黄土高原丘陵沟壑区封禁30年前后狼牙刺种群动态研究

以荒草坡为对照，对黄土高原丘陵沟壑区阳坡、半阳坡和半阴坡3个生境条件下经30年封禁后的狼牙刺种群动态进行系统研究，分析了种群的年龄结构、分布格局，编制了静态生命表，绘制了存活曲线. 结果表明，黄土高原丘陵沟壑区不同生境自然恢复的狼牙刺种群年龄结构均属于进展型,幼龄个体多，老龄个体少，其中以半阳坡种群密度最大，不同坡向狼牙刺种群的存活曲线均接近于DeeveyⅡ型.种群分布格局总体上呈聚集型,随年龄增加聚集强度增加.影响狼牙刺群落恢复和种群生长的环境因素主要是水分因子和光照因子.狼牙刺种群恢复状况良好，说明封禁措施是有效的.

Dynamics of Sophora davidii population in a hilly region closed for thirty years in Loess Plateau

Taking wild grass ground as the reference, this paper studied the dynamics of Sophora davidii population on the sunny, semi-sunny and semi-shady slopes of hilly region in Loess Plateau after 30 years closed for reforestation, and analyzed the age structure, spatial distribution pattern, life table, and survival curve of the population. The results showed that S. dvidii population in the region belonged to progressive type, with more young and less old individuals. Among the three habits, semi-sunny slope had the highest population density. The survival curve of S. dvidii population was approached to Deevey 11 type. The population pattern was of clustered distribution, with the aggregating intensity increased with age. Water and light were the main environmental factors affecting the recovery and development of S. davidii community. The better recovery of S. davidii population suggested that the measures of closing the land for reforestation were efficient.