2种白木香所产沉香的木材组织构造和化学成分比较

【目的】比较新品种“热科沉香‘1号’”和普通白木香经打钉法结香2年后所产沉香的组织构造和化学成分,为筛选出优良的白木香种质或优树提供参考。【方法】采用木材解剖学方法观测木材三切面,从宏观和微观角度观察2种沉香的木材组织构造;利用气相色谱-质谱联用(GC-MS)方法检测2种沉香的化学成分,并进行对比分析。【结果】1)“热科沉香‘1号’”对创伤的修复能力较弱,结香颜色呈黄褐色,结香体积更大且容易结香,沉香物质主要积累在导管和轴向薄壁组织中;普通白木香对创伤的修复能力较强,结香颜色呈棕褐色,结香体积较小且速度较慢,沉香物质主要积累在内涵韧皮部和木射线薄壁组织中。2) GC-MS分析结果表明,2种白木香所产沉香倍半萜和色酮类成分的总相对百分含量分别为75.88%和70.41%,但“热科沉香‘1号’”所产沉香以色酮类成分为主,普通白木香所产沉香倍半萜和色酮类成分含量相当。3)“奇楠”沉香的标志性成分2-(2-苯乙基)色酮与2-[2-(4-甲氧基)苯乙基]色酮之和在“热科沉香‘1号’”所结沉香中的含量为25.19%,而在普通白木香所结沉香中的含量为5.97%,前者约为后者的4.22倍。【结论】“热科沉香‘1号’”所产沉香的质量更优,是一种易产香、产量高、质量优的种质,值得进一步培育和评价。     

Effects of plant growth regulators,carbon sources and pH values on callus induction in Aquilaria malaccensis leaf explants and characteristics of the resultant calli

The endangered tropical tree, Aquilaria malaccensis, produces agarwood for use in fragrance and medicines. Efforts are currently underway to produce valuable agarwood compoundsn tissue culture. The purpose of this study was to develop an optimal growth medium, specifically, the best hormone combination for callus suspension culture. Using nursery-grown A. malaccensis, sterilized leaf explants were first incubated on basic Murashige and Skoog(MS) gel medium containing 15g/L sucrose and at pH 5.7. Different auxin types including 1-naphthaleneacetic acid(NAA), 2,4-dichlorophenoxyacetic acid(2,4-D), and indole-3-butyric acid(IBA), were tested at various concentrations(0.55, 1.1 and 1.65 μM) using the basic medium. Leaf explants were incubated for 30 days in the dark. Callus induced by 1.1 μM NAA had the highest biomass dry weight(DW) of 17.3 mg; however the callus was of a compact type. This auxin concentration was then combined with either 6-benzylaminopurine(BAP) or kinetin at 0.55, 1.1, 2.2 or 3.3 μM to induce growth of friable callus. The 1.1μM NAA + 2.2μM BAP combination produced friable callus with the highest biomass(93.3mg DW). When testing the different carbon sources and pHs, sucrose at 15g/L and pH at 5.7 yielded highest biomasses at 87.7mg and 83 mg DW, respectively. Microscopic observations revealed the arrangement of the friable cells as loosely packed with relatively large cells, while for the compact callus, the cells were small and densely packed. We concluded that MS medium containing 15 g/L sucrose, 1.1 μM NAA + 2.2 μM BAP hormone combination, and a pH of 5.7 was highly effective for inducing friable callus from leaf explants of A. malaccensis for the purpose of establishing cell suspension culture.     

广东省奇楠沉香引种栽培试验研究

奇楠沉香是沉香中的精品,具有适应性好、抗病虫害能力强的特性。通过对广东省引种栽培奇楠沉香的种源、造林地、施肥、抚育管理及病虫害防治等的试验研究,总结归纳一套适宜于广东省引种栽培奇楠沉香的技术措施。     

白木香山地栽培技术研究

通过对白木香从采种、育苗和山地栽培的一整套技术措施进行了初步总结,结果表明:白木香种子繁殖技术简单,也可采用扦插繁殖;白木香年生长量的80%集中在5-10月份;定植后4年间年均高生长量达0.81m,地径生长量达1.59 cm;定植4年时白木香幼林平均树高3.47 m、平均地径6.73 cm。     

Seedling survival and growth of Aquilaria malaccensis in different microclimatic conditions of northeast India

We studied seedling survival and growth of Aquilaria malaccensis in three different environmental conditions(homegardens,green house and in different canopy conditions) of northeast India.Results show that mean seasonal survival was highest in green house(95.53%±2.33),followed by homegardens(89.3%±1.89) and different canopy conditions(77.62%±6.73);the highest values were found during February to April for both the homegardens(96%±1.68) and green house(98% ± 0.88) and lowest during November to January(78%±2.99) in homegardens and May to July(90%±4.53) in green house.In case of transplanted seedlings in different canopy conditions,mean seasonal survival was highest during May to July(98%±1.92) and lowest during August to October(66%±12.81).However,mean seasonal growth of collar diameter was highest in different canopy conditions(23.99%±1.76) compared to green house(21.52%±2.70) and homegardens(12.44%±1.33) and it was highest during rainy season(May to July) and lowest during dry winter(November to January) in all the three experimental sites.These variations may be due to the different microclimatic conditions as well as nutrient status of the soil in all the three experimental sites.Although,seedling quality plays a great role in their survival and growth,based on the result of green house experiment,it can be concluded that maintenance of seedlings in green house conditions during their early growth period may improve both the survival and growth for large scale plantation of the species.Thus,the species can be reintroduced in its natural forest range to compensate the loss of natural population of this precious species in northeast India.     

Quality assurance (QA) in international forest monitoring programmes: activity, problems and perspectives from East Asia and Europe

? The quality of monitoring is defined by its ability to provide data that (i) allow estimates of the status of the target resource with defined precision level, (ii) permit change detection with defined power, and (iii) are comparable through space and time. To achieve these requirements a Quality Assurance (QA) perspective is essential.

? To what extent QA was considered and data quality achieved in international forest monitoring programmes in East Asia and Europe? What is missing?

? Past and present QA activity in forest monitoring in East Asia and Europe revealed that most attention was given to evaluate and promote comparability of measurements, with special emphasis on analytical chemistry. Much less attention was given to field sampling and to the overall monitoring design. QA approaches were unbalanced among the various investigations, and several problems with data comparability remained over years.

? Despite considerable work on data quality control, parts of the monitoring process are still poorly covered by QA and revealed weaknesses in design and implementation. More comprehensive, formal and stringent QA procedures are necessary in international monitoring initiatives. Steps currently being undertaken for a more comprehensive QA approach are presented.

     

泡桐速生丰产施肥技术研究进展

综述了近几十年来我国泡桐林施肥技术的研究概况,理清了未来的研究热点和方向,重点阐述了林木配方施肥的理论基础及立地养分效应配方施肥模型。综合国内外现有研究成果,提出了建立泡桐林施肥基础数据库、减小林木施肥所造成的环境污染、实现环境保护的新观点,并指出我国泡桐速生丰产林施肥的发展方向是按立地类型、分生长阶段的目标产量及效益下的测土配方施肥。     

野生牛蒡红枣复合饮料的加工工艺研究

以牛蒡、红枣为原料,研究牛蒡汁、枣汁浸提的复合汁的最佳工艺条件。充分利用原料中的营养成分,从而加工制得了含多种维生素和矿物质天然成分的新型饮料。     

Ecological benefits provided by alley cropping systems for production of woody biomass in the temperate region: a review

In temperate Europe alley cropping systems which integrate strips of short rotation coppices into conventional agricultural fields (ACS) are receiving increasing attention. These systems can be used for crops and woody biomass production at the same time, enabling farmers to diversify the provision of market goods. Adding trees into the agricultural land creates various additional benefits for the farmer and society, also known as ecosystem services. However, tree-crop interactions in the temperate region have not been adequately substantiated which is identified as a drawback to the practical implementation of such systems. In order to bridge this gap, the current paper aims to present a comprehensive overview of selected ecosystem services provided by agroforestry with focus on ACS in the temperate region. The literature indicates that compared with conventional agriculture ACS have the potential to increase carbon sequestration, improve soil fertility and generally optimize the utilization of resources. Furthermore, due to their structural flexibility, ACS may help to regulate water quality, enhance biodiversity, and increase the overall productivity. ACS are shown as suitable land use systems especially for marginal sites. Based on the available data collected, we conclude that ACS are advantageous compared to conventional agriculture in many aspects, and therefore suggest that they should be implemented at a larger scale in temperate regions.     

Participatory technology development in agroforestry: methods from a pilot project in Zimbabwe

An on-farm agroforestry pilot project was initiated by the Zimbabwe Forestry Commission in 1988. The main objective of the project is to investigate a range of options to solve problems of woodland depletion faced by small-scale farmers. This paper describes the first two years of on-farm experimentation. The first season's trials are described, and the rationale for moving towards an approach of greater farmer participation in the research process is given. Steps taken to promote experimental tree planting on farms are described, and methods used are illustrated by examples from the project. Critical awareness-raising techniques, steamming from Freirian philosophy, have been central to the methods. The need for a partnership between formal and informal farmer-based research is discussed, as is a model for agroforestry research and development. The latter is proposed in a way that formal research develops the components of agroforestry practices, whilst farmers are encouraged to experiment with a combination of these components in order to develop practices appropriate to local conditions.     

Intensive plantation cropping,a source of sustainable food and energy production in the tropical rain forest areas in southeast Asia

About 90% of the annual losses of tropical rain forests are caused by transformation into arable land. Most of the cropping activities on the former forest land are characterised by low input, partly shifting cultivation practices, leading to fast degradation of the lands which are finally abandoned owing to infertility. Success in protecting land from further degradation is determined by the economic viability of the respective system. Therefore, sustainability of agricultural systems depends on their economic sustainability. Intensive plantation cropping on former rain forest land appears to offer such an incentive to prevent the land from further degradation by employing the best technology available.Examples of intensive oil palm cultivation as a sustainable cropping system, in terms of economy and ecology, are given. Oil palm cultivation in a suitable environment outyields most annual crops and reveals a significant potential for efficient conversion of solar energy.With the employment of sound agronomic measures the present production potential can be fully realised and new techniques in the production of tissue cultured planting material provide further improved economic viability and environmentally sound cropping systems. Such an intensification offers excellent prospects for reducing the rate of deforestation in the humid tropics.     

Scaling up the impact of agroforestry: Lessons from three sites in Africa and Asia

This paper assesses recent lessons in scaling up agroforestry benefits, drawing on three case studies: fodder shrubs in Kenya, improved tree fallows in Zambia and natural vegetative strips coupled with the Landcare Movement in the Philippines. Currently more than 15 000 farmers use each of these innovations. Based on an examination of the main factors facilitating their spread, 10 key elements of scaling up are presented. The key elements contributing to impact were a farmer-centered research and extension approach, a range of technical options developed by farmers and researchers, the building of local institutional capacity, the sharing of knowledge and information, learning from successes and failures, and strategic partnerships and facilitation. Three other elements are critical for scaling up: marketing, germplasm production and distribution systems, and policy options. But the performance of the three case-study projects on these was, at best, mixed. As different as the strategies for scaling up are in the three case studies, they face similar challenges. Facilitators need to develop exit strategies, find ways to maintain bottom-up approaches in scaling up as innovations spread, assess whether and how successful strategies can be adapted to different sites and countries, examine under which circumstances they should scale up innovations and under which circumstances they should scale up processes, and determine how the costs of scaling up may be reduced.

     

Comparative seed ecophysiology of wild and cultivated Carica papaya trees from a tropical rain forest region in Mexico

To ascertain the effects of centuries of cultivation practices on seed behavior and dormancy mechanisms, we compared seed size and germination characteristics of wild and cultivated (domesticated) populations of Carica papaya L. Germination experiments were carried out under various conditions of temperature, light, seed soaking and gibberellic acid treatments. Wild papaya seeds showed responses to treatment that are characteristic of seeds of many rain forest pioneer trees. Seeds were small and light sensitive, whereas cultivated papaya seeds were 33% larger and their light responses as well as other physiological traits indicated that cultivation had resulted in a lessening in the importance of specific environmental conditions for dormancy breaking and germination.     

Anthropogenic grasslands in Southeast Asia: Sociology of knowledge and implications for agroforestry

Anthropogenic grasslands, meaning grasslands that have been influenced and modified by humans, are one of the most important land covers of the tropics, but their management is dominated by conflicted and contested views, which is reflected in the problematic record of grassland development intervention. This chapter analyzes the historic, cultural, political, and institutional factors that affect the way grasslands are viewed, drawing largely on data from Southeast Asia. These data suggest that perceptions of grasslands are colored in part by the marginal place that they occupy in the cosmology of western industrialized societies, which idealize forest covers. Consequently, national and international agencies view grasslands not as a common land cover but as a development problem. The agendas of government and development agencies are often not grounded in a proper understanding of the local human and bio-physical ecology of grasslands or of successful local agroforestry practices; and research on many of the most important dimensions of grassland management is poorly conducted and/or utilized. The recent rise in scientific interest in indigenous knowledge, environmental history, and non-equilibrium systems, has opened up new possibilities for the study of grasslands. Agroforestry, given its inherent bridging of nature and culture, is ideally suited to benefit from these possibilities, by focusing research attention on the bio-social factors that determine the appearance, disappearance, and maintenance of anthropogenic grasslands.

     

Forest policy and sustainable forest management in Bangladesh: an analysis from national and international perspectives

This paper includes a review of international sustainable forestry development followed by an analysis of forest policies in Bangladesh. There have been four different government forest policies in Bangladesh since 1894. The first two forest policies (1894 and 1955) were exploitative in nature. Most of the regulatory documents were developed during the first two policy periods. The third forest policy instituted in 1979 by the sovereign Bangladesh government had contradictory elements and mutually inconsistent policy statements. It addressed for the first time forestry extension through mass motivation campaign. Current forest policy formulated in 1994 has been considered to be the most elaborate policy in the history of the country. Under this policy, participatory social forestry has been institutionalized in Bangladesh. The analysis shows that, although it is possible to attain the stated policy targets, progress is slow and is blocked on several fronts. A number of identified technical, managerial and logistical problems are hindering policy and program implementation. In addition, corruption contributes to the observed problems. The real strength of Bangladesh forestry is locally based, participatory forestry, co-management of protected areas and highly motivated people who increasingly recognize the need for a healthy forest ecosystem that will provide future economic stability. Because it is the rich homestead forests of Bangladesh that generate the majority of commercial forestry products, it is important that education continues at the grass-roots level. In addition, educated forestry and environment professionals have been identified as the future driving forces towards better, and sustainable, forest management. Results of this study make it clear that Bangladesh and other developing countries are not presently in a position to accept and adopt internationally derived forest policies due to inadequate institutional support, political instability and poor governance. Therefore, along with development of criteria and indicators of sustainable forest management and forest certification, international policy scientists must consider institutional development, professional skill development, identification and adoption of indigenous technology and long-term financial support in developing countries. Without these, all international processes, policies and directives will be of little value and produce few substantive results.     

The screening toolbox of bioactive substances from natural products: a review

Hunting lead compounds from natural products plays a vital role in finding successful drug candidates. The efficiency of screening campaigns is mainly determined by the validity of selected screening models. To screen desired lead compounds, researchers have developed a plethora of experimental screening models. However, the considerable diversity of screening models from animal models, tissue models, to cell models and so on, may cause some trouble in choosing the suitable one. This review provides a toolbox of experimental screening models that have been used to discover new drug candidates from natural products. Two screening indexes are designed for different research directions in this screening toolbox. Index I is proposed from the direction of screening different objective substance populations, including plant extracts, active fractions and pure compounds; index Π is according to screening different drug properties, including pharmacological properties, pharmacokinetic properties and affinity binding properties. We hope that the abbreviated bibliographies will help readers to quickly retrieve useful information by two screening indexes and provide certain reference value for choosing more appropriate screening models. Finally, we discuss ways of improving model systems, as well as future directions.     

疏枝对华北落叶松种子园结实的影响

对进入结实盛期的华北落叶松种子园,采取不同的疏枝方式,比较其对华北落叶松大小年现象及种子品质的影响。在同一个无性系中选择5个单株,分别对5个单株采取不同的疏枝措施,强度由小到大,分别去掉母树主枝的1/4、1/3、1/2、2/3,以不疏枝为对照,结果发现:随着疏枝强度的加大,第2年和第3年(小年)的结实量与疏枝强度呈正相关,种子品质也相应提高,说明通过人工疏枝措施,可降低明显的大小年现象,提升种子品质。     

Mastering the scientific peer review process:tips for young authors from a young senior editor

Are you a student at a higher institution or an early-career researcher who is striving to understand and master the peer review process so to increase the odds...     

Current status and predicted impact of climate change on forest production and biogeochemistry in the temperate oceanic European zone: review and prospects for Belgium as a case study

Reviews of the current statuses of forests and the impacts of climate change on forests exist at the (sub)continental scale, but rarely at country and regional levels, meaning that information on causal factors, their impacts, and specific regional properties is often inconsistent and lacking in depth. Here, we present the current status of forest production and biogeochemistry and the expected impacts of climate change on them for Belgium. This work represents a case study for the temperate oceanic zone, the most important bioclimatic zone in northwestern Europe. Results show that Belgian forests are mainly young, very productive, and have a high C-sequestration capacity. Major negative anomalies in tree vitality were observed in the 1990s and—as result of disturbances—in the last decade for sensitive species as poplars and European beech. The most severe disturbances were caused by extreme climatic events, directly (e.g. storms) or indirectly (e.g. insect outbreaks after a mild autumn with an early/severe frost). Because of atmospheric deposition and soil fertilization (due to the previous use of the land), nutrient stocks of Belgian forests are likely to sustain the future enhancement in productivity which is expected to follow the increase in atmospheric CO₂ concentration that will occur in years to come. However, in the long term, such (enhanced) forest production is likely to be limited by nutrient deficiencies at poor sites and by drought for sensitive species such as beech and (particularly) Norway spruce. Drought conditions will likely increase in the future, but adverse effects are expected on a relatively limited number of tree species. The potential impacts of windstorms, insects and fungi should be carefully investigated, whereas fires are less of a concern.