林龄

对其客观分布规律进行统计分析，揭示了样圆与郁闭度的关系，以及林龄与各测树因子之间的结构。

According to their dispersed Iaw analysed statistically , the relationship of round sample plot and crown closure , and the structure between age of stand and factors of tree measuring have been shown .

针对上海城市人工林密度偏大、林分衰退现象明显的状况，为了分析密度对城市人工林林木生长发育及林分结构的影响，研究不同林龄的林分密度效应，探讨城市人工林的自维持机制。

For Shanghai urban plantation density is larger , the condition of forest decline phenomenon obviously , in order to analyze the density of urban plantation forest growth and forest stand structure , the influence of the different forest age of stand density effect .

随着林龄的增大，pH值也逐渐减小。

The pH value was decrease with the increase of the stand ages . 6 .

湿地松NDVI与林龄、地形之间的关系

The Relationship Between NDVI , Stand Age and Terrain Factors of Pinus elliottii

树体养分的平均浓度C随林龄t增大而降低，降低速率与施肥强度Q相关；

The average nutrient concentration in eucalyptus ( C ) decreased with tree age ( t ) increasing , and its decreasing rate related to fertilization levels ( Q ) .

林龄为2a时，幼林的小气候效应对土壤温度产生影响；

When it is of 2 years , it begins to influence the temperature of the siol .

在第四章中，我们研究了环境依赖型的非线性林龄结构的森林发展系统：其中有效造林更新率取为β（？），依赖于林木总量N（t）。

In the fourth chapter , the environmental-dependent non-linear forest age structure of forest development have been studied : Where β(? ) is effective forest renewal rate , and depend on total forest N ( t ) .

两种林龄四川桤木蒸腾速率（Tr）与PAR呈正相关关系，4年生四川桤木Tr值都大于9年生四川桤木。

Both plantation transpiration rate ( Tr ) is positively correlated with PAR , Tr values of 4 years old Alnus are greater than 9 years old ones .

不同林龄I-69杨根际、非根际土Al-P、Fe-P和O-P含量无明显差异，盐渍土壤中它们的生物有效性较低。

There was no obvious difference in Al-P , Fe-P and O-P between rhizosphere and non-rhizosphere soil .

利用日本落叶松种子园半同胞家系，按田间设计要求建立家系对比试验林，林龄10a生通过鉴定。

Larix kaempferi seed orchard half sib-family contrast test-woodland was built according to the field design , which being studied after 10 years .

另外，由于营造单纯林，林分密度高，水分亏缺，以及感染枯梢病等，使生育期更加缩短，章古台樟子松更新的林龄为40～45a。

Additional , the high density of the pure stand and the disease also shorten the maturity period .

表层（0-10cm）土壤有机碳（SOC），尤其是土壤轻组有机碳（LFOC）能很好的解释土壤累积呼吸量不同林龄间差异。

Top soil organic carbon ( SOC ), especially soil light fraction organic carbon ( LFOC ) well explained the variation of cumulative RS among the stands .

株数枯损量的高峰期是林龄10～20a，枯损率高峰期为3.3～4.5a；

The peak Period of mortality for number of stems was 10 ~ 20 years stands , and for mortality rate tvas 3 . 3 ~ 4 . 5 years ;

随着林龄的增大，次生林与原始暗针叶老龄林间的Bray-Curtis指数也有增大的趋势。

With increasing age , the value of Bray-Curtis index between secondary forest and old-growth dark brown coniferous forest had an increasing trend .

在福建南平地区，对林龄和密度不同的两片杉木人工林的凋落物和森林降水化学进行了3a（1994～1996）的定位研究。

Chemistry of litter and rain fall was monitored for three years ( 1994 ~ 1996 ) at two sites established in Chinese fir ( Cunninghamia lanceolata ) plantations with different stand ages and densities in Nanping , Fujian .

落叶松和红松的生物量估算参数随林龄无明显变化趋势，樟子松BEF、BCEF和R随林龄的增大而减小，并逐渐趋于稳定。

The biomass estimation parameters of Larix and Korean Pine have not obvious trend with stand age , while the BEF ^ BCEF and R of Pinus sylvestris var. Mongolia decreases with the stand age increasing , and gradually stabilized .

不同年龄木麻黄林地根际CEC值、水解性总酸度、交换性盐基总量、交换性Mg2+均大于非根际土壤；幼林龄根际交换性Ca2+低于非根际；

In different stages of C. equisetifolia plantation development , the CEC , hydrolytic acidity and exchange Mg ~ ( 2 + ) in rhizosphere soil were more than those in non-rhizosphere soil , except for exchange Ca ~ ( 2 + ) in young C.

5a的研究结果表明，林龄20～30a的白桦天然林最适林分密度为1100株·hm-2，修枝强度不应超过1/2树高。

The 5-year study indicates that the optimal thinning treatment for 20 ~ 30-year-old natural birch stands is to maintain a stand density of 1 100 stems · hm - 2 and the pruning intensity should not exceed 1 / 2 tree height .

结果表明，采用数量化回归途径建立马尾松林分生长的预测模型是可行的，且所建模型具有较高的预测精度，但用于拟合回归模型的数据以采用林龄为4a以上的测定资料为宜。

The results show that adoption of the quantitative regression way is feasible for establishing such models , and prediction precision of the models is higher , but it is suitable that growth data of the plantation to be fitted the regression models should be more than 4 years old .

进行抚育管理的林地思茅松的保存率和幼树的生长量都明显高于未进行抚育管理的林地，特别是到林龄为2.5a时，其差异更为显著。

Other data also shows the survival rate and increment of young tree in plantation by tending management are significantly higher than that without tending . Especially at 2.5a , the difference becomes more significant .

林分平均木及林分各器官生物量均随林龄增加而增加，平均木在1822a生物量年增加速率最大，而林分是在1218年生。

With stand age increasing , biomass of stand average tree and each organ increase . The annual growth speed of biomass is the biggest at 18 22 year for stand average tree , but the biggest at 12 18 year for the stand .

林龄结构指标：0.495，0.046；

Structure of different age-class forest indicator : 0.495 , 0.046 ;

纯林同龄的林龄面积分布结构的指标参数

On Index Coefficient of Age-area Distribution Structure for Evenaged Pure Forest

不同林龄植被培肥改良土壤效益研究

Benefits of Different Age Forest Vegetation on Soil Fertilization and Amelioration

在林龄20多年后，群落发展可进入最后阶段。

The last stage will be arrived after about 20 years .

因此，林龄增大，防治指标应提高。

Thus the index of control should increase with age increase .

根据不同林龄、危害程度、生境等条件设立6个研究样地，每个月定期在其中观察松鼠活动行为，调查危害情况。

We selected 6 research plots on the basis of habitat condition .

同龄纯林的林龄分布结构变化方程

A Dynamics Equation of Age-Area Structure for Evenaged Pure Forest

不同林龄人工林对退化生态系统土壤肥力质量的影响

Effect of Different Age Forests on Soil Fertility Quality of Degraded Ecosystems

不同林龄Ⅰ-69杨根际土离子浓度和养分状况

Ion and Nutrient Status in Rhizospheres of Poplar Stands at Different Ages