Predicting non‐native fish dispersal under conditions of climate change: case study in England of dispersal and establishment of pumpkinseed Lepomis gibbosus in a floodplain pond

Predictions of future climate change include shifts in patterns of precipitation, evapotranspiration and water run‐off, resulting in increased periods of drought as well as variability and intensity of rainfall events. In the United Kingdom, the non‐native North American sunfish, pumpkinseed Lepomis gibbosus (L.), is expected to benefit from these changes. We examine how hydrological variability induced by predicted changes in climate will affect the dispersal and spread of pumpkinseed in England by: (i) determining the relationship between discharge regime and pumpkinseed propagule pressure; (ii) examining a newly‐established pumpkinseed population following a flood event in 2007; and (iii) comparing the growth and life‐history traits of this new population with fish collected from the source population to demonstrate how the pumpkinseed's life‐history plasticity contributes to its success as a coloniser. Using Bayesian modelling, we determined that the number of pumpkinseed escapees is likely to increase with increasing discharge. The newly‐established pumpkinseed population showed fast juvenile growth, early age at maturity and small size at maturity. These traits differed significantly from the source population, specifically total length (TL) means at ages 1 and 2 were significantly greater in the new population, whereas TL at age 4 was significantly greater in the source population, and a significantly higher proportion of mature females were found at smaller size classes in the newly established pumpkinseed population. This study demonstrates the potential link between hydrological variability (current and future) and the dispersal of non‐native pumpkinseed, leading to the establishment of new populations.     

丙烯酸松香的溴化及产物的阻燃性研究

以丙烯酸松香与液溴加成,合成了溴化丙烯酸松香;研究了反应温度、原料的物质的量比、反应时间等因素对反应过程及产物性能的影响.用FT-IR、1 HNMR和热重分析(TG)等对溴化丙烯酸松香进行了表征.结果表明,当反应温度为-2 ～ 4℃、反应时间5 ～ 6h、液溴与丙烯酸松香的物质的量比值约为1.2时,收率可达93%.溴化丙烯酸松香不仅具有较好的阻燃性,同时还拓宽了松香的应用范围,提高了其附加值.     

The potential of intercropping as an alternative land use system in temperate North America

The success of many intercropping systems in North America is attributable to the generation of a short term return from an agricultural crop during the early, unprofitable years of a longer term crop that is fruit, nuts or wood. This highly-efficient use of land and related profitability are important not only in the development of intercropping systems per se, but also in other applications which have tremendous potential independent of profitability. For example, intercropping can be effectively used during the establishment phases of hardwood plantations where it is essential to have a high level of weed control, the costs of which are often recovered with the agricultural production. Intercropping can also be used to grow trees rapidly and with a form that can be easily integrated into recreational or park situations, or urban fringe areas. In an urban context, intercropping can be used to grow trees in agricultural areas that are likely to be developed where traditional forestry options are not appropriate and the value of younger, thrifty trees may enhance property values far in excess of the cash value of the wood.     

The effect of cattle foot traffic on soil compaction in a silvo-pastoral system

In India, small farmers have generally found that the growing of eucalypts as a cash crop provides poor returns, and many have reverted to growing annual crops. Farmgate prices have been much lower than retail prices, due to the existence of middlemen, and retail prices have fallen to lower levels than expected as markets have become saturated. This article describes the situation in eastern Gujarant, where farmers sold their eucalypts directly to buyers at prices close to those in organised wood markets. An important reason for this unusual situation is the absence in Gujarat of controls on eucalyptus sales, which has helped producers to avoid dependence on rent-seeking intermediaries. The survey shows that growing eucalyptus can be a profitable activity for small farmers, given the right circumstances.     

-蒎烯氧化制备诺蒎酸

利用水和叔丁醇的混合溶液作为反应的溶剂,用高锰酸钾氧化β-蒎烯制备诺蒎酸,考察了叔丁醇含量、高锰酸钾和碱用量以及温度对产物收率的影响.最佳反应条件:反应温度15～25 ℃,β-蒎烯、KMnO4、NaOH物质的量的比为1:3:1.5,用 30 % 的叔丁醇水溶液做溶剂,诺蒎酸的收率(质量分数)在 70.0 % 以上.     

用β-蒎烯为原料合成高纯度对异丙基苯酚

研究了以松节油中β-蒎烯为原料，通过氧化、酸催化开四元环和脱氢三步反应，合成了高纯度对异丙基苯酚，总产率达到31％。并对酸催化开四元环和脱氢步骤中各因素对反应的影响进行了探讨。发现诺蒎酮开四元环转化反应选择在40％的磷酸溶液催化下，80℃反应1h效果较好，产率达到67．9％。4-异丙基环己烯酮与硫脱氢生成对异丙基苯酚，反应选择密封反应2h效果较好，产率达到63％。