林木

In this context, attention should also be given to research and development of sustainably harvested non-wood products.

在这方面也应注意可持续收成的非林木产品的研究和发展。

There were no significance influence on tree height growth by different intercrops, but tree diameter at breast height was increased significance by intercropped cotton.the yield of different intercrops were not influenced by tree at first year.

从不同间作物在造林第一年的产量来看，林木没有对间作物的生长产生影响，各间作物的RCI值均在0附近。

5The different intercrops had different effects on soil physic-chemical characteristics. Soil bulk density、soil organic matter and soil available nitrogen were improved significance by intercropped cotton.

不同间作物对林木高生长没有产生显著差异，但对胸径生长的影响达到了显著性差异水平，间作棉花在第一年促进了三倍体毛白杨胸径的生长。

In order to assess the change of triploid populus tomentoza pulp plantation long-term-site productivity, The paper studied on effects of aboveground litterfall, fine root turnover and wet dust precipitation in nutrient cycling of triploid populus tomentoza pulp plantations at different ages,namely 2a、4a、5a、6a.It studied influence of different factors on decomposition of leaf、tree bark and twig of triploid populus tomentoza to select the operations to accelerate the decomposition and nutrient release. Finally, it studied influence of different intercrops on plantation site productivity and the relationship of intercrops and triploid populus tomentoza to select suitable intercrops. The main results as follows:(1)The aboveground litterfall of triploid populus tomentoza increased along with age from 216.03±59.7gm~(-2) at 3a to 482.38±101.3gm~(-2) at 7a, The N returned by litterfall wasl8.38±2.46kg.hm~(-2)a~-121.63±2.25kg.hm~(-2a~-139.51±4.61kg.hm~(-2a~-138.89±4.89kg.hm~(-2a~(-1) at 3a、5a、6a、7a respectively. The P returned by litterfall was 5.80±0.62kg.hm~(-2)a~(-1)、8.16±0.94kg.hm~(-2)a~(-1), 11.31±1.33kg.hm~(-2)a~(-1)、11.76±1.37kg.hm~(-2)a~(-1) at 3a、5a、6a、7a respectively. The nutrient returned by fine root turnover increased along with age, too. The N returned by fine root turnover was 3.85±0.41kghm~(-2)a~(-1)、5.22±0.63kghm~(-2)a~(-1),7.62±0.89kghm~(-2)a~(-1),9.17±1.22kghm~(-2)a~(-1) at 3a、5a、6a、7a respectively. The P returned by fine root turnover was 0.73±0.07kghm~(-2)a~(-1)、1.69±0.09kghm~(-2) a~(-1)、1.92±0.31kghm~(-2)a~(-1)、1.96±0.21kghm~(-2)a~(-1) at 3a、5a、6a、7a respectively. The leaf was the principal pathway to return nutrient to soil among litterfall, fine root turnover and wet dust precipitation. The proportion of returned N by leaf was 74.84%、71.96%、78.58%、75.03% at 3a、5a、6a、7a respectively,The proportion of returned P by leaf was 85.93%、80.31%、83.04%、83.23% at 3a、5a、6a、7a respectively. Therefore, it is important to protect and utilize the leaf in order to maintenance and enhance the long-term-site productivity of triploid populus tomentoza pulp plantation.

本文采取时序研究法，以3a、5a、6a、7a共4个不同年龄的三倍体毛白杨纸浆林为对象，研究了地上凋落物、细根周转、湿沉降在林分N、P营养元素循环中的作用及不同年龄林分N、P营养元素循环的特征，以评价三倍体毛白杨纸浆林长期立地生产力的变化；采取网袋法研究了不同因素对落叶、树皮、树枝分解的影响，以确定加快其分解、促进养分释放的措施：同时研究了不同间作物对林地影响、林木与间作物之间关系，以选择能维持立地生产力的合适的间作物种类等内容，得到以下结论：(1)随着年龄的增加，三倍体毛白杨地上凋落物的数量从3a的216.03±59.7gm~(-2)增加到7a的482.38±101.3gm~(-2)，通过凋落物归还的N分别为：3a时为18.38±2.46kg.hm~(-2)a~(-1)，5a时为21.63±2.25kg.hm~(-2)a~(-1)，6a时为39.51±4.61kg.hm~(-2)a~(-1)，7a时为38.89±4.89kg.hm~(-2)a~(-1)，归还的P分别为：3a时为5.80±0.62kg.hm~(-2)a~(-1)，5a时为8.16±0.94kg.hm~(-2)a~(-1)，6a时为11.31±1.33kg.hm~(-2)a~(-1)，7a时为11.76±1.37kg.hm~(-2)a~-1随着年龄的增加，通过细根周转归还的养分也在增加，归还的N分别为：3a时3.85±0.41kghm~(-2a~(-1)，5a时5.22±0.63kghm~(-2)a~(-1)，6a时7.62±0.89kghm~(-2)a~(-1)，7a时9.17±1.22kghm~(-2)a~-1归还的P分别为：3a时0.73±0.07kghm~(-2a~(-1)，5a时1.69±0.09kghm~(-2)a~(-1)，6a时1.92±0.31kghm~(-2)a~(-1)，7a时1.96±0.21kghm~(-2)a~-1从地上凋落物、细根周转、湿沉降三种不同途径归还林地养分所占的比例来看，地上凋落物中的落叶是归还养分主要途径，年龄在3a、5a、6a、7a时，通过落叶归还的N所占比例分别为74.84%、71.96%、78.58%和75.03%，归还的P所占比例分别为85.93%、80.31%、83.04%和83.23%。

This valley was lumbered hard during the past decade.

在过去十年里，这个山谷的林木被大肆采伐。

Years later, forest has returned to most of the once barren mountains.

台中东势因为1999年9月21号7.3级的地震，留下大片的山崩痕迹，十年过后，崩塌的山体长出了茂密的森林，但有些地却奇怪的秃了一片，长不出林木。

The main purpose of this paper is to research the effects of Eco-mat mulching sands on soil and the tree growth.

本文研究了在沙地造林初期覆盖生态垫对林地土壤、林木生长等方面的作用机理及作用效果。

Annual exports of tree seeds, flowers, seeds and 200 tons of quick-frozen 20 million ear of corn.

公司每年出口林木种子、花卉种子200吨及速冻玉米2000万穗。

On the basis of the analysis of physicochemical properties of soil, analyzes variance characters of soil physical properties and nutrient properties in different land use ways and slope locations in the western edge mountains of Sichuan basin, and the results indicate that, in the respect of soil physical properties, it is either the soil structure coefficient or the degree of aggregation that is contained in farm land is obviously less than that is contained in reforested land and waste land, and because of the effects that forest crop root system and forest floor take, the soil physical properties of forest plantation is far better.

在土壤理化指标测定基础上，分析了四川盆地西缘中低山坡地不同土地利用方式和坡位下土壤物理性质与养分性质的分异特征，结果表明：土壤物理性质方面，耕作土壤的结构系数和团聚度明显低于人工林和荒草地，人工林由于林木根系和枯枝落叶层的作用，土壤物理性状明显较好。

Logistic model was used to model tree mortality of Pinus tabulaeformis based on the data from 105 remeasured plots in Beijing.

同时，林木枯损率在维持种群动态变化、生态系统生物多样性和结构多样性等方面也起到了重要的作用。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。