大头:一个带缺憾的英雄——长篇小说《流水》人物与作家简评

长篇小说《流水》最令人难忘的人物是派出所所长——大头。林域生能用简练的笔墨成功地塑造一个有血有肉、鲜明独特的人物形象,得力于作家的厚实功力。大头这个人物突破了"高大全"的传统英雄模式,作家大胆地写出英雄身上的缺憾,体现了其对社会与人生、人性与环境、理想与现实的敏锐思想与多种探索。

Review of forest ecology studies in China

As the most important type or component in the terrestrial ecosystems, forest ecosystem makes its role obviously prominent and important on environment and human being. It possesses non-substitutable functions in the process of sustainable development. However, due to the complexity of the forest ecosystem and the relatively delay or lack of the related research technology, the science is still in the case of immature and questions. This paper summarized and reviewed briefly the development and the present case of the forest ecology, then pointed out the existing problems in the forest ecosystem researches. In the end, we discussed several fields that need to pay more attention to in future researches.

Correlations Between Plant Biomass and Soil Respiration in a Leymus chinensis Community in the Xilin River Basin of Inner Mongolia

This paper reports on two years of measurement of soil respiration and canopy-root biomass in a Leymus chinensis community in the Xilin River basin of Inner Mongolia. Correlations between components of plant biomass and soil respiration rates were examined. From respiration data based on CO2 uptake by NaOH and corresponding root biomass values for each run of 10 plots, a linear regression of CO2 evolution rates on root dry weights has been achieved for every ten days. By applying the approach of extrapolating the regressive line to zero root biomass, the proportion of the total soil respiration flux that is attributable to live root respiration was estimated to be about 27% on average, ranging from 14% to 39% in the growing season in 1998. There were no evident relations between the total canopy biomass or root biomass and CO2 evolution rates, but a significant exponential relation did exist between tire live-canopy biomass and CO2 evolution rates.

Climate Change Impacts on Central China and Adaptation Measures

In Central China, the obvious climate change has happened along with global warming. Based on the observational analysis, the climate change has significant effects, both positive and negative, in every field within the study area, and with the harmful effects far more prevalent. Under the A1B scenario, it is reported that temperature, precipitation, days of heat waves, and extreme precipitation intensity will increase at respective rates of 0.38℃ per decade, 12.6 mm per decade, 6.4 d and 47 mm per decade in the 21st century. It is widely believed that these climate changes in the future will result in some apparent impacts on agro-ecosystems, water resources, wetland ecosystem, forest ecosystem, human health, energy sectors and other sensitive fields in Central China. Due to the limited scientific knowledge and researches, there are still some shortages in the climate change assessment methodologies and many uncertainties in the climate prediction results. Therefore, it is urgent and essential to increase the studies of the regional climate change adaptation, extend the research fields, and enhance the studies in the extreme weather and climate events to reduce the uncertainties of the climate change assessments.

Isolation of Marine Actinomycetes from the Mangrove Swamps for Biotechnological Exploration

The mangroves are specialized marine environments widely distributed along the coast lines, which support biologically diverse groups of organisms including microbes. The microorganisms present in this ecosystem contribute significantly in the food web of the tropical marine ecosystem. In the present investigation, Actinomycete isolates obtained from mangrove sediments have been studied for diversity as well as for their bioactive potential. Seven different Actinomycete isolates （MS 1-MS7） were obtained from the sediments collected from the mangrove swamps. The phylogenetic analysis of these isolates showed that out or seven isolates, 3 isolates belong to Streptomyces sp., which has bioactive potential as several bioactive metabolites have been isolated from this group. One bacterium showed genetic similarity with Corynebacterium sp.. The microbes from this group are used for very important industrial applications. Three Actinomycete isolates showed very low similarity with the reported strains from the gene bank. In suggests that, these cultures could be novel and further research work is warranted to prove this speculation. In antagonistic studies, three Actinomycete isolates showed promising results. This investigation highlights the importance of mangrove ecosystem as a rich source of diverse Actinomycete strains for biotechnological applications.

Evapotranspiration and its main controlling mechanism over the desert riparian forests in the lower Tarim River Basin

Evapotranspiration(ET) and its controlling mechanism over the desert riparian forests in arid regions are the important scientific basis for the water resources managements of the lower reaches of the inland rivers of China. Nearly three years of continuous measurements of surface ET, soil water content at different depths and groundwater table over a typical Tamarix spp. stand and a typical Populus euphratica stand were conducted in the lower reach of the Tarim River. The ET seasonal trends in the growing season were controlled by plant phenology, and ET in non-growing season was weak. The diurnal variations of ET resulting from the comprehensive effects of all atmospheric factors were significantly related with reference ET. The spatial pattern of ET was determined by vegetation LAI, more vegetation coverage, more ET amount. Groundwater is the water source of surface ET, and the soil water in shallow layers hardly took part in the water exchange in the groundwatersoil-plant-air system. The temporal processes of ET over the Tamarix stand and the Populus stand were similar, but the water consumption of the well-grown Populus euphratica was higher than that of the well-grown Tamarix spp. Further analysis indicates that plant transpiration accounts for most of the surface ET, with soil evaporation weak and negligible; groundwater table is a crucial factor influencing ET over the desert riparian forests, groundwater influences the processes and amounts of ET by controlling the growth and spatial distribution of desert riparian forests; quantifying the water stress of desert riparian forests using groundwater table is more appropriate, rather than soil water content. Based on the understanding of ET and water movements in the groundwater-soil-plant-air system, a generalized framework expressing the water cycling and its key controlling mechanism in the lower reaches of the inland rivers of China is described, and a simple model to estimate water requirements of the desert riparian forests is presented.

Study on Reasonable Planning of Urban Forest Range

This paper stresses the necessity of defining range of urban forest and provides the basis for reasonably determining rangeof urban forest and some basic principles to be followed.