云南野生花卉数据库的建立及应用

通过对众多的野外调查材料和有关文献资料的收集分析、整理,运用计算机软件建立了云南野生花卉数据库,为云南花卉资源的查询、生物多样性保护提供了有力的信息支持。在论述云南野生花卉数据库的建库目的、意义之后,对该数据库的结构及其数据查询、统计、报表打印、图片处理等功能作了详尽介绍,并评述了云南野生花卉数据库的应用价值。     

施肥对油茶春梢生长及叶片矿质元素含量的影响

为了实现对油茶的高效精准施肥,以普通油茶良种‘长林4号’盆栽大苗为试材,研究了不同施肥策略及复合肥不同氮、磷、钾配比对春梢生长及叶片主要矿质元素氮磷钾元素含量的影响。研究结果表明:复合肥和有机肥的施用量对春梢长度影响显著,而复合肥不同氮磷钾配比对春梢长度无显著影响;冬季有机肥的施用对春梢叶片氮磷钾矿质元素含量无显著影响,而不同复合肥施用量、氮磷钾配比和施用频次显著影响春梢叶片氮钾元素含量,对叶片磷元素的含量影响则不显著;冬季施用25 g/株有机肥、5月份施用N∶P2O5∶K2O配比为5∶1∶5的复合肥15 g/株,对促进油茶春梢生长、改善春梢叶片氮钾营养效果最佳。     

大兴安岭北部林区森林防火基础设施建设成效及对策

大兴安岭北部林区森林防火基础设施建设项目是建国后国家一次性用于国有林区森林防火投资最大的基础设施建设工程。介绍了该项目建设的基本情况,总结了主要建设成效,分析了存在问题,提出了相关对策建议。     

林间履带式多功能底盘的设计

针对林间运输需求,提出了履带式多功能底盘的整体设计方案,并对该底盘的几个关键部件进行了设计。     

杨树低产林成因及对策——以宿州市踊桥区祁县镇为例

通过设立固定标准地对杨树的中幼林龄期和近熟林龄期生长情况进行调查分析,了解踊桥区祁县镇不同立地条件下杨树长势,判断林分立地条件对生长量影响的关键因子,并进行了标准地土壤剖面结构、理化性质和土壤养分含量对比,结论如下：影响杨树生长的关键因素是林地土层厚度,分析了杨树低产林形成原因是：土壤层浅、瘠薄、空隙度小、质地粘重。并提出相应对策：杨树低产林改造;加强中幼林抚育、进行土壤改良;发展林下经济改善土壤结构理化性质;营造复层林、间接改良土壤,提高林地综合利用率。     

Micropropagation of Selected Genotype of Aloe vera L.—An Ancient Plant for Modern Industry

Aloe vera Linn. (Syn. Aloe barbadensis Mill; Gwar-patha in Hindi) belongs to family Liliaceae. The plant, for its medicinal properties, has commercial value. Some of the genotypes of Aloe vera are consumed as a vegetable and processed to make curry and other edible products. We report here on the development of an efficient method for rapid clonal propagation by shoot proliferation from axillary meristem(s) of selected germplasm of Aloe vera. Explants were pretreated with 0.1% aqueous solution of both streptomycin and bavistin separately, each for 15 min. These were surface sterilized with 0.1% aqueous solution of mercuric chloride (HgCl₂) for 4–5 min and washed several times with autoclaved water. These were kept in a chilled, sterile antioxidant (200.0 mg L^?1 of ascorbic acid, 50.0 mg L^?1 of citric acid, and 25.0 mg L^?1 of polyvinylpyrrolidone; PVP) solution and cultured on semi-solid Murashige and Skoog's (MS) medium. The bud explants produced multiple (10.3 ± 0.675/explant) shoots on MS medium containing 13.32 μM of 6-Benzylaminopurine (BAP) and 100.0 mg L^?1 of ascorbic acid, 50.0 mg L^?1 each of citric acid and PVP, with 25.0 mg L^?1 each of arginine and adenine sulphate as additives. The shoots were further multiplied by (a) repeated transfer to fresh MS medium with additives + 13.32 μM BAP, and (b) subculturing on MS medium with a lower (4.44 μM) concentration of BAP. On MS medium containing 4.44 μM of BAP and additives, a maximum number (27.8 ± 0.63) of shoots were produced. In liquid MS medium with 4.44 μM of BAP, the rate of shoot multiplication increased and the vigor of the shoots improved. One hundred percent of the cloned shoots rooted under in vitro conditions on hormone-free half-strength MS salts containing 200.0 mg L^?1 of activated charcoal at 32 ± 2°C. The cloned shoots treated with 2.46 mM of indole-3-butyric acid (IBA) or 2.473 mM of β-naphthoxyacetic acid (NOA) for 5 min rooted under ex vitro conditions in the greenhouse. The rooted plants were hardened in the greenhouse and stored under an agro-net house. The cloned plants were transferred under different field conditions at various sites in Western Rajasthan. These plants grew normally. The higher rate of shoot multiplication and easier approach of direct rooting and hardening make this method superior to the methods previously reported on cloning/tissue culture of Aloe species. From a single shoot bud, approximately 5000 plants can be produced within 180 days.     

A Case Study Assessment of Agroforestry

Summary

Finding sustainable land-use systems within the Panama Canal Watershed will be necessary for future management by the Panamanian government. Agroforestry is a land-use option for small-scale farmers living within the Watershed that can help achieve the goals of both conservation and productivity. This case study qualitatively evaluates current agroforestry projects in the Canal Watershed using an analytical framework based on other evaluations of agroforestry systems in Central America. Designated criteria for the analysis include: management objectives, project life span, incentives, technology, economic feasibility, community involvement, and extension. These factors can present obstacles to wide-scale adoption of agroforestry systems by small-scale farmers, thus preventing the realization of associated benefits of agroforestry. The analysis of the three field sites visited in March 1998 is followed by recommendations for expanding agroforestry practices among farmers in the Watershed.     

Balancing Conservation and Economics

Summary

Ecotourism has been used successfully in many countries to promote economic well-being, conserve natural resources, and promote community development. A thorough examination of the factors that make a successful and unsuccessful ecotourism program was conducted in this paper. This analysis was performed in order to formulate recommendations for the development of an ecotourism program in the Panama Canal Watershed that will meet these objectives. A careful look at the conservation of natural areas, community development, and the economics of ecotourism fleshed out the good and the bad of existing programs. Case studies from other developing countries were used in order to set up criteria that should be used in Panama's blossoming ecotourism industry. Panama has a vast array of natural and cultural resources that can benefit from a carefully planned ecotourism program. When planning this initiative it is very important to take the politics of the country and communities into consideration, make sure the project is scaled to the carrying capacity of the natural resources and community involved, use existing infrastructure, train a skilled local work force, and maintain monitoring programs that ensure that an unsuccessful program be either improved or terminated.     

The Prospects for Integrated Watershed Management in the Panama Canal Watershed

Summary

The Panama Canal is inextricably linked to the Watershed which contains it. Effective policy is critical to manage this resource efficiently. Currently, a myriad of divisions along socio-political, organizational and technical lines are hindering integration of practical knowledge and policy experience. This lack of integration is resulting in inefficient management of the natural resources of the Panama Canal Watershed. This paper will rely on the policy sciences framework to describe, analyze and address this problem. It will begin by highlighting important organizations and their efforts in the Panama Canal Watershed, to understand the social context. Next, the trends and conditions which have shaped the problem will be described, to provide a historical context and help make projections for the future. Finally, alternatives will be presented to address the problem. Some of these options include: prototyping exercises to build practice-based experience, workshops designed to teach integration skills and to provide a common experience base for the participants, and an information coordinator to equalize the flow of information between organizations.     

Contras and Comandantes

Summary

In the 1980s, Nicaragua's Sandinista government faced armed mestizo and indigenous insurgencies in much of the nation's central and eastern regions. After the Sandinistas lost the 1990 elections, the in-coming government signed peace agreements with the insurgents and facilitated their return to civilian life. With the war over, the Nicaraguan army greatly reduced its troop strength, leaving tens of thousands of people unemployed. Within a few years, however, many former insurgents and soldiers took up arms again for multiple and complex reasons. This paper examines how three groups that rearmed influenced forest conservation in the buffer zone of Nicaragua's Bosawas Biosphere Reserve between 1991 and 1999. The three groups were the mestizo Northern Front 3-80 (FN 3-80) and the Andrés Castro United Forces (FUAC), made up of former ‘Nicaraguan Resistance’ and Sandinista soldiers respectively, and the Miskito YATAMA movement. The presence of these armed groups impeded the government from taking coercive action to remove farmers from the reserve's nucleus. It also limited the advance of cattle ranching. At times, the groups favored logging, at times they did not. The armed conflicts have tended to keep out prudent foreign investors and encourage the presence of smaller companies willing to take greater risks.