Comparison of two noninvasive methods for measuring the pigment content in foliose macrolichens

Photosynthesis Research - Chlorophyll content in lichens is routinely used as an accurate indicator of lichen vigor, interspecific differences, and the effect of site-related environmental...     

造纸污泥土地利用的资源价值与潜在风险

随着造纸工业的发展,造纸污泥产生的环境问题日益显露出来。造纸污泥含水量高达75％-80％,有机物含量高,易腐烂、有恶臭、不便于运输和施用,必须对污泥进行稳定化、无害化处理。造纸污泥经过堆肥无害化处理后可以作为一种价廉优质的有机肥料,造纸污泥不仅含有丰富的有机质,且含有N、P、K等其他营养元素,土地利用不会导致重金属、有机污染物、硝酸盐淋失等污染风险。大量的研究表明,施用造纸污泥及其堆肥,可以增加土壤的有机质含量,降低土壤容重,促进团粒结构形成,改善土壤结构,提高土壤孔隙度和保水、保肥能力,增强土壤酶活性。施用造纸污泥还可改善土壤的养分状况,且具有一定的增产效果和后效。造纸污泥经过堆肥后制成有机肥或有机复混肥是解决造纸污泥出路的主要途径。     

广西杧果病虫害调查初报

对广西24个市(县)杧果病虫害进行了系统的调查。发现病害有20种,主要为白粉病、炭疽病、细菌性角斑病、蒂腐病等,其中杧果水泡病、杧果畸型病和杧果红点病为国内新发现的杧果病害;发现害虫94种,隶属于8目38科,主要为杧果小齿螟Pseudonoorda minor Munroe、杧果横线尾夜蛾Chlumetia transversa Walker、杧果茶黄蓟马Scirtothrips dorsalis Hood、桔小实蝇Dacus dorsalis Hendel、杧果扁喙叶蝉Idioscopus incertus Baker等。腹足纲有害生物1种。     

桂热杧系列品种（系）的亲缘关系分析

从100条ISSR引物中选取12条多态性好的引物,对广西亚热带作物所选育的16个杧果（Mangifera indica L．）品种（系）及其可能亲本共22个样品的亲缘关系进行了分析。结果表明：这12条引物共扩增出127条DNA谱带,其中多态性条带为85条,条带多态百分率为66．93％。聚类分析显示,所有供试品种（系）之间的亲缘关系都比较近,相似系数在0．81以上;如果以相似系数0．82为标准,可将供试的22个品种（系）分为3大类。利用ISSR技术能较好地区分桂热杧系列品种（系）的亲缘关系。     

哀牢山湿性常绿阔叶林树干4种附生苔藓植物的水分变化对光合、荧光参数的影响

以云南哀牢山湿性常绿阔叶林中的附生苔藓植物为对象,研究林内4种树干附生苔藓植物阿萨羽苔(Plagiochila assamica Steph.)、西南树平藓(Homaliodendron montagneanum(Müll.Hal.)M.Fleisch.)、刀叶树平藓(H.scalpellifolium(Mitt.)M.Fleisch.)、大羽藓(Thuidium cymbifolium(Dozy et Molk.)Dozy et Molk.)的吸水力、失水特征和脱水耐性,稳定碳同位素(δ~(13)C)值,以及水分变化对苔藓净光合速率和荧光参数的影响。结果显示:(1)4种附生苔藓植物均具有较强的吸水能力和较低持水力,脱水耐性较强,脱水后均可迅速复水;(2)4种附生苔藓植物的δ~(13)C值较低,其水分利用效率小于其他维管束植物;除大羽藓外,其余3种附生苔藓雨季的δ~(13)C值与水分利用效率均高于干季;(3)4种附生苔藓植物的净光合速率(Pn)随着含水量的降低而降低,在含水量小于60%~80%时,其最大光化学效率(Fv/Fm)急剧下降,反映出这些附生苔藓植物的光合、荧光特性对水分变化非常敏感。     

Pile settlement and volume reduction measurement during forced-aeration static composting

In this study, a settlement measurement device was used to track the settlement of different layers in composting piles, and time courses of settlement velocity, bulk density distribution, and effective bulk density were investigated. Settlement is divided into two stages: the physical compressive settlement and the mass loss settlement. At the end of the former stage, bulk density (rho') and pile height (h) follow rho'=Ah(B), where A is a fitting parameter for the initial bulk density of the composting material, and B is the compression parameter. The physical compressibilities of composting mixtures are night-soil sludge and garden refuse (1:1) >sewage sludge and cornstalks (5:4) >night-soil sludge and garden refuse (2:3) >sewage sludge and bark (1:1). Adding the proportion of bulking agent in the proper extent effectively retarded composting settlement. Bark exhibits a better supporting capability than cornstalk does as a bulking agent.