松树繁殖新途径—针叶束嫁接技术

在三年中,用湿地松(Pinus elliottii Engelm)、火炬松(Pinus taeda Linn)、马尾松(Pinus massoniana Lamb.) 成年树嫩枝上的一束针叶为接穗,以25月龄幼苗为砧木,通过嫁接、保湿、诱发短枝茅抽梢成株等11项试验及观察因子的研究(试验数量达2000余株),成功地总结出一套松针束嫁接技术。该嫁接方法显著优于沿用已久的松树枝接法,是嫁接技术的一项重大革新。本文系统总结了松针束嫁接的技术要点。     

灰木莲容器苗培育基质筛选试验

以松皮粉、黄心土、森林表土、火烧土、泥炭5种基质设置6种配比处理开展灰木莲容器苗培育试验，选用苗高、地径、苗木质量指数、容器基质重量等指标进行苗木质量评定，并依据造林效果进行检验。结果表明：不同处理间的苗高、地径和容器基质重量均达到极显著差异，苗木质量指数亦差异显著；处理3（黄心土50％＋松皮粉25％＋表土25％）的苗木质量和造林效果最好，其次是处理5（黄心土60％＋松皮粉25％＋火烧土15％）和处理4（黄心土50％＋松皮粉50％），处理2（黄心土75％＋泥炭25％）最差；建议生产上添加25％．50％的松皮粉作为灰木莲容器育苗基质。     

湿加松无性系生长性状的遗传变异及选择效果研究初报

对1块6.5年生的湿加松无性系测定林的生长性状进行了测定和分析,试验表明,开展湿加松无性系选育是可行的、有效的.具体结果如下:(1)控制湿加松生长变异的因素中,遗传因素与非遗传因素的重要性大约各占50%;而对遗传因素的影响强度,主要为家系效应,其次为无性系效应.树高、胸径、材积的家系平均遗传力分别为0.967,0.88...     

落叶松人工林天然更新及近自然经营

红松在落叶松下更新能够将其诱导形成红松针阔混交林,笔者就落叶松林内阔叶树组成、红松更新情况、林下灌木和近自然经营进行了调查分析,发现落叶松的长势、其伴生阔叶乔木的状况在下坡位均占优势,下坡位更新的红松密度最大。林下植被均较丰富,为红松幼年生长提供了良好的森林环境。     

Ecological lessons from long-term studies in experimental forests: Ponderosa pine silviculture at Pringle Falls Experimental Forest, central Oregon

The United States Department of Agriculture (USDA) Forest Service celebrated the 100th anniversary of its network of experimental forests in 2008. For a century, the network of experimental forests have contributed immensely—both in the US and around the world—to the practical understanding of the environment and to the formation of management approaches and policies that affect our use of forests and the natural resources they contain. Experimental forests provide places for long-term science and management studies in major vegetation types across the 789,140 km² of public land administered by the Forest Service. They also provide an incredible wealth of records and knowledge of environmental change in natural and managed forest ecosystems across the United States. Pringle Falls Experimental Forest (Pringle Falls), southwest of Bend, Oregon, is the oldest experimental forest in the Pacific Northwest and is the site of some of the earliest forest management and silviculture research in this region. Research at this site began in 1914, and it was formally established as part of the national network of experimental forests in 1931 as a center for silviculture, forest management, and insect and disease research in ponderosa pine forests east of the Oregon Cascade Range. As part of the celebration of the Centennial Anniversary of the network of experimental forests, it is timely to examine a few of the ecological lessons that have resulted from long-term studies at Pringle Falls. Two different yet interconnected themes are traced: (1) management of existing old-growth ponderosa pine; and (2) management of young or immature ponderosa pine. Examples of ecological lessons, drawn from long-term studies established or followed by James W. Barrett, Matt D. Busse, Patrick H. Cochran, Walter G. Dahms, F. Paul Keen, Ernest L. Kolbe, Edwin L. Mowat, William W. Oliver, Ram Oren, Chester T. Youngberg, and Jianwei Zhang illustrate how work at Pringle Falls has both pursued and influenced societal demands for forest management strategies, and how this trajectory has cycled back to the themes under which the experimental forest was first established. Finally, these two themes are integrated as drivers for new landscape-scale long-term research at Pringle Falls, designed to evaluate the effects of thinning and fuel reduction treatments on multiple, interacting forest stresses of fire, insects, wind, and climate change.     

Fine-Root Production and Aboveground Development for Loblolly Pine,Silver Maple,and Cottonwood

Fine-root production was studied in recently established loblolly pine (Pinus taeda), silver maple (Acer saccharinum), and cottonwood (Populus deltoides) biomass plantations. Dry weights of fine roots produced in ingrowth cores were recorded from April 2008 to March 2009 to quantify the temporal variation of fine-root production among the species. Similarly, fine-root production was compared to the monthly height and diameter increments, soil temperature, and moisture content. Species showed no significant difference in fine-root production; however, fine-root production varied by month. Fine-root production in September was significantly different from that of December and January combined, February, and May. Loblolly pine produced 49 g m^?2, whereas silver maple and cottonwood produced 37 g m^?2 and 35 g m^?2 of fine roots, respectively, during the study period. Fine-root production was not correlated with height increment, diameter increment, soil temperature, and soil moisture.     

松材线虫危害后马尾松林土壤氮素的矿化特性

选择合肥大蜀山森林公园受松材线虫危害程度不同的马尾松林为研究对象,采用室内模拟试验对林氮素的转化性质,增加了土壤氮素淋失的危险性。地土壤氮素矿化特征进行了研究。结果表明:不同林分土壤氮素转化速率差异显著(P<0.05),受损严重的林分氮素矿化速率显著高于轻度受损林分,特别是硝化速率更为显著(P<0.01)。松材线虫病危害改变了马尾松林土壤     

不同包装方式对低温贮藏平菇生理特性和细胞壁变化的影响

为探讨低温贮藏下不同包装方式对平菇生理特性及细胞壁变化的影响,将平菇置于5℃冰箱中冷藏,分别以敞口PE保鲜袋和封口PE保鲜袋进行试验,以完全裸露放置作为对照,分析贮藏期间不同包装方式对平菇的感官品质、丙二醛（MDA）含量、可溶性蛋白质含量、抗氧化物酶活性,细胞壁代谢相关酶活性等指标的影响,并对平菇进行石蜡切片,观察其细胞壁的微观结构变化。结果表明,随着贮藏时间的延长,与对照相比,PE保鲜袋处理的平菇保鲜效果显著提升,明显抑制了失重率、MDA含量的增加,减缓了硬度、白度（HW）值的增大,降低了蛋白质含量的损失,延缓了过氧化物酶（POD）、过氧化氢酶（CAT）和纤维素酶（Cx）活性峰值的出现,更好地保持了平菇的品质。在整个处理组中,平菇的HW值、失重率、MDA含量不断增大且封口处理低于敞口处理;硬度值逐渐减小,封口处理硬度较敞口处理低;蛋白质含量呈现先升高后降低的趋势,封口处理蛋白质含量显著低于敞口处理;POD活性先升后降,在0～4 d,封口处理POD活性高于敞口处理,4～8 d急速下降且低于敞口处理;CAT活性呈现先降再增的趋势,贮藏前期0～2 d与贮藏后期第6至第8天CAT活性较高,0～6 d敞口处理高于封口处理,后低于封口。通过对平菇菌褶石蜡切片发现,伴随着采后贮藏天数的增加,平菇子实体细胞结构变得杂乱无序、模糊不清,细胞间隙变大,且封口处理比敞口处理细胞结构有序、规整。由此可知,低温贮藏下,PE包装处理贮藏效果明显优于全部裸露放置,封口包装保鲜效果优于敞口保鲜效果。     

松树皮基质发酵方案的初步探究

【目的】探索松树皮基质的较佳发酵方案。【方法】以新鲜樟子松树皮为试验基质,尿素为氮源,添加EM菌剂和木醋液进行发酵,共设置9种(M1~M9)不同发酵方案,以不添加EM菌剂和木醋液的处理为对照,分析各处理松树皮发酵温度、理化性质及木质纤维素、单宁含量的变化情况。【结果】发酵后,与对照相比,M5(C/N 30、500倍EM菌剂和500倍木醋液)、M6(C/N 70、500倍EM菌剂和500倍木醋液)和M2(C/N 30、500倍EM菌剂)3个处理的发酵温度均明显高于其他处理,且高温持续时间长,松树皮的各项理化性质均得到改善,单宁、木质纤维素含量降解幅度较大。【结论】发酵过程中,EM菌剂起关键作用,再添加木醋液可进一步加快发酵进程,提升发酵效果,初始C/N的影响仅次于EM菌剂,当其值为30~70时松树皮的发酵效果较好,M5、M6、M2处理是松树皮的较佳发酵方案。     

膨润土褐铁矿改性白云石催化松木棒气化工艺优化

针对白云石催化剂在生物质催化气化过程中易碎、易产生积碳失活问题,为提高其催化活性、抗积碳和再生性能,采用固定床下吸式气化炉试验系统,以Fe-Dol-Ben(膨润土/褐铁矿改性白云石)为催化剂,松木屑废料经成型为棒状颗粒为原料,进行高温水蒸气催化气化试验。研究气化温度(700～1000℃)、铁含量(质量分数为5%～20%)以及催化剂使用次数(1～4)等因素对松木棒催化气化性能及催化剂表面积碳影响。试验结果表明,水蒸气和松木棒的质量比(气料比)为1,催化剂的铁质量分数为15%,气化温度为900℃时气化气中氢气的体积分数达到最大值58.38%,Fe-Dol-Ben催化剂积碳量随气化温度升高逐渐减小,试验区间内1 000℃时达到最小值,较700℃减少了80%。气化气中氢气的体积分数随铁含量增加呈先增加后降低的趋势,积碳量呈先降低后增加,在铁质量分数为15%催化效果较好。Fe-Dol-Ben催化剂较相同条件下分别用膨润土及改性前白云石催化时积碳量分别减少了80.6%和53.6%。对催化剂进行再生再利用试验表明,使用后的Fe-Dol-Ben催化剂进行700℃煅烧再生后,其晶相与催化前基本相同,将其多次再生循环利用,随着使用次数的增加气化气中氢气的体积分数逐渐降低,催化剂的积碳量逐渐增大,使用4次并用于催化气化时氢气的体积分数仍接近50%,保持较好催化效果。综合气化效果、积碳量及经济性因素,Fe-Dol-Ben铁质量分数为15%,气化温度选取900℃为较理想工况。该研究可为改性白云石Fe-Dol-Ben催化剂的研制及生物质高温水蒸汽催化气化技术提供参考。