采用随机区组试验研究了内蒙古高原荒漠草原亚带短花针茅（Stipa brevi flora）草原群落不同载畜率对草原群落结构和功能群生产力的影响。结果表明：随着载畜率的增加，群落的植物种数逐渐减少，在每个载畜率水平下，冷蒿（Artemisia fr...采用随机区组试验研究了内蒙古高原荒漠草原亚带短花针茅（Stipa brevi flora）草原群落不同载畜率对草原群落结构和功能群生产力的影响。结果表明：随着载畜率的增加，群落的植物种数逐渐减少，在每个载畜率水平下，冷蒿（Artemisia frigida）占有绝对优势地位，优势度为35．66％～41．95％；群落的地上生物量随载畜率的增加而降低，各功能群地上生物量组成中，灌木类处于主体地位，分别占据了群落68％（CK）、77．40％（LG）、73．25％（MG）、76．91％（HG）的生物量；在植物生活型功能组成中，灌木类和杂类草、多年生丛生禾草和杂类草功能群，在生物量上具有生态互补效应（niche complementary effect）。展开更多
Nitrogen （N） and phosphorus （P） are the major nutrients that constrain plant growth and development, as well as the structure and function of ecosystems. Hence, leaf N and P patterns can contribute to a deep under...Nitrogen （N） and phosphorus （P） are the major nutrients that constrain plant growth and development, as well as the structure and function of ecosystems. Hence, leaf N and P patterns can contribute to a deep understanding of plant nutrient status, nutrient limitation type of ecosystems, plant life-history strategy and differentiation of functional groups. However, the status and pattern of leaf N and P stoichiometry in N-deficiency desert ecosystems remain unclear. Under this context, the leaf samples from 57 plant species in the Karamori Mountain Ungulate Nature Reserve, eastern Junggar Desert, China were investigated and the patterns and interrelations of leaf N and P were comparatively analyzed. The results showed that the average leaf N concentration, P concentration, and N：P ratio were 30.81 mg/g, 1.77 mg/g and 17.72, respectively. This study found that the leaf N concentration and N：P ratio were significantly higher than those of studies conducted at global, national and regional scales; however, the leaf P concentration was at moderate level. Leaf N concentration was allometrically correlated with leaf P and N：P ratio across all species. Leaf N, P concentrations and N：P ratio differed to a certain extent among plant functional groups. C4 plants and shrubs, particularly shrubs with assimilative branches, showed an obviously lower P concentration than those of C3 plants, herbs and shrubs without assimilative branches. Shrubs with assimilative branches also had lower N concentration. Fabaceae plants had the highest leaf N, P concentrations （as well as Asteraceae） and N：P ratio; other families had a similar N, P-stoichiometry. The soil in this study was characterized by a lack of N （total N：P ratio was 0.605）, but had high N availability compared with P （i.e. the available N：P ratio was 1.86）. This might explain why plant leaves had high N concentration （leaf N：P ratio〉16）. In conclusion, the desert plants in the extreme environment in this study have formed their intr展开更多
基金financially supported by the National Natural Science Foundation of China(41201056)the National Basic Research Program of China(2014CB954202)+2 种基金the West Light Foundation of the Chinese Academy of Sciences(XBBS-2014-20)the Program of Joint Foundation of the National Natural Science Foundationthe Government of Xinjiang Uygur Autonomous Region of China(U1503101)
文摘Nitrogen （N） and phosphorus （P） are the major nutrients that constrain plant growth and development, as well as the structure and function of ecosystems. Hence, leaf N and P patterns can contribute to a deep understanding of plant nutrient status, nutrient limitation type of ecosystems, plant life-history strategy and differentiation of functional groups. However, the status and pattern of leaf N and P stoichiometry in N-deficiency desert ecosystems remain unclear. Under this context, the leaf samples from 57 plant species in the Karamori Mountain Ungulate Nature Reserve, eastern Junggar Desert, China were investigated and the patterns and interrelations of leaf N and P were comparatively analyzed. The results showed that the average leaf N concentration, P concentration, and N：P ratio were 30.81 mg/g, 1.77 mg/g and 17.72, respectively. This study found that the leaf N concentration and N：P ratio were significantly higher than those of studies conducted at global, national and regional scales; however, the leaf P concentration was at moderate level. Leaf N concentration was allometrically correlated with leaf P and N：P ratio across all species. Leaf N, P concentrations and N：P ratio differed to a certain extent among plant functional groups. C4 plants and shrubs, particularly shrubs with assimilative branches, showed an obviously lower P concentration than those of C3 plants, herbs and shrubs without assimilative branches. Shrubs with assimilative branches also had lower N concentration. Fabaceae plants had the highest leaf N, P concentrations （as well as Asteraceae） and N：P ratio; other families had a similar N, P-stoichiometry. The soil in this study was characterized by a lack of N （total N：P ratio was 0.605）, but had high N availability compared with P （i.e. the available N：P ratio was 1.86）. This might explain why plant leaves had high N concentration （leaf N：P ratio〉16）. In conclusion, the desert plants in the extreme environment in this study have formed their intr
