乡村景观格局热效应研究

利用Quickbird和ETM影像对浙江省绍兴县北部平原220 km2区域内50个村庄景观格局热效应进行了研究.通过环境亮温与建筑、水体、草地、林地、绿地(草地+林地)5种地类斑块共45个景观指数间的数量关系分析,结果表明:各景观指数与环境亮温间具有良好的线性关系;众多景观指数可分为密度类指数、覆盖率类指数、形状指数、核心区规模指数、100 m缓冲区相关指数、其它指数6类,其中优势斑块和景观总体的密度类指数、覆盖率类指数是环境亮温的主要作用因子;有关建筑斑块及核心区景观总体规模的指数(建筑的覆盖率、块均面积、聚合度,核心区的总面积、总周长、总块均面积)与环境亮温为正相关关系,其它多为负相关,因此建成区规模较小、各地类以众多小斑块均匀分布、建筑覆盖率低且形状狭长的村庄更有助于环境降温.建立了4个亮温预测模型(Ra~2＞0.9),筛选出相应的亮温预测及调控因子组;在核心区,环境亮温的单因子拟合效果欠佳,景观格局结构指数的作用不能忽略,结构指数对亮温的作用贡献约占总量的25%.     

杉木与马褂木混交效果分析

采用标准地调查、树干解析等方法对安溪白濑国有林场10年生的马褂木纯林及马褂木、杉木混交林(9杉1马、8杉2马、7杉3马)的树高、胸径、蓄积量等进行对比分析,结果表明:4种林分的树高、胸径、蓄积量间有显著或极显著差异;在相似的郁闭度下,林分蓄积量大小排序为7杉3马>8杉2马>9杉1马>马褂木纯林;不同混交比例对土壤肥力有较大影响,随着林分中马褂木树种数量增加,林地土壤的有机质含量、全N、水溶性N、速效P等土壤肥力指标显著提高。综合分析结果表明,7杉3马为杉木、马褂木混交的最佳比例。     

风沙地防护林滴灌技术应用效益分析

将滴灌技术应用于风沙地防护林,并对其应用效益进行了初步分析。结果表明,滴灌条件下的造林成活率和林木生长量均高于常规灌溉,具有节水、节能、省工等效果。     

阳离子半纤维素的制备及对纸张的增强作用研究

以三倍体毛白杨硫酸盐法制浆造纸过程中预提取出来的半纤维素为原料,在乙醇-水介质中制备季铵型阳离子半纤维素.讨论了醚化剂用量、NaOH用量、反应温度、反应时间等对取代度的影响.结果表明,最佳合成条件为:氢氧化钠用量6%、醚化剂用量30%、乙醇用量50%、反应温度60℃、反应时间3.0h,在此条件下可以得到取代度为0.034的阳离子半纤维素.采用红外光谱对改性前后半纤维素的结构变化进行表征,并使用所合成的阳离子半纤维素作为纸张增强剂,研究了它对纸张的增强作用.研究发现,当阳离子半纤维素的加入量为0.7%(取代度为0.034)时,可显著提高纸张的强度.     

青岛市城阳区5种绿化植物滞尘能力研究

大气颗粒物污染是当今城市面临的主要问题。作者对青岛市城阳区5种常用绿化植物的滞尘及抗尘能力作了研究,结果表明：火棘具有较强的滞尘及抗污染能力;紫叶小檗、三叶草、地锦抗性中等;金叶女贞虽有较强的滞尘能力,但粉尘对其质膜透性及叶绿素含量影响较大,不适于在污染地区应用。     

释放花绒寄甲卵对光肩星天牛幼虫的防治效果

采用木块法饲养花绒寄甲成虫,然后将其所产的卵块保存在5℃恒温条件下,以确定低温保存后花绒寄甲卵的生活力、初孵幼虫的行为学和对光肩星天牛幼虫的寄生率,并比较林间释放花绒寄甲卵与树干打孔注药(氧化乐果)防治光肩星天牛幼虫的防治效果.结果表明:低温保存49天与花绒寄甲新产卵的孵化率没有差异,花绒寄甲1龄幼虫在室内可存活1～8天、平均2.26天,爬行速度为6.5～100 cm·h-1,平均25.23 cm·h-1,室内及林间释放花绒寄甲卵后其初孵幼虫均能找到光肩星天牛幼虫并进行寄生;如果温度和湿度适宜,按照每头光肩星天牛幼虫释放15～25粒花绒寄甲卵时其寄生率可达90%;树干打孔注药与林间释放花绒寄甲卵后光肩星天牛幼虫的虫口减退率均在85%以上,两者的控制效果基本无差别.     

外生菌根菌对红松苗木生长的影响

采用沟施接种方法对3年生红松苗木进行野外单接种及混合接种的试验结果表明：菌株010和菌株025为供试菌株中对红松苗木生长促进效果最佳的菌株,与对照相比,高生长分别提高19．57％和17．04％,地径生长分别提高13．64％和15．91％。接种菌株组合GT001／GT005的苗木高生长仅比对照提高3．80％,其他3个菌株组合的高生长均低于对照;地径生长与对照相比提高0～9．10％。与单接种相比,仅接种菌株组合GT001／GT005苗木的高生长高于单接种菌株GT001和菌株GT005的苗木;接种菌株组合044／009苗木的地径生长介于单接种菌株044和菌株009的苗木之间,而接种其他3个菌株组合苗木的地径生长均低于各自单接种的苗木。     

Does the mutualism between wood ants (Formica rufa group) and Cinara aphids affect Norway spruce growth?

Ant–aphid mutualisms, in which ants tend aphids, which in turn provide honeydew to the ants, are widespread and have been shown to affect plant growth. In boreal forests the effect of ant–aphid mutualism on tree growth can vary with stand age, because forest clear-cutting harms the ecologically most dominant ant partner in such mutualisms, wood ants (Formica rufa group). We studied whether the mutualism between wood ants and Cinara aphids affects the growth of boreal Norway spruces (Picea abies L. Karst.) in stands of different ages. In boreal forests, conifers, unlike deciduous trees, have only few defoliating insects, and therefore we expected the growth loss of conifers due to sap sucking by aphids not to be compensated by reduced insect herbivory due to predation by wood ants. The study was conducted in medium-fertile spruce-dominated stands in eastern Finland. We used stands of four different age classes (5, 30, 60 and 100 years) and selected ten spruces heavily visited and ten spruces lightly visited by ants around five medium-sized ant mounds in each stand age class. The access of ants was blocked on half of the trees in both groups. In the 5-year-old stands, the mean annual height growth of individual heavily visited seedlings was 16.3% greater than in the ones where ant traffic was blocked, but this difference was not significant. In the 30-year-old stands, the mean annual radial growth of the heavily visited spruces was 7.3% smaller than in trees where ant traffic was blocked, and this difference was significant. The mutualism had no significant effect on the radial growth in the 60- and 100-year-old stands. In the 60-year-old stands, however, the spruces that were visited heavily prior to the beginning of the study grew significantly less relative to their past growth than the initially lightly visited trees during the study. This suggests that the ant–aphid mutualism may have long-term effects on tree growth. The ant–aphid mutualism had no significant effect on the growth at the stand level. The results indicate that ant–aphid mutualism can have a significant effect on the growth of individual spruces, but the effect is negligible at ecosystem level.     

花卉生产经营及其对农民收入的影响分析——基于云南省和广东省的调查数据

通过对中国花卉主产省——云南和广东的实地调研,结果发现：花卉经营收入是农户农业收入的重要组成部分,对农业总体收入会产生明显的影响,花卉生产推动了农业经济结构和农民收入结构的优化。构建计量模型研究得出：花卉的基本要素投入、种植面积以及劳动力投入对花农的花卉收益和总收入会产生正面影响,而花农的生产经验是稳定收入的重要保障,教育水平也会制约着花农的生产经营和效益水平。     

海峡西岸经济区现代农业发展战略思考与若干对策

建设海峡西岸经济区是福建省委、省政府提出的新一轮创业的发展战略,全面推进现代农业发展是海峡西岸经济区先行创业过程中必不可少的重要任务.本文阐述了海峡西岸现代农业建设的战略定位,即以壮大品牌农业引领现代农业发展,以强化安全农业保障现代农业发展,以闽台农业合作推进现代农业发展;并提出了海峡西岸现代农业发展中的若干思路与对策.