Beijing Foresty Machinery Institute

The stand basal area, closely related to age, site quality, and stand density, is an important factor for predicting forest growth and yield. The accurate estimation of site quality is especially a key component in the stand basal area model. We utilized sample plots with Picea asperata Mast. as the dominant species in the multi-period National Forest Inventory (NFI) dataset to establish a site index (SI) model including climate effects through the difference form of theoretical growth equations and mixed-effects models. We combined the SI calculated from the SI model, stand age, and stand density index to construct a basal area growth model for Picea asperata Mast. stands. The results show that the Korf model is the best SI base model for Picea asperata Mast. The mean temperatures in summer and winter precipitation were used as the fixed parameters to construct a nonlinear model. Ultimately, elevation, origin, and region, as random effects, were incorporated into the mixed-effects model. The coefficients (R2) of determination of the base model, the nonlinear model including climate, and the nonlinear mixed-effects model are 0.869, 0.899, and 0.921, with root-mean-square errors (RMSEs) of 1.320, 1.315, and 1.301, respectively. Among the basal area models, the Richards model has higher precision. And the basal area model including an SI incorporating climatic factors had a higher determination coefficient (R2) of 0.918 than that of the model including an SI without considering climatic effects. The mixed-effects model incorporating climatic and topographic factors shows a better fitting performance of SI, resulting in a higher precision of the basal area model. This indicates that in the development of forest growth models, both biophysical and climatic factors should be comprehensively considered.

Biomass conditioner made from agricultural and animal husbandry waste for resource disposal could be used to improve desertified soil, which is one of the effective ways of ecological management on desertified grasslands in northwest Sichuan. To clarify the effects of different raw material conditioners on alpine desertified grassland in northwest Sichuan, we analyzed the effects of three conditioners on soil nutrients and microbial community characteristics. With no conditioner as the control (CK), three different biomass conditioners were set up with an application rate of 12 t·hm-2, including mushroom dregs (JZ), straw (JG) and biochar (SWT). The results showed that all biomass conditioners could significantly increase soil available nutrients and active organic carbon by 23.0%-521.6%. Among the three conditioners, JG had the best effect, with an improvement range for soil nutrient and organic carbon of 65.1%-521.6%. Because biomass conditioner was only applied in the first year, soil available nutrients and active organic carbon in the second year decreased by 4.5%-92.3% compared with that of the first year, while soil organic carbon and microbial biomass carbon content of the second year increased by 5.6%-458.0%. The biomass conditioners changed the relative abundance of the dominant bacteria in the microbial community. JG significantly affected bacterial flora, while JG and JZ affected fungal flora. Compared with CK, JG significantly reduced the diversity of soil bacteria and fungi. The Shannon index was decreased by 2.9% and 31.8%, while the Simpson index was increased by 175.0% and 320.9%, respectively. Results of the redundancy analysis showed that the contents of soil available nutrients and active organic carbon were important factors affecting microbial community composition. The contents of soil nitrate and microbial biomass carbon had greater impacts on bacterial community composition, explaining 65.9% of community variations. The contents of soil available potassium and microbial biomass carbon had a greater impact on fungal community composition, explaining 83.2% of community variation. According to the comprehensive comparison, straw conditioner could significantly increase soil available nutrients and active organic carbon, and benefit the growth of beneficial bacteria and fungi, which could be used as a promotion measure to improve soil quality of alpine desertified grassland in northwest Sichuan.

The binder can improve the physical characteristics of biomass pellets by forming solid bridges and increasing the adhesion of biomass materials. Taking pine sawdust as raw material and brown sugar water with different concentration as a binder, this study adopted spraying and stirring methods, respectively, and mixed brown sugar water with biomass in diverse proportions. The characteristic of pellets such as durability, relaxation ratio and compressive strength were studied by orthogonal design. Through range analysis, BP (Back Propagation) neural network factor significance analysis and mapping the relationship between physical properties and factors according to the importance of each factor, the effect of densification variables on the physical characteristics of biomass pellets was studied, and the outcome of adding brown sugar water binder to raw material by spraying method in improving the densification quality of biomass was explored. Results showed the brown sugar water binder added to pine sawdust by spraying method could mix the binder and biomass raw material more evenly compared with the stirring method. The relaxation ratio of pellets obtained by spraying method was reduced by 13.47%. The optimal densification conditions of pine sawdust were when the compaction pressure was 100 MPa, the mass ratio of brown sugar to water was 2:1, the proportion of brown sugar water to biomass material was 3%, and the adding method was spraying.

The biodiversity crisis and ecosystem degradation caused by habitat destruction and human activities can be reduced by organizing protected areas. However, many protected areas currently take the form of “green islands,” which has led to serious habitat isolation in many places. We thus introduce herein a landscape-scale adjoining conservation (LAC) approach for the protection and restoration of ecosystems across the boundaries between protected areas and surrounding non-protected areas. The strategy of the LAC approach is to effectively expand conservation areas by connecting isolated areas of important ecosystems or habitats outside of protected areas. The methodology of the LAC approach involves integrated analyses that consider both habitat quality and landscape patterns. Forest-habitat quality is characterized by species composition and stand structure, and habitat connectivity is quantified by the max patch area of habitat and total habitat area. The focal statistic is useful for examining habitat clumps that result from landscape fragmentation. As a case study, we apply the LAC approach to adjoining restoration of broadleaf Korean pine mixed forest on the Changbai Mountain in northeastern China. We developed a metric called the Restoration Efficiency of Landscape Expansion (RELE) to evaluate the LAC approach. The results indicate that a minimal restoration effort can produce significant effects in terms of the expansion of contiguous habitat, as quantified by RELE.

PDF HTML阅读 XML下载 导出引用 引用提醒 基于C-Plan系统保护规划软件的长白山阔叶红松林保护效率 DOI: 10.5846/stxb201404040643 作者: 作者单位: 北京林业大学林学院 省部共建森林培育与保护重点实验室 北京,黑龙江科学院自然与生态研究所 哈尔滨,北京林业大学自然保护区学院 北京,中国林业出版社 北京,北京林业大学林学院 省部共建森林培育与保护重点实验室 北京,北京林业大学林学院 省部共建森林培育与保护重点实验室 北京 作者简介: 通讯作者: 中图分类号: 基金项目: 科技部"十二五"科技支撑项目(2012BAC01B03) Conservation effectiveness of broadleaved korean pine forest in Changbai Mt. based on C-Plan systematic conservation planning software Author: Affiliation: BeiJing forestry university,,,,,Beijing forestry university Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:阔叶红松林(Broadleaved Korean pine forest)是北温带物种最丰富的地带性群落之一,是极危动物东北虎(Panthera tigris altaica)的重要栖息地。长白山地区是阔叶红松林在中国范围内的中心分布区,中国政府建立了由24个自然保护区组成的网络来保护阔叶红松林及其他自然生态系统。以长白山地区为研究区域,在系统保护规划方法流程框架下,选择阔叶红松林生态系统中具有代表性的物种和群落做为优先保护对象,并制定量化保护目标,利用系统保护规划软件C-Plan,计算了研究区域规划单元的不可替代性值、各保护对象在保护网络中实现其保护目标的贡献值(Ti)及包含多个保护对象的保护区域的保护效率值(C),以此在多角度评估保护网络及其中各自然保护区的保护效率。结果显示:现有保护网络涵盖了本研究确立保护对象种类的90.4%,已达到保护目标的保护对象占其总数的25.3%。以保护阔叶红松林为"标尺"衡量各保护区的保护效率,长白山国家级自然保护区与松花江三湖省级自然保护区保护效率值最高,其余各保护区保护效率值不足10,整个保护网络保护效率值为59.99。不可替代性分析结果显示:仍有79.97%的高保护价值规划单元未被现有保护网络覆盖,空间上存在明显空缺。将空缺纳入保护网络后,新保护网络的保护效率值将提高到96.32,提高了36.33,77种保护对象达到保护目标(占保护对象总数的92.8%),5种保护对象仍未能达到保护目标,但保护对象贡献值Ti均不同程度提高,保护成效显著。 Abstract:Broadleaved Korean pine forest is one of the zonal communities with most abundant species in the North Temperate Zone. It is also an important habitat for the endangered animal of Amur tiger (Panthera tigris altaica). Changbai Mountain have been the center of China distribution areas for broadleaved Korean pine forest. A network of 24 nature reserves have been established by the Chinese government to protect Broadleaved Korean pine forest and local natural ecosystem.The paper applied the C-Plan,by following the theoritical framwork of systematic conservation planning, we seletced the representative species and communities in Broadleaved Korean pine forest ecosystem as priority conservation objects and set quantitative conservation target which is in the light of the biodiversity characteristic of broadleaved Korean pine forest. In addition, three key indicators were also caculated: (1) The irreplaceability value of planning unit of study areas; (2)the contribution value (Ti) to the reserved network by the conservation objects; (3) the conservation effectiveness value (Ti) of the protected area which contains multiple objects. All those results were aimed to multiple perspectives evalutating the conservation effieiency of the reserved network and the reserves in it. The evaluation results indicated: the existing conservation network has covered 90.4% of the protection objects 25.3% of protection objects reached the protection target.The highest conservation effectiveness value occurred in Changbai Mountain Reserve and Songhuang River Reserve.The rest of reserves has conservation effectiveness value less than 10. The conservation effectiveness value of whole conservation network is 59.99. The results of irreplaceability analysis indicated that 79.97% of planning units with high protection value has not been covered by existing conservation network.There are obviously GAP in layout. The new conservation network's conservation effectiveness value was 96.32, increased by 36.33 after including GAPs into conservation network. For 77 kinds of protection objects, it reached the protection target. It accounted for 92.8% of total protection objects. 5 kinds of protection objects could not reach protection target, while their protection efficiency has greatly enhanced.The protection effectiveness of the study area was significantly enhanced. 参考文献 相似文献 引证文献

We cloned a Cinnamoyl-CoA Reductase gene (BpCCR1) from an apical meristem and first internode of Betula platyphylla and characterized its functions in lignin biosynthesis, wood formation and tree growth through transgenic approaches. We generated overexpression and suppression transgenic lines and analyzed them in comparison with the wild-type in terms of lignin content, anatomical characteristics, height and biomass. We found that BpCCR1 overexpression could increase lignin content up to 14.6%, and its underexpression decreased lignin content by 6.3%. Surprisingly, modification of BpCCR1 expression led to conspicuous changes in wood characteristics, including xylem vessel number and arrangement, and secondary wall thickness. The growth of transgenic trees in terms of height was also significantly influenced by the modification of BpCCR1 genes. We discuss the functions of BpCCR1 in the context of a phylogenetic tree built with CCR genes from multiple species.

As a core feature of high-end CNC machine tools, the torque carrying performance of five-axis milling head directly affects the machining accuracy and reliability. Through theoretical analysis and derivation, combining experimental prototype, the A/C-axis cutting torque formula of five-axis milling head on woodworking is obtained. The reliability analysis provides a theoretical basis for drive motor selection and five-axis milling head structural optimization and improvement.

Pile-turning is an important technical means to control the ventilation, oxygen supply and material blending during trough composting. In order to examine the effect of pile-turning frequency on composting process and product quality, we set up four different control methods of pile-turning. The results show that treatment with pile-turning is better than the one without it in compost maturity level. Treatment of turning every 3 days with the best results: the largest organic matter degradation rate (32.6%), the least nitrogen loss (328.2 mg / kg), has been proven a good control methods of pile-turning.