Advanced Materials Research Vols. 726-731

Abstract: In order to explain the water utilization mechanism of Pinus Yunnanensis plantations in the Central Yunnan Karst Plateau, SW China, and their adaptive strategies to arid karst habitat, the authors collected and analyzed the stable ¹⁸O isotope values of stem water of Pinus Yunnanensis in Bajiang valley, and their accompanying trees and bushes and their potential water sources. The IsoSource model was applied to compute the probable contribution of multiple potential water sources to total plant. The results show that in the ecosystem of Pinus Yunnanensis plantations, there exists significant evaporative isotopic fractionation during the process of hydraulic infiltration from precipitation to ground water and soil water and that of hydraulic redistribution in the soil profile. Water utilization positions and proportions of Pinus Yunnanensis and its accompanying trees and bushes vary from season to season, and they are evident competitors for water. During dry seasons, mature Pinus Yunnanensis uses 68.6% of 0-55cm soil water while the contribution of 30-110cm soil water and groundwater to the young Pinus Yunnanensis reaches 55.8% and 31.7% respectively. In rainy seasons, the use ratio of 0-55cm surface soil water by young Pinus Yunnanensis, Pistacia weinmannifolia and Rhododendron spiciferum are 63.1%, 56.3% and 86.2% respectively while the mature Pinus Yunnanensis uses rainfall, groundwater and fog droplets of canopy interception.

Abstract: Grassland ecosystem is the main terrestrial ecosystem. It has become one of the seriously destroyed terrestrial ecosystems, and grassland greenhouse gases emission has a great influence on the global climate change. Nitrous oxide (N₂O) in atmosphere is a member of greenhouse gases, and it plays an important role in circulation of nitrogen in terrestrial ecosystem and constitutes a key method for nitrogen output. Based on domestic and foreign references, the aim was to overview the production mechanism and major influential factors of N₂O in soil from grassland ecosystem. The major influential factors were soil temperature, soil moisture, soil organic matter, grazing and reclamation. Finally, the paper concluded that N₂O emission from grassland ecosystem was the result of the interaction of many factors.

Abstract: Microbiologic experiments together with Tessier sequential extraction and ICP-OES determination showed that distributions of Pb, Cu, Cd and Cr in soil of Guiyu, an e-waste dismantling region in South China, have changed after activities of native combined Bacillus cereus. Exchangeable fractions of these heavy metals were 1.52, 12.32, 3.98 and 34.50-fold those of original ones after 8 h interaction, here the organic phases were supposed to be the main alteration origin. The changing interaction time brought different impacts on concentration variation of heavy metals. Decabromodiphenyl ether (BDE209) influenced combined Bacillus cereus to redistribute the shares of heavy metals. BDE209 of 1 mg/L favored the alteration to make heavy metals become more bioavailable, while 5 mg/L and 10 mg/L of BDE209 baffled this alteration. However, influences of these strains on heavy metal speciation could be generally enhanced at the presence of BDE209, particularly for Cu and Pb Therefore, non-residual fractions were easier to be transferred into bioavailable ones after interaction with biomass, thus favoring the subsequent bioremediation of soil.

Abstract: Plants could make the environment beauty and improve air quality. But the plants need adapt to the growing environment. In the industrial area or cities, ozone (O₃) is a common pollutant; it could hurt human health and hinder the plants growth . This research used a custom-made fumigation equipment to evaluate the tolerance ability of 7 species of Taiwan protophyte with 200, 400 and 800 ppb O₃ gas exposure. The results of this research showed that among all tested trees, Aglaia formosana and Cerbera manghas had the strongest tolerance to O₃ and then the Millettia pinnata and Palaquium formosanum, Nageia nagi, Terminalia catappa in series, the Tournefortia argentea was the least.

Abstract: To assess the effects of land use type conversion on soil liable organic carbon pool, in this paper we collected soil samples in natural secondary forests and Chinese fir plantations that reached mature forest state in Miaoshanwu Forest Ecosystem Research Station of Fuyang city, Zhejiang province. We compared soil liable organic carbon in the depth of 060 cm by means of fixed plots investigation method and laboratory analysis method. The content of TOC, WSOC, EOC and LFOM showed a downward trend with the conversion of natural secondary forests to Chinese fir plantations, and the variations in amplitude were 12.1%-44.9%, 2.7%-11.7%, 1.2%-16.5% and 17.8%-39.8%, respectively. There were significant differences between WSOC and TOC content in the depth of 010 cm. The available ratios of EOC and WSOC of Chinese fir plantations were significantly higher than those of natural secondary forests in the depth of 0-10cm. Soil labile organic carbon and soil nutrients were significantly related to TOC, except that the relationship between WSOC and available P was not significant. The correlation coefficient between soil liable organic carbon and total N was the highest, while the lowest correlation coefficient existed between soil liable organic carbon and available P.

Abstract: Ecological Civilization has become the focus of global common concern, while the campus is playing an important role in the process of the construction of ecological civilization. This article gives a definition to the Ecologically Civilized Campus, makes analysis on the ecological responsibility of the school as well as the establishment of the path for the ecologically civilized campus. Establishing an ecologically civilized campus is a rational choice for the construction of ecological civilization.

Abstract: This study focuses on the analysis of algae growth when nitrogen is enough and phosphorus is different though the method of enclosure experiments. and to determine the influence of phosphorus for algae population structure. The results showed that the optimum value for algae grew is ρ_p=0.14mg·L^-1 in the different phosphorus concentrations, and algae grew better at phosphorus concentration more than 0.14mg·L^-1 than less than it. Community structure of phytoplankton has a little change between the experiments.The dominance of diatom is much larger than that of other phylum.The phosphorus can influence algae growth but has little effect on phytoplankton succession.A further research about the reason of phytoplankton succession in Xiangxi bay is needed.

Abstract: The experiment was conducted by a small perspex ring groove, which generated intermittent water flow, under axenic condition and constant temperature and light, to understand the effects of water flow on colony formation of Microcystis aeruginosa in the early spring raw water. The results showed that colony formation of Microcystis aeruginosa were observed in the control group and treatment groups. Colony characteristics in the treatment groups were more significant than in the control group, and the cell number of maximum colony in the treatment groups were 2.6-4 times more than in control group. So, water flow promoted to the colony formation of Microcystis aeruginosa, and colony of Microcystis aeruginosa most easily formed at flow rate of 25cm·s^-1. The phenomenon may be the interaction of the polysaccharide produced by algae in light and cell-cell higher contact rate in water flow. There are optimal flow rate of colony formation for too high water flow producing mechanical shear force to reduce colony formation. The represent study provided the scientific basis for revealing colony formation of algae.

Abstract: The experiment was conducted by small perspex ring groove, which generated infinitely long water flow, under axenic condition and constant temperature and light, to understand the effects of water flow on Microcystis aeruginosa growth in early summer and autumn raw water. The results showed that the algae growth was promoted and the specific growth rate was accelerated by water flow. The maximum biomass of M. aeruginosa in autumn raw water was higher than in early summer raw water at every flow rate. The optimum flow rate of M. aeruginosa in early summer and autumn raw water were 25 cm·s^-1 and 35cm·s^-1, respectively. The phenomenon may be the interaction of the colloid produced by death and decomposition of algae, and colony formation in M. aeruginosa under fluid motion. Therefore, The decomposition and morphology of Microcystis have an important role to growth and reproduction of algae, the results provided the scientific basis for revealing algal blooms.

Abstract: This paper evaluated the energy and emergy characters and indicators of the protected grape production system in the five major producing areas in China based on the emergy analysis. The research results indicate that the total emergy input in the Northwest region is the largest. The protected cultivation in all the five regions is heavily dependent on the purchased resource and nonrenewable resource emergy. The Southwest region is found to have the lowest environmental pressure and the highest sustainability.