Along with the economy development , human activities not only straightly threatened the ecological environment but decreased the population number of anura 随着经济的发展，人类活动直接威胁着无尾两栖类的生存环境，也造成其种群数量大幅度减少。
6 . the population quantity of orient subspecies of great bustard only is 500 to 800 individuals . and the distribution takes on obvious island isolation , ! 大鸨乐方亚种在我国的种群数量仅500 80o只，且分布地呈现明显的斑块状隔离，是典型的濒危物种。
The growth and decline of the population of liriomyza huidobrensis had a close relation with the population quantities of its parasitic enemies and assumed the forms of double peaks 南美斑潜绳的种群消长与南美斑潜蝇寄生蜂的种群数量密切相关，呈显著的双高峰。
The first , the living planet index , measures biodiversity , based on trends in more than 3600 populations of 1300 vertebrate species around the world 第一个指标叫做生命地球指数，该指数根据地球上1 , 300种种群数量达3 , 600多个的脊椎动物的变化趋势来衡量生物多样性。
The plots within ski trails had relatively few birds over all and low species diversity ? a measure of both the number of species and the number of individuals in each species 被测定的项目有物种的个数和一个物种的种群数量，结果显示，滑雪场中的鸟类总数和多样性最低。
In effect , " no net loss of biodiversity in hong kong " means important sites are protected for perpetuity and viable populations of species are sustained in hong kong 事实上，本港生物多样性零净损失表示永久保护本港的重要生境，并维持本地生物品种的种群数量于可繁殖水平。
Cease of livestock grazing by management is urgent for conservation of the giant panda and other species of rare and edangered plants and animals since quit of logging in 1998 要扩大大熊猫局部种群数量、改善大熊猫栖息地质量，必须要通过管理减轻人类对大熊猫栖息地的影响、特别是放牧的影响。
We get the probability distribution of the population by the theory and method of markovian process , and discuss the model coefficients influencing on subsistence of a population 利用马尔可夫过程的理论和方法，得到生物种群数量变化的概率分布，最后讨论了各模型参数的变化对生物种群生存的影响。
Early attempts to predict population viability were based on demographic uncertainty whether an individual survives from one year to the next will largely be a matter of chance 早期尝试去预报人类生存能力基于种群数量统计学的不确定，无论一个单独的幸存者从一年到了下一年因为一个重要的机会而增多。
Habitats of the giant panda have been fragmented in recent years due to long - term various human activities , which results in the drastic diminishing of the distribution area of this endangered species 近年来，大熊猫栖息地不断被割裂，分布区急剧缩小，主食竹类大面积开花枯死，导致大熊猫在种群数量上发生了变化。
