Based on the data obtained from 12 cruises from 2002 to 2003 in the Pearl River estuary, species composition, dominant species succession, abundance variations and environmental factors influence on planktonic copepods were examined. The Pearl River estuary can be divided into three regions according to its surface salinity, region I(salinity<25), region Ⅱ(salinity from 25 to 30) and region Ⅲ(salinity>30). Results showed that total 65 species were identified. The number of zooplankton species was higher in regions Ⅱ and Ⅲ than that in region I. The average abundance of copepods in the Pearl River estuary was 118 ind·m-3. It was higher in regions Ⅱ (165 ind·m-3) and I (129 ind·m-3) than that in region Ⅲ (62 ind·m-3), and it was also higher in spring and summer than that in winter. Dominant species presented obvious regional and temporal patterns. Another result from 9 cruises carried out in region I showed that copepods abundance differed monthly and generally increased from the inner to the outer of the estuary. Salinity was an important factor influencing species composition, distribution and abundance of copepods in the Pearl River estuary.
An in situ experiment was carried out to examine the effects of large filtering zooplankton——Daphnia pulex's on phytoplankton community strcuture in a shallow entrophic lake on the campus of Jinan University. Ceratium hirundinella and Pediastrum simplex are dominant and blooming-forming phytoplankton species in this lake. Daphnia pulex were cultured in the laboratory to reach the body-size of 20 mm, then was transfered into the transparent bottles (4.5 L). Four gradients are set:0 ind(A), 10 ind(B), 20 ind(C) and 30 ind(D), with three replications for each concentration gradient. The bottles were tied together and were floated at a depth of 50cm below the surface water in the pond. After 12 days of the experiment, the phytoplankton abundance and composition in the experimental bottles were significantly different among three treatments. The densities of Ceratium hirundinella and Meclosira granulate declined significantly with the increase of the density of D. pulex in those treatments. The densities of Cyclotella and Scenedesmus in the treatment D were very low, but in the treatments B and C, where the predation from D. pulex were low or moderate, phytoplankton abundance were even higher than in the control treatment A; the density of Chloropyhta showed no clear decrease in all the treatments. The results indicated that the impact of the large zooplankton D. pulex on phytoplankton communities is not only closely related to its own population density, but also closely related to phytoplankton species. It can suppress the population abundance of C. hirundinella by a mechanistic damage; For small phytoplankton species, D. pulex can stimulate the their growth by promoting the nutrients cycle when the predation pressure from D. pulex was low or moderate.
In order to study the biological characteristics of Rhizobia in A. cincinnata,12 rhizobia strains were isolated from A. cincinnata stand in Gaofeng forest farm of Guangxi, southern China. The physio-biochemical characteristics of these strains were detected, and the isolated strains were also inoculated to the A. crassicarpa in order to study the formation of root rhizobia nodule. The results showed:(1)According to the growth rate, the 12 isolated strains could be divided into 9 fast-growing strains and 3 slow-growing strains. (2) Inorganic nitrogen (NH4++NH3-) could be utilized by most strains, but the utilization of sugar sources by strains shown diference. (3) In the experiments treated with 3-keto-lactose, beef-protein and tarch hydrolysis respectively, all of 12 tested strains shown negative response, while in B.T.B reaction and citrate utilization, the results shown positive response. In litmus milk experiment, all of strains produced alkai. (4) Inoculation of 12 isolated strains of A. cincinnata to A. crassicarpa could effectively stimulate the formation of rhizobia nodule in the fine root of A. crassicarpa. Based on the nodule size and nitrogen fixing enzymes activity, the strains of J003, J004, J005, J008 and J012 were identified as the better strains. It provided the scientific information to isolate and utilize the native rhizobia strains in southern China.
In this paper, Phaeodactylum tricornutum was used to study the compensatory growth of micro-algae under phosphorus limitation. Five P concentration levels were set up at 1/20(P1), 1/10(P2), 1/8(P3), 1/4(P4), 1/2 (P5) of f/2 phosphorus media respectively, while f/2 culture media was served as control (Pck). P. tricornutum had been treated under phosphorus stress for 10 days, then, the nutrient stresses were removed by introducing f/2 media, the cultures were cultured for 16 more days with inoculative cell density (2.5×105cells·mL-1)and normal nutrients supply. Cell density, biomass, content of intracellular dissoluble carbohydrate and protein were measured during these two periods. It was found that cell density, biomass, content of intracellular carbohydrate and protein of P. tricornutum were lower than that of the control under phosphorus limitation (p<0.05). During the phosphorus recovery stage, cell density and biomass of P1、P2 and P3 treatments were higher than those of the control during prophase and metaphase (p<0.05), and their maximal average relative growth rates were 0.73、0.70、0.68 d-1 respectively, which were higher than that(0.55 d-1) of the control(p<0.05). The difference of cell density and biomass between P4 treatment and the control was not significant. The cell density and biomass of P5 treatment were lower than control significantly during prophase and metaphase (p<0.05). As the culture time increased, the difference of cell density、biomass、content of intracellular protein and dissoluble carbohydrate between the treatments and the control trended to be equivalent.
Ecological characteristics of Pinus kwangtungensis community at Yangdongshan-Shierdushui Nature Reserve, Lechang, Guangdong were studied by using the quardat method. The results showed that there are 152 species of vascular plants in 54 families in a sampling area of 2000 m2, including two species of national protected plant Pinus kwangtungensis and Fokienia hodginsⅡ. The Simpson and the Shannon-Wiener indexes of species diversity are 0.866 and 3.966, respectively. The dominant families are Theaceae, Lauraceae, Fagaceae, and Ericaceae, etc. Most of the floristic of family are Pan-tropical and North temperate distributing types, which showed the characteristics of transition from south subtropical to mid-subtropical elements. Analysis on the age structure of the population indicated that Pinus kwangtungensis is a decay population in this nature reserve, which has few young individual, and likely to be replaced by other latifoliate floristic species in the future. In order to protect the rare and endangered species, Pinus kwangtungensis, the most important thing is to protect the habitats, taking necessary measure if possible.
Effects of 5 kinds of antibiotics (chloramphenicol, ampicillin, streptomycin, kanamycin, gentamycin) at different concentrations on the growth of Isochrysis zhangjiangensis were studied, the axenic culture was obtained by mixed antibiotics. The results showed that:(1) There were differences among different antibiotics, chloramphenicol was the most susceptible antibiotic, the inhibition rate was 27.02% at the concentration of 50 μg·mL-1, more than 50 μg·mL-1 the inhibition rate was 80%. I.zhangjiangensis was not susceptible to ampicillin, streptomycin, kanamycin and gentamycin, there was stimulation at the lower concentration of the last three antibiotics. (2) Except for ampicillin at the concentration of 50 μg·mL-1, there were bacteriostasis effects of the other treatments. (3) Mixed antibiotics (500 μg·mL-1streptomycin,1000 μg·mL-1 kanamycin, and 50 μg·mL-1 gentamycin) were added to the culture medium by 4 combinations, the axenic culture was obtained, and there were stimulation on the growth of I.zhangjiangensis.
In April 2005 and November 2004, leave sulfer content of 116 garden plant species from 9 sampling sites in Shenzhen City, Guangdong was measured. Among the sampled plants, five species had a higher sulfer content over 10 mg·m-3, 12 species with a content from 5 to 10 mg·m-3, sulfer content for other species were lower than 5 mg·m-3. This result showed that these plants used for garden plantation can absorb sulfer from atmosphere and have a ability to remove sulfer from atmosphere. There is a positive correlation between SO2 concentration in the air and the sulfur content in the leaves of Hibiscus rosa-sinensis and Bougainvillea spectabilis willd, while a negative relationship between sulfur content in the air and the sulfur content in the leaves of Murraya paniculata. An obvious seasonal dynamics was observed in the sulfur contents of plant leaves, which is higher in early spring than autumn.
Nanomaterials have wide applications in the fields of medicine, environment protection and biology engineering. However, there is little study on the safety of nanomaterials in these applications. In this paper, Senedesmus obliquus, Chlorella ellipsoidea, Tetraselmis tetrathele are used as experimental materials to study the effects of Copper nanoparticles and Copper powder on the growth of microalge. The result shows that different size of Copper particles affected the growth of the microalgae differently. High concentration of Copper particles decreased the cell density and Chla contents of the microalgae, at of 2.0mg·L-1 concentration. Copper nanoparticle can restrain microalge growth completely. The endurance of Chlorella ellipsoidea is the weakest, most of Chlorella ellipsoidea under the 1.3mg·L-1 Copper nanoparticle were killed, the toxicity of Copper nanoparticle is significantly stronger than Copper powder(p<0.05), Senedesmus obliquus under the concentration of 33.3mg·L-1 and 333.3mg·L-1 Copper powder or Chlorella ellipsoidea under the concentration of 83.3mg·L-1 Copper powder can grow slowly, but the Senedesmus obliquus-1 Copper nanoparticle or Chlorella ellipsoidea at the level of 8.3mg·L-1 Copper nanoparticle and 833.3mg·L-1 Copper powder are almost killed completely.
An economic microalgae Haemalococcus pluvialis CG-11. was used as experimental materia1, and was cultivated in the BBM medium. The influence of the physical factors(temperature, illumination and pH)on growth, chlorophylla content, carotenoid content, dry weight and astaxanthin content of the green vegetative cell was studied. These experiments were carried out separately as three single factor tests when four temperatures (16℃, 20℃, 24℃ and 28℃), four illuminations (30 μmol photons m-2·s-1, 60 μmol photons m-2·s-1, 90 μmol photons m-2·s-1, 120 μmol photons m-2·s-1) and four pH (6.0, 7.0, 8.0, 9.0) were adapted. The results showed that H. pluvialis CG-11. grew well in the range of 20～24℃. The optimum light intensity was about 90 μmoL photons m-2·s-1, and neutral or alkalescent environment was suitable to H. pluvialis CG-11. growth at pH 8.0.
Metazoan zooplankton was sampled in the Henggang Reservoir, a hypertrophic reservoir in Guangdong Providence in May and November of 2005. The results showed that the zooplankton was characterized by a few species with low abundance. 4 species of cladocera, 4 species of adult copepod and 17 species of rotifer were observed. The total species number in May and November was 15 and 20, respectively. Rotifer was the most common group. The mean relative abundances of rotifer in May and November were 82.8% and 78.8% respectively. The dominant species were Asplanchna priodonta, Brachionus calyciflorus and Brachionus diversicornis. Copepod was a less common group; its mean relative abundances in May and November were 16.6% and 19.9%, respectively. Copepod was composed mainly by nauplⅡ and copepodid. Phyllodiaptomus tunguidus was the common species in adult copepod. Cladocera was the least common group; its mean relative abundances in May and November were only 0.6% and 1.3% respectively. Moina marocopa was the common species in this group. The composition, abundance and biomass of zooplankton had tempo-spatial heterogeneity in the reservoir. The mean abundance was 242.6 ind·L-1 in May and 138.5 ind·L-1 in November. The mean biomass was 0.912mg·L-1 in May and 0.317 mg·L-1 in November. The abundance and biomass of zooplankton tend to decrease from riverine to lacustrine, corresponding to the morphology and hydrodynamics of Henggang Reservoir. Compared with other waters, the high abundance of Asplanchna priodonta in Henggang Reservoir lead to higher biomass of zooplankton than other tropical eutrophic lakes, such as Xinghu Lake, which had similar zooplankton abundance. However, both abundance and biomass of zooplankton in Henggang Reservoir were far lower than those temperate eutrophic reservoirs.
The Sweetfish Plecoglossus is a kind of amphidromous fish endemic to east Asia. In order to determine taxonomic status of controversial Chinese sweetfish, mitochondrial cytochrome b gene sequences of 2 Chinese sweetfish from Liaoning and Guangdong were determined, combined with 9 GenBank-downloaded homologous sequences of the same genus from Japan and South Koea, 11. individual fishes were analyzed. Of the aligned 402bp nucleotide sequences, there existed 8 variable sites and 2 information sites. The contents of A+T and G+C of the gene are 51.4%, 48.6%, respectively. The ratio of transition verse transversional is 4.9. Kimura-2 parameter model based neighbour-joining tree indicated that Chinese sweetfish mosaic clustered with those from Japan and South Korea; no geographic structure within and between geographic populations were found, and genetic distance among different populations were equivalent, suggesting that they were closely related. According to the geographic distribution of abroad populations, they might belong to the same subspecies of P.altivelis altivelis. As Chinese sweetfish were nested within and genetic closely related to others, Liaoning and Guangdong sweetfish might belong to P.altivelis altivelis too. As no sequences from P.altivelis ryukyuensis were available to our study, this conclusion needs further research. Although no obvious genetic structure were found between Liaoning and Guangdong populations, it did not necessarily mean that all Chinese sweetfish belong to the same subspecies, as diversified coastal regions and habitats might exist in China, and sample size were limited and cytb is relatively conservative in this study. To determine the taxonomic status and populations structure of Chinese sweetfish, intensive and extensive population samples are needed using both mitochondrial and nuclear markers.
The avifauna and bird resources in mount Yangtai forest park of Shenzhen City were surveyed from January to December 2006. There are 105 species 79 genera 36 families and 14 orders which include 65 species of resident, 8 of summer types, and 33 of winter types. The avifauna is composed of 64 Oriental realmspecies (61.0%), 33 Palaearctic realmspecies (31.4%) and 8 Eurytopic species (7.8%). Among breeding birds, the rate of the Palaearctic species and Oriental species is 1:1.9, which showes more characseristics of Oriental realm.
In order to understand the cause of a fish killing accident occurred in a fish pond in Guangzhou in September 2006, fish acute toxicity test by Brachydanio rerio and root tip micronucleus test by Vicia faba were conducted with the contaminated water. 96h LC50 values of water samples from a chemical factory discharge area and the central pond were 1.69%, 23.95%, respectively; micronucleus frequencies were 27.8‰, 13.7‰ respectively. COD, BOD, oils, NH3-N, TP of both water samples were over-standard. The result showed that effluent of the chemical factory is the main cause of fish kills. Moreover, the effluent significantly enhanced the micronucleus frequencies, and increased the risk of potential mutagenicity.
In order to develop a method for counting the number of seawater fungi using culture medium flat, the samples were collected by different sampling methods with sterile syringes, organic glass hydrophore, and (then) were diluted by two liquids-seawater and freshwater-and incubated by five culture mediums-Potato agar (PA), Potato dextrose agar (PDA), Malt extract media (MA), Czapek-dox agar (CA) and Yeast extract peptone dextrose agar (YPD). Each medium was blended with seawater and freshwater, respectively. Results showed that 1) the amount of fungi in the same medium had no obvious difference with different sampling method; 2) there were hardly any fungi in PDA and PA mediums blended with seawater; 3) a few mildews developed in MA medium without obvious differences among the disposals of different liquids in sample dilutions or medium blend; and 4) the populations of fungi-mainly yeasts-in YPD and CA mediums showed differences among the different disposals, with the highest fungal loads observed in seawater YPD medium when seawater sample was diluted by freshwater. Thus, it demonstrated that the seawater YPD with sample diluted by freshwater was more suitable for counting fungi in seawater than other treatments in the present study.
The main soil types and soil water physical properties of water conservation forest were studied in the paper, in Baipenzhu Reservoir of Guangdong Province.Results showed that the soil types of horizontal zonality were lateritic red soil. there are 4 soil types including lateritic red soil mountainous red soil, mountainous yellow soil and mountainous shrub meadow soil in vertical zonality. The vertical sequence of mountain soil types is very distinctness.The bulk weight was about 1.338 g·cm-3. Contents of sand particles increased with altitude. Total porosities, non-capillary porosity and capillary porosity of the soil were 45%～50%,5%～9% and 35%～50% respectively. And non-capillary porosity was lower than capillary porosity. Under the different vegetation types, maximum water holding capability of soil were 30%～50%(be equivalent to 50～60 mm precipitation).Storage water capacity were 500～850 t·hm-2(be equivalent to 50～85 mm precipitation), that of shrub meadow soil was the highest and mixed needleleaf broadleaf forest was second and gully broad leaved forest was the smallest. Drainage capacity was about 130～180 t·hm-2 with that of shrub meadow soil was the highest and secondary broadleaved forest was the smallest. In Baipenzhu Reservoir of Guangdong Province, Drainage and Storage water capacities of the total forest areas were 62.69 and 316.29 ten thousand tons respectively. The effects and capabilities of dispel flood and compensate scanty of forest were very remarkable. Nevertheless, compared with the same forest types, the non-capillary porosity of water conservation forest in Baipenzhu Reservoir was relatively small than that of tropical and subtropical forests. The storage water capacities was smaller than that of the averages of forest types in Guangdong Province. Therefore, it is necessary to strengthen the conservation of water conservation forest and improvement the water conservation capacities of soil in Baipenzhu Reservoir.
The advance of the gas regulation function for an agro-forestry ecosystem, as one kind of the ecosystem services, including its pattern of receiving and releasing gas, the measure methods and relative factors, the effect for the agricultural managements and the changed atmosphere on agro-forestry ecosystem, is summarized.While being assessed, the function can be divided into three main parts(regulating C and O, absorbing or releasing CH4 and N2O, cleaning SO2), then the operational assessment formulas and parameters are proposed here. The gas regulation function for the agro-forestry ecosystem of Foshan in 2005 was assessed, the result was that valued 1.818 billion yuan(RMB).
There are diverse and dynamic social values for natural resources in coastal ecosystems. Conversely,these social values play a role in natural resource policy and management. Failure to address human dimensions goals has been seen in many coastal restoration projects. This review provides a discussion of 10 human dimensions goals. These include:to develope coastal recreation and tourism;to enhance community investment;to enhance educational opportunities;to protect or improve human health;to protect traditional,cultural and historic values;to enhance non-marked values and improve aesthetic values;to improve general market activity;to reduce property damage/enhance property value;to enhance transportation and commerce;to improve commercial fisheries and shellfisheries.
Nitric oxide is a bioactive and signal transmitting molecule that does not only directly exert physiological regulations on many life activities of plants such as germination, growth and senescence but also participates in the adapting of plants to environmental stresses working as the key signal carrier in defense response, such as drought stress, heat and chilling stress, salt stress, UV-B radiation, and ozone exposure, heavy metal, mechanical stress and disease resistance. Nitric oxide presents synergistic effects with phytohormones in physiological regulation and signal transmission, such as Ethylene, Abscisicacid, Saliccylicacid, indole-3-acetic acid and cytokinin, it is one of nitric oxide regulation mechanisms for plants to resorts to phytohormones to play its physiological functions. In present, it is an important study to investigate endogenous NO mechanisms for plants physiological regulation and signal transmission.
Based on the treatment methods of river pollution at home and abroad in last few years, this paper introduced pollution types and present condition of river sediment pollution, explained current severity of river pollution and the importance of repair. The main contents of river ecosystem repair were elaborated and initial understanding to the ecosystem repair was discussed in this paper. A few types of engineering technique of the ecosystem repair that are still in experimental stage were also introduced., The overall objective of river ecosystem repair is to recover a river system, and achieve the coexistence between human and river ecosystem.
Ecological effect of heavy metals in soil on microbes was studied in recent years, and this article summarized the main results. Microbial community structure, physiological and biochemical parameters were chiefly studied. For heavy metals pollution, especially high concentrations, microbial biomass and community structure had negative effects. However, microbial community structure is a complex system and corresponding methods are not very perfect, which brought difficulty to study. Pay more attention to getting simple and direct methods will help to solve this problem. Meanwhile, microbial physiological and biochemical parameters were favorable supplement to microbial community structure for heavy metals pollution, a good choice and appropriate arrangement of methods would be one of the helpful factors to study successfully.
The amount of resource consumption increased dramatically, increasing the pressure on the environment, is the further development of economic and social problems to be solved. From nation-building resource-saving and environment-friendly society's basic requirements, our province with the situation in the province speeds up the construction of a resource-saving and environment-friendly society and economic development. Promote economic growth, a fundamental change in our province is to achieve sustainable economic and social development, taking the lead to basically achieve socialist modernization only way. All ecological scientific knowledge together to create ecological civilization of the future, is the construction of a resource-saving and environment-friendly society.
