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珙桐(Davidiainvolucrate)为中国一级保护植物,系第三纪古热带植物的孑遗树种,属于珍稀濒危的单属单种植物。近年来,由于区域开发项目的增多,致使这种古老而珍稀树种的天然分布生境和天然种群数量急剧下降。为此,本文通过大面积的野外调查和查阅资料,研究了珙桐的生物和生态特性,系统分析了珙桐在不同地质阶段的地理分布状况,探讨了促使其种群数量动态变化的主要原因。不同年份标准样地调查表明,在没有人类干扰的区域,珙桐种群数量随年份增加;但是在有人类干扰的区域,珙桐种群数量随年份减少;随着人口密度和人类活动的增加,珙桐种群数量呈对数曲线y=-100.7ln(x)+178.09的速度下降,这表明珙桐种群已由优势种群衰退到濒临灭绝的程度。基于对珙桐的现有研究,提出了珙桐的保护措施。图3参31。
Davidia involucrate is a Chinese protected plant, which is a relict species of Tertiary ancient tropical plants, belonging to the rare and endangered single single plant. In recent years, due to the increase of regional development projects, the natural distribution habitats and natural populations of this ancient and rare species have dropped dramatically. Therefore, this paper studies the biological and ecological characteristics of Davidia involucrata through large-scale field investigation and access to information, and systematically analyzes the geographical distribution of Davidia involucrata in different geological stages, and discusses the main reasons for the dynamic change of the population. The survey of standard plots in different years shows that in the area without human disturbance, the population of D. vannamei increases with the year; however, in the area with human disturbance, the population of D. vannamei decreases with the year; with the increase of population density and human activities, The population of T. involucrata showed a logarithmic curve y = -100.7ln (x) +178.09, indicating that the population of M. involucrata has declined from the dominant population to the point of extinction. Based on the existing research on Davidia involucrata, the protection measures of Davidia involucrata were proposed. Figure 3 reference 31.