Chinese Journal of Applied Ecology

A preliminary research on the dieback of Abies fabri in Emei Mountain

Chen Chuying, Liao Liping

1992, 3(1): 1-8.

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In this paper, the dieback reasons of Abies fabri in Emei Mountain were interdisciplinarily investigated. Results show that the dieback of A.fabri trees is not significantly related to the aluminium content of soil and plant and destructive disease and insect pests, but is in close relationship with the development of swamp under the forest. The acid rain near Jinding, the top of Emei Mountain, can accelerate the growth of acidophilous moss and the development of swamp.

Effect of salinity on the growth and some eco-physiological characteristics of mangrove Bruguiera sexangula seedlings

Zheng Wenjiao, Lin Feng

1992, 3(1): 9-14.

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This paper deals with the effect of seawater salinity in sand culture medium on the shoot increments of viviparous propagules and some eco-physiological characteristics of Bruguiera sexangula (Lour.) Poir. seedlings. The results showed that: 1) When the salinity is higher than20‰, the shoot increment postponed and survival rate declined. 2) With increase in salinity (5—35‰), the height growth of seedlings decreased and leaf became smaller in size. 3) With increasing salinity from 5‰ to 35‰, the content of chlorophyll in leaves increased, whereas the content of soluble sugar in leaves decreased, but the soluble protein content was not significantly affected under different saline conditions. 4) The Cl content in leaves increased with increase in salinity. 5) As the salinity increased from 5‰ to 35‰, the transpiration intensity and stomatal conductance of leaves declined. The more adaptable range of salinity for B. sexangula seedling to grow was bellow 15‰ salinity.

Water balance in forestbelt and grassland

Zhu Jinwei, Wang Weihua, Fan Shixiang, Zhao Huanyin

1992, 3(1): 15-19.

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Variational regularity of various components of water balance in forestbelt, grassland and bareland is explored from view point of water balance. The distribution proportions of various components of water balance in forestbelt, grassland and bareland are respectively: 1) All precipitation100%; 2) evapotranspiration96.4%, 95.7% and 89.5%; 3) slope runoff 3.6%, 4.3% and 10.5%. Since the forestbelt consists of canopy and forestland, their compositions of various components of water balance and variational regularity were analysed. The effect of forestbelt on river runoff is discussed.

Study on field water regime in Western Liaoning Province Ⅰ Estimation of water balance for dryland crops and its regulation

Liu Zuoxin, Zhuang Jiping

1992, 3(1): 20-27.

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Field water balance for corn, sorghum and soybean is estimated. The influence of four treatments on various components of water balance equation and on water regulation is studied. Crop growth, yield response and water use efficiency (WUE) under different treatments are analysed. Results show that the field water storage capacity in treatment of plowing with winter irrigation (P+WI) is higher than those of plowing without irrigation (CK), plowing with spring irrigation(P+SI) and subsoiling (35—40cm)with winter irrigation (SL+WI). Plowing with winter irrigation can increase about 100mm of available water within lm cinnamon soil profile, which accounts for two thirds of total available water capacity. It is enough for main crops to resist severe spring and summer droughts and to increase water use effeciency(WUE). Plowing with winter irrigation (P+WI) together with subsoiling(SL) at interval of two or three years is the best combined practice.

Characteristics of natural contents of soil elements in Karakoram and West-Kunlun Mouatains of Qinghai-Tibet Plateau

Xia Zenglu, Li Senzhao, Lou Jinfa

1992, 3(1): 28-35.

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Natural contents of 23 elements in soils of Karakoram and West-Kunlun Mountains of Qinghai-Tibet Plateau are demonstrated in this paper. The characteristics of regional difference of soil elements in this region, the world and China are discussed using contrating and regional differential coefficient methods. Through correlation and principal component analysis, the relationship of intergrowth and association among soil elements and the cluster characteristics manifesting in soil types are revealed, and the correlation and differential characteristics of elements in soils of this region are further explained.

Effect of urease inhibitor hydroquinone on urea-N transformation in soil

Zhou Likai, Zhao Xiaoyan, Li Ronghua, Wu Guanyun, Wang Zhengping

1992, 3(1): 36-41.

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Based on incubation tests with labelled and unlabelled urea, this payer discussed the effects of hydroquinone on hydrolysis of urea, release and volatilization of ammonium, nitrification, denitrification and immobilization. It is concluded that hydroquinone not only delays the hydrolysis of urea and decreases the followed volatilization of ammonia, but more importantly, influences the process of further transformation of hydrolyzates of urea, increases the effective and sustained supply of urea-Nand decreases its total loss. The authors considered that in the study of urease inhibitors, objects in mind would not only be their direct effects, but also their influences on a series of processes of urea-Ntransformation. Only doing these, can we have a further understanding on the mechanism of their actions and give a fuller evaluation about their effects.

Index system and its weights for integrated evaluation of ecological agriculture

Wu Jianjun, Wang Zhaoqian, Hu Bingmin

1992, 3(1): 42-47.

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The significance of integrated evaluation of ecological agriculture (IEEA) and its research status at home and abroad were briefly discussed. The principles, index system and its weights for IEEAwere explored with an example of integrated evaluation on the practice of ecological agriculture at Ganshan Township of Deqin County.

Linear programming model and optimal exploitation strategies for livestock populations in alpine meadow ecosystem

Li Yiming, Wang Zuwang, Pi Nanlin, Zhou Li

1992, 3(1): 48-55.

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Empirical data on the menyuan horse farm grazingland in Qinghai of. China were used for linear programming model and optimal exploitation strategy study. The optimal population structure and optimal slaughter program of tibetan sheep, improved sheep and yak were put forward respectively. On grazingland where livestock populations are composed of tibetan sheep, improved sheep, yak and horse, improved sheep is a principal ingredient, amounts of yak and horse are kept at quantitatively lower limit, and tibetan sheep is totally eliminated. On grazingland where livestock populations are composed of tibetan sheep, yak and horse, tibetan sheep is a principal ingredient, and amounts of yak and horse are kept at quantitatively lower limit. Based on this program to manage the grazingland, the economic revenues can be increased. And these programs can lighten over intakes of livestock populations at the grazingland in winter and spring. The price analysises demonstrate that the current price system of livestock products need to be readjusted in Qinghai province.

Formative regularity of aboveground biomass of Agropyron and Elymus species

Kang Bowen

1992, 3(1): 56-61.

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The formative regularity of aboveground biomass of six species of Agropyron and Elymus in transition region from dry to desesrt steppe at Yanchi county of Ningxia is studied from the view point of population. Results show that the height growth of tested herbages is varied with seasonal changes. The growth and development of Elymus junceus are earlier and faster than those of other 5 species. The aboveground biomass and available nutrients of E. junceus change with time and reach to the peak in growing season, their maximal values in milky stage being141.3 and 86.0g·m^-2 respectively. The optimal utilization period of forage grasses is pointed out and suggestions on grass prodution are put forward.

Seasonal variation of two physiological types of Tortanus eggs from Xiamen waters and their temperature effect

Chen Feng, Li Shaojing

1992, 3(1): 62-68.

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The features of two physiological types of eggs laid by three species of Tortanus incubated in laboratory were observed during Jan., 1986 to Sep., 1987. It is shown that the eggs are covered by semitransparent case, and only T.derjuginii can lay a certain amount of non-viable eggs without case. In T. derjuginii, eggs with narrower case (≤15μm) and corrugating regularly are subitaneous ones, and those with wider case and corrugating irregularly are diapause ones. The viability of diapause eggs increases significantly with increasing case width. There is no morphological differentiation between subitaneous and diapause eggs in T.forcipatus, and it is noteworthy that no diapause egg in T.dextrilobatus has been occurred. It is suggested that the complicated variation in egg features of Tortanus might be attributed to the population genetic characteristics of producing two physiological types of eggs. Experimental result shows that the diameter and case width of eggs laid by T.dextrilobatus females collected seasonally from Xiamen waters are negatively and positively correlated with temperature respectively, after rearing the females under the laboratory condition for 12 hours and 6 days. It is suggested that the seasonal variation in a short period of 6 days could demonstrate the acclimation of Tortanus to the seasonal temperature fluctuating.

Effect of acidic water with addition of Al and Ca on early development and gill ultrastructure of silver carp

Jin Hongjun, Jiang Feng, Zhou Fengfan, Yang Rong

1992, 3(1): 69-75.

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The effects of acidic water with addition of Al and Ca on the embryo hatchability, fry survival and juvenile gill ultrastructure of silver carp (Hypophthalmichthys molitrix)were studied under laboratory conditions. All eggs were died at pH4.0 within24 hours. The increase in pHvalue was accompanied by a progressive increase in the hatchability of embryo exposed to pH4.5—6.0 and in the survival of fry with age in day from 5 to 15 exposed to pH4.0—6.0. The addition of 0.5mg Al³⁺/L not only further reduced the hatching of embryo, but also caused decrease in the survival of fry under acidic pH. The addition of 3.0mg Ca²⁺/L significantly increased the hatching of embryo under pH4.5 and 5.0. The added 2.0mg Ca²⁺/Lincreased the survival of fry to a certain extent at pH4.5, especially at pH5.0. The exposure to pH4.5 for 8 hours resulted in a severe damage of gill ultrastructure of juvenile; The addition of 1.0mg Al³⁺/L to pH4.5 water enhanced the syndrome; 5.0mg Ca²⁺/L added obviously mitigated the gill damage by acidic water.

Removal of pollution indicating bacteria in simulated stabilization pond systems

Wan Dengbang, Qiu Changqiang, Sun Xingxiang, Ma Ning

1992, 3(1): 76-80.

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In this paper, the removal efficiencies of total coliforms(TC), fecal coliforms(FC), fecal streptococcus(FS) and heterotrophic plate count(HPC) in simulated stabilization pond systems were studied. In the system treating10 t of wastewater per day, the densities of TCand FCdecreased by 4 orders of magnitude in9 days at 16℃. Bacterial enumeration in the system treating90 t of wastewater per day was conducted yearly. The densities of TCand FCin its effluent decreased by 2.5 and 3 orders of magnitude respectively. The effluent quality of the system, in terms of TC, reached approximately to Ⅲ degree of surface water quality standard. According to WHO's standard, the effluent quality, in terms of FC, was of "slight pollution". The results indicated that the two systems can effectively remove TCand FC.

A preliminary study on indication of bryophytes to air pollution (including acid rain) in southwest China

Gao Chien, Cao Tong

1992, 3(1): 81-90.

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Based on field investigations of species of epiphytic bryophytes and their distribution, frequency and coverage in one of most polluted areas in southwest China, the IAP (Index of Atmospheric Purity) was calculated. According to the results, the area investigated could be divided into three regions: 1) seriously polluted region, with 0—2 species of epiphytic bryophytes, IAP <10 and precipitation pH3—3.5; 2) polluted region, with 4—13 species of epiphytic bryophytes, IAP10—30 and precipitation pH4—5; and 3) basically no-polluted region, with more than19 species of epiphytic bryophytes, IAP40—90 and precipitation pH5.5—6.5. The experiments of effects of artificial acid rain on bryophytes growth showed that most of sampled species died within a half year under the acid rain with pH<3; 80% plants died in a year under the acid rain with pH4.5, and some species tolerating to acidity could grow well after a year under the acid rain with pH3.

Advance in simulation study on plant surface temperature

Ma Youxin, Zhang Keying

1992, 3(1): 91-95.

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Various simulation models for studying plant surface temperature at home and abroad since 1960's are mainly reviewed, which include empirical models of single and multiple regressions for partial surface of plant and micrometeorological models of single leaf and vegetation surface in steady and non-steady states. In addition, the existing problems in simulation modelling are discussed and the future main projects of simulation study on plant surface temperature are put forward.

A preliminary study on the control of Pieris rapae using Phryxe vulgaris

Sun Xuekui, Qiao Yaug, Zhou Shixiu, Chao Chienming

1992, 3(1): 96-98.

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In the integrated pest management of Pieris rapae, release of Phryxe vulgaris is an effective control practice. Field experiment shows that releasing30—60 pairs of tachinid flies per hectare, the average parasitized rate of Phryxe vulgaris is 6.8—8.7%, and the emergence rate of tachinid fly is 94.5% when releasing tachinid pupae.

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