meadow was significantly higher than that in K. humilis and K. pygmaea meadows (P<0.01). The herbaceous litter in K. tibetica swamp was significantly higher than those in K. pygnaeca and K. humilis meadows. The effects of plant litter are enhanced when ground water and soil moisture levels are raised. The relative importance of litter and vegetation may vary with soil water availability. In the K. tibetica swamp, total biomass was negatively correlated to species richness (P<0.05); aboveground biomass was positively correlated to soil organic matter, soil moisture, and plant cover (P<0.05); belowground biomass was positively correlated with soil moisture (P<0.05). However, in the K. pygnaeca and K. humilis meadow communities, abo展开更多
Aims Elevated atmospheric CO_(2)has the potential to enhance the net primary productivity of terrestrial ecosystems.However,the role of soil microorganisms on soil C cycling following this increased available C remain...Aims Elevated atmospheric CO_(2)has the potential to enhance the net primary productivity of terrestrial ecosystems.However,the role of soil microorganisms on soil C cycling following this increased available C remains ambiguous.This study was conducted to determine how quality and quantity of plant litter inputs would affect soil microorganisms and consequently C turnover.Methods Soil microbial biomass and community structure,bacterial community-level physiological profile,and CO_(2)emission caused by different substrate C decomposition were investigated using techniques of biological measurements,chemical and stable C isotope analysis,and BIOLOG-ECO microplates in a semiarid grassland ecosystem of northern China in 2006 and 2007 by mixing three contrasting types of plant materials,C_(3)shoot litter(SC_(3)),C_(3)root litter(RC_(3)),and C4 shoot litter(SC4),into the 10-to 20-cm soil layer at rates equivalent to 0(C0),60(C60),120(C120)and 240 g C m2(C240).Important Findings Litter addition significantly enriched soil microbial biomass C and N and resulted in changes in microbial structure.Principal component analysis of microbial structure clearly differentiated among zero addition,C_(3)-plant-derived litter,and C4-plant-derived litter and among shoot-and root-derived litter of C_(3)plants;soilmicroorganismsmainly utilized carbohydrates without litter addition,carboxylic acids with C_(3)-plant-derived litter addition and amino acidswith C4-plant-derived litter addition.We also detected stimulated decomposition of older substratewith C4-plant-derived litter inputs.Our results showthat both quality and quantity of belowground litter are involved in affecting soil microbial community structure in semiarid grassland ecosystem.展开更多
以准格尔黑岱沟露天煤矿复垦区8种优势种植物的叶片及对应叶片枯落物为研究对象,通过对其碳、氮、磷、钾含量及生态化学计量学特征的研究,探讨退化生态系统植物内稳性、不同植被类型与NP限制率的关系,以期为黄土高原植被恢复与重建以及...以准格尔黑岱沟露天煤矿复垦区8种优势种植物的叶片及对应叶片枯落物为研究对象,通过对其碳、氮、磷、钾含量及生态化学计量学特征的研究,探讨退化生态系统植物内稳性、不同植被类型与NP限制率的关系,以期为黄土高原植被恢复与重建以及不同物种的合理配置提供合理建议,为完善生态化学计量学理论提供支撑。结果表明,不同植物叶片C、N、P、K的变化范围分别为418.2～564.1、7.19～33.21、0.82～2.37、4.98～32.77 g kg-1。不同植物叶片的生态化学计量学特征N∶P、P∶K、N∶K、C∶N、C∶P、C∶K比变化范围分别为7.16～22.45、0.036～0.23、0.70～4.55、14.92～64.44、218.54～557.36、12.78～121.14。该地区3种植被类型钾含量差异显著,草本植物叶片钾含量显著高于乔木林和灌木林。不同植被类型植物叶片N∶P比表现为灌木（18.86）〉草本（15.44）〉乔木（14.68）,说明该区灌木林主要受P含量的限制,草本和乔木植物主要受N、P含量共同限制,该地区植被恢复应该以灌木为主。展开更多
基金Supported by the Hundred Talents Programs of the Chinese Academy of Sciencesthe National Natural Science Important Foundation of China (Grant No. 30730069)
文摘Alpine Kobresia meadows are major vegetation types on the Qinghai-Tibetan Plateau. There is growing concern over their relationships among biodiversity, productivity and environments. Despite the im-portance of species composition, species richness, the type of different growth forms, and plant bio-mass structure for Kobresia meadow ecosystems, few studies have been focused on the relationship between biomass and environmental gradient in the Kobresia meadow plant communities, particularly in relation to soil moisture and edaphic gradients. We measured the plant species composition, her-baceous litter, aboveground and belowground biomass in three Kobresia meadow plant communities in Haibei Alpine Meadow Ecosystem Research Station from 2001 to 2004. Community differences in plant species composition were reflected in biomass distribution. The total biomass showed a de-crease from 13196.96±719.69 g/m2 in the sedge-dominated K. tibetica swamp to 2869.58±147.52 g/m2 in the forb and sedge dominated K. pygmaea meadow, and to 2153.08±141.95 g/m2 in the forbs and grasses dominated K. humilis along with the increase of altitude. The vertical distribution of below-ground biomass is distinct in the three meadow communities, and the belowground biomass at the depth of 0-10 cm in K. tibetica swamp meadow was significantly higher than that in K. humilis and K. pygmaea meadows (P<0.01). The herbaceous litter in K. tibetica swamp was significantly higher than those in K. pygnaeca and K. humilis meadows. The effects of plant litter are enhanced when ground water and soil moisture levels are raised. The relative importance of litter and vegetation may vary with soil water availability. In the K. tibetica swamp, total biomass was negatively correlated to species richness (P<0.05); aboveground biomass was positively correlated to soil organic matter, soil moisture, and plant cover (P<0.05); belowground biomass was positively correlated with soil moisture (P<0.05). However, in the K. pygnaeca and K. humilis meadow communities, abo
基金National Natural Science Foundation of China(40741006,30521002,30821062).
文摘Aims Elevated atmospheric CO_(2)has the potential to enhance the net primary productivity of terrestrial ecosystems.However,the role of soil microorganisms on soil C cycling following this increased available C remains ambiguous.This study was conducted to determine how quality and quantity of plant litter inputs would affect soil microorganisms and consequently C turnover.Methods Soil microbial biomass and community structure,bacterial community-level physiological profile,and CO_(2)emission caused by different substrate C decomposition were investigated using techniques of biological measurements,chemical and stable C isotope analysis,and BIOLOG-ECO microplates in a semiarid grassland ecosystem of northern China in 2006 and 2007 by mixing three contrasting types of plant materials,C_(3)shoot litter(SC_(3)),C_(3)root litter(RC_(3)),and C4 shoot litter(SC4),into the 10-to 20-cm soil layer at rates equivalent to 0(C0),60(C60),120(C120)and 240 g C m2(C240).Important Findings Litter addition significantly enriched soil microbial biomass C and N and resulted in changes in microbial structure.Principal component analysis of microbial structure clearly differentiated among zero addition,C_(3)-plant-derived litter,and C4-plant-derived litter and among shoot-and root-derived litter of C_(3)plants;soilmicroorganismsmainly utilized carbohydrates without litter addition,carboxylic acids with C_(3)-plant-derived litter addition and amino acidswith C4-plant-derived litter addition.We also detected stimulated decomposition of older substratewith C4-plant-derived litter inputs.Our results showthat both quality and quantity of belowground litter are involved in affecting soil microbial community structure in semiarid grassland ecosystem.
文摘以准格尔黑岱沟露天煤矿复垦区8种优势种植物的叶片及对应叶片枯落物为研究对象,通过对其碳、氮、磷、钾含量及生态化学计量学特征的研究,探讨退化生态系统植物内稳性、不同植被类型与NP限制率的关系,以期为黄土高原植被恢复与重建以及不同物种的合理配置提供合理建议,为完善生态化学计量学理论提供支撑。结果表明,不同植物叶片C、N、P、K的变化范围分别为418.2～564.1、7.19～33.21、0.82～2.37、4.98～32.77 g kg-1。不同植物叶片的生态化学计量学特征N∶P、P∶K、N∶K、C∶N、C∶P、C∶K比变化范围分别为7.16～22.45、0.036～0.23、0.70～4.55、14.92～64.44、218.54～557.36、12.78～121.14。该地区3种植被类型钾含量差异显著,草本植物叶片钾含量显著高于乔木林和灌木林。不同植被类型植物叶片N∶P比表现为灌木（18.86）〉草本（15.44）〉乔木（14.68）,说明该区灌木林主要受P含量的限制,草本和乔木植物主要受N、P含量共同限制,该地区植被恢复应该以灌木为主。
