种群密度与平均年龄有线性相关。
But there are linear correlation between population density and mean age.
种群密度随径级增大而减小。
The population density decreases with the increase of diameter class.
全年种群密度变化呈单峰型。
种群密度亦趋于均匀化。
种群密度亦趋于均匀化。
结果表明，池鹭的种群密度和生物量最高。
The results showed that the population density and biomass of Ardeola bacchus were higher.
常微模型只考虑时间因素对种群密度的影响。
Time is only considered as the effect on population density in ordinary model.
终将舞毒蛾的种群密度控制在经济允许水平之下。
The species' density of the gypsy moth will be controlled under economic permitted level.
桃蚜种群密度小。
准确估计害虫种群密度是进行虫害预测预报的基础。
To forecast the outbreak of pest insects is based on the estimation of population density.
结果表明，幼虫的种群密度愈高，理论抽样数就愈少；
The results showed that the higher the population density of the larvae, the less is the theoretical number of sampling clumps;
东方田鼠扩散的趋势与其种群密度及补充量的变动一致。
Trends in the dispersal of the vole were consistent to the variance of population density and recruitment in the voles.
分布的聚集强度与密度有关，随种群密度的升高而增大。
Its aggregation degree increased with the increase of population density.
因为没有天敌，火蚁的种群密度达到阿根廷的十倍甚至百倍。
With no natural enemies, their densities reached 10 to 100 times that of Argentina.
为了狩猎的需要，这种鸟类的每平方千米种群密度必须超过200只。
For shooting to go ahead, the density of birds must exceed 200 grouse per square kilometre.
水位涨落以及淹水时间的长短与飞蝗发生的面积和种群密度关系密切；
The occurrence area and species-group density was closed with water level fluctuation and flood time.
结果表明：温度对该种轮虫种群密度及种群增长率均有显著影响（P。
The results showed that temperature affected the population density and population growth rate significantly(P<0.
目的调查长乐国际机场登革热媒介种群密度，预防和控制登革热暴发流行。
Objective By investigating population density and breeding characters of Dengue vectors in Fuzhou Changle International Airport to prevent and control Dengue fever.
他们在研究过的三个案例中发现西尼罗河热在美国的的流行与鸟类种群密度的下降相关。
Three of the cases they studied found that the rise of West Nile virus in the U.S. corresponded to decreases in bird population density.
许多环境数学模型是用常微分方程表示的，它只考虑了时间对种群密度的影响。
Many environment mathematical models are ordinary differential equations where time is considered only as its effect on population density.
两种草杂的种群密度(X)与甘蔗产量损失率(y)之间的关系呈双曲线关系。
The results indicated that there existed hyperbola relationships between the density (x) of two weed's communities and the impairment loss percentage (y) of sugarcane yield.
目的了解济南地区农村改厕对蝇类种群密度的影响，评价农村改厕的卫生效果。
Objective To know the toilet reforms influence to the flies species density in the countryside of Jinan, evaluating the sanitary result of toilet reform of countryside.
一方面，没有任何种群在所有的时间里完全只受“种群密度无关”因素的影响。
For one thing, no population can be driven entirely by density-independent factors all the time.
一方面，没有任何种群在所有的时间里完全只受受“种群密度无关”因素的影响。
For one thing, no population can be driven entirely by density-independent factors all the time.
如果种群参数如出生率和死亡率随种群密度的变化而变换，就可以说是密度制约的。
Population parameters such as birth and death rates which vary with density are said to be density dependent.
结果表明：烟草潜叶蛾幼虫在田间呈聚集分布，聚集强度不因种群密度的改变而改变。
The results are as follows: The distribution pattern of larvae is aggregative ( negative binomial distribution) . The aggregation dose not change with the densities of population of leaf miner.
对兴隆山马麝资源的种群密度、种群数量和种群结构以及负增长原因进行了研究分析。
The population numbers, densities, structure and reasons of negative increasing of Moschus chrysogaster in Xinglong Mountain were studied in the paper.
基于种群径级结构分析，木荷种群密度随个体胸径的变化趋势类似于偏正态分布形曲线。
Based on analysis of population size class structure, the trend of population density of Schima superba changing with individual DBH was similar to skew normal distribution.
这主要受植物种群密度、结构，传粉者适应性和活动能力以及是否自交亲和等因素的影响。
This is influenced by factors such as plant population density and structure and the adaptability of pollinator as well the presence or absence of self-incompatibility mechanisms.
我在这里发现，食草哺乳动物的种群密度与生物量，堪与状况最好的东非大草原地区相比。
I determined that densities and biomass of herbivorous mammals in Nagarahole were comparable to some of the best East African Savannah areas.
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