Suspended solids and its effects on the underwater light in Meiliang Bay, Taihu was studied and found: Inorganic suspended solids in the total suspended solids had the apparent positive linear relationship with the total suspended solids (R2=0.972 4), but the organic suspended solids is slightly relationship with total suspended solids(R2=0.292 1); The algal content in the total suspended solids decreased with the increasing water depth and at the depth of 20 cm the algal content was the highest, in the surface water the content was lower than that at the depth of 20 cm. The relationship between organic suspended solids and chlorophyll a was less significant(R2=0.134 4). The distribution of spectrum was that the intensity of green light was the greatest, blue light greater, red light the weakest in the surface water, the intensity of red light was the greatest, green light greater, blue light the weakest.
The responses of Spirulina maxima (blue-green alga) and Chlorella minutissima (green alga) to short-term (6 h) UV-B treatment and long-term (1-80 d) UV-B treatment were investigated using Chlorophyll (Chl) fluorescence, UV spectrophotometer and improved Fridovich method. After short-term treatment (6 h) under different UV-B intensity (0-2.0 w·m-2), FV/FM of the two species were both substantially inhibited, and that of S. maxima were inhibited more than that of C. minutissima. However, the secretion of UV-B absorbing substances and SOD activity in two species after short-time treatment were not related to UV-B. Under long-term treatment (1-80 d) with the same UV-B intensity (0.9 or 1.8 w·m-2), FV/FM of S. maxima were decreased firstly followed by remarkable increasing, while that of C. minutissima were decreased gradually. Within the treatment time, the secretion of UV-B absorbing substances and SOD activity increased gradually in S. maxima, while there are no changes in C. minutissima.
Complex tea orchard with ground cover plant Hedyotis uncinella Hook & Am (Rubiaceae, Hedyotis) was established in Hongxing Tea Plantation, Yingde city, Guandong province. In order to gain more knowledge of the arthropod assemblage structure, the values of assemblage diversity index (H), species richness index (R), evenness index (J), species dominance index (d) and assemblage concentration index (C) of tea tree habitat were calculated and their relationships were studied using the methods of Factor Analysis and Path Analysis. Results of Factor analysis showed that the five primary eigenvalues of arthropod assemblage comprehensively fell into three principal components. The first principal component mainly represented assemblage diversity and evenness. The second and the third components largely stood for species richness and assemblage concentration index, respectively. The proportions of variance of the three principal components were 50.279%, 26.92% and 22.466%, respectively. Path Analysis outcomes indicated that the diversity of arthropod assemblage had a significant and positive correlation with the species richness of arthropod assemblage and natural enemy assemblage, while a significant and negative correlation with assemblage concentration index. Thus, the diversity of arthropod assemblage could be increased by promoting the species richness of arthropod assemblage and natural enemy assemblage, whereas decreasing assemblage concentration index through establishing complex tea plantation.
Densities of Skeletonema costatum and its environmental factors were investigated in Zhelin Bay from May 2000 to June 2002. Our results showed that densities of S. costatum were greater in the inner bay than those in the outer bay, however one peak was observed in a typical annual dynamics monitoring. The relationship between densities of S. costatum and the environmental factors was studied by correlation analysis. Both N and P are likely to be the limit factors for S. costatum, especially P.
Measurements on gas exchange parameters have been made in leaves of three 2 to-3 year-old Acacia species seedlings transplanted and grown under different polluted sites for 4 months by using LCA-4 photosynthesis system. Possible effects of air pollution imposed on plants and their tolerance were evaluated. The net photosynthetic rate(Pn), stomatal conductance(gs) and the photochemical efficiency of the PSII(Fv/Fm) differed among species and generally decreased under polluted area. The transpiration rate(E) and water use efficiency (WUE) in leaves of Acacia macradenia maintained relatively stable among all the three experimental sites, but Pn/E of Acacia floribunda and Acacia fimbriata decreased under polluted sites, when compared with those under the relatively clean area. Based on the changes in Pn, gs, and Fv/Fm, and compared these Fv/Fm values with other plants, it can be concluded that the three Acacia species exhibited moderate tolerance, and Acacia floribunda and Acacia fimbriata showed slightly higher tolerance than Acacia macradenia.
Chlorophyll-a and phosphorus were measured in 19 reservoirs in Guangdong province, South China in flood and dry seasons of 2000. The results showed that Liuxihe reservoir, Xinfengjiang reservoir, Gongping reservoir and Baipenzhu reservoir, which located in the up-stream of the rivers, had low concentration of phosphorus and chlorophyll-a all the year. On the contrary, Qiyeshi reservoir, Shiyan reservoir and Hedi reservoir as well as Dajingshan reservoir, which located in down-stream of the rivers or located in Leizhou Peninsula, where is well developed farm area, had high concentration of both phosphorus and chlorophyll-a. The other reservoirs had obvious seasonal patten: the concentration of phosphorus were higher in the flood season than in the dry season. Phosphorus limitation was more serious in a dry season, which caused a significant change in the phytoplankton species composition from a flood season to a dry season. The dominant species in the flood season had a high half-saturation concentration of phosphorus, and they lost the advantage in the dry season. The species, Microcystic spp. and Melosira spp., which have a low half-saturation concentration of phosphorus dominate in both the flood and the dry seasons. The correlation coefficient between PO43--P and chlorophyll a was higher in dry season than in flood season, and higher near the dam than in the riverine. It was higher than the correlation coefficient between TP and chlorophyll a concentrations.
In the flood season and dry season of 2000, the water quality and plankton distribution of Tangxi Reservoir were investigated to evaluate its trophic state. According to the comprehensive trophic level index (TLI), the values of Tangxi reservoir were between 30 and 50. It showed that the reservoir was mesotrophic. The phytoplankton abundances varied from 0.81×106 to 6.57×106 cells·L-1, and were higher in the flood season than in the dry season. The phytoplankton was primarily composed of Cyanophyta, Chlorophyta and Bacillariophyta. Most of the dominant species were eutrophication indicators such as Microcystis flos-aquae, Melosira granulata, Melosira minmum and Chlamydomonas sp.. The zooplankton abundances were between 43.25 ind.·L-1 and 812.2 ind.·L-1, and the dominant species were mostly eutrophication indicators: Keratella cochlearis, Brachipnus angularis, Asplanchna priodonta and Mesocyclops leuckart. In comparison with 1984, the dominant phylum changed from Cyanophyta to Bacillariophyta. Both trophic state and the phytoplankton abundance increased greatly. During a Microcystis bloom occurred in 2000, the maximum phytoplankton abundance in the surface water reached 11.97×106 cells·L-1.
Floristic composition of the main evergreen broadleaved forest in Maofengshan, Guangzhou, was analyzed based on community plots survey data. The results showed that 209 species of vascular plants falling into 147 genera and 77 families were found in the 14 400 m2 plots. Dominant families of the flora were Euphorbiaceae, Lauraceae, Rubiaceae, Gramineae Myrsinaceae, Papilionaceae, Theaceae, and Aquifoliaceae. As for generic distribution, the Pantropic areal type was the majority of genera, followed by Old World Tropics and Tropical Asia, while typical genera were rare and showed the basic features of lower subtropical flora.
The contents of the nutritional component in scallop brim were analyzed and hydrolyzed by the neutral proteases produced by the strains of Bacillus subtilis ASI.398. The content of protein in scallop brim was about 67.6% in dry weight. Then the four factors influencing the degree of hydrolysis were investigated and the optimal conditions of hydrolyzing proteins were obtained. The temperature of hydrolysis was 50℃, concentrations of neutral proteases and base material were 0.5%(250 U·ml-1) and 6% respectively, hydrolysis time was 3 h.
This paper makes a research on the technical conditions about how to abstract cellulase from Helix pomatia pomatia. The optimum conditions were studied through orthogonal experiment. The results manifest that the best abstraction pH and temperature were 5.0 and 0℃ respectively, and the optimum time is about 10 hours. On the basis of the above conditions we abstracted primary product of cellulase through partition chromatography and found the most active unity of cellulase is 1.402 U·ml-1.
According to the status of the sound environmental quality on the both sides of Chencun steam in Zhujing Delta, the sound environmental impact in the areas from 0 to 200 meters of the dredging project of Chencun stream was predicted and assessed by the prediction model. During the building period, the equivalent sound level is basically conform to the national standard, and the environmental quality would not be impacted. During operation period, the environmental quality could be impacted in certain extent. The maximum noise impact is in Linyue village while the minimum noise impact is in Yaogu farm. The maximum day equivalent sound level is 66.3 dB(A), the minimum day equivalent sound level is 63.5 dB(A). The maximum night equivalent sound level is 58.8 dB(A), the minimum night equivalent sound level is 54 dB(A). The percentage of exceeding the national standard are 5.8%-10.2% in daytime, 8%-17.6% at night.
To study the impact of pollution sources on the eutrophication characteristic of reservoirs, three reservoirs (Shiyan, Dajingshan and Dashuiqiao) were sampled to measure the nutrients and planktons in 2000. The trophic state index of the three reservoirs indicated that the Shiyan reservoir is eutrophic, Dajingshan reservoir and Dashuiqiao reservoir are meso-eutrophic. The eutrophication of the three reservoirs was characterized with the pollution sources, especially, the reservoirs have different dynamics of trophic levels. Shiyan reservoir was principally polluted by municipal sewage. The nitrogen and phosphorous concentrations and plankton abundance in Shiyan reservoir are the highest of the reservoirs, and highly abundant Euglena Ehr. was observered in both flood season and dry season. Shiyan reservoir is heavily loaded with organic pollution. Dashuiqiao reservoir is mostly polluted through agricultural activity, the concentrations of PO4-P and TP in the flood season is much higher than in the dry season. The Cyanophyta's abundance is dominant in the flood season and the Bacillariophyta in the dry season. Dajingshan reservoir was polluted by industrial sewage mainly. In this reservoir there were distinct seasonal variations in TP concentration and zooplankton abundance, and the variations were controlled by pumping water from a river.
Trchycarpus nana is a national grade-2 protected rare plant that grows in Yunnan Province. On the basis of a survey, the paper has ascertained the areas of the plants growth in Yunnan Province and found six more growth spots as NanHua and YaoAn. It confirms that Trachycarpus nana plant grows principally in Central Yunnan Plateau, with Chuxiong at its heart. The paper also makes a preliminary study of the plant's biological and ecological features and thus paves the way for protection and utilization of this rare and near-extinctive plant.A probe is also made into the causes of the plant's near-extinctiveness,so as to facilitate taking protective measures.
The experiment was conducted in the area of weathering purple sandy rock from July in 1998 to September in 1999 to investigate the adaptability of some grasses on highway slope by the coverage with the ocular estimate. The results showed that the grasses with good adaptability were mainly tropical or subtropical graminaceous grasses. The coverage of Chinese pennisetum, Crested dogstail and Kikuyu grass were the highest, and that of Common Bermudagrass and Weeping alkaligrass were higher.Although the coverage of Crested dogstail and Korean lovegrass were high throughout the experiment, their color were not very green. The growth vigor of Indian couchgrass and Bahiagrass were strong during the last period of time. Among the temperate grasses, Tall fescue had a good tolerance to hot weather.Colonial bentgrass and Cocks foot can not tolerate drought, hot and barren soil, and declined quickly next year. Perennial ryegrass grew well in the first year. The leguminous forage grew strong especially during the dry winter and spring seasons. Alfafa had strong tolerance to drought and barren soil and cover well. The adaptability of red clover was also good. Kentucky bluegrass and zoysia grass grew slowly during their seedling time, and Weeping alkaligrass was not suitable to purple soil, and Carpet grass was not suitable to drought in high and dry area, they all cover slowly during the first period of time, and their coverage were low throughout the experiment. Bahiagrass and Birdsfoot trefoil could be utilized selectively.
Degradation of lignin with 7 fungal strains was determined. The results showed that Aspergillus oryzae 2013, A. oryzae 2014, A. oryzae 2015 and Aspergillus niger are capable of degrading more than 90% lignin in a short period of time. At the same time, bacteria isolated from the field environment were unable to degrade lignin.
There are still many problems to be solved in the management of the city's lawn. This article studied the impact of mowing and removal of weed on lawn growth. The result indicated that mowing was more effective than removal of weed in preventing other grasses from overgrowing and helping the main grasses grow better, keeping the lawn tidy and beautiful, and maintaining a high coverage, and it would eventually help to save labor and money in the lawn management. Several proposals were put forward for the management of city lawn.
Cd contamination of agricultural soils as a result of industrial discharge is a serious threat to human and animals'health. Current status of Cd pollution, remedial mechanisms, advantages and disadvantages of different methods, and feasibility of application are reviewed in this article. In addition, principle, characteristics and new biotechnological methods involving genetic engineering used in phytoremediation of Cd contaminated soils and future prospect are discussed in details. The alternative methods provide novel approaches to restore the polluted ecological systems using highly efficient plants and organisms.
This paper reviews application and effectiveness of constructed wetlands in developing countries. Constructed wetlands are suitable for wastewater purification in developing countries including China, especially in the rural areas and small cities. Constraints of wetlands for wastewater treatment application include poor understanding of the technology involved, lack of information on the impacts of wastewater to plants (especially to native plant species) and the large-scale land requirement for constructing wetlands than the traditional wastewater treatment plants.
In recent decades, molecular markers have been applied extensively in ecological studies, and shown the importance in further our understanding of ecosystem and function. This potentiality represents several points including: ① The molecular markers are applied primarily in population ecology at present. In the future, greater potential of utilizing molecular markers will be realized in the study of evolutionary ecology, conservation ecology, restoration ecology and ecosystem ecology; ②some molecular markers will be used in brand new research areas; ③ several different molecular markers will be combined in solving questions in order to improve data quality; ④ with new molecular marker to be developed, novel and extensive development will be foreseen in the area of ecology. However, molecular markers also have associated limitations when they are used in ecological investigations, such as high running cost, low repetitions, and radioactive problems. It is important to choose and optimize different molecular markers when different ecological issues are to be addressed.
From the existing ecological literatures on Korean pine (Pinus komiensis) covering the period from 1994 to now, the dynamic processes of the Korean pine were described, and the main contend characteristics and problems were analyzed. In addition, the trend of ecological study on Korean pine forest was also predicted.
According to the official gazette on the Chinese environmental conditions and the relevant statistic data, this paper presents the environmental changes and causes of the inland surface water in the last decade of China. The analysis indicated that the water depravation in China tended to be mostly controlled in the past ten years. Water pollution is shifting from industry source to municipal wastewater and agriculture. The paper proposed corresponding strategies for controlling such pollution.
In this paper, according to the principles of sustainable development and fundamental ecology, the authors combine the current conditions of natural reserves and the characteristics of eco-tourism together to demonstrate three key factors in developing an eco-tour in Guangdong Natural Reserves: feasibilities, possible problems and settlements, and providing the prospect of the development.
