ent-Eudesmane sesquiterpenoids, galloyl esters of the oak lactone precursor, and a 3-O-methylellagic acid glycoside from the wood of Platycarya strobilacea

ent-Eudesmane sesquiterpenoids, 8,11-dihydroxy-2,4-cycloeudesmane, 11-hydroxy-2,4-cycloeudesman-8-one and 2,4-cyclo-7(11)-eudesmen-8-one, were isolated from the wood of Platycarya strobilacea, which has been used as an aromatic tree since at least the 18th century. On charring the wood, 2,4-cyclo-7(11)-eudesmen-8-one was detected in the smoke. In the charred wood, the concentrations of ellagitannins, such as galloyl pedunculagin, dramatically decreased, whereas concentrations of pentagalloyl glucose, and other gallotannins were relatively stable. In addition, two other compounds, the 6′-O-m- and p-digalloyl oak lactone precursor and the 3-O-methylellagic acid 4′-O-(4″-O-galloyl)-xylopyranoside, were isolated from the charred wood along with m- and p-digallic acid.     

化香树果序总黄酮提取动力学研究

以化香树果序为原料,60%的乙醇水溶液为溶剂提取黄酮类化合物,在不同温度下对总黄酮的传质动力学进行了研究。采用平板模型,以Fick第二定律为基础,建立了化香树果序总黄酮提取的动力学方程,求得了速率常数、活化能、相对萃余率等一系列动力学参数。研究结果可为化香树果序总黄酮提取工程放大和深入理论研究提供一定的依据。     

中国化香属一新种

龙州化香新种图１ＰｌａｔｙｃａｒｙａｌｏｎｇｚｈｏｕｅｎｓｉｓＳ．Ｙ．ＬｉａｎｇｅｔＧ．Ｊ．Ｌｉａｎｇ,ｓｐ．ｎｏｖ．ｆｉｇ．１．ＳｐｅｃｉｅｓａｆｉｎｉｓＰｌｏｎｇｉｐｅｄｉＷｕ,ｓｅｄｄｉｆｅｒｔｆｏｌｉｓｏｍｎｅｔｅｒｎａｔｉｓ,ｌａｍｉｎｉ...     

光氮耦合作用对化香幼苗碳平衡的影响

为了研究大气氮沉降和次生林冠层郁闭度增加对化香幼苗更新的影响,本文通过模拟鄂东南典型次生林光环境和土壤氮素供给的变化趋势,研究了化香幼苗叶功能性状、生物量分配及气体交换对光氮变化的响应,最后应用全株碳平衡模型模拟了整株光补偿点的变化（LCP_-wholeplant）。结果表明：光对化香幼苗叶功能性状和生物量分配均存在显著影响,氮素供给增加对其叶功能性状和生物量分配影响不明显,但是,光和氮素供给互作对根质量比（RMR）影响显著。幼苗叶片的表观量子效率（Ф）、最大光合速率（A_max）在郁闭光（3.0%,6.0%透光率）下随氮素供给增加而降低,在林窗光条件下（12.0%,25.0%透光率）随氮素供给增加而增加。富氮营养导致郁闭条件下（6.0%,3.0%透光率）化香幼苗的整株光补偿点（LCP_-wholeplant）升高,但却导致林窗条件下（25.0%,12.0%透光率）化香幼苗的整株光补偿点（LCP_-wholeplant）降低。因此,大气氮沉降将使化香种群更加依赖于林窗和干扰更新。     

Inconsistent interspecific and intraspecific differentiation of climate envelopes in a subtropical tree

Aims Comparisons of climate envelopes among species have shown that niche conservatism tends to break down over time. Here, we use the Asian tree genusPlatycarya(Juglandaceae) as a case study to test this tendency at relatively short timescales in a single lineage. This, together with a reanalysis of the extant literature, should help evaluate prospects of using correlations between climate and species occurrence data to infer evolutionary processes.     

茂兰喀斯特区圆果化香的种内和种间竞争强度分析

为了探讨喀斯特区圆果化香(Platycarya longipes)群落内物种间的竞争关系,该研究通过对茂兰国家级自然保护区圆果化香群落内36株对象木及1502株竞争木的调查,结合Hegyi的单木竞争指数计算了喀斯特圆果化香的种内和种间竞争强度.结果显示:(1)圆果化香的种内竞争强度(387.05)显著高于其种间竞争强度...