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1.
The study was undertaken to develop agrotechniques for raising short-rotation, high-density (SRHD) energy plantations as a renewable energy source by using planting densities of 10,000 and 14,000 plants/ha. Under Species × Spacing × Fertilizers (N:P:K), the effect of fertilizers was more evident on plant height than on stem diameter. The species as Grevillea robusta, Bauhinia variegata, and Eucalyptus showed the most statistically significant vertical and radial growth in both of the spacings. The N:P:K::50:25:25 kg/ha produced statistically significant growth. The photosynthesis rate, as recorded, showed that Salix tetrasperma had high rates of CO2 assimilation but poor aerial growth.

The photosynthetic rate under varying fertilizer treatments remained unchanged, but the biomass improved significantly. In G. robusta, excellent aerial growth was observed despite a low rate of photosynthesis (even at low water potential). The dry weight of Eucalyptus was recorded (60 and 233 t/ha; spacing 1 m × 1 m and 1 m × 0.71 m) after 3 yr. After 10 yr, the highest dry weight was recorded again in Eucalyptus at 1,471.44 t/ha. The lowest moisture content (36–38%) was recorded in Morus alba, while the highest moisture content was recorded in Eucalyptus (66–70%). In all tested species, G. robusta (26%) showed the maximum calorific value.  相似文献   

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木荷容器育苗基质肥料配方研究   总被引:1,自引:1,他引:1  
对不同配比的泥炭-谷壳中施用不同量的缓效肥对木荷(Schima superba)容器苗生长和芽苗移栽成活率的影响进行了研究.结果表明:基质配比为泥炭+谷壳=7:3时有利于木荷苗高和地径的生长且其芽苗移栽成活率较高;在此基质配比下,施肥量为A2(1.5 kg缓释肥/m~3)或者是A3(2.0 kg/m~3)时木荷容器苗各个生长指标均较优.考虑生产成本,以基质施肥量配方A2即泥炭+谷壳(7:3)+1.5 kg缓释肥/m~3为较优的基质配比和施肥量.  相似文献   

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Payments for environmental services (PES) are conservation instruments in place in various Latin American countries. They are generally undergoing adjustment and implementation changes, and they are widely implemented in indigenous communities. This article aims to suggest a relevant group of context variables in PES implementation. Characterizing the local context of two indigenous communities located in Oaxaca, Mexico, and analyzing the relationship between the local context and PES implementation and outcomes perceptions.

The work is based on 75 surveys administered to beneficiary families of the instrument in the two localities. The results suggest three conclusions:

The pertinence of the nine focal variables: “Forest cover, Opportunity costs, Livelihoods, Trust and cooperation, Motivations toward conservation, Management practices, Internal organization, Land tenure and Rules for the management and use” to the characterization of the local context. And the relevance of the new focal variable “Presence and experience with Civil Society Organizations”.

The coincidence between the contextual variables and the determinants of the success of conservation instruments.

Finally, the incidence of “Trust and cooperation” and “Internal organization” in the implementation of equitable PES schemes. And the importance of linking sustainable production to PES conservation schemes.  相似文献   


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程明娟  连海兰  李涛 《林产工业》2012,39(2):31-34,40
麦草碱木素是我国造纸工业重要的剩余物,但是麦草碱木素的结构决定了其反应活性较低,从而使其应用受到较大的限制。笔者根据麦草碱木素的特点分别对比超声破碎仪不同的超声条件(时间:10、20、30、40min;振幅:60、80、100)和不同的溶液质量比(100:0,60:1,20:1)对麦草碱木素的活化效果,并探索用活化后的木素代替部分苯酚(10%、20%、30%、40%)制备酚醛树脂胶黏剂的可行性。研究结果表明:超声波作用可显著提高酚羟基的含量。超声波作用时间在20min、振幅80、溶液质量比20:1时效果相对较好。经过超声波活化的木素按20%的量替代苯酚制备LPF,压制的胶合板的胶合强度都达到国家Ⅰ类胶合板的要求,并能与未改性的酚醛树脂(PF)胶黏剂相媲美。  相似文献   

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以撑绿竹为研究对象,通过肥料配比、施肥量和施肥方式3个因素不同水平的正交试验,对撑绿竹的施肥技术进行了研究。结果表明,促进撑绿竹胸径增粗的最佳施肥模式为:肥料配比(N:P2O5:K2O)为3:2:1,施肥量为1.2 kg/丛,施肥方式为撒施;提高撑绿竹繁殖率的最佳模式是:肥料配比(N:P2O5:K2O)为5:2:1,施肥量为0.6 kg/丛,施肥方式为穴施;增加撑绿竹生物量的最佳施肥模式为:肥料配比(N:P2O5:K2O)为5:2:1,施肥量为0.6 kg/丛,施肥方式为撒施。  相似文献   

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云南松毛虫是柏木上的主要食叶有害生物,笔者通过比较人工摘茧、氧化乐果治理、灭幼脲治理、白僵菌治理、苏脲Ⅰ号胶悬剂混合白僵菌治理得出结论:苏脲Ⅰ号胶悬剂与白僵菌混用是治理云南松毛虫的最好方法,在3龄前幼虫期能较快速有效控制云南松毛虫对柏木的危害,也能长期有效地抑制云南松毛虫的大发生。  相似文献   

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在建立乡级林业地理信息系统(GIS)过程中,最主要的工作是设计并建立森林资源数据库。使用通用GIS软件(PCARC/INFO)和数据库管理系统软件(LOTUs1-2-3)设计森林资源数据库主要包括5个步骤:(1)将用户的观点模型化;(2)定义实体及其关系;(3)实体表示;(4)匹配成ARC/INFO的数据模型;(5)组织成地理数据集.  相似文献   

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冷压制造结构用单板层积材时,单位压力、加压时间、陈放时间、涂胶量和胶种是影响其强度性能的重要因素,同时各因素的变化还直接影响到生产成本和生产效率。试验表明,理想的冷压工艺条件为:单位压力 0.98 MPa、加压时间 7 h、陈放时间 40 min、涂胶量 180g/m2(单面)。  相似文献   

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Accurate prediction of stem diameter is an important prerequisite of forest management.In this study,an appropriate stem taper function was developed for upper stem diameter estimation of white birch(Betula platyphylla Sukaczev) in ten sub-regions of the Daxing'an Mountains,northeast China.Three commonly used taper functions were assessed using a diameter and height dataset comprising 1344 trees.A first-order continuous-time error structure accounted for the inherent autocorrelation.The segmented model of Max and Burkhart(For Sci 22:283-289,1976.https://doi.org/10.1093/forestscience/22.3.283) and the variable exponent taper function of Kozak(For Chron 80:507-515,2004.https://doi.org/10.5558/tfc80507-4) described the data accurately.Owing to its lower multicollinearity,the Max and Burkhart(1976) model is recommended for diameter estimation at specific heights along the stem for the ten sub-regions.After comparison,the Max and Burkhart(1976) model was refitted using nonlinear mixed-effects techniques.Mixed-effects models would be used only when additional upper stem diameter measurements are available for calibration.Differences in region-specific taper functions were indicated by the method of the non-linear extra sum of squares.Therefore,the particular taper function should be adjusted accordingly for each sub-region in the Daxing'an Mountains.  相似文献   

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Agroforestry Systems - A correction to this paper has been published: https://doi.org/10.1007/s10457-021-00641-7  相似文献   

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MCoTI-I and MCoTI-II (short for Momordica cochinchinensis Trypsin Inhibitor-I and -II, respectively) are attractive candidates for developing novel intracellular-targeting drugs because both are exceptionally stable and can internalize into cells. These seed-derived cystine knot peptides are examples of how natural product discovery efforts can lead to biomedical applications. However, discovery efforts are sometimes hampered by the limited availability of seed materials, highlighting the need for efficient extraction methods. In this study, we assessed five extraction methods using M. cochinchinensis seeds, a source of well-characterized cystine knot peptides. The most efficient extraction of nine known cystine knot peptides was achieved by a method based on acetonitrile/water/formic acid (25:24:1), followed by methods based on sodium acetate (20 mM, pH 5.0), ammonium bicarbonate (5 mM, pH 8.0), and boiling water. On average, the yields obtained by these four methods were more than 250-fold higher than that obtained using dichloromethane/methanol (1:1) extraction, a previously applied standard method. Extraction using acetonitrile/water/formic acid (25:24:1) yielded the highest number of reconstructed masses within the majority of plant-derived cystine knot peptide mass range but only accounted for around 50% of the total number of masses, indicating that any single method may result in under-sampling. Applying acetonitrile/water/formic acid (25:24:1), boiling water, and ammonium bicarbonate (5 mM, pH 8.0) extractions either successively or discretely significantly increased the sampling number. Overall, acetonitrile/water/formic acid (25:24:1) can facilitate efficient extraction of cystine-knot peptides from M. cochinchinensis seeds but for discovery purposes the use of a combination of extraction methods is recommended where practical.  相似文献   

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金刺塔仙人掌快速繁殖技术研究   总被引:1,自引:0,他引:1  
以金刺塔仙人掌嫩茎为外植体进行离体培养 ,茎段的最高分化率为 87%。在改良的MS(氮元素减半 ) +BAP1mg/L +IAA0 .2mg/L平均每个茎段可诱导不定芽 9~ 1 3个。在生根培养基中 ,以MS培养基 (氮元素减半 )加NAA0 .2mg/L ,根诱导率在 91 %。当苗高 3cm以上 ,根长 2cm以上时 ,开盖 2d移入温室 ( 2 0~ 2 6℃ ) ,炼苗 3d后移栽于蛭石 :河沙 :腐殖土为2 :3:5的混合基质的土壤中 ,成活率达 89%。  相似文献   

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Bioenergy production has increased significantly in the last decade, and recent legislative efforts such as the discussion draft for the American Clean Energy and Security Act of 2009 and the Energy Independence and Security Act (EISA) of 2007 Energy Independence and Security Act. (2007). H. R. 6: 110th United States Congress. http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=110_cong_bills&docid=f:h6enr.txt.pdf (http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=110_cong_bills&docid=f:h6enr.txt.pdf)  [Google Scholar] are expected to encourage even more growth. The growing demand for bioenergy will necessitate production of large quantities of woody biomass and plant residues if it is to be met. However, concerns are being raised as to how increased pressures will affect the sustainability of woody biomass. In order to avoid potential pitfalls and ensure the sustainability of wood-based bioenergy systems, a set of sustainability indicators needs to be developed. Some of these indicators can be based on standards similar to those developed for sustainable forest management, energy balances, greenhouse gas emission reductions, and existing codes and guidelines for biomass harvesting. This article discusses a potential set of sustainability indicators encompassing ecological, economic, and social principles for harvesting woody biomass for bioenergy. The extent to which existing standards and certification systems reflect these indicators is elaborated upon. Methods for making these standards operational are also suggested.  相似文献   

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Living snow fences are windbreaks designed to mitigate blowing snow problems by trapping snow in drifts before it reaches a road. Research studies on living snow fences are limited and extension publications consequently lack precise design protocols. This study investigated 18 sites in New York State planted with living snow fences of various vegetation types and ages ranging from 1 to 11 years after planting. Key plant growth variables of fence height and optical porosity were measured along with distance upwind and downwind. This data was combined with site specific snowfall estimates and established equations to calculate the snow storage capacity of each fence, average annual snow transport (blowing snow) at each site, and length of the downwind drift. Capacity/transport ratio of each fence/site was identified as a key variable. Height increased linearly over time and porosity decreased. Three years after planting, height and porosity was sufficient so that capacity/transport ratios were greater than 1:1, indicating substantial snow trapping potential much sooner than commonly reported. Four to eleven years after planting, capacity/transport ratios were between 3:1 and 110:1. Capacity/transport ratios of 15:1 or greater occurred as early as 5 years after planting and were correlated with estimated drift lengths <10 m. The influence of capacity/transport ratio on drift length is not accounted for in current publications and setback recommendations range from 30 to 180 m. The results of this study can improve the understanding, design and function of living snow fences.  相似文献   

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