马尾松丰产经济栽培技术试验初报

试验表明：不同挖穴规格的幼林生长达到概率保证为９５％的统计学上显著与极显著差异水平，以４０ｃｍ×３０ｃｍ×２５ｃｍ的穴规格为最好。种源差异及主副处理的交互作用由于试验林尚小，未达到统计学上的显著差异水平。     

废旧材料在景观设计中的再利用——以三峡截流纪念园景观设计为例

以三峡截流纪念园景观设计项目为例,介绍其利用废旧材料进行景观设计的做法,对废旧材料的再利用不仅能表达废旧材料所代表的特定文化含义,更体现了一种循环经济思想。希望为大家解决工程废旧材料问题提供参考。     

伊春市福轩木业公司细木工板生产线改扩建项目经济效益可行性分析

结合伊春市福轩木业公司细木工板生产线改扩建项目实际,对细木工板项目的投资及经济效益进行了详细分析,论证了该项目的经济可行性。     

低碳城市的发展策略研究

以低碳城市为主要研究对象,重点阐述了低碳城市的理论内涵,介绍了国内外典型低碳城市的发展现状,为中国发展低碳城市提供一定参考。     

西部退耕还林(草)工程生态与经济协调发展途径的选择

通过农民问卷调查结果和退耕还林(草)工程特点的分析,以解决农民关心的焦点问题和反映工程的两重性特点为依据,提出实现退耕还林(草)工程生态与经济协调发展目标的两条途径,这就是:政策调动;产业化发展。     

农村兴办“庄园”经济的思考与对策

“庄园”是新农村建设和乡村振兴的重要载体。文章阐述了“庄园”经济的概念、主要特征和经营方针,归纳分析了“庄园”经济的组织型式和主要经营模式,提出了大力发展“庄园”经济的主要对策和建议。     

森林生态经济效益计算方法初探——论生态经济级差地租

提出生态经济级差地租的概念。生态经济级差地租可以作为计算森林生态经济效益的依据,其中生态经济级差地租Ⅰ反映了林地自然生产力的高低,生态经济级差地租Ⅱ则是由森林所处区域的生态需求大小所决定。生态供给能力调整系数(生态经济级差地租Ⅰ)和生态需求经济价格调整系数(生态经济级差地租Ⅱ)可作为各地区生态经济综合价格调整系数。     

森林人家休闲健康旅游发展对策

从创新休闲模式,提升产业结构的理念出发,提出发展森林人家亟待解决的问题和对策。     

论经济可持续发展战略下的金融稳定

文章指出金融是否稳定决定了经济可持续发展能否实现,阐释了金融稳定与经济可持续发展的辩证关系,分析了我国当前金融不稳定因素,提出了旨在促进经济可持续发展的维护金融稳定的措施。     

Impact of three silvicultural treatments on growth,light-energy processing,and related needle-level adaptive traits of Pinus strobus from two regions

Our goal was to quantify and compare the impact of three silvicultural treatments (STs) on growth, light-energy processing, and needle-level morphological adaptive traits for eastern white pine (Pinus strobus L.) from large, central Ontario (ON) and small, isolated Newfoundland (NL) populations. The interest in STs is to reduce weevil (Pissodes strobi) incidence; however, there are potential adaptive changes and productivity trade-offs. The light levels for the STs were, on average, 100%, 42.0%, and 20.4% transmittance for the full-sun, and intermediate- and high-shade STs, respectively. After 8 years, overall height growth was 4.10, 3.25, and 1.70 m for full-sun, and intermediate- and high-shade STs, respectively (P < 0.001). Across all STs, ON populations had greater total height (14%), basal diameter (12%), current leader length (25%), and tree volume (49%) than NL populations (all P < 0.001). At low light levels (10 and 25 μmol m⁻² s⁻¹), high-shade ST trees had higher photochemical quenching (qP) and lower chlorophyll fluorescence (F_pc) compared with intermediate-shade and full-sun STs. At 100 μmol m⁻² s⁻¹ and beyond, full-sun ST trees had higher qP and lower F_pc than intermediate- and high-shade STs. Average total chlorophyll concentration (CHL) and content (CHLC), and carotenoid concentration (CAR), increased in response to the intermediate-shade ST but did not respond further, or decreased in the high-shade ST. Region was significant for CHL, CAR, chlorophyll a:b and CHL:CAR ratios and CHLC, with ON greater than NL, but was reversed for CHL:CAR ratio. Tree height and volume showed a curvilinear and linear relationship to light level, respectively. Tree height showed a positive linear relationship to qP, apparent photosynthesis, chlorophyll a:b ratio, and needle N (all P < 0.001). Tree height showed a negative linear relationship to F_pc, CHL:CAR ratio, specific needle area, C:N ratio, and needle area N⁻¹ (all P < 0.001). There were modest trade-offs between weevil protection and productivity in the intermediate ST due to the compensatory physiological and morphological adaptations to the limiting light, however, the trade-off with growth at the high-shade level was severe. For NL, consideration should now be given to the introduction and mixing of seed from local seed sources with more southern mainland seed sources, which would decrease the inbreeding effect and provide wider variation for natural selection for a more fit future population.