Vegetation-permafrost relationships in the zone of sporadic permafrost distribution in the Kamchatka Peninsula

Studies on vegetation and permafrost table depth in the zone of sporadic permafrost distribution in the Uksichan River valley (the central Kamchatka Peninsula) have provided evidence that these components of biogeocenosis are interrelated and develop coordinately. In open larch forests with green forest mosses dominating in the ground vegetation layer, the permafrost table lies approximately 60 cm below the soil surface. When the ground vegetation layer is dominated by sphagnums, the permafrost table rises to 40–20 cm. In areas with a dwarf shrub-lichen ground layer, the soil thaw depth increases. A hypothesis is proposed that cyclic successional replacement of plant communities may take place in open larch forests on permafrost soils, including four consecutive stages with dominance of green mosses, sphagnums, lichens, and dwarf shrubs. In areas disturbed by fires, pioneer moss or herbaceous communities develop in the ground layer.     

贵州南部河谷热带性植物资源及开发利用

贵州南部河谷热带性植物共计464种、2变种。主要构成3种植被类型:大型羽状复叶林、稀树草坡灌丛与肉质多刺灌丛。可分为11类经济用途:药用(139种)、纤维(38种)、野果(21种)、观赏(21种)、鞣料(18种)、饲料(13种)、油脂(13种)、淀粉(12种)、紫胶虫寄主(11种)、芳香(6种)、染料(5种)。资源流失与环境变化,使现存资源的保护与深层次利用成为当前的主要问题。     

SEQUENTIAL GENERATION OF STREAMFLOW1

ABSTRACT: An auto-regressive model has been developed for hydrologic data simulation. The model is computationally easier, parsimonious in number of model parameters and more stable in statistical characteristics than the existing auto-regressive model. The proposed model was used for synthesizing 10 sequences, each of 100 year length, of monthly flows for the river Beas. The statistical parameters were calculated using 49-year historical record for the river. The data was also synthesized using existing auot-regressive model. The synthesized sequences have been compared. The results indicate that the proposed model is as good as the existing auto-regressive model in preserving the mean and standard deviation of historical record. It is further shown that the proposed model requires less parameters than the auto-regressive model for simulation of long-term dependence.     

WATER TREATMENT PLANT STAGING POLICY1

Economics of treatment plant staging or capacity expansions is governed by the initial water demand rate, Q₀; the anticipated demand growth rate, G; the discount rate, D; the cost of operation, maintenance, and repair (OMR); the useful plant life, T, as a function of the quality of design, construction, and OMR; the treatment plant load factor, L_f; the salvage value of the plant at the end of the project period; the efficiency of the plant-staging design, eta; and the length of the project period, T_s. Various staging policies are investigated to find an optimal policy. The desirability of adopting a staging policy is governed by the magnitude of percent savings that can be achieved by adopting this policy instead of a no-staging policy. A detailed analysis of the problem shows that the percent savings because of staging increase with an increase in Q, G, D, T, and eta;. A reduction in the plant load factor increases the total costs. Information about the effect of variation in the parameters should help the planner and designer to work out an economical schedule of treatment plant capacity expansions.     

Comparison of the Vegetation and Seed Bank on Hedge Banks of Different Ages in Brittany,France

The composition of the herbaceous cover and the seed bank of old and recent hedge banks in Brittany were studied and compared. Concentration method was used for seed bank samples. Grimes plant strategies were used to explain observed patterns. The analysis of the seed bank of these hedge banks showed that the species richness and diversity differed in relation to the date of construction of the hedge banks. The seed banks of recent hedge banks were richer and more diversified than those of old hedge banks. Differences in the floristic composition of the established plant cover between the recent and old hedge banks were determined by multivariate analyses. The species exclusively found in the seed bank and in the herb cover of recent hedge banks were mainly grassland species, whereas the species that only occurred on old hedge banks tended to be woodland species. The floristic composition of the two compartments (established vegetation and seed bank) was very different. A multivariate analysis revealed that the difference between the composition of the seed banks of recent and old hedge banks was less than that between the composition of the established vegetation and seed bank of hedge banks of the same age. Both seed bank and vegetation of recent hedge banks were dominated by ruderal species, whereas old hedge vegetation was dominated by stress-tolerant woodland species, indicating that mechanically constructed hedge banks may impose limitations on colonization by late woodland species.     

庐山野生观赏植物资源的保护与开发利用

按园林用途对庐山的野生观赏植物资源进行了分类介绍,分析了在保护、开发和利用方面存在的问题,同时对野生观赏植物资源在我国园林生态建设方面的独特作用提出了一些建议.     

电厂山区性河流取水工程安全设计分析

通过对代表性山区河流电厂的取水工程安全实例分析 ,根据取水方式不同 ,建议应采取的措施分为 :直接在天然河道上布置取水构筑物时 ,取水头部上下端加设三角形挡沙板 ,取水口上游设导沙丁坝 ,抬高取水头高程和进水底槛高程 ,并且可考虑设置两套取水系统 ,枯水期直接利用河道取水头取水 ,洪水期从移动式泵车取水 ;在河道上设置拦河低坝取水时 ,必须设置配套取水防沙设施 ,如排沙闸或冲沙闸 ,进水闸前设导沙坝 ,冲刷闸前设导沙坎 ,泄洪闸前设冲沙廊道和导流堤 ,还可在河道上设置潜水丁坝等。     

A technology for the treatment of olive-mill waste water in a continuously fed plant

A bench-scale pilot plant has been developed for the treatment of olive-mill water. The plant is fed in a continuous mode and implements a primary treatment (sand filtering and irradiation with UV-rays) and a secondary treatment (anoxic and aerobic biological treatment). Satisfactory results were obtained and the treated green water falls under the limits of the Italian legislation. Veratric and ferulic acid biodegradation were studied under anoxic conditions in order to verify the requirements for optimal biodegradation. Electronic Publication     

高等职业技术教育的模式比较

本文分析了我国蓬勃发展的高职教育形势,对国内外主要职业教育的培养模式进行了比较,以期为我国高等职业技术教育的健康发展提供帮助。     

三峡库区资源植物调查初报

本文通过实地考察表明,三峡库区有资源植物2068种,其中药用植物1006种、纤维植物140种、油脂植物76种、观赏植物74种、野果植物54种、芳香植物54种、树脂树胶植物68种、淀粉与糖类植物52种、鞣料植物32种、珍稀植物47种以及其它类型植物465种。