Basic ecological characteristics including water body,soil and biology and their correlativity were systematically studied by field investigation on the sampling belt from estuary of Lishui River to Muping Lake.The results showed that: (1) Current velocity decreased almost linearly from the estuary to central lake.Water depth was high in estuary and low in central lake.Other indices in water body such as transparency,NO3-N,NH4+-N,total N and total P were maintained fluctuation within a range.(2)The soil in central lake contained higher organic matter,N and P contents,while relatively lower soil organic matter,N and P contents were found in estuary.(3) Water plants could not survive in estuary,and central lake was the main regime for the growth of water plants,where had higher species richness,biomass and biodiversity.(4) The favorable hydrological and soil environments such as appropriate water flowing and fertile soil provided suitable conditions for the growth of water plants,and high current velocity and infertile soil in the central lake were the main reasons explaining for the inexistence of water plants.Correlative analysis showed that mutual effects existed among water physiological and chemical characteristics,soil physiological and chemical characteristics and biological characteristics,and that current velocity was the decisive or key factor in regulating the changes of ecological characteristics.
Titanium dioxide (TiO2) was applied as photocatalyst to treat the ceftriaxone sodium solution with high pressure mercury lamp and fluorescent dysprosin lamp as ultraviolet and simulated sunlight source respectively.Ultraviolet spectroscopy was used to determine the concentration of reactant during the degredation of ceftriaxone sodium.The effects of light source,photocatalyst dosage,irradiation time,the existence of electron acceptors and other ions on ceftriaxone sodium degradation were investigated in details.The results indicated that after 5 hours,the degradation ratio of ceftriaxone sodium reached to 93.4% and 73.8% by photocatalytic oxidation with UV and simulated sunlight irradiation under the conditions of initial ceftriaxone sodium concentration 500 mg·L-1 and TiO2 concentration 2.5 g·L-1 and 2.0 g·L-1 separately.The results also showed that the addition of electron acceptors could enhance the photocatalytic efficiency significantly while the presence of some inorganic ions like HCO3-,SO42-,Cl-might lead to the decrease of the photocatalytic efficiency remarkably.
Zhangheyuan Nature Preserve is located in the southwest of Nanzhang county,Hubei province.Based on the field investigation and known data,the distribution of national key preserved wild plants in this area was studied.The results showed that there were 21 species of national key preserved wild plants,among which 3 species belonged to the first class(including Ginkgo biloba,Taxus chinensis and Taxus chinensis var.mairei) and 18 species belonged to the second class(Cephalotaxus oliveri,Picea neoveitchii,Fagopyrum dibotrys,Cercidiphyllum japonicum,Glycine soja,Ormosia hosiei,Liriodendron chinense,Magnolia officinalis,Magnolia officinalis ssp.biloba,Emmenopterys henryi,Zelkova schneideriana,Canvptotheca acuminate,Cinnamomum camphora,Phoebe bournei,Phoebe zhennan,Toona ciliate,Torreya fargesii and Phellodendron chinense).Each accounts for 45.65%,37.50% and 47.37% of the species distribution in Hubei province,respectively.The characteristics of the national protected plants in Zhangheyuan Nature Preserve were concentrative distribution,small population,severe fragmentization and distinct elevation distribution.Some effective conversation suggestions also had been put forward in this study.
Blooming of Chattonella marina has caused massive fish kills and considerable economic loss in recent years along the southern coast of China.However detailed toxic mechanisms involved in these fish kills still remain uncertain.Hemolytic toxins produced by C.marina has been suggested to be the major causative factors for the observed fish kills.The extraction of hemolytic toxins from Chattonella marina Hong Kong strain(CMHK) was investigated in laboratorial conditions.The haemolytic process of the extraction from CMHK to red cells was observed with microscope.Hemolytic toxins were separated with TLC.The results showed that optimal condition for breaking the cell walls of algae by ultrasonic was 400 w of power for 15 minutes at 4℃,and the hemolytic toxins synthesized by CMHK could consist of at least 4 components,which included one lipid and three glucolipid fractions.The hemolysin toxins could break the red blood cells of rabbits(RBCs) through its hydrophobe group linking to the surface of RBCs.These findings will be of great significance for the future studies on the toxic mechanisms.
A preliminary test on the toxic effects of abamectin+chlorpyrifos,EC,chlorpyrifos and lambda cyhalothrin on the Semanotus bifasciatus (Motschulsky) was carried out in Beijing Forestry University Forest Protection Laboratory in March 2007.The results showed that all the 3 pesticides could kill the adults of Semanotus bifasciatus (Motschulsky),but the effect of the chlorpyrifos was the most obvious,and the mortality rate in 5 days reached to 94.7%.Then field experiments were done with the Beta cypermethrin,abamectin+chlorpyrifos,E.C and profenofos in Mushi Forest Farm,Shandong province in 2008.The results indicated that the Beta cypermethrin 2000 times liquid was the most effective and economical,and that the pesticides did not change the attractive effect of trap log.
The fresh feces of badger (Meles meles) were collected from the dam of Jing-Hang Canal near Yangzhou,and five DNA extraction methods including amylum-subsiding method,preprocess-organicsolvent extraction method,NaCl modified method,GuSCN-SiO2 method and QIAamp DNA Stool Mini Kit method were used to extract the DNA from them.The results showed that the highest amplification success rate was in the amylum-subsiding method.In this study,fecal sample was lysed rapidly with digested solution,then DNA was extracted using chloroform/phenol after incubation with proteinase K,following by purification to remove numerous potential PCR inhibitors.The mitochondrial DNA control region and 5 microsatellite loci were amplified.showing that the mitochondrial DNA control region sequenced successfully.Our results suggested that DNA extraction based on this method was reliable.
Projction dimension reduction and optimaztion of dimentional data about the distribution of Grapholitha funebrana in U.S.A plum orchard were done based on projection pursuit(PP) technology.The result showed that spatial distribution of Grapholitha funebrana and directions and direction-levels were closely related on U.S apricot and plum.The larvae of Grapholitha funebrana aggregated on the centre and external of U.S plum,with much more larvae on the east and north.The density of Grapholitha funebrana forecasted in directions and direction-levels showed that the forecast and reality were in high optimization.The errors due to variables could be reduced by projection pursuit technology.Besides,the estimate could be much more accurate when there were more variables;and the tiny gap could show a very high weight value.
442 species of butterflies have been found in Nanling National Nature Reserve,some of which are new records and new species in China.For them,339 species inhabite in evergreen broad-leaved forest;369 species in mountain evergreen broad-leaved and coniferous mixed forest,and 71 species in mountain top mossy evergreen broad-leaved forest.The numbers of butterflies belonging to the Oriental region,the Palearctic region and spreading in different flora are 360,48 and 34,or accounting for 81.45%,10.86% and 7.69% of the total,respectively.The butterfly fauna in Nanling is very similar with that in Fujian province,sharing 77.27%,indicting that these butterflies in those two sites have the same origin and evolutionary process.In Feb.,2008,the ice storm caused severe damages to the forest ecological systems of Nanling located from 500 to 1 000 m above the sea level.The population density of all kinds of butterfly decreased badly.The number of butterflies living in forests from 700 to 800 m above the sea level represented only 23 percent of which from 1 100 to 1 200 m above the sea level.Generally,the population density of all kinds of butterfly was really low;the decreasing rate was about 90% compared with the past years.The number of Papilionidae population in the surveyed sites was only 37.5% of that found in the past common years.
Mosquito fish,an invasive species,was introduced into mainland China in 1927 and entered Guangzhou during 1960s.The diel feeding rhythm of mosquito fish taken from Ming Lake,an artificial lake in Jinan University in summer,2007 was investigated in this study.Population structure of mosquito fish in summer was very complex,consisting of female,male and larvae fish groups.These feeding groups had different feeding rhythm in this season.Female feeding rhythm showed two peaks at 10:00 and 22:00.The second peak was the highest,and the food in the fish gut was 11.70±11.60 mg and feeding index was 190.22±155.61 at that time.Larvae fish feeding rhythm had two peaks at 6:00 and 18:00,and the highest one peaked at 6:00,when the food in the gut was 1.08±1.09 mg and feeding index was 128.44±105.49.Male fish feeding rhythm had a single peak at 14:00,at which the food in the gut was 0.71±0.96 mg and feeding index was 71.80±107.65.Different feeding rhythms among these three feeding groups could reduce the intra-specific competition.
The relative fatness of 102 tiger frog (Hoplobatrachus rugulosus) in Jinhua,Lin'an and Lishui,Zhejiang province was studied from June to October in 2007.The results showed that there were no significant differences in different seasons,sexes or ages in the relative fatness(P>0.05).The indexes of mass/length(Kwl) showed more significant differences between summer and autumn,adult and subadult(P<0.01),but different sexes had no significant difference(P>0.05).Compared with the relative fatness,Kwl was more sensitive than K in statistics,and this suggested that two indexes should be used together in Anuran relative fatness research.The results are useful for the wild Anuran's conservation.
Fish can affect the quality of water in reservoirs.Tilapia is one of the main aquaculture fishes in southern China.This study evaluated the effect of tilapia on water quality using enclosure experiments in Dajingshan Reservoir.The results showed that fish increased the mean total nitrogen(N),total phosphorus(P) and chlorophyll a content by 42%,129% and 347%,respectively.It was likely that fish excretion increased nutrient loading and enhanced phytoplankton growth.While phytoplankton biomass increase would lead to a decrease of water transparency.The results indicate that the bottom-up control on phytoplankton through fish excretion is stronger than the top-down effects through fish grazing.
In China,water pollution resulted from heavy metals has drawn significant attention.It is very urgent for us to adopt some effective strategies to control or treat the heavy metals in polluted water.It has been shown that using biosorption of microalgae in the treatment of heavy metals is low cost,convenient and efficient.In this paper,the status of water pollution and basic characteristics of heavy metals in water were introduced.Toxic effects of heavy metals on phytoplankton,aquatic animals,and human beings were also reviewed.Besides,three major methods commonly used in the treatment of heavy metals in polluted water were presented and compared.And then,the advantages of microalgal biosorption on heavy metals were summarized;some underlying mechanisms involved in the biosorption as well as the influence of environmental factors on the biosorption were presented and discussed.Finally,prospects and direction for the development of microalgal biosorption on heavy metals in the near further were put forward.
Water resource is abundant in China,with the total water storage of 2812.4 billion m3;besides,the biodiversity in China is ranked in the third place around the world.Nevertheless,fish community diversity in many water areas is decreasing in China because environmental pollution has become much more serious;hydrophytes in waters have been destroyed;many lakes have been diked;and fish catch has been exorbitant.Research on fish community diversity can be used to show the change of ecosystem structure and function stability at the community level.This paper reviewed the perspectives of fish community diversity.The advantage and disadvantage of different sampling methods in fish community studies were also discussed,including observing under water,pop net,drop net,gill net,electrical catch,trawl net,purse net,settled net,etc..The different indexes of fish community diversity were introduced.Effects of environmental factors on the fish community were also presented,such as the distance from the lake bank,water depth,hydrophytes,bottom style,dissolved oxygen,etc..The relationship between fish community diversity and ecosystem function was also discussed.This review can provide some theoretical references for the research on fish community diversity and thus improve correlative studies.
Diel vertical migration (DVM) of zooplankton,normal migration (ascent at dusk and descent at dawn) in a common sense,is an adaptive behavior against the variations of environment.This behavior not only determines the vertical habitats of zooplankton,but also indirectly affects their horizontal distributions and life history traits,and thereby plays a key role in the survivorship and recruitment of zooplankton population.Main hypotheses for DVM mechanism include: the light-driving hypothesis;the predator-avoidance hypothesis and the energy and resource utilization hypothesis.The predator-avoidance hypothesis has been demonstrated by a large number of experiments.Two temporal scales underlie the theoretical models on DVM: one is for the researches on the short-term behavioral mechanism and the other for the long-term life history strategies.With the advances in the experimental technology and the development of theory and modeling tools,these researches on the two temporal scales are getting integrated in a unified framework.
Plants can assimilate,absorb and fix the organic matters,inorganic matters and heavy metals in the aquaculture wastewater,and thereby they can reduce the TP,TN,TSS,COD and BOD of the aquaculture wastewater.At the same time,plants can provide eligible conditions for the metabolism of microbes and other organisms as they can transmit oxygen in the waters via their prosperous aerenchyma and roots.The constructed wetland can purify aquaculture wastewater via the physical,chemical and biological actions of plants,microbes and matrixes.The application of plants in aquaculture wastewater treatment is the basis for the sustainable and ecological aquaculture.This paper summarized the progress in algae and higher plants in aquaculture wastewater treatment in recent years.
