Table of Content

25 October 1992, Volume 3 Issue 4

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Articles

¹³C/¹²C ratio in tree ring of subtropical monsoon evergreen broad-leaved forest and CO₂concentration in atmosphere

Sun Guchou, Lin Zhifang

1992, 3(4):  291-295. 

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The ¹³C/¹²Cratio (δ¹³C) in tree ring of subtropical monsoon evergreen broad-leaved forest is determined in this paper. The average δ¹³Cis-28.53±0.84（n=5） for Aporosa yunnanensis from 1962 to 1983, -28.46±0.53（n=6） for Machilus chinensis from 1951 to 1984, -29.19±0.80 （n=6） for Cryptocarya concinna from 1951 to 1984 and -28.42±0.41（n=4） for Schirna superba from 1975 to 1984. Deviation of δ¹³Cfrom mean increases year by year, and calculated CO₂ concentration in atmosphere increases by 1.21 μl/Lyearly.

Internal and external nutrient cyclings ot poplar tree Ⅰ. Changes of nutrient storage in different parts of poplar tree before and after leaf fallen

Shen Shanmin, Yu Wantai, Zhang Lu, Lian Hongzhi

1992, 3(4):  296-301. 

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There are big changes of nutrient storage in different parts of poplar tree before and after leaf fallen in west Liaoning. Foliage is the major nutrient pool for the growing poplar tree. Its Nstorage is about two third of Nin total and Pand Kare more than one third. 60% of Nand 50% of Pin foliage are transferred to other parts of the tree during leaf fallen, with Kcontent almost unchanged and Ca,Mg and Si contents significantly increased.The trunk, branch and root are the reservoirs for N,Pand organic nutrients in winter,their storage of Nand Pis much higher than in sumer,but that of Kand Si is slightly decreased.Ca is almost unchanged and Mg is slightly increased.

Effect of temperature on pressure-volume analysis and water absorption of plant tissues

Guo Liansheng

1992, 3(4):  302-307. 

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One year old branches of 25 years old Norway spruce are taken from middle layer of canopy,and their water parameters are measured in a pressure chamber electrically controlled at 15,20,25,30 and 35℃. Pressure-volume analysis indicates that high temperature will induce the decrease of π₀ and π_p values, and different temperature has little effect in ROWC_πp and RWC_πp. Similar results are obtained using Hammel's method of gradually increasing pressure without temperature control. Tests of water absorption by plant tissues under 5-30℃ show that the water absorbing capacity increases with increasing temperature.

Eco-spatial distribution pattern of major pests and diseases of Camellia oleiferra

Hong Wei, Luo Shunyue, Chen Shunli, Chen Jianzhong

1992, 3(4):  308-312. 

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The spatial distribution pattern of seven pests and diseases of Camellia oleilerra is studied with methods of spatial distribution analysis. I'ts shown that Colletorichum camelliae, Agaricodochium camelliae and Enproctis pseudoconspersa are distributed evenly, Meliola camelliae, Seletrotum rolfsii and Parametriotes these are randomly, and Audraca bipnnetata is aggregativelly.

Population patterns of main communities on halomorphic meadow of Keerqin sandy land

Fu Xing, Nan Yinhao

1992, 3(4):  313-320. 

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The population patterns of main communities on halomorphic meadow of Keerqin sandyland and their formations are studied with methods of variance/mean, Greig-Smith's variance analysis for nested quadrats and Hill's pattern analysis. The results show that most of the species in Aneurolepidium ehinense and Arundinella hirta communities and all species in ecotone of these two communities are appeared as aggregated distribution. Its smallest scale is 0.01m², and the biggest is 6.4×6.4m². The minimum sampling size of grid should be less than 0.05×0.05m², and the optimal sampling size is 40.96m². The small scale pattern is caused by seed dispersion and nutrient reproduction, the middie scale one is caused by extension of stolon and long rhizome,and the large scale pattern is determined by total salt content of soil and soil pH.

Meteoro-ecological basis of rice chalkiness formation

Jia Zhikuan, Gao Rusong, Zhang Songwu

1992, 3(4):  321-326. 

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On the basis of field experiments with 19 rice rarities and various sowing dates in 13 places of whole country, meteoro-ecological basis of rice chalkiness formation is analysed in this paper. Results show that mean daily temperature in 15 days after rice full heading is the main factor affecting rice chalkiness. According to dynamic analysis of relationship between rice chalkiness and mean daily temperature in 15 days after full heading, it is known that rice chalkiness increases with raising temperature, the turn point being about 29℃(some difference among varities), and when the temperature closes to or exceeds 29℃, the chalkiness will be increased suddenly.

Measurement of damage and loss rates by rice leafroller and dynamic economic threshold model

Jiang Xuehui, Zhang Xilin

1992, 3(4):  327-332. 

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According to the laboratory observation and tests,the 5th instar larva of rice leafroller feeds on the highest amount of rice lcaves, its percentages being 68.42% and 71.6% respectively, as compared with the total fed amount by the 2nd and 3rd generations.The 4th instar larva is on the second place, with 18.30% and 15.78% of total fed amount by the same two generations. The results show that damage can be avoided by controlling the larvae before the 3rd instars.The relationship between different damage levels by larvae and yield losses is also analyzed.The results indicate that the 2nd generation of larvae mainly led to the decrease of 1000-grain-weight of rice and grain numbers per ear,and empty grain ratio is also affected. The damage by the 3rd generation of larvae is the increase of empty grain ratio and the fall of 1000-grain-weight.The leaves fed on by the 2nd generation are mainly the 4th and 5th leaves from the flag leaf. Mild damage by the 2nd generation can slightly increase rice yields. Leaves fed on by the 3rd generation are mainly flag leaf and the 2nd leaf(next to the flag leaf),the yield loss is heavily greater than that by the 2nd generation.The 3rd generation is the key generation to be controlled.Based on the experiments,the dynamic economic threshold model fitting for different generations and various instars has been obtained.

Energy conversion efficiency of pond ecosystem cultivated mainly with black carp

Wu Naiwei, Bian Wenji, Yao Honglu

1992, 3(4):  333-338. 

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The energy conversion efficiency (ECE)of pond ecosystem cultivated mainly with black carp(Mylpharyngdon piceus) at Suzhou suburb during 1985-1987 is analyzed. The results show that productions of black carp, common carp and bream carp are respectively accounted for 82.49, 78.03 and 79.34% of total energy output in the ponds with net production levels of 7.5, 11.25 and 25.15t/ha. The ECE of total energy input (including solar and supplementaty energies)converted into total energy output of fish is 0.19, 0.24 and 0.31%, and that of solar radiation energy converted into gross or net primary productivity is 0.76, 0.90 and 0.96% or 0.61, 0.72 and 0.77% respectively. The ECEof net primary productivity converted into net production of filtering fishes is 4.02, 4.63 and 5.27%, and that of supplementary energy converted into net production of fishes is 12.20, 11.33 and 11.74% respectively.Among the three ponds with different net production levels, that with net production of 15t/ha is an optimd:\PDF\.pdfal one.

Chemical behavior of heavy metals in rhizosphere Ⅲ. The rhizosphere effect of iron oxide transformation in soils and its ecological significance

Wang Jianlin, Liu Zhiyu

1992, 3(4):  339-345. 

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The present paper deals with the characteristics of iron oxide transformation in rice rhizosphere and its ecological significance in two paddy soils and two red soils after growing rice (Oryza sativa L.) in rhizobox experiment.It was shown that the contents of Feo, Fed and Fee and the ratio of Feo/Fed were lower in rice rhizosphere grown in paddy soils, and the same was true for Fee content in red soils.However, the amounts of Fed and Feo and the ratio of Feo/Fed were higher in rice rhizosphere cultivated in red soils. The Mssbauer spectroscopic results indicated that Q.S. increased, while Hi decreased in rhizosphere soils as compared to nonrhizosphere soils.Meanwhile,the Fe(Ⅱ) was more in rice rhizosphere grown in paddy soils, and there existed a new iron oxide mineral,i.e.maghemite in the rhizosphere in one of red soils.These findings suggested that iron oxide in rhizosphere microecosystem were activated as the results of the rice root's physiological activity and exudation, microorganism's action on the root surface and in the rhizosphere. In addition, the results of DTA-TGrevealed that the water retention capacity was higher in rhizosphere mieroecosYstem because of much more amorphous iron oxides and organic matter etc. in it. Rhizosphere effect of iron oxide transformation would affect: 1) adsorption and desorption of heavy metals and other pollutants; 2) bioavailability of soil iron oxides: 3) absorption of other nutrients such as Pand Mn by crops: 4) matter flow and the effective use of water and nutrients in the rhizosphere microecosystem; and finally the ciop growth and quality of agricultural products.

Nitrogen pollution from agricultural non-point sources and its control in water system of Taihu Lake

Ma Lishan

1992, 3(4):  346-354. 

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Field experiments and simulation tests show that the nitrate content in percolating water is positively correlated with the application rate of nitrogenous fertiIizers. The nitrogen specific load of agricultural non-point sources is obtained by statisticaltreatment, and the effective countermeasures for nitrogen pollution control from these sources are put forward.

Purification effect of slow rate land treatment system on organic pollutants in municipal wastewater from west Shenyang

Zhang Lishan, Yu Dianchen, Liu Hailing, Yao Jiabiao, Zhu Yan, Yin Zhaohua, Jiang Ping, Ke Fu

1992, 3(4):  355-362. 

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The purification effect of slow rate land treatment system (SR-LTS) on organic pollutants in wastewater and the residual rate of organic pollutants in soil are studied in this papter. It's shown that the sYstem has a good purifying effect on organic pollutants, most of the organic pollutants in wastewater being not detected in effluent and some priority organic pollutants in it being significantly decreased, among which, the concentrations of benzene, chlorobenzcne, 1,2-dichlorobenzene and 1,4-dichlorobenzene, phenol, dibutyl-phthalate and γ-666 are much lower than the recommended quality standard of surface water, The removal efficiency for most priority organic pollutants is 95-100%, and their residual rate in soil is 0-3%.

Benthic macroinvertebrate communities in Qinglong River and assessment of its water quality

Cai Xiaoming, Ren Jiuchang, Zong Zhixiang, Shang Yuchang, Yang Jianmei, Xu Chongren, Li Songgang, Ke Bing

1992, 3(4):  364-370. 

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In this paper, the kinds of benthos in Qinglong River,their quantity, distribution, composition and relation with environmental conditions are discussed, and the water qualityof the river is assessed by Beck, Gleason, Shannon, Simpson and other biotic indices. The results show that the BMCare chiefly composed of three kinds of benthos: aquatic insects, annelida and mollusca, and except specific transects, most parts of the river are of clean water.

Ecological effect of genetic engineered organism and its assessment

Wen Dazhong

1992, 3(4):  371-377. 

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Genetic engineered organism will be widely spread to natural environment with the development of genetic engineering,which will cause some environmental and ecological problems.In this paper, the potential ecological effects resulted from the application of genetic engineered organism in uncontrolled environment are reviewed, and a concept of genetic engineering ecology is proposed and discussed. Some suggestions for developing this research field are put forward.

Ecological planning and construction of economic development zone

Chen Tao, Sun Yongbin, Chen Wei, Shi Zuomin, Cui Qiu, Zhang Changhuai, Yong Deyi

1992, 3(4):  378-385. 

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This paper discusses the theories and methodologies of ecological planning and construction of Shenyang development zone, and the attention is focused on the paths of its coordinative development on economy and environment,which are: 1)Selecting optimized program of coordinative development, 2)Controlling thermoelectricity production and developing intensive heat supply and advanced technological industry with lower energy loss, 3)Economizing water resource and promoting utilization rate of water cycle, and 4)Implementing ecological management under direction of ecological principles.

Respiration of non-photosynthetic organs of Korean pine in spring

Yang Sihe, Wen Shiyun, Lin Jihui, Yin Zhongfu

1992, 3(4):  386-388. 

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This paper summarises the recent determinations in respiration of branch, stem and root of Korean pine in natural forests of Changbai Mountain. Patterns of their diurnal variations are similar. The peaks for branch,stem and root are respectively 2.25,3.36 and 0.92μmol.s^-1.m^-2at 12-16 o'clock.The variation of their respiration rate is closely related with ambient temperature.Q₁₀ value ranges from 1.5 to 3 for stem,and from 2.5 to 4 for root.

Relationship between Robinis pseudoacacia inoculated with vesicular-arbuscular mycorrhizal fungus and environmental condition

Su Fengyan, Xu Qingde, Li Weiguang, Lei Qidi

1992, 3(4):  389-391. 

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After inoculated with vesicular-arbuscular mycorrhizal fungus(VAMF),the growth of R. pseudoacacia,its infection ability and spore number are varied with soil condition and phosphorus application rate. In a pot experiment applicated with P, the host plant biomass and infection rate are higher when the total Pcontent in soil is 0.073%, but decreased markedly,when the Pcontent is up to 0.08%. More spores are found at 4-6cm depth of rhizosphere soil when the soil total Pcontent is 0.076%. In an inoculated drab soil, the infection rate of seedlings at 3 months old is 65.8%, but their biomass is not significantly increased. After forestation with inoculated seedlings on an infertile hilly land, the biomass of host plant at 5 months old is increased by 17.6%.