选择海拔为3 762 m（低海拔样地）和4 137 m（高海拔样地）处囊种草（Thylacospermum caespitosum）群落作为研究样地，分别选取9个直径约50 cm的囊种草丛，测定其下土壤的养分、水分和温度等指标，并以邻近无囊种草生长区域的土壤为对照，试图揭示囊种草对土壤微环境的修饰作用对海拔的响应。结果表明：囊种草的生长提高了其下土壤养分含量；改善了土壤水分状况；调节了土壤温度，在其冠层下维持了一个温度较为恒定的环境。随着海拔升高，环境条件的恶劣程度加大，环境压力增大，高海拔样地的土壤养分、水分和温度均低于低海拔样地，而囊种草对这些土壤环境条件的改善作用则随海拔的升高而加强。
Two Thylacospermum caespitosum communities at altitudes of 3 762 m and 4 137 m in the alpine area of Gansu were chosen as studied sites. Nine Thylacospermum caespitosum individuals with 50 cm diameter at each altitude were chosen, the soil microenvironment conditions under T. caespitosum of each site were studied, at the same time, nine open areas in same diameter without cushion were chosen as controls. The nutrients, water content and temperature of soil under each selected cushions were determined and compared with those of open area without cushions. The results showed that at both site, T. caespitosum improved the soil nutrient contents under their canopies, improved the water condition of soil beneath them, and maintained relatively constant temperature environments under their canopies, they increased the extreme low temperature and decreased the extreme high temperature of soil beneath them, and made the soil temperature under their canopies not to change much during a day. The study showed that with the increasing of the altitude, the environmental stress increased, the nutrients, water content and temperature conditions of soil at 4 137 m were all lower than those of soil in 3 762 m. This indicated that the soil microenvironment modification of T. caespitosum increased with environment stress.
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