刈割驼绒藜（Ceratoides latens）补偿生长效应与同化碳素运移分配

Subshrub Ceratoides latens is not only high quality forage with rich nutrients, but also an important ecological barrier for maintaining stability of the ecosystems and inhibition of soil erosion. In most cases, mowing can promote compensatory growth of above- and underground part of plant, and also been reported to be able to stimulate root exudation. We select Ceratoides latens as research object and conduct controlled experiments in both field and greenhouse to study following scientific questions: (1) observing the compensatory capacity of Ceratoides lateens with regard to canopy and root with conventional method; (2) investigating the distribution pattern of energy and assimilated carbon among root, stem, leaf, and rhizosphere soil to elucidate the compensatory growth mechanism of Ceratoides lateens by measuring heat value and feeding and tracing stable isotope (13CO2); (3) studying storage changes of assimilated carbon in pools of canopy, root, microorganism and rhizosphere soil and carbon flux among them to explore effects of cutting on the carbon turnover of plant-soil system by measuring microbial biomass, soil enzyme activity and microbial carbon content with physiological and biochemical methods for microorganism. Our study aims to provide theoretical basis for scientific developing and sustainable utilizing Ceratoides lateens, having great enlightening significance for exploring ways of low carbon husbandry (reducing carbon emission).

半灌木驼绒藜不仅是营养丰富的优良牧草，而且是维持原生态系统稳定、抑制土壤侵蚀的重要生态屏障。在多数情况下，刈割促进植物地上枝叶和地下根系补偿生长；有报道刈割会刺激根系分泌。本申请项目以广泛分布的驼绒藜为对象，野外样地实验与温室盆栽实验相结合，采用常规方法观测研究驼绒藜根、冠补偿生长特征；采用热值测定和稳定同位素（13CO2）饲喂-示踪的实验技术，研究能量和同化碳素在根-茎-叶及根际土壤间的分配，揭示驼绒藜补偿生长机理；采用微生物生理生化方法，测定微生物量、土壤酶活性、微生物碳和土壤有机碳，研究刈割驼绒藜群落的同化碳素在冠层－根系－微生物－根际土壤各碳库碳贮量变化及库间碳流量，进而探讨刈割对植物－土壤系统碳素周转的影响。这些研究旨在为科学开发与可持续利用驼绒藜资源提供应用基础的理论依据，对于探索低碳畜牧业（减少碳排放）途径的研究具有启示性意义。

驼绒藜（Ceratoides latens）广泛分布于亚洲中 部荒漠和荒漠化草原地区，常以建群种形成的半灌木植被不仅是维持荒漠-荒漠草原生态系统稳定、抑制土壤侵蚀的重要生态屏障，而且是难得的优良放牧场和割草场。所以，本申请项目的研究更显得十分重要。 .本项目集中研究刈割驼绒藜补偿生长特征及其同化碳素运输分配规律，进而探讨刈割驼绒藜对草原化荒漠土壤微生物和土壤酶活性的影响。历经4年的潜心研究，发现刈割驼绒藜促进其地上枝叶和地下根系发生超补偿生长效应；改变同化碳素运移分配格局，有助于同化碳素向茎、叶和根际土壤运输分配；进而刺激根系分泌活动，引起土壤微生物数量增加，土壤酶活性增强。”.这些研究结果，不仅可为干旱-半干旱地区受损植被恢复重建和荒漠化防治提供基础依据，而且可为驼绒藜资源的可持续开发利用提供实际参考；有助于开展草原生态系统碳素循环研究，对于探索低碳畜牧业（减少碳排放）途径的研究具有启示性意义。