菊花抗寒性与营养特性的研究

寒菊抗寒性比秋菊强，气温－２～－５℃时，秋菊严重冻害，寒菊多数品种仍能正常生长和开花。在同一生长条件下，寒菊比秋菊叶水分含量低２％～３％，可溶糖含量高０．５％～３％，氮含量低０．２％～０．５％，钾含量高０．１６％～０．４０％。这是寒菊抗寒性优于秋菊的重要生理因素。秋、寒菊磷、锌含量差异不显著，秋菊铁，锰元素含量均高于寒菊。     

三种不同植被恢复模式地上生物量及其营养元素含量研究

在广西忻城县喀斯特石山区对三种不同植被恢复模式 (任豆间种竹子模式、金银花模式、竹子模式 )地上部分生物量进行测定 .结果表明 :① 3种不同植被恢复模式的净生物量 ,显示出金银花(1 19t·hm-2 ·a-1) >竹子 (1 0 4t·hm-2 ·a-1) >任豆间种竹子 (1 0 1t·hm-2 ·a-1) ;②各种模式地上部分生物量的主要营养 (N ,P ,K)含量 ,显示出任豆间种竹子 (75 0 9kg·hm-2 ) >竹子 (33 4 0kg·hm-2 ) >金银花(2 2 95kg·hm-2 ) ;③各种模式地上部分生物量的主要营养含量的分配 ,均显示出N >K >P的规律。     

管氏肿腿蜂寄生对松墨天牛幼虫体质量和营养物质含量的影响

管氏肿腿蜂是多种林木钻蛀性害虫的抑性寄生蜂,雌蜂通过蜇刺抑制寄主氧化反应。为明确肿腿蜂寄生后寄主体内营养物质含量的变化,运用考马斯亮蓝法、蒽酮比色法和残余法,对蜇刺后第0日(初始组)、第2日(寄主初麻痹时)、第14日(子代幼蜂初孵时)处理组和对照组的松墨天牛幼虫体质量、蛋白质、总糖和脂质含量进行测定。结果表明:管氏肿腿蜂寄生后,寄主体质量持续下降;体内蛋白质含量在寄主麻痹初期极显著升高,而在幼蜂初孵时则极显著下降;脂质含量在寄主初麻痹时未见显著变化,而幼蜂孵化前升高显著;但寄主体内的总糖含量变化不显著。研究结果说明,管氏肿腿蜂雌蜂寄生寄主,对寄主体内蛋白质、糖类、脂质代谢产生了影响。     

Changes of soil chemistry,stand nutrition,and stand growth at two Scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) sites in Central Europe during 40 years after fertilization,liming, and lupine introduction

Long-term (40 years) effects of two soil amelioration techniques [NPKMgCa fertilization + liming; combination of PKMgCa fertilization, liming, tillage, and introduction of lupine (Lupinus polyphyllus L.)] on chemical topsoil properties, stand nutrition, and stand growth at two sites in Germany (Pfaffenwinkel, Pustert) with mature Scots pine (Pinus sylvestris L.) forest were investigated. Both sites are characterized by base-poor parent material, historic N and P depletion by intense litter-raking, and recent high atmospheric N input. Such sites contribute significantly to the forested area in Central Europe. Amelioration resulted in a long-term increase of pH, base saturation, and exchangeable Ca and Mg stocks in the topsoil. Moreover, significant losses of the forest floor in organic carbon (OC) and nitrogen stocks, and a decrease of the C/N ratio in the topsoil were noticed. The concentrations and stocks of OC and N in the mineral topsoil increased; however, the increases compensated only the N, but not the OC losses of the forest floor. During the recent 40 years, the N nutrition of the stands at the control plots improved considerably, whereas the foliar P, K, and Ca concentrations decreased. The 100-fascicle weights and foliar concentrations of N, P, Mg, and Ca were increased after both amelioration procedures throughout the entire 40-year period of investigation. For both stands, considerable growth acceleration during the recent 40 years was noticed on the control plots; the amelioration resulted in an additional significant long-term growth enhancement, with the NPKMgCa fertilization liming + being more effective than the combination of PKMgCa fertilization, liming, tillage, and introduction of lupine. The comprehensive evaluation of soil, foliage, and growth data revealed a key relevance of the N and P nutrition of the stands for their growth, and a change from initial N limitation to a limitation of other growth factors (P, Mg, Ca, and water).     

北美引进泡泡树的研究进展

泡泡树是一种原产于北美洲的乔木果树,其果实味美,营养丰富,富含多种矿质元素、维生素和氨基酸,具有较高的开发利用价值.目前,国内的一些科研单位已对泡泡树进行了引种栽培试验,并获得了成功.同时,对泡泡树的营养成分、繁殖技术、种植技术、遗传多样性等方面进行了研究,并取得一定进展.本文将对泡泡树研究现状进行整理,分析当前泡泡树...     

林木叶片最适养分状态的模拟诊断

为研究叶片最适养分状态,提出了模拟诊断方法。将砂姜黑土上Ⅰ-69杨(Populus deltoides Bartr.cv.“Lux”)的改土培肥试验各处理作为模拟诊断的样地。用典型相关分析方法选择采样时间、确定与林木生长有密切关系的叶片养分元素。用抛物线函数作为叶片最适养分状态的诊断函数。选择变量同时考虑叶片养分的含量和养分之间的比例。经过4年多的研究得出Ⅰ-69杨最适叶片养分状态为:造林第1年7月叶片含P_2O_50.55—0.75％;造林后第2年7月叶片含N3.20—4.20％;造林后第3年5月含N3.00—3.70％;造林后第4年5月叶片中的N/K为1.00—1.60。     

辐射松种子不同营养袋规格育苗试验研究

经过连续3 a对辐射松种苗特性及育苗技术的试验研究的结果表明：营养袋规格：10 cm×15 cm,营养土配方为腐殖含量50％的平均苗高23.2 cm,平均地径0.3 c m,达到一级苗标准.