Table of Content

10 May 2008, Volume 27 Issue 05

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Articles

Soil carbon storage and CO₂ flux under different vegetation types in Qilian Mountains.

CHANG Zong-qiang;FENG Qi;SI Jian-hua;LI Jian-lin;SU Yong-hong

2008, 27(05):  681-688 . 

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Based on field survey, field-orientation observation and laboratory analysis, this paper studied the soil carbon storage and CO₂ flux under natural forests (Picea crassifolia, Sabina przewalskii, and alpine shrub), artificial larch forest, rangeland, and cropland at the paired plots with same elevation, slope direction, and soil type in the National Nature Reserves of Qilian Mountains. The results indicated that the soil organic carbon (SOC) content under natural forests, rangeland, cropland and larch plantation was 59.45-84.7, 78.30, 13.51 and 43.25 g·kg^-1, mean SOC density was 15.96-19.95, 17.74, 10.63 and 15.97 kg·m^-2, and mean SOC turnover time was 27-36, 25, 23 and 33 years, and the soil CO₂ flux under P. crassifolia, S. przewalskii, alpine shrub, rangeland, cropland, and larch plantation was 584.03, 517.63, 601.00, 796.89, 281.75 and 569.92 g C·m^-2·a^-1, respectively. Under the same vegetation type, SOC content and density decreased with soil depth inereasing, while SOC turnover time was in adverse.

Interspecific association of trees species in Quercus wutaiensis communities in Ziwu Mountain related to quadrat size.

LI Gang; ZHU Zhi-hong;WANG Xiao-an;GUO Hua

2008, 27(05):  689-696 . 

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A series of parameters including χ² test, interspecific association coefficient (AC), Person’s correlation coefficient (r), variance ratio (VR), and total number of species pairs which do not exist synchronously in a given quadrat size (Na) were used to study the interspecific associations and their elationships with quadrat sizes of the dominant tree species inQuercus wutaiensis communities in Ziwu Mountain of Loess Plateau. Based on the 2×2 contingency table and species abundance data, the effects of different quadrat size on these parameters were examined. The χ²test and AC nalyses showed that significant interspecific associations only appeared at the quadrat sizes of 25 m² and 50 m². Person’s correlation analysis displayed that there were significant interspecific associations at the quadrat sizes from 25 to 200 m², and the r value changed steadily at the quadrat sizes from 25 to 100 m². However, VR didn’t disclose the overall associations of multi-species at different quadrat sizes. The fluctuation of Na was the smallest when the quadrat size was 100-200 m² and the number of quadrats was 40-80. In order to reveal the relationships between species pairs more exactly, the quadrat size should be 100 m², and the number of quadrats should be 45. Under such conditions, the interspecific associations of the tree species inQ. wutaiensis communities in Ziwu Mountain of Loess Plateau could be measured objectively.

Restoration capability of alpine meadow ecosystem on Qinghai-Tibetan Plateau.

ZHOU Hua-kun;ZHAO Xin-quan;ZHAO Liang;LI Ying-nian;WANG Shi-ping;XU Shi-xiao;ZHOU Li

2008, 27(05):  697-704 . 

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The alpine meadow ecosystem on Qinghai-Tibetan Plateau has been degrading in -recent- years. Based on the long-term observation data about boveground net primary productivity, yearly precipitation, yearly mean air temperature, and the mean precipitation and air temperature in growth season collected from Haibei Alpine Meadow Ecosystem Research Station, this paper assessed the restoration capability of alpine meadow ecosystem in Haibei Area of Qinghai-Tibetan Plateau， aimed to provide scientific information and suggestions to sustain the development of alpine meadow ecosystem in this area. The results indicated that the aboveground net primary productivity of the ecosystem was more related to the dynamic changes of precipitation and temperature. The effect of precipitation and temperature on the net primary productivity was obvious only in present year, but not in the following years. Therefore, the alpine meadow ecosystem appears to have a higher restoration capability. By comparing the restoration capability between the alpine meadow ecosystem in study area and the four natural ecosystems in Israel and South Africa, it was found that the alpine meadow ecosystem was superior to the four natural ecosystems. To-sustain-the alpine meadow ecosystem, it is important to utilize the alpine grassland resources efficiently and to restore the degraded grassland timely.

Characteristics of biomass allocation of Dicranopteris dichotoma.

LIU Ying-chun^1,2;LIU Qi-jing¹;WANG Hong-qing¹;MA Ze-qing^1,2;XU Wen-jia^1,2

2008, 27(05):  705-711 . 

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From biological aspect, this paper studied the basic characteristics of biomass allocation of Dicranopteris dichotoma in typical hilly area with granite and purple sandy shale. The results indicated that the total biomass of D. dichotoma had less difference among the sampling sites, but the allocation of above and under-ground biomass was different, being mainly affected by environmental conditions. The aboveground biomass increased, while underground biomass decreased from the top to the bottom of the hill. Among the models of D. dichotomabiomass allocation, those with the product of crown breadth (D₁·D₂) and plant height (H₁) as independent variable were best fitted. The rhizome ofD. dichotoma mainly distributed in 0-4 cm soil layer, with most at around 1 cm depth. However, sandy soil deposition made the rhizome distributed deeper and in stratification. The length of living rhizome had a negative correlation with soil depth, and a linear correlation with root biomass. In mountainous area of South China, D. dichotoma is an economic and effective plant for water and soil conservation, and thus, its protection and application should be enhanced.

Natural regeneration of Taxus chinensis var. mairei and its seed dispersal by frugivorous birds.

DENG Qing-shan;ZHU Qiong-qiong;LU Chang-hu

2008, 27(05):  712-717 . 

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The spatial pattern of naturally regenerated population of Taxus chinensis var. mairei and its seed dispersal by frugivorous birds in Xianyu Mountain of southern Anhui Province were investigated from September to December, 2006. The results showed that the naturally regenerated population was clumped distributed on the hillside at the altitude of >540 m and with an area of about 1.1 hm², and grew with bamboo (Phyllostachys heterocycla) in mixture. There were 1.331individuals of T. chinensis var.mairei in total, including 1 167 individuals of seedlings with the height less than 30 cm, which accounted for 87.68% of total. The population was of slowly increasing type, and resented a clumped spatial pattern. Ten species of frugivorous birds were found to feed on T. chinensis var. mairei seeds, of which, Urocissa erythrorhyncha, Hemixos castanonotus and Hypsipetes mcclellandii were the most important predators and dispersers. They swallowed the whole seed, digested the red aril, and excreted the seed intactly. One or two seeds could be found in each fresh feces of the frugivorous birds. The dropping seeds under parent trees were eaten by insects or decayed. Seeds under parent trees could germinate, but death rate was greatly high. Our study suggested that frugivorous birds played important role in T. chinensis var. maireiregeneration. They could transport the seeds to the new sites profitable for the seed germination and further growth.

Ecological distribution of Cyanophyta communities on saline-alkaline soils in Songnen Plain.

ZHANG Wei; FENG Yu-jie

2008, 27(05):  718-722 . 

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With three typical saline-alkaline grassland soils in Songnen Plain as test objects, this paper measured their electrical conductivity, iron composition, and organic carbon, and compared the nitrogenfixing Cyanophyta comunities on the soils. The results showed that the physicochemical propertie of test soils and the Cyanophyta communities had their own characteristics. There were seven genera of nitrogen-fixing Cyanophyta, with filamentous cyanobacterium as the dominant. The Cyanophyta had a slightly different distribution on the three saline-alkaline soils, with the richest species on moderate saline-alkaline soil, and different species had different selection of habitats. Songnen Plain is a kind of fragile ecosystem, and its soil physicochemical characteristics and algal distribution are relatively special. Therefore, its ecoprotection and management should be enhanced.

Effects of temperature and substrate type on germination of Nitraria sphaerocarpa.

LI Qiu-yan¹;FANG Hai-yan²

2008, 27(05):  723-728 . 

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This study examined the effects of temperature, seed size, and substrate type on the germination of Nitraria sphaerocarpa. The results showed that either on filter paper or on sand substrate, the germination percentage, mean germination time, and germination rate index of N. sphaerocarpa were significantly affected by temperature, but not by seed size. On sand substrate, the germination percentage was higher at constant temperature of 25 ℃-35 ℃ and alternating temperature of 20 ℃/30 ℃, but lower at 10 ℃. The mean germination time was decreased with increasing temperature. On filter paper and sand substrate, the base temperature, optimum temperature, and maximum temperature of germination were 9.0 ℃, 25.3 ℃ and 45.2 ℃, and 4.8 ℃, 34.1 ℃ and 45.0 ℃, respectively. This extended temperature range forN. sphaerocarpa germination and the ability of N. sphaerocarpa to germinate rapidly suggested the high potential of N. sphaerocarpa to establish on sandy land.

Effects of soil water condition on membrane lipid peroxidation and protective enzyme activities of Pinus sylvestris var. mongolica seedlings.

SUN Yi-rong^1,2; ZHU Jiao-jun¹;KANG Hong-zhang³

2008, 27(05):  729-734 . 

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Mongolian pine (Pinus sylvestris var. mongolica) has been widely planted on sandy soil in northern region of China, but a decline in forest growth and even death has occurred in the earliest Mongolian pine plantations on Keerqin sandy soil located at Zhanggutai of Liaoning Province. Aiming to study the decline problem of Mongolian pine, a water gradient experiment was conducted to assess the effects of soil water stress on the membrane lipid peroxidation, osmotic substances, and protective enzyme system of twoyear old P. sylvestris var. mongolica seedling’s needles. The water gradient experiment was designed with reference to the annual mean precipitation of main sites on Keerqin over 50 years. The results showed that with the aggravation of drought stress, the SOD activity of the seedling’s needles increased after an initial slight decrease, while POD activity had gradually increased. The osmotic substances including soluble sugar (SS), soluble protein (SP) and proline (Pro) presented distinct ascending trend with drought stress, and the ascending range was the largest for SS and SP, e.g., the contents of SS and SP at -16.18 bars were 1.8 and 2.4 times than those at -4.50 bars, respectively. The MDA content, plasma membrane permeability (RC), and rate of O₂^-_· increased gradually with decreasing soil water potential, and the increasing range of the rate of O₂^-_· was the largest. The above results suggested that P. sylvestris var. mongolica could endure and adapt to drought stress in some extents through physiological and biochemical mechanisms, especially through increasing osmotic substances. However, the cellular tissues at the soil water potential of -16.18 bars were un-reversibly damaged due to the accumulation of O₂^-_· and the aggravation of membrane lipid peroxidation.

Responses of hybrid Napiergrass “Guimu1” to different topdressing rate of fertilizer N in cluster-peak depression of karst region.

XIAO Run-lin; SHAN Wu-xiong;FANG Bao-hua; LIU Xiao-fei; WANG Jiu-rong

2008, 27(05):  735-739 . 

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In a field experiment in karst cluster-peak depression of karst region, this paper studied the responses of hybrid Napiergrass (Pennisetum purpureum) ‘Guimu1’ to different topdressing rate of fertilizer N. The results indicated that under N topdressing, the plant height, tiller number, hay yield, coarse protein content, and watersoluble sugar content of ‘Guimu1’ were higher than CK. The plant height was significantly higher under high N topdressing; the tiller number and hay yield were significantly higher under medium N topdressing; and the coarse protein and water-soluble sugar contents were significantly higher in all N topdressing treatments then CK. N topdressing was beneficial to the plant growth and nutrient accumulation of ‘Guimu1’, but the annual net income of high N topdressing was lower than that of CK. Among the three topdressing rates of N, only medium rate of N topdressing had a significantly higher annual net income than CK.

Effects of mercury and chlorimuron-ethyl on soil urease activity and its kinetic characteristics.

YANG Chun-lu¹;SUN Tie-hang²;HE Wen-xiang³

2008, 27(05):  740-744 . 

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With incubation test, this paper studied the effects of mercury (Hg), chlorimuronethyl, and their combination on the urease activity and its kinetic characteristics in meadow brown soil and black soil. The results showed that g had negative effects on the activity,K_m,V_max, and V_max/K_m of soil urease, with the affecting range of 39%-98%, 46%-74%, 90%-98%, and 20%-68%, respectively. The relationship between soil urease activity and HgCl₂ concentration could be described with logarithmic equation, and the K_m, V_max, and V_max/K_m of soil urease were linearly negatively correlated with HgCl₂ concentration. Chlorimuron-ethyl could activate soil urease activity, possibly because of the enhancement of initial velocity of urease reaction. The combination of Hg and chlorimuron-ethyl also had negative effects on the urease activity and its kinetic characteristics, with the affecting range similar to that of Hg, but poorer correlations were observed with the pollutants concentration. The addition of chlorimuron-ethyl made the interaction between Hg and soil urease more complicated.

Degradation of soil polycyclic aromatic hydrocarbons by immobilized microbes.

HU Guang-jun^1,2;LIANG Cheng-hua¹;LI Pei-jun²;ZHANG Hai-rong²;XU Hua-xia²;JU Jing-li²;YAO De-ming²

2008, 27(05):  745-750 . 

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By using four immobilized microbial agents TB02, TB07, TBB03 and TBB08, the degradation of soil phenanthrene, anthracene, pyrene, chrysene and benzo(a)pyrene was studied, and fitted with Michaelis-Menton and Monod dynamic models. The results showed that all the agents had the ability of degrading test polycyclic aromatic hydrocarbons (PAHs), among which, TB02 was most effective. Under the action of TB02, the degradation of test PAHs was faster, halflife was the shortest, while the cost was lower. On the contrary, TB07 required more time to fully display its degradation ability. When the phenanthrene, anthracene, pyrene, chrysene, and benzo(a)pyrene had an initial concentration of 20 mg·kg^-1, their degradation rate by TB02 after 42 days was 84.32%, 85.24%, 82.59%, 43.75% and 62.25%, and that by TB07 after 133 days was 95.00%, 95.24%, 90.93%, 74.82% and 72.20%, respectively. Through the comparison of the half-life of test PAHs, it was indicated that the degradability of these PAHs was decreased in the order of henanthrene>anthracene>pyrene>benzo(a)pyrene>chrysenemodel.

Population diversity of soil bacteria along the Qinghai-Tibet railway by DGGE analysis.

LI Lu-bin¹; LIU Zhen-jing¹;ZHUANG Cai-yun;ZHOU Jin-xing;YANG Kai²;HAN Ji-gang³

2008, 27(05):  751-755 . 

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Soil samples were collected from ten different-altitude sites along the QinghaiTibet railway, and the community DNA was extracted from the soil samples directly. Bacterial 16S rRNA gene fragment was amplified by nested PCR from the community DNA. Soil bacterial population diversity was analyzed by 16S rDNA-PCR-DGGE. The results showed that the bacterial population diversity was abundant in this high altitude area. Vegetation type was an important factor influencing the bacterial diversity and population similarity in this area, and the altitude acted as a minor impact factor. The bacterial population diversity of soil samples with similar vegetation type decreased with the increasing altitude.

Influence of bovine serum albumin on the adsorption equilibrium between Cu²⁺ and δ-MnO₂

ZHANG Li-na¹;MA Zi-chuan^1,2; LIU Jing-ze²

2008, 27(05):  756-761 . 

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This paper studied the adsorption equilibrium between Cu²⁺ and δ-MnO² in solution in the presence of bovine serum albumin (BSA) to be beneficial to understand the environmental chemical behavior of Cu²⁺. The results showed that in the presence of BSA, the change pattern of Cu²⁺ adsorption onto δ-MnO₂ with pH was a typical Sshape curve. BSA made the adsorption leap of Cu²⁺ moved to high pH range, and the degree was related to the adding order of BSA, i.e., Ⅳ (BSA added first)> Ⅲ (Cu²⁺ and BSA added simultaneously)≈Ⅱ (Cu²⁺ added first). The Cu²⁺ adsorption in the presence of BSA was fitted Langmuir adsorption isotherm, and the saturated Cu²⁺ adsorption quantity decreased with increasing BSA concentration and changed with the adding order of BSA, i.e., I (without BSA)>Ⅱ≈Ⅲ>Ⅳ. In addition, the maximum capacity of Cu²⁺ onto δ-MnO₂ increased with increasing temperature. The adsorption of Cu²⁺ onto δ-MnO₂ was reversible at pH 3.0 but irreversible at pH 5.0. BSA had no influence on the reversibility of Cu²⁺ adsorption onto δ-MnO₂.

Physiological and biochemical properties of Bruguiera gymnorrhiza seedlings under cadmium stress.

TAO Yi-ming;CHEN Yan-zhen; LIANG Shi-chu;LIANG Yang-lin

2008, 27(05):  762-766 . 

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In a sand culture experiment, Bruguiera gymnorrhiza seedlings were treated with Hoagland nutrient solution containing different concentrations of CdCl₂. After two months later, the lipid peroxidation, chlorophyll content, and activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) and their isoenzymes in the seedlings were analyzed. The results showed that Cd induced the peroxidation of membrane lipid, resulting in a significant decrease of chlorophyll content. Cd mainly affected the activities of the POD isoenzymes with negative ions and higher mobility, and 1 mmol Cd·L^-1 could significantly inhibit the activities of CAT isoenzymes RC₁ and RC₂ in the root. It was suggested that the analysis of POD isoenzyme in B. gymnorrhiza leaf and of CAT isoenzyme inB. gymnorrhiza root could be used to monitor the Cd pollution of mangrove.

Effects of cadmium stress on the seedlings growth and physiological characteristics of different wheat cultivars.

WANG Yun;CHEN Yao;QIAN Ya-ru;DU Yin-ping;ZHANG Yan;DONG Ying

2008, 27(05):  767-770 . 

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In a hydroponic experiment, four wheat cultivars (Yumai 4, Yangmai 15, Baofeng 7228, and Ningmai 13) were used as test objects to study the effects of cadmium (Cd) stress on their seedlings growth and antioxidant enzyme system. The results indicated that under Cd stress, the plant growth, chlorophyll formation, and nitrate reductase activity were inhibited significantly, catalase (CAT) and peroxidase (POD) activities decreased dramatically, while H₂O₂ and malondialdehyde (MDA) contents increased. Such responses differed with test wheat cultivars, and Yangmai 15 had a higher Cdtolerance than the others.

Effects of soil cadmium pollution on Allium sativum seedling growth and root antioxidant system.

ZHAO Hu¹; ZHENG Wen-jiao²; Chen Jie¹

2008, 27(05):  771-775 . 

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With soil culture experiment, this paper studied the effects of Cd on the seedling growth and root antioxidant system of Allium sativum roots. The results showed that under lower concentrations (<5 mg·L^-1) of Cd, the average fresh and dry mass per plant, root length and aboveground height increased slightly, root vigor, soluble protein content, SOD, POD and CAT activities increased obviously, and root antioxidant enzyme system still kept balance, reflecting in the little difference of root MDA content with the control. However, when the Cd concentration was higher than 5 mg·L^-1, the average fresh and dry mass per plant, root length and aboveground height decreased markedly, the increments of root vigor and soluble protein content abated, the balance of antioxidant enzyme system was broken, and the MDA content increased obviously. The study also showed the absorbed Cd by A. sativum was mainly accumulated in roots, and only small amount of Cd was transfered to the leaves.

Effects of continuous exposure to deltamethrin on the acetylcholinesterase activity in blood serum of tilapia.

CHEN Jia-zhang¹; LENG Chun-mei²;HU Geng-dong¹;QüJian-hong¹

2008, 27(05):  776-779 . 

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This paper studied the acetylcholinesterase (AChE) activity in blood serum of tilapia exposed to 1.0, 2.0, 3.0, 5.0, and 10.0 μg·L^-1 of deltamethrin at water temperature 23 ℃-27 ℃. The results revealed that the AChE activity was （2.75±0.21） U·ml^-1 at 23 ℃ and （2.73±0.26） U·ml^-1 at 27 ℃, with the variation range of -12.0% to 13.1% and -11.0% to 14.2%, respectively. After ten days exposure to >2.0 μg·L^-1 of deltamethrin at 25 ℃±1 ℃, the AChE activity was inhibited, and the inhibition rate was surpassed 40% at the 20th day of exposure. The highest inhibition rate (62.3%) was observed on the 25th day of exposure to 5 μg·L^-1 of deltamethrin. The fluctuation of water temperature from 23 ℃ to 27 ℃ had no significant effects on the AChE activity, while high concentrations (≥2.0 μg·L^-1) of deltamethrin could inhibit the AChE activity, and the inhibition rate was increased with exposure time.

Pollinating insect species and their foraging behaviors on Medicago sativa.

LIU Hong-ping; LI Xiao-xia;WANG Xiao-juan

2008, 27(05):  780-784 . 

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Medicago sativa is a kind of typical allogamic plants, and mainly depends on the pollinators such as bees for its seed production. In this paper, the pollinating insect species and their foraging behaviors on M. sativa at the Zhangye station of Hexi Corridor were investigated. There were 22 pollinating insec species belonging to 4 orders and 11 families, among which, native bee species Megachile abluta, M. spissula, Xylocopa valga, Andrena parvula and Anthophora melanognatha were the main pollinators. M. abluta, M. spissula and X. valga were of unipeak type with diurnal foraging activities trom 11:30 to 15:30, while A. parvulaand A. melanognatha were of double-peak type with diurnal foraging activities on 9:30-11:30 and 16:30-18:30, indicating a complementary relationship among the pollinators. The main pollinators had significant differences in their tripping frequency and landing time, and their foraging behaviors were correlated with their body sizes.

Hydroacoustic measurement of spawning stocks of Megalobrama hoffmanni in Qingpitang reach of Xijiang River.

¹Pearl River Fishery Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510380, China;²Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China

2008, 27(05):  785-790 . 

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With Simrad EY60 split-beam echosounder, the spawning stocks of Megalobrama hoffmanni in Qingpitang spawning grounds were observed from April to May, 2006. The echoes from M. hoffmanni were identified by its distinctive characteristics, and the ancillary information from gill nets sampling and tethered fish measurements of target strength were also important. The results showed that the aggregation and lingering behaviors of M. hoffmanni were obvious. During the period of aggregation, the average swimming speed of M. hoffmanni was 0.24 m·s^-1, being lower than the corresponding value of ther fishes (0.49 m·s^-1). The target strength of M. hoffmanni in situ ranged from -33.8 to -52.3 dB, with an average of -42.2 dB. From April 27 to May 1, M. hoffmanni migrated to Qingpitang spawning grounds gradually, and the peak density appeared. In May 1, the number of spawning fish was about 98 000, and the total mass was 48 tones. Our results indicated that the stationary acoustic observation method for M. hoffmanni identification and discrimination was effective.

Effects of water temperature and light intensity on the behaviors of Pelteobagrus vachelli fingerlings.

WANG Wu; LI Wei-chun; MA Xu-zhou; HE Li; YE Fei-fei

2008, 27(05):  791-796 . 

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The observation on the behaviors of Pelteobagrus vachelli fingerlings under varied water temperature and light intensities in a tank showed that the individual fingerlings had special selection between white and black substrates. At water temperature 30 ℃ and 20 ℃, the fingerlings swam more actively when the light intensity was lower than 15 lx, but the swimming activity reduced when the light intensity was higher than 15 lx. The duration the fingerlings stayed on white substrate decreased when the light intensity was less than 5 lx, and the decrement was larger at 30 ℃ than at 20 ℃. When the light intensity was higher than 5 lx, this duration tended to be less changeable. There were 4 types of schooling patterns, i.e., aggregating, scattering, resting, and group swimming. The formation of resting pattern was due to lower water temperature (7.0 ℃-9.0 ℃), while aggregating pattern was caused by high light intensity. The fish showed swimming in schooling under downy light intensity (1.2-209.0 lx), and the fish school dispersed when the light intensity was lower than 1.6 lx.

Biodiversity of vespid wasps in spatial and temporal dimensions in northern Zanjan Province of Iran

Roohollah Abbasi¹;Maedeh Mashhadikhan²;Mehdi Abbasi³;Bahram Kiabi⁴

2008, 27(05):  797-802 . 

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Vespidae is one of the major families of Hymenoptera with more than 115000 described species. In the present paper, Simpson and ShannonWiener diversity indices, Simpson, Camargo, Smith and Wilson, and modified Nee evenness indices, and richness index based on rarefaction method were adopted to study the biodiversity of vespid wasps in spatial and temporal dimensions in northern Zanjan Province of Iran. In spatial dimension, Zanjan and Gilvan showed the highest and the lowest species diversity, evenness, and richness, respectively; while in temporal dimension, 16 July-6 August showed the highest species diversity and richness, and 18 May-27 May and 23 August-2 September showed the highest and the lowest species evenness, respectively. Significant differences in species abundance between localities of study area were observed by Kruskal-Wallis nonparametric test.

Remote sensing estimation models of wetland vegetation LAI in Sanjiang Plain.

JIN Hua-an^1,2; LIU Dian-wei¹;WANG Zong-ming¹;SONG Kai-shan¹;LI Fang¹; YANG Fei^1,2;DU Jia^1,2;LI Feng-xiu^1,2 

2008, 27(05):  803-808 . 

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By using the normalized difference vegetation index (NDVI) extracted from CBERS-02 data and the leaf area index (LAI) data obtained from field measurement, this paper analyzed the relationships between the NDVI and the LAI of total samples of meadow, marsh vegetation, shrubs, and islanded forests of the wetland vegetation in Honghe Nature Reserve of Sanjiang Plain. The linear and non-linear regression models between NDVI and LAI of different wetland vegetation types were established, and the spatial distribution of LAI in the Honghe Nature Reserve was mapped. The results showed that it was unsatisfactory for the whole samples to estimate the LAI, with the correlation coefficient being only 0.523. After the total samples were divided into four vegetation types, i.e., meadow vegetation, marsh vegetation, shrub and islanded forest, the correlation coefficients and the estimation accuracy were improved evidently. Cubic-equations-were found to be the best in the different forms of the regression models for retrieving the LAI of wetland vegetation by using CBERS data, with the R² value being 0.723, 0.588, 0.837, and 0.720, respectively. It was indicated that with the combination of field-measured data and remote sensing-based vegetation classification, CBERS-02 data could be used for the larger scale estimation of the physiological parameters of wetland vegetation.

Cityscape pattern of Shenyang based on QuickBird image and GIS.

HU Jian-bo^1,2; LI Xiao-yu¹;CHEN Wei¹;HE Xing-yuan¹

2008, 27(05):  809-815 . 

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By using QuickBird image and GIS, this paper studied the landscape pattern and patch properties within the ThirdRing Road of Shenyang City. In the study area, rural landscape and urban landscape coexisted, with most patches in urban landscape. The under-construction patches, either in area or in patch number, occupied a considerable proportion, illustrating that Shenyang is in the phase of rapid urbanization. The study area could be separated into five concentric circles with 2 km radius interval, taking city center as the circle center. Each class land-use type was approximately concentrated in one of the circles, and the sequence starting from the inner was road<old residence<park and square=public facility=railway<industry=under-construction=water<all rural lands=road protection forest. The residence distance from the center was in the order of tower≤old multi-storey≤mixture≤new multi-storey≤villa. Road area was larger than road protection forest area, while the later had larger quantity of vegetation. Road protection forest promoted the greening rate of transportation landscape effectively. Rural area was smaller than urban area, and most of shadow was in urban landscape; while rural landscape had larger quantity of vegetation, which could affect the greening rate of study area significantly. The greening rate of four major classes of landuse〖KG*2/3〗type was residence (23.3%)<industry (28.92%)<public facility (32.32%)<park and square (73.83%), while the shadow rate was residence (26.22%)>park and square (16.33%)>public facility (13.41%)>industry (8.73%). Among the residential classes, old multi-storey residence had a greening rate of 19.76%, which was larger than the regular towers (10.31%), but smaller than the rest seven classes. Garden class had larger greening rate than regular class when they were of the same height type, but not for shadow rate. As for the four garden classes, the sequence of greening rate was tower<mixture<new multistorey<villa, while the sequence of shadow rate was in adverse. For the four regular classes, the sequence of greening rate was tower<new multistorey<mixture<villa, while the sequence of shadow rate was inverse.

Biodiversity and forest ecosystem health: Some key questions.

CHEN Liang¹;WANG Xu-gao²

2008, 27(05):  816-820 . 

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Ecosystem health in relation to biodiversity is a major subject in ecology. Firstly, it is biodiversity that makes ecological processes operating. Secondly, biodiversity is the material base of ecosystem for its ability in resisting disturbances and in adapting to environmental changes. The maintenance of ecosystem health relies on the biodiversity, productivity, and regeneration of the system. Thirdly, the assessment of ecosystem health depends on our knowledge in ecological processes, while the biodiversity and its function in ecosystem is the base of ecological processes. This paper summarized the relationships between biodiversity and forest ecosystem health in terms of the heterogeneity of forest ecosystem, inter-species relationships and key species, invasion of exogenous species, and “green desert”, and discussed the related problems in China.

In this paper, the characteristics of wetland degradation in China were introduced from the aspects of functional area loss, material and energy imbalance, structure breakage, and ecological function impairment, and the causes of the degradation were summarized from natural and human’s aspects, respectively. Three evaluation systems for the wetland degradation were recommended, and related protection measures were put forward.

AN Na;GAO Nai-yun; LIU Chang-e

2008, 27(05):  821-828 . 

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In this paper, the characteristics of wetland degradation in China were introduced from the aspects of functional area loss, material and energy imbalance, structure breakage, and ecological function impairment, and the causes of the degradation were summarized from natural and human’s aspects, respectively. Three evaluation systems for the wetland degradation were recommended, and related protection measures were put forward.

Effects of elevated ozone on anti-oxidative system in plants.

RUAN Ya-nan^1,2;HE Xing-yuan¹;CHEN Wei¹; XU Sheng¹;SUN Yu¹

2008, 27(05):  829-834 . 

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As a major greenhouse gas, ozone concentration is increasing in troposphere. The elevated ozone is highly toxic to plants, which can cause visible foliar injury and increase the level of active oxygen in plant, but also, can stimulate the activity of plant anti-oxidative system. To study the effects of elevated ozone on the anti-oxidative oxygen system in plants is an important topic in researching the responses of plants to global change. In this paper, the research advances in toxic mechanism of elevated ozone to plants, resistance responses of plants to elevated ozone, and effects of CO₂ and ozone on plant anti-oxidative system were summarized, which could be helpful to improve the understanding about the effects of elevated ozone on plants.

Research advances in biosurfactant remediation of hydrophobic organicscontaminated soil.

MA Man-ying^1,2; SHI Zhou¹;LIU You-shi²

2008, 27(05):  835-840 . 

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In this paper, the hazards of hydrophobic organic contaminants (HOCs) accumulation in soil environment and the advantages of applying biosurfactants in the remediation of HOCs-contaminated soil were briefly introduced, the main remediation mechanism of biosurfactants, i.e., promoting the dissolution, desorption, and biodegradation of HOCs was elucidated, and the effects of the type and concentration of biosurfactants and the physical and chemical properties of soils on the remediation were analyzed. The prospects of the application and development of biosurfactants in the remediation of HOCscontaminated soil were also discussed.

Research advances in habitat suitability index model.

JIN Long-ru^1,2; SUN Ke-ping³;HE Hong-shi^1,4;ZHOU Yu-fei^1,2

2008, 27(05):  841-846 . 

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As a method of habitat evaluation, habitat suitability index (HSI) model has been widely used in the programming and evaluation of land management. In this paper, the development and application of HSI model in wildlife habitat evaluation were summarized, with the focus on the establishment of HSI model by 3S technologies and the current situation in habitat evaluation by integrating HSI model with other ecological models. The applications of various statistical approaches in evaluating and testing HSI model, as well as the limitations and pitfalls of HSI model, were discussed, and the perspectives of HSI model in wildlife habitat evaluation were approached.

Affecting factors and countermeasures of eco-city construction in Daqing.

ZHAO Shu-kui¹;TAN Shu-mei¹;Wang ji-zhen²

2008, 27(05):  847-852 . 

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Daqing is a typical resourceoriented city and the biggest petrochemical base in China. Aiming at the three problems in the construction of ecocity in Daqing, i.e., desertification, alkalinization and deterioration of grassland, serious environmental pollution by petrochemical production, and neglect of the optimization of urban spatial districts, this paper analyzed the advantages and disadvantages possessed by Daing City, and put forward corresponding countermeasures and concrete steps. Firstly, owing to the serious desertification, alkalinization and deterioration of grassland, it’s necessary to restore and reconstruct grassland ecosystem to highlight the characteristics of Dading City as a grassland-oriented city. Secondly, being a precious resource of Daqing, swamp is needed to be strictly protected, and in the meanwhile, an artificial-natural integrated swamp ecosystem is suggested to be set up to give full play to the multiple service functions of the swamp. Thirdly, because of the serious environmental pollution by petrochemical production, environmentfriendly oil field project is expected to be launched to meet the need of an ecocity. Fourthly, as the optimization of urban opening spatial system is the key to establish eco-city, optimized measures are needed to be taken to build ecohighways, eco-squares and eco-residential districts, to install scenery road lamps, and to construct environment-friendly buildings.

Disease-, insect pest-, and weed control of rice production in China by using biodiversity technology.

GAN Xiao-wei¹; LUO Shi-ming²

2008, 27(05):  853-857 . 

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Disease, insect pest, and weed are the major constraints on rice production. The practice of using biodiversity to control these constraints is in accord with the idea of sustainable agricultural development. In recent years, the studies of using biodiversity technology to control rice disease, insect pest and weed grew up quickly in China. This review summarized the research achievement and progress in China on the disease-, insect pest-, and weed control by using resistance gene resources in rice breeding, integrative riceduck farming, organic rice farming, and bio-ingredients. Suggestions for further study on this subject were proposed. The use of rich genetic resources of rice for resistance varieties by traditional breeding program, and of molecular biology technique should be strengthened. Further study on the use of ecosystem diversity for disease-, insect pest- and weed control of rice production, and on the compatibility or antagonism of various biodiversity methods would be very helpful to develop a technical package for sustainable rice production.

Adsorption of polycyclic aromatic hydrocarbons in seawater by mangrove leaf litter.

LU Zhi-qiang^1,2;ZHENG Wen-jiao³;MA Li⁴

2008, 27(05):  858-861 . 

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Under laboratory conditions, this paper studied the adsorption of different concentration (40, 400 and 4 000 μg·L^-1) polycyclic aromatic hydrocarbons (PAHs) including low molecular weight acenaphthylene, phenathrene and chrysene and high molecular weight benzo［g,h,i］perylene in seawater by the leaf litters of Kandelia candel and Avicennia marina at different decomposition status. The results showed that at the same concentrations, the total amount of test PAHs adsorbed by the K. candel and A. marinaleaf litters had no significant difference, in spite of their decomposition status. The adsorbed amount of the PAHs tended to increase with their increasing concentrations. The litters had a higher adsorption rate of or exhibited selective adsorption to phenathrene and chrysene when the PAHs concentrations were lower, and had a higher adsorption rate of benzo［g,h,i］perylene when the PAHs concentrations were higher. These results indicated that mangrove leaf litter at different decomposition status had higher adsorption rates of PAHs in seawater. It is suggested that cleaning up the mangrove leaf litter in time could be one of the most effective ways to remove PAHs from seawater.

Application of SunScan canopy analysis system in measuring leaf area index of soybean.

LIU Gang; XIE Yun;GAO Xiao-fei; DUAN Xing-wu

2008, 27(05):  862-866 . 

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SunScan canopy analysis system is an instrument for indirectly measuring leaf area index (LAI). The instrument can give LAI values by measuring the ratio of transmitted radiation through canopy to incident radiation, based on the canopy geometry features described by ellipsoidal leaf angle distribution parameter (ELADP). In 2005 and 2006, the LAI values of soybean plants at the Heshan Farm of Nenjiang County, Heilongjiang Province were measured with LI-3100 LAI apparatus and SunScan canopy analysis system, the ELADP value was calibrated for accurate LAI, and the precision of the LAI values measured by SunScan canopy analysis system was validated. The results showed that the ELADP value for soybean canopy was 4.0, and the LAI values measured by SunScan canopy analysis system were consistent with those measured by LI3100. The regression correlation of the LAI values measured by the two instruments was significant. During the growth season of soybean, the measurement error of SunScan canopy analysis system had a slight change, i.e., the LAI was underestimated by 7.2% from 50 to 85 days after sowing and overestimated by 12.5% from 96 days after sowing, but close to that measured by LI-3100, with an error of 2.0%. In conclasion, SunScan canopy analysis system could be used to measure the LAI accurately if the ELADP was calibrated for different canopies.