内蒙古荒漠草原4种优势植物生物量分配对不同放牧强度的响应

放牧是荒漠草原主要利用方式之一，生物量是生态系统获取能量能力的主要体现。目前对荒漠草原优势植物生物量分配及权衡研究相对缺乏。本研究以内蒙古荒漠草原为研究对象，设置3个不同放牧梯度(轻度放牧，中度放牧，重度放牧)，并以不放牧作为对照，通过对群落特征和4种优势植物短花针茅(Stipa breviflora)、无芒隐子草(Cleistogenes songorica)、冷蒿(Artemisia frigida)、银灰旋花(Convolvulus ammannii)生物量进行分析，揭示不同放牧梯度下优势植物生物量分配特征及生物量权衡机制。结果表明：随着放牧强度增加，荒漠草原群落地上、地下生物量、凋落物、盖度、4种优势植物地上地下生物量呈降低趋势；4种优势植物生物量均表现出向地下权衡，且随着放牧强度增加，权衡值变大；4种优势植物地上地下生物量均与群落盖度和凋落物含量呈显著正相关关系，冷蒿和银灰旋花根冠比均与群落盖度和凋落物含量呈显著负相关关系。本研究为理解地上地下生物量分配提供了一个新的视角和方法。

Biomass Allocation of Four Dominant Plant Species in Inner Mongolia Desert Grasslands in Response to Different Grazing Intensities

Grazing is one of the main utilization methods in desert grasslands. Biomass is the main manifestation of the energy acquisition capacity of the ecosystem. At present,there is a relative lack of research on biomass allocation and trade-offs of dominant plants in desert grasslands. In this study,three different grazing gradients (light grazing,medium grazing,and heavy grazing) were set up in Inner Mongolia desert grassland,and no grazing was used as the control. The above-ground and below-ground biomass of four dominant plants (Stipa breviflora,Cleistogenes songorica,Artemisia frigida,Convolvulus ammannii) were analyzed to investigate the biomass distribution characteristics and biomass trade-off of dominant plants under different grazing gradients. The results showed that with the increase of grazing intensity,the above-ground and below-ground biomass,litter,cover,and above and below-ground biomass of the four dominant plants tended to decrease;All four dominant plant biomasses showed a trade-off to the belowground,and the trade-off value became larger as the grazing intensity increased;The above and below-ground biomass of the four dominant plants showed significant positive correlations with community cover and litter content,while the root/shoot ratio of Artemisia frigida and Convolvulus ammannii showed significant negative correlations with community cover and litter content. This study provides a new perspective and method for understanding above- and below-ground biomass distribution.