Table of Content

25 July 1997, Volume 8 Issue 4

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Articles

Dynamics of population biomass and its density-density dependent regulation in alder and cypress mixed forest

Shi Peili, Yang Xiu, Zhong Zhangcheng

1997, 8(4):  341-346. 

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The biomass dynamics, density dynamics, and density-dependent regulation of biomass dynamics in alder and cypress mixed forest were studied at Yangting County of Sichuan Province. The results show that the biomass of alder accords with logistic growth in the past 18 years. and that of cypress conforms to power function growth in tile Past 20 years. The densities of alder and cypress show a negative power function growth in the past 18 years. In the mixed forest, density-dependent death is tile key factor determining the dynamic, of population biomass. The mean individual biomass is approximately related to the density by the -3/2 power law, and the self-thinning indices of alder and cypress are -2.33 and -3.97, respectively. The increase in mean individual biomass is greater than its decrease caused by population density reduction. As a result, the biomass of the two populations still increases during the period of density-dependent regulation, and the biomass of cypress population increases more vigorously.

Nutrient return and productivity of mixed Cunninghamia lanceolata and Michelia macclurei plantations

Wang Silong, Liao Liping, Ma Yueqiang

1997, 8(4):  347-352. 

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Baed on the field experiment and laboratory analysis, characteristics of ecological processes, such as nutrient return, uptake, and of productivity of mixed Cunninghamia lanceolata. and Michelia mncclurei plantations was investigated in comparison with pure C. lanceolata plantations. The results show that in the mixed plantations, the process of nutrient return was greatly enhanced, and the soil fertility and the productivity were raised significantly. For example, in a 15 years old mixed plantation. the branch and leaf litters were respectively twice and triple that in the pure one with the same age, and the litter was mainly corn of fallen leaf of M'macclurei, which decomposes much easier. As a result, the amount of nutrients returned to the soil in the mixed plantation was 2-3 times as much as that in the pure. The annual mortality of fine roots Of the mixed plantation. corresponding to 65.9% of aboveground litter fall, was about twice as much as that in the pure. Tile soil total N, NH₄⁺-N and available K contents of mixed plantation were increased by 64.3, 82.3 and 63.1 % respectively against the pure, soil porosity and water status were also improved. The productivity, measured as annual net production, of mixed plantation was increased by 52.7%. The ratio of return/uptake of five major elements in mixed plantation is twice as big a, that in the pure, indicating that the mixed plantation cycles its nutrients more efficiently, and sustains ifs productivity at a higher level with a minimal human support.

Effect or ecofactors on the growth and physiological characteristics of ginseng under forest

Liu Qijing, Dai Hongcai

1997, 8(4):  353-359. 

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With simulation experiment, the relationship between the phenology and growth of ginseng (Panax ginseng) under forest and some ecofactors, e. g., light. soil water and temperature was studied. Ginseng could grow best under conditions of 10～35% relative light intensity, 0.6～0.8 crown density and 30～45% soil water content. Its phenological process and growth were significantly affected by air temperature. It began to shoot when the air temperature was about 5℃, and its height growth became fast at about 15℃ in early May, and stopped at the beginning of June. It is advantageous for its growth through adjusting the niche conditions artificially.

Characteristics of gap in Korean pine broad-leaved forests in Changbai mountain

Wu Gang

1997, 8(4):  360-364. 

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Selecting gap disturbance as an important factor in sustaining the dynamic balance of Korean pine broad-leaved forests. the gap-forming manner. its distribution pattern, frequency of gap disturbance, and percentage of gap area in Korean pine broad-leaved forest were Systematically analyzed. The results show that most of the gaps in Korean pine broad-leaved forest are produced by 2 fallen trees, the frequency of gap is 0.92 hm²·yr^l, with a pened of 751 years, the size of expanded gap (EG) and that of canopy gap(CG) are 100～600 and 50～350 m², statistically centralized at 400～500 and 200～250 m², respectively, the area of expanded gaps and canopy openings average 141.82 and 67.63m², respectively.

Relationship between transpiration of shrubs under artificial Acacia mangium stand on hilly land of South China and its microclimate during wet season

Zhao Ping, Zeng Xiaoping, Yu Zuoyue

1997, 8(4):  365-371. 

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The diurnal patterns of transpiration of 6 kinds of understory shrubs in an artificial Acaia mangium stand which is common in Guangdong hilly lands are measured, and the relation between leaf transpiration and microclimatic factors such as light, temperature, heredity inside the feat is analysed. The shrubs have a similar diurnal variation of water consumption through transpiration. Among the shrubs measured. Rhodomyrtus tomentosa, a sunny species which can still pew well in shady environment, exhibits the highest transpiration rate. Another sunny species Litsea cubeba takes the second place. Other shrubs transpire modestly. The transpiration of all shrubs is negatively correlated with air humidity and positively with air temperature, full radiation, and photosynthetically active radistion in forest. Two ecophysiolo- gical factores, leaf temperature and stomatal diffusive resistance, are positively and negatively correlated with iran₈Piratbo, respectivesy.

Seed rain of Glycine soja

Li Jun, Zheng Shizhang, Qian Ji, Ren Wenwti, Ye Peihong

1997, 8(4):  372-376. 

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Studies on the temporal and spatial dynamics of Glycine soja seed rain and its relationship with meteorological factors show that there are three peaks in the course of pod exploding and seed dispersing, which are related to fine day (relative humidity), but little to temperature. The temporal distribution pattern of seed dispersal is depended on the exploding habit(exploding force) of pod and its location on the plant, but has no relation to wind direction(wind force≤rank 7 on the Beaufort scale).

Floral structure of different evolutionary types of Clycine L

Lu Jingmei, Liu Youliang, Li Xiliang, Hu Bo, Zhuang Bingchang, Zhu Changfu

1997, 8(4):  377-380. 

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Optical microscopic study shows that there exists a significant difference of floral structure between G. soja and G. max. For G. soja. its papilionaceous flower has two separated dragonbone petals, and tubular calyx has no organizational differentiation in anatomic structure. But for G. max, its two dragonbone petals are fully united, calyx consists of epidermis and unreg ular parenchymal cells, and small degenerated vascular bundles are distributed uniformly between parenchymal ce1ls,. It is suggested that the Glycine with highly evolutionary and symmetric papilionaceous flowers still maintains the structural character of its original flowers.

Optimized Pattern of agriculture-animal husbandry combination in Songnen Plain of Northeast China

Wang Jianguo, Liu Hongxiang, Meng Kai

1997, 8(4):  381-386. 

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Using the methodology of experimental ecology and with a currently adopted pattern of mono- culture as a check. the properties of productivity, nutrient cycling and balance, water use efficiency and energy in foe patterns of grain-grain-animal husbandry and grain-grass-anmal husbandry were studied. Models for sustainable development of agriculture in black soil regions were put forward, and their application prospects were discussed.

Structural similarity analysis on arthropod communities in pine forests

Tan Binglin, Ding Yong, Huang Mingdu

1997, 8(4):  387-390. 

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The comparative study on the structural similarity of arthropod communities in pure Pinus elliottii forest(P), mixed Pinus elliottii and Schima Superba forest (M₁) and mised Pinus elliottii and Acacia auriculaeformis forest (M₂) shows that M₁and M₂ have the similar arthropod communitites, but different from P. The structures of their canopy and shrub-herb layer are also dissimilar. The analysis methods used in this study can better reflect the structural similarity, dissimilarity and continuity of the arthropod communities in different habitats, and fuzzy clustering is more effective than systematic clustering.

Interactions between Nilaparvata lugens and Sogatella furcifera in their commensality

Wang Rongfu, Cheng Xianian, Zou Yunding

1997, 8(4):  391-395. 

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The interactive effects of Nilaparvata lugens and Sogatella furcifera in their commensality were studied with nylon net method. The results indicated that within 96 hours, the rest rates of these two kinds of insects on rice plants were gradually increased with time, finally reaching 21.5～25.0%, and there was no difference from each other. In pulse experiment, the female ratio and brachyptery of Sogatella furcifera were increased by 22.1 and 398.1%, and in removal experiment, the reproduction, female ratio and brachyptery of Sogatella furcifera were decreed by 8.8, 20.8 and 48.0%, respectively. Positive or negative effect of the interaction on reproduction, sex ratio and wing-form was observed and meaning and pattern of the interaction were also discussed in this paper.

Nitrogen nutrition of wheat Rhizoctonia cerealis

Tan Genjia, Ding Kejian, Ji Boheng, Chen Xiaolin

1997, 8(4):  396-398. 

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Ammolium sulfate, sodium nitrite, urea, tyrosine, serine, lysine, alanine, arginine, leucine, histidine, cysteine and proline were selected as Nsource to prepare Czapek medium and to study their effect on the growth of wheat R.cerealis. The results showed that leucine and proline were the most favorable amino acids for the growth of R.cerealiss. It could utilize nitrates. nitrites and ammonium stilts more effectively, but could not utilize histidine and lysine. The relationship between the nitrogen nutrition of R.cerealis and its development and the nutrition status of wheat plant were discussed.

Bait-searching behavior of Hormonia axyridis male imagoes

Zou Yunding, Chen Gaochao;Geng Jiguang, Ji Jin, Meng Qinglei, Sun Shihuang

1997, 8(4):  399-402. 

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The bait-searching behavior of Hormonia axyridis male imagoes was studied under two illuminations. The results showed that each of 5 feeding stimuli could arouse searching behavior from area-dissipated to area-concentrated type. The longer the feeding time, the bigger the giving-up time(GUT) which was determined by the size of the last consumed prey. The effect of illumination intensity on searching behavior was not significant.

Effect of livestock exclusion on abundance of grasshoppers on Aneurolepidium chinense and Stipa grandis steppes

Qiu Xinghui, Li Hongchang

1997, 8(4):  403-406. 

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Grasshopper abundance was compered between Aneurolepidium chinense and Stipa grandis steppes which were grazed and excluded from livestock. The abundance of Dasyhippus barbipes dominated on Stipa grandis steppe is 4～5 times as high as that of Chorthippus dubius on Aneurolepidium chinense steppe. After exclusion from livestock for 13 years, the total biomass of grasshopper is increased by 24% on Anearolepidium chinense steppe, and is decreased a little on Stipa grandis steppe. The livestock exclusion leads to changes in structure and compeition of grasshoppers. The abundance of Angaracris barabensis, Dasyhippus barbipes, Myrmeleote ttix palpalis and Oedaleus asiaticus is decreased and that of Chorthippus fallax, Mongolotet tix japonicus vittatus and Omocestus haemorrhoidalis is increased. The biomass of Calliptamus abbreviatus and Chorthippus dubius is increased on Aneurolepidium chinense steppe, but decreased on Stipa grandis steppe.

Ecological distribution and physiological adaptation to saline-alkali environment of C₃ and C₄ plants in Northeastern China prairie area

Wang Ping, Yin Lijuan, Li Jiandong

1997, 8(4):  407-411. 

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In this article, the photosynthetic types of 233 plant species in Northeastern China prairie area were indentified, and the relationships of their relative distribution with latitude, soil salt content and soil pHvalue were analyzed. Afurther study of physiological adaptation of several typical C₃ and C₄ grasses to saline-alkali environment was conducted. The result shows that among the identified 233 species, 144 species are C₃ plants, belonging to 94 genera of 28 families. and 89 species are C₄ plants, belonging to 55 genera of 17 famities. At high latitude districts, C₃ plants show a higher growth dominance. but al low latitude and saline-alkali districts, C₄ plants show a relatively dominant distribution, and especially in severely saline-alkali districts, C₄ plants become evidently dominant species. Tile difference of plant distribution depends on its adaptation mechanism to the saline-alkali environment: C₃ plants conduct a penetrative regulation through their accumulation of proline and other organic solutes, and C₄ plants do this through the accumulation of intra-vocuole ions. Compared with C₃ plants, C₄ plants show a better adapting capability to tile saline-alkali environment.

Enzymic activity of alkaline meadow soil with different grassland vegetations

Guo Jixun, Jiang Shicheng, Lin Haijun, Jin Laondng

1997, 8(4):  412-416. 

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In soils with different grassland plant communities. the activities of urease, phaphatase and celluase were in the order of A. chinense community > Calamaguostis elegies community > Puccinellia tenuiflora community> C. virgata community> Suaeda glauca community> alkaline spot; and dehydrogenase activity was in the order of C. epigeios community > A.chi nense community> C.virgata community> P.tenuiflora community> i community >alkaline spot. The temporal dynamics of urease, phaphatase and Celluase activities was parabolas in shape, the maximum in August and the minimum in June or October. The dehydrogenase activity reached the highest value in June, and the lowest value in October. Interrelated analysis showed that soil factors affecting urease activity were total N>Organic matter > soil unit weight > total P > pH; for phaphatase. were total P >organic matter > pH> total N > soil unit weight; for dehydrogenase were total N >organic matter> total p>soil unit weight > pH; and for celluase, were total N > organic matter > total P > pH > soil unit weight. The enzymic activities were gradually strengthened with increasing biomass, but the correlation between dehydrogenase activity and microorganism biomass was not obvious.

Fractal relationship between aboveground biomass and plant height of Aneurolepidium chinense population

Ma Keming, Zu Yuangang

1997, 8(4):  417-420. 

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By the use of the principles and methods of fractal geometry, the relationship between aboveground biomass and plant height of Aneurolepidium chinense population was studied. The results show that there is a good static fractal relationship between them, and the resulted fractal dimension is an efficient description of foe accumulation of aboveground biomass in each organ. Their dynamic fractal relationship shows that during the whole growing season, the increase of aboveground biomass has a selfsimilarily, being a fractal growth process, and the pattern of this increase is the fractal dimension D. Baed on these results, a fractal growth model of AAneurolepidium chinense population is established, which regards the mature grass as the result of the amplification of seedling growth.

Changes of land use pattern in eastern Shenyang

Chang Yu, Su Wengui, Gao Ramping

1997, 8(4):  421-425. 

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Historical aerial photographs from 1976 to 1989 and GIS technology were used to analyze the spatial pattern of land use and its changes in eastern Shenyang. The results showed that the mean patch size of coniferous forest and rice lands was increase, while the unirrigated land, deciduous forest and brush were decreased. Fractal dimension was slightly increased, indicating that the patch shape became complicated gradually. The indices of diversity and evenness were increased while the indices of dominance and contagion were decreed fm 1.6327 and 89.2022 to 1.3226 and 88.2744 respectively, which indicated that the spatial distribution of patches trended to be uniformed, and that the status of aggregate distribution of patches would be decentralized with time. The cause of these changes of land use pattern in eastern Shenyang was also explained.

Energy conversion and nutrient cycling in grassdyke-fish pond ecosystem

Wang Dejian, Xu Qiand, Liu Yuanchang

1997, 8(4):  426-430. 

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The simulation study on the energy conversion and nutrient cycling in the grndyke-fish pond ecosystem shows that for this ecosystem, the photo-utilization rate of forage is 0.83%, and the conversion efficiency of feed energy into fish is 7.3%. Comparing with grain for fish farming, the efficiency of forage is 1.6 times greater. The conversion efficiency of feed nutrients (CEFN) to fish is 16.8, 32.3 and 2.0% respectively for N, Pand K. The recovery of nutrients in fishpond sediment is 23.4% for Nand 56. 1% for P, and the CEFNto hog carcass is 20.5, 33.6 and 4.6%, respectively for N, P and K. The recovery of nutrients in the feces is 36.4% for N, 63.8% for P and 39.4% for K. The conversion efficiency of fed energy and nutrients to fish is higher in compound system than in single one.

Economic benefits of rice-fish-duck complex ecosystem——a preliminary study

Zheng Yonghua, Deng Guobin, Lu Guangmin

1997, 8(4):  431-434. 

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The study slowed that in a rice-fish-duck. co-growth ecosystem，the rice production was increased by above 10%, with an additional increase of 1036. 5 kg·hm^-2 fish and 238.9～489.3 kg·hm^-2 adult duck. The total N, P, K and Organic matter contents of paddy soil were increased by 27.9, 44.3, 6.5 and 28.2%, respectively, and the insect pest of rice was also decreased. This ecosystem largely increased the output and economic benefit, being a well recycled and highly effective agro-ecosystem.

Influence of medium pH on population growth and reproduction of Brachionus calyciflorus

Wang Jinqiu, Li Deshang, Luo Yibing, Wang Fang

1997, 8(4):  435-438. 

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With the method of population accumulation culture, the population growth and reproduction of rotifer(Brachionus calyciflorus ) were observed in pH 3.5～11.5 media with an increment of 1 pH unit. The results show that rotifer population grows faster at pH6.5～8. 5 and fastest at pH 8.5, indicating that in this pH range, the instantaneous rate(r) is fast and the density is the maximum. At pH5.5～9.5. the r value is positive. but at pH3.5～4.5 and 9.5～10.5, it is negative, i. e.. the population shows a negative growth. Rotifer can survive at pH3.5～11.5, but the optimum pH for population growth is 8.5. where the rotifer shows a maximum reproductive sped. and the absolute egg density is the highest (132 cells·ml^-1 ). The relative egg density is the highest at pH9.5, 2～4 times larger than that at other pH values.

Effect of selenium and fulvic acid on seed germination of wheat and its physiological properties

Xu Yun, Wang Zijian, Wang Wenhua, Peng An

1997, 8(4):  439-444. 

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The effect of selenite and soil-extracted fulvic acid (FA) on seed germination of wheat and its growth and that of FA on inhibiting the toxicity of selenite are studied by ed germination test. The results show that FAand low concentration Na₂SeO₃ can promote the seed germination of wheat and its seedling growth, while high concentration of selenite reduces the germination rate of seed. its vigor and α-arnylase activity, and the growth of seedling markedly. FA has a definite effect on the inhibition of selenium toxicity.

Allelopathic effect of tomato

Zhou Zhihong, Luo Shiming, Mou Ziping

1997, 8(4):  445-449. 

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The methods of bioassay, pot experiment and water culture were adopted to explore the allelopathic effect of tomato on several plant acceptors. The results showed that tomato had an autotoxidity effect. Its aquatic extract could significantly inhibit the seedling growth of Cucumis sativas, Raphanus sativa, Lactuca sativa, Brassica perkiensis, Brassica oleracea, but its volatiles had no significant effect on that of Phaseolus aureus, Brassica perkiensis, Lactuca sativa, and tomato itself. After the tomato seedlings were transplanted for 40 days, their root exudates had a significant inhibition on the growth of Cucumis sativas, but no effect on Lactuca sativa. It is suggested that the autotoxidity effect of tomato is one of causes obstructing its continuous cropping, and tomato should be avoided to intercrop with Lactuca sativas in wateror shed culture.