濒危种裂叶沙参种群生命表和存活曲线的研究及其与广布种泡沙参的对照(英文)

STUDY ON POPULATION LIFE TABLE AND SURVIVORSHIP CURVES OF ADENOPHORA LOBOPHYLLA, AN ENDANGERED SPECIES, COMPARED WITH A.POTANINII, A WIDESPREAD SPECIES

以近缘广布种泡沙参为对照，本文编制了濒危种裂叶沙参种群的标准生命表、存活曲线以及海拔２３００～２４００ｍ、２７００～２９００ｍ、２９００～３１００ｍ和３１００～３４００ｍ区域４个种群的生命表，存活曲线。根据其生活史，讨论了裂叶沙参各种群特定年龄的存活量、死亡量和死亡率等重要参数。裂叶沙参种群存活曲线属ＤｅｖｅｙＣ型，１～５年生死亡率最高，个体最长寿命２５年。而泡沙参种群的死亡高峰期是１～３年，个体最长寿命２１年。导致裂叶沙参种群幼龄个体死亡的内在原因是其较弱的抗逆性和适应能力；外在原因是严重的干旱、外界干扰和群落内的光照不足。裂叶沙参种群适应不良环境的能力较泡沙参弱：在海拔２７００ｍ以下地区，由于外界干扰和环境干旱，除水份条件较好的特殊生境，大多种群呈严重衰退趋势，不能满足编表条件，只有海拔２７００ｍ以上区域的种群呈稳定或扩展趋势；而泡沙参各种群在不同海拔区域均呈稳定或扩展趋势，满足编表条件。从海拔２３００ｍ到３４００ｍ，不同裂叶沙参种群个体寿命呈：短长短的格式，与外界严酷较好严酷的环境相对应。这表明裂叶沙参种群在严酷环境条件下改变了其生存对策，缩短了个体寿命。

Comparing with the affinity and widespread species Adenophora potaninii population,the standard life table,survivorship curves of whole population,as well as the life tables,the survivorship curves of 4 populations of Adenophora lobophylla at altitude 2300～2400m,2700～2900m,2900～3100m,3100～3400m have been compiled.According to their life cycles,some important parameters such as the number of survivor ( l x ),the number of death ( d x ),the rate of death ( q x )at specific age,etc.have been discussed.The survivorship curvcs of A.lobophylla population pertained to “Deevey C” shape.The period of the highest death rate of A.lobophylla was in 1～5 years old,and the oldest individual was 25 years old.While A.potaninii population was rather different:the peak period of death rate was in 1～3 years old,and the age of the oldest individual was 21 years old.The ability to adapt the unfavorable condition was assumed to be weaker than that of A.potaninii population.The principal factors that led the young seedling of A.lobophylla population to die were imputed to the serious drought during 1～2 years old and the deficiency of solar light in the communities during 3～5 years old as well as in weaker intrinsic resistance to unfavorable environmental conditions.As the altitudc increases from 2300 to 3400m,the life spans of different A.lobophylla populations showed the pattern:shorter longer shorter responding to the harsh favorable harsh environmental condition.Under the harsh environmental conditions the life span of A.lobophylla population was shorter.