荫蔽度严重影响种群的密度。
如何提高梅花鹿种群的密度与数量是今后梅花鹿研究的主要方向。
How to enhance the Sika deer population density and the quantity are the outline in Sika deer ecology research.
本文研究了浙江省松阳县关山源地区黄山松种群的密度与生物量动态以及它们之间的相互关系。
This study was carried out at Guanshanyuan, Songyang County, Zhe-jiang Province. Density and biomass dynamics as well as their interrelationship for Pinus taiwanensis populations are described.
在调节种群增长方面，它与捕食一起是最重要的密度制约因子。
Together with predation, it is the most important density-dependent factor in regulating population growth.
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.
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.
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.
并提出用害虫种群潜在密度确定卷叶螟经济阈值的方法。
Economic threshold for this pest insect was estimated by measuring the increasement rate of population density.
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.
樟子松种群自疏规律为：平均胸径与密度的关系符合负幂函数模型。
Regulation of self- thinning is that relationship between DBH and average density of population accords with negative power function.
合理的移栽密度对龙须草种群增长和产量形成具有重大意义。
Reasonable transplanting density has great significance for E. binata population increase and yield form.
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.
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.
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.
影响蚊虫种群密度的最重要的因子是最低温度，然后依次是最高温度、月温度变化和雨天数。
The most important factor influencing mosquito population is the lowest temperature, and then the highest temperature, month temperature change and precipitation days.
分析了梭梭种群的径级结构、高度结构、密度和空间分布格局变化等。
The diameter structure, the height structure, the density and the distribution pattern were worked out.
早霜、晚霜、松毛虫、叶蜂及落叶松早期落叶病等都能直接影响鞘蛾食物的质量和数量，进而间接地使鞘蛾种群密度降低。
Early and late frost, Dedrolimus superans, sawfly and needle cast of larch could reduce the quality and quantity of foods of larch casebearer and had indirect effects on its population density.
种群的死亡过程和繁殖过程使种群平均密度有较明显的波动，但对种群总体水平无明显影响，种群结构也无明显变化。
The death and reproduction of the population make the mean density fluctuate but do not obviously change the overall level of population number and the population structure.
由于单个的冰核细菌细胞并不具有冰核活性，因此，研究植物上冰核细菌的种群数量或密度是研究冰核细菌与植物霜冻害关系的关键。
Single cell of INA bacteria can not act as ice nucleus, therefor the key to the study on the relationships between INA bacteria and frost injury to plants is to study the population of INA bacteria.
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.
以放牧生态系统为例，本文分析了系统组分种密度相关的种群调节中的正、负反馈和机制。
Taking the grazing ecological systems as an example, the positive and negative feedback of the density dependence population regulations was analysed.
试验结果表明：水体增温对水库浮游植物的种群组成、优势种的优势度、藻类密度和生物量均有影响。
The results of investigation and indoor simulated test showed there were effects of increased water bodies temperature on the structure, dominant, density and biomass of phytoplankton community.
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.
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.
由于种内互助作用的存在及食植者采食速率、食植者密度等因子的影响，牧草植物种群存在多个稳定平衡点。
There are multiplicity of stable states in herbage populations owing to the influences of intraspecific mutualism, feeding rate and density of herbivores.
最高密度种群的产卵量一直相对较低。
The amount of eggs under high raising density was successively a little lower.
人工种群植株不同密度间个体生长差异显著，尤其是人工二年生种群植株中、低密度区比高密度区个体生长得较大，体现了密度制约的效应。
Plants, especially in population of two years, have bigger bodies in low and middle densities than that in high densities in field. It's the effect of density dependence.
磷是水体中藻类种群和密度的第一限制性营养元素，因此在水体富营养化的治理上，可能取决于对磷的控制措施。
Phosphorus is the first limiting nutrient density to the algae populations, and therefore control the eutrophication, may depend on the phosphorus control measures.
分析了白皮松的群落学特征、径级结构及其密度变化规律；绘制了存活曲线和死亡曲线，从多角度研究了白皮松幼林种群的动态变化规律。
The community feature, size-class structure, the regulation of changing density were analyzed and the survival curve, the death curve and the life table were worked out.
其他因素也可能影响片断化的遗传后果，如植物的生活史、种群密度及种群经历的片断化时间等等。
Other factors, such as life-span, population density and fragmented time plant population has experienced, may also influence the genetic consequences of fragmentation.
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