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大气氮(N)沉降增加加速了生态系统N循环,导致生态系统磷(P)需求增加。开展不同N:P处理对荒漠草原植物生长和生态化学计量特征影响的研究,不仅可为预测长期大气N沉降增加条件下植物和土壤的相互作用提供新思路,而且可为全球变化背景下我国北方草地植被的可持续管理提供科学指导。该文通过2013–2014年针对甘草(Glycyrrhiza uralensis)设立的不同N:P的盆栽控制试验,研究了不同N:P处理对甘草生物量和碳(C)、N、P化学计量学特征(叶片、根系和土壤)的影响,比较了C:N:P化学计量学特征在叶片、根系和土壤3个库间的差异和联系,探讨了土壤C:N:P化学计量比对甘草生长和养分摄取的指示作用。结果显示:N:P的适当减小降低了土壤和甘草(叶片和根系)的C:P和N:P,提高了甘草地上和地下生物量,说明适量的P添加提高了土壤P有效性和甘草P摄取能力、促进了甘草生长和生物量积累。但过低的N:P处理(高P添加)使土壤C:P和N:P显著下降,抑制了甘草对N的摄取,从而不利于甘草生长;甘草叶片和根系(尤其叶片)C:N:P化学计量学特征均与土壤C:N:P化学计量学特征存在不同程度的相关性,意味着土壤C、N、P及其计量关系的改变会直接作用于植物。以上结果表明,适当的人为P添加可通过调节土壤和植物叶片C:N:P化学计量学特征,缓解土壤和植物间P的供需压力,从而减缓长期大气N沉降增加对荒漠草原群落结构的不利影响。
Increased deposition of atmospheric nitrogen (N) accelerates the N cycle of ecosystems, resulting in an increase in demand for phosphorus (P) in ecosystems. The study on the effects of different N: P treatments on the plant growth and ecological stoichiometry of desert steppe not only provides new ideas for predicting the interaction between plant and soil under the condition of long-term increase of N deposition in the atmosphere, but also provides a new idea for the interaction between plant and soil in the global change context. Sustainable management of grassland vegetation provides scientific guidance. In this paper, we studied the effects of different N: P treatments on the biomass, carbon (C), N and P stoichiometry (leaf shape) of Glycyrrhiza uralensis from 2013 to 2014 under different N: , Root system and soil). The differences and correlations of C: N: P stoichiometry traits in three stocks of leaves, roots and soil were compared. The effects of soil C: N: P stoichiometry on the growth and nutrient contents of licorice The role of intake instructions. The results showed that the appropriate reduction of N: P decreased C: P and N: P in soil and licorice (leaf and root), increased above and below biomass of Glycyrrhiza uralensis, indicating that proper P addition increased soil P availability and Glycyrrhizin P Uptake Capability Promotes Licorice Growth and Biomass Accumulation. However, too low N: P treatment (high P addition) significantly decreased soil C: P and N: P, inhibited the uptake of N by licorice, which was not conducive to the growth of licorice; Licorice leaves and roots (especially leaves) C: N : P stoichiometry all have different degrees of correlation with soil C: N: P stoichiometry, which implies that soil C, N, P and their changes in metrology will directly affect plants. The above results indicate that proper man-made P addition can alleviate the pressure of supply and demand of P between soil and plant by adjusting the C: N: P stoichiometry of soil and plant leaves, thus reducing the negative effect of long-term atmospheric N deposition on the desert grassland community structure influences.