Enzymatic activities of three ectomycorrhizal types of Quercus robur L. in relation to tree decline and thinning

In a declining oak forest, a thinning treatment was performed in August 2004, targeting trees belonging to two decline classes. The whole ectomycorrhizal (EM) community was dominated by the fungal symbionts Clavulina cinerea, Tomentella sublilacina and Russula spp. The potential activities of eight secreted enzymes, involved in mobilizing nutrients (N, P) from soil organic matter, were measured on these three EM types in winter and spring 2006 using multiwell microplate photometric and fluorogenic methods. The enzymatic activities recorded in winter were generally significantly higher than in spring. Most of the enzyme activities studied, and particularly phosphatase and β-glucosidase, changed according to both decline class and sylvicultural treatment. In spring, each anatomotype displayed different enzymatic profile according to the decline class. These results suggest that the potential enzymatic activity of ectomycorrhizae adapts to the changes resulting from the sylvicultural treatment and reacts to the anthropic disturbance by adjusting to the new resource structure.     

鱼腥草注射液体外抗菌活性研究

研究了鱼腥草注射液的体外抗菌活性.以水蒸气蒸馏法制备鱼腥草中药注射液,金黄色葡萄球菌为供试菌种,通过活菌记数法、加氨苄西林钠辅助法对鱼腥草注射液的体外抗菌活性进行研究.结果表明:鱼腥草注射液在体外有一定的抑菌作用,其抗菌效果比生理盐水明显要强.以活菌记数法、加抗生素辅助法测定中草药的体外抗菌活性,方法可行,数据可靠.     

南充地区野生荩草种质资源形态多样性研究

对南充地区不同海拔、不同坡度、不同生境等15份野生荩草材料进行调查,研究其生境特点及外部形态变异规律,结果表明:南充地区荩草野生资源丰富,在田边、路旁、地埂、山坡草地阴湿处至海拔1 000 m均有分布,能适应不同的土壤类型;不同高度、坡度外部形态变异甚大,自然高度的变异系数达49.58%,叶长、宽,茎直径、节间长,拉直高度变异系数均大于30%,叶色为深绿、黄绿、紫红3种;南充地区野生荩草分为粗壮低矮型、高大直立型、纤细低矮型3大形态类型。     

Differences in Species Composition and Stand Characteristics of Mixed Upland Hardwood Forests of North Alabama as Reflected by the Presence of Eastern Redcedar (Juniperus virginiana L.)

The mixed hardwood forests of North Alabama and adjacent states contain stands of varied specks composition and stand structure, with much variation associated with the presence of Eastern redcedar (Juniperus viginiana L.) within the stands. This study quantified the composition of 44 stands within these forests with discriminate analysis, cluster analysis and tree area ratio modeling. Little variation in the presence of specific species was found on plots with Eastern redcedar when compared to plots without this species, but the number of individuals and their portion of the total stand structure did vary between the two types of stands. Twenty-seven species were grouped into six clusters, with associated species differing between plots with and without eastern redcedar. Eastern redcedar sites did appear to reflect lower productivity, with the trees smaller in diameter and shorter in height. Additional stand structure information is also discussed.     

蒙古栎育苗试验

蒙古栎是辽西地区的地带性树种，能与油松形成稳定的松栎混交林。在蒙古栎植苗造林试验中发现，蒙古栎植苗造林成活率、保存率不高，重要原因之一是蒙古栎形成的吸收根量少。对此，采用垫砖法、去芽法和多芽法进行了蒙古栎育苗试验。结果表明，3种方法都能增加苗木的侧须根数量，但以垫砖法效果更为明显，可以作为蒙古栎少量育苗的简便方法而应用。如果大量育苗，可以试用截根育苗法。去芽法须进一步催芽，待重新萌发出新芽以后再进行播种。多芽法由于苗木生长较差。不宜采用。     

蒙古栎数量化综合选优方法及标准的研究

利用吉林省中东部蒙古栎天然实生林优树8个主要性状的实测材料，根据性状权重制定了综合评分标准及优树入选的最低分数限，经对原优树复选检验，选优效果良好，且评选的优树能够保质保量。     

蒙古栎橡子营养成分的研究

本试验对我区蒙古栎橡子的营养成分进行了比较全面的分析测定，并与玉米、高梁等常用的粮食及饲料营养成分进行对比研究。结果表明：蒙古栎橡子中含蛋白质８．５２％，脂肪４．５６％，粗纤维９．７３％，还含有１８种氨基酸和丰富的矿物质元素以及糖类等，总能量达１４６０２ＫＪ／ｋｇ，其营养价值和热值均与玉米和高梁相近，是一种有很高开发利用价值的野生植物资源。     

中条山栓皮栎材种出材率表的编制与应用

根据中条山森林经营局当地市场情况，将栓皮栎材种分为规格材、非规格材和薪材废材三类，编制了材种出材率表，采用理查德方程和二次多项式分别拟合规格材出材率、薪材废材出材率与胸径的关系，相关系数分别为０．９４４８和０．９４１６，并用“１００％－规格材出材率－薪材废材出材率”获得非规格材出材率。已将此表运用于中条山森林经营局的营林设计和生产中     

秦岭锐齿栎上一种新腐朽病害

报道了秦岭林区锐齿栎树上一种新的腐朽病害,其病原菌为钩针纤孔菌Inonotushamusetulus。根据采集的病原标本材料对该病原菌进行了详细描述,并根据野外调查对此新病害的症状和危害进行了报道。     

低温及乙烯利处理鳞茎对药百合的影响

调查了不同的低温处理和乙烯利浓度对药百合生长发育的影响。结果表明 ,在用 2 0 mg· L- 1 浓度的乙烯利处理鳞茎后 ,配合 5～ 8℃的温度 2 8d可缩短发芽日数、到花日数 ,增加了花蕾数、叶数和株高