人类活动对亚热带森林大气CO2浓度及两种木本植物碳水化合物含量的影响

研究了包括旅游、宗教活动及工厂废气等不同类型的人类活动对亚热带森林大气CO₂浓度及两种木本植物荷木和马尾松碳水化合物代谢的影响.结果表明,人类不同形式的活动不但影响了CO₂日进程变化,而且使CO₂的垂直分布发生了改变.与对照相比,人类活动引起森林大气(5～15m)CO₂上升了4～11μl·L^-1.马尾松和荷木叶片的可溶性糖和非结构性碳水化合物随人类活动的加强而下降,其下降趋势与CO₂上升趋势基本一致.树木上层(15m)叶片的可溶性糖和淀粉受影响较明显,纤维素含量受人类干扰相对较小.荷木和马尾松的碳水化合物代谢对人类活动的响应不同.     

木荷光合特性日变化及其与环境因子相关性分析

运用LCA4型便携式全自动光合测定系统,在自然条件下,于9月上旬的晴天里对空旷地生境中木荷叶片光合作用日进程进行测定,结果表明木荷冠层叶片的净光合速率日进程曲线为双峰型,在午间出现明显的“午休”现象。用逐步多元回归方法得到净光合速率日变化的最优化方程为Y=-5.0105+0.0052X1+0.3869X3-0.3576X4(复相关系数R=0.9558,F值=24.6384,显著水平p=0.0004,剩余标准差S=0.7893)。偏相关分析和通径分析表明,光合有效辐射、空气相对湿度和气温与净光合速率的日变化有着极显著或显著的相关关系,是影响光合速率主要的环境因子,影响大小的顺序为光合有效辐射>空气相对湿度>气温。     

木荷花挥发性成分的GC-MS分析

采用无水乙醚超声萃取得到新鲜木荷(Schima superba)花浸膏提取物,顶空固相微萃取富集挥发性成分,气相色谱-质谱联用仪分析,归一化法计算各组分的相对含量.鉴定出挥发性化合物中的51个成分,约占相对总含量的99%;挥发性成分中含氧化合物的含量超过93%,其中主要的化合物及其相对含量为酮代异佛尔酮(26.33%)、氧化芳樟醇(19.53%)、环氧芳樟醇(8.80%)、3,7-二甲基-2,6-辛二烯-1-醇(8.23%)、白藜芦素(7.89%)、4-羟基3,5,5-三甲基-2-环己烯-1-酮(6.54%)、2,6,6-三甲基-1,4-环己二酮(4.06%)、苯乙醇(2.17%)、2-甲基-2-壬烯-1-醇(2.04%)等.     

木荷种群在演替系列群落中的遗传多样性

利用ISSR分子标记对木荷种群在3个演替系列群落中的遗传多样性进行了研究。12个随机引物共检测到203个可重复的位点,其中多态位点183个,总多态位点百分率（P）为90.15%,平均多态位点百分率为82.27%。Shannon信息指数（I）估算的总遗传多样性为0.524 4,平均为0.477 8。Nei指数（h）计算的总基因多样性为0.358 7,平均为0.326 5。3个种群的P、I、h大小顺序均为针叶林>针阔混交林>常绿阔叶林。AMOVA分子变异显示91.56%变异来源于种群内,8.44%变异来源于种群间。种群间的遗传分化系数（G_ST）为0.089 7,基因流（N_m）为5.073 1。种群间的遗传相似度平均为0.928 4,遗传距离平均为0.074 4,针叶林种群与针阔混交林种群遗传相似度最高。     

杉木、木荷纯林及其混交林凋落物量和碳归还量

2005年5月-2007年4月,研究了福建省建瓯市水土保持科教园内19年生杉木人工林、木荷人工林和杉-荷混交林凋落物量和碳归还量.结果表明：3种人工林的年均凋落物量分别为2470.85、4171.96和4285.99 kg·hm^-2·a^-1,不同人工林中凋落物均以落叶为主,占林分年总凋落量的68.62%～87.26%.杉木人工林凋落物量在每年的4-5月、7月和12月出现3次较大峰值,而木荷人工林和杉-荷混交林凋落物量的峰值仅出现在每年的3月份.与人工纯林相比,混交林促进了阔叶树种的单株凋落物量增加,但抑制了针叶树种的凋落物量.落叶是3种人工林凋落物碳归还的主体,人工林碳年归还总量大小顺序与年均凋落量相同,其中杉-荷混交林最高(2.12 t·hm^-2·a^-1),杉木人工林最低(1.19 t·hm^-2·a^-1).与针叶和阔叶人工纯林相比,针阔混交林的凋落量大、碳归还量高,具有良好的碳吸存能力.     

基于液流格型特征值和标准化方法分析胸径和土壤水分对荷木液流的影响

基于液流格型特征值-偏度和峰度分析了不同胸径荷木在水分利用方面的差异,并利用标准化的方法消除强影响因子(光合有效辐射,PAR)对液流的影响,研究了弱影响因子(土壤湿度)与液流的关系.结果表明：荷木胸径越大,偏度越小,液流密度峰值越靠后,相应的液流峰值越大,蒸腾量也越大.与旱季相比,荷木大树在湿季偏度较小,液流密度到达峰值时间靠后,峰值大,蒸腾量也大;而小树偏度在旱、湿季的差异不明显,蒸腾量差异也不大.用PAR峰值对荷木个体蒸腾和土壤湿度进行标准化后,荷木个体蒸腾与土壤湿度呈更明显的正相关关系.在土壤湿度较大的季节,荷木大树的蒸腾量随土壤湿度增加而上升的速率基本稳定;而中等木和小树的某些个体则明显下降,说明这些树木的蒸腾和吸收土壤水分的能力可能接近极限.     

Upstream biomanufacturing of pharmaceutical colchicine

The plant-based colchicine potentially affects major diseases such as cardiovascular events, cancers and gout. Gloriosa superba seeds are a conventional pharmaceutical source of colchicine. The demand for pharmaceutical-grade colchicine has increased due to the shortage of feasible upstream manufacturing, encompassing all stages in the processes of biosynthesis and biomanufacturing before the raw material is ready for purification. Consequently, developing sustainable upstream industrial colchicine biofactories is imperative, especially in curtailing drug costs. A new upstream bioprocess has been established, using specialized biorhizomes with comprehensive specific-enzymes that catalyze the construction of biogenic functionalized intermediates that are converted into colchicine. This review emphasizes a novel biorhizome approach for biomanufacturing pharmaceutical-grade natural colchicine, a biosynthetic pathway elucidation and its challenges to synthetic biotechnology.     

增施氮磷肥对木荷林凋落物生产量及其养分的影响

以浙江天童常绿阔叶林木荷群落为对象,2011年研究了不同施氮磷肥水平下凋落物生产量和养分动态特征.结果表明: 增施氮磷肥处理后,木荷群落凋落物的年生产量在6.82～8.30 t·hm^-2·a^-1,呈“三峰型”季节动态模式;凋落物年平均氮含量(P处理除外)和年平均磷含量增加;凋落物氮磷含量季节动态发生改变,而对凋落物氮年归还量(60.05～7147 kg·hm^-2·a^-1)和磷年归还量(2.94～3.93 kg·hm^-2·a^-1)没有显著影响.与对照相比,试验初期(2011年春季)各施肥处理下的凋落叶氮磷比普遍较高,而2011年冬季较低,说明长期施加氮磷肥可能改变森林生态系统原有的氮磷限制状况.     

Breeding antarctic krill in captivity

Antarctic krill were maintained in large aquaria at Port of Nagoya Aquarium, Japan, under controlled photoperiod and were fed on phytoplankton and enriched animal feed. Maturation and spawning were induced after the light?:?dark (L?:?D) cycle was increased from 8?:?16 or 12?:?12 to 24?:?0, or when the L?:?D cycle was held constant at 14?:?10. This study is one of the first studies that demonstrate initiation of maturation and spawning events of krill under controlled photoperiod. Out of three experimental batches of krill, a total of 28 spawning events were observed. The mean number of eggs per event was 1424 with a range between 139 and 3458. The mean hatching success per batch was 19.1%. The relation between photoperiod and maturity/spawning is discussed. Furthermore, hatching is compared to previous studies and the reason for the low success is discussed.     

Modelling Southern Ocean ecosystems: krill, the food-web, and the impacts of harvesting

The ecosystem approach to fisheries recognises the interdependence between harvested species and other ecosystem components. It aims to account for the propagation of the effects of harvesting through the food-web. The formulation and evaluation of ecosystem-based management strategies requires reliable models of ecosystem dynamics to predict these effects. The krill-based system in the Southern Ocean was the focus of some of the earliest models exploring such effects. It is also a suitable example for the development of models to support the ecosystem approach to fisheries because it has a relatively simple food-web structure and progress has been made in developing models of the key species and interactions, some of which has been motivated by the need to develop ecosystem-based management. Antarctic krill, Euphausia superba, is the main target species for the fishery and the main prey of many top predators. It is therefore critical to capture the processes affecting the dynamics and distribution of krill in ecosystem dynamics models. These processes include environmental influences on recruitment and the spatially variable influence of advection. Models must also capture the interactions between krill and its consumers, which are mediated by the spatial structure of the environment. Various models have explored predator-prey population dynamics with simplistic representations of these interactions, while others have focused on specific details of the interactions. There is now a pressing need to develop plausible and practical models of ecosystem dynamics that link processes occurring at these different scales. Many studies have highlighted uncertainties in our understanding of the system, which indicates future priorities in terms of both data collection and developing methods to evaluate the effects of these uncertainties on model predictions. We propose a modelling approach that focuses on harvested species and their monitored consumers and that evaluates model uncertainty by using alternative structures and functional forms in a Monte Carlo framework.