Table of Content

10 June 2008, Volume 27 Issue 06

Previous Issue    Next Issue

Articles

Combustibility ordering and sorting of 35 woody plant species in Kunming area.

LI Shi-you^1,2; MA Chang-le¹; LUO WEN-biao¹; LI Sheng-hong¹; WANG Xue-fei¹; YUAN Jun-jie³; YANG Lin³

2008, 27(06):  867-873 . 

Asbtract ( 1796 )   PDF (350KB) ( 909 )  

A combustion experiment with the living branches and leaves from 35 woody plant species in Kunming area was conducted with the equipment designed by the authors. The combustibility parameter, namely, the ratio between the area of smoke temperature net rising curve’s apex per unit mass fuel in flaming stage and the ignition time, was put forward, based on the determinations of lighting time, smoke temperature, and mass losing in flaming stage. The combustibility ordering and sorting of the 35 species were carried out, based on the combustibility parameter and lighting time, and the reliability of combustibility ordering was verified through two ways. The results showed that among the test woody species, 14 species (such as Rhododendron siderophyllum) were hard combustible, 5 species (such as Viburnum cylindricum) were combustible, and 16 species (such as Sabina chinensis) were easily combustible. The mean difference of ignition time was 36.2 seconds between combustible and easily combustible species, and 276.7 seconds between combustible and hard combustible species. In the study area, combustible and easily combustible woody plant species accounted for 60%, and hard combustible species accounted for 40%. Low proportion of hard combustible species could be a reason for the frequent forest fire in Kunming area.

Comparison of soil seed bank structure in natural wetlands and their corresponding reclaimed paddy fields at lower reaches of Yangtze River in Anhui, China.

FENG Wei¹; WU Xin-min²; PAN Gen-xing¹; XU Xing-wang²; QIANG Sheng³ 

2008, 27(06):  874-879 . 

Asbtract ( 2101 )   PDF (360KB) ( 895 )  

By the method of microscopic examination, the soil seed bank structure and diversity of two natural wetlands (Shibasuo Lake and Shengjin Lake) and their corresponding reclaimed paddy fields at the lower reaches of Yangtze River in Anhui, China were investigated. The total seed storage in topsoil (0-10 cm) was 83 499-109 141 ind·m^-2 for natural wetlands and 9140–47452 ind·m^-2 for reclaimed paddy fields. In natural wetlands, the seeds were of 16-30 grass plant species, being dominant with Polygonaceae and Cyperaceae or yperaceae and Gramineae; while in reclaimed paddy fields, the seeds were of 7-16 grass plant species, with the dominant of Gramineae. The seed storage and species numbers were greater in Shengjin Lake than in Shibasuo Lake. Higher seed bank storage and more species were observed in the paddy fields from Shibasuo wetland with 30 years of cultivation than from the Shengjin Lake wetland with over 50 years of cultivation. The shift of paddy fields from natural wetlands reduced the seed bank storage and the seed species number markedly, indicating that biodiversity was strongly disturbed when the ecosystem was managed by human. Therefore, conservation of natural wetlands is of significance in sustaining the biodiversity and ecofunction of Yangtze River basin.

Characteristics of soil temperature in tropical seasonal rain forest in Xishuangbanna, Southwest China.

GAO Ju-ming^1,4;ZHANG Yi-ping¹;YU Gui-rui²;SONG Qing-hai¹;YANG Zhen^1,4; SUN Xiao-min²;ZHAO Shuang-ju³

2008, 27(06):  880-887 . 

Asbtract ( 2052 )   PDF (863KB) ( 807 )  

Soil temperature is an important environmental factor in forest, which not only closely relates with plant growth, but also influences soil respiration. An optimal soil temperature can improve soil fertility via promoting soil microbial activity and litter decomposition. Therefore, the study on soil temperature will be helpful to understand the changes of carbon flux in forest ecosystem. Based on the data from 2003 to 2006 in a tropical seasonal rain forest in Xishuangbanna, the diurnal, seasonal, and inter-annual variations of soil temperature at different depths were analyzed, and the results indicated that the diurnal variation of soil temperature in near-surface soil layer demonstrated a sine trend, while that in deeper soil layers was relatively stable. With the increase of soil depth, the variation magnitude of soil temperature decreased, the peak of soil temperature lagged behind, and the phase change was obvious. The seasonal variation of soil temperature was obvious too, with the highest value in rainy season (May to October), lowest value in foggy-cool season (November to the next February), and intermediate value in dry-hot season (March to April). Different soil layers were different in the seasonal variation of soil temperature. The inter-annual variation of soil temperature was a single-peak curve, with the lowest temperature in January and the highest temperature in July. Generally speaking, the variation range of soil temperature was decreased in the order of yearly soil temperature>inter-annual soiltemperature>soil temperature among different soil layers>diurnal soil temperature.

Adaptability of endangered plant Dipteronia dyerana under irradiance and water stress.

DENG Yun¹;WANG Bing¹;SU Wen-hua¹;ZHANG Guang-fei¹;OUYANG Zhi-qin²

2008, 27(06):  888-893 . 

Asbtract ( 1567 )   PDF (253KB) ( 1058 )  

A greenhouse experiment was conducted to study the adaptability of Dipteronia dyerana cuttage seedlings under different irradiance and water supply. The results showed that both waterlogging and high irradiance induced the decrease of total chlorophyll content and the increase of Chl a/b. Under high irradiance, the leaf area and specific leaf mass were increased, which offset the declined activity of light-harvesting complex Ⅱ (LHCII) and avoid the high irradiance damage. Soil drought and low irradiation led to the decrease of F_v/F_m. Leaf area decreased significantly under soil drought, and specific leaf area decreased under low irradiation. Soil drought was the main limiting factor in D. dyerana population distribution, and this effect was enhanced under low irradiation. Habitat’s moderate disturbance was suggested to conserve D. dyerana and to slow down its community’s natural succession.

Ecological effect of street-greening in Harbin City.

LIU Hui-min¹;WANG Da-qing⁴;CHE Yan-shuang¹;ZHANG Chao¹;ZHENG Yang²;ZOU Chun-lei³;WANG Hong-yan⁴;CHE Dai-di¹

2008, 27(06):  894-902 . 

Asbtract ( 1548 )   PDF (873KB) ( 766 )  

Studing the effects of the composition and structure of street green space on urban environment and microclimate is of theoretical and practical significance in the greening design of urban street green space. In the spring, summer and autumn of 2006, the ecological indices relating to the greening of three newbuilt avenues Nanzhi Road, Changjiang Road and Shangwu Road in Harbin City were investigated, and the ecological effects of the greening was analyzed by gray correlative degree analysis. The results showed that the ecological effect of streetgreening differed with the avenues, seasons, and time periods of the day. On Changjiang Road, air temperature decline reached extremum at 12:00-14:00 in summer, shading degree presented extremum at 16:00-18:00 in spring, negative ion increment presented maximum at 7:00-8:00 in spring, humidity increment presented maximum at 11:00-13:00 in spring, CO₂ absorption presented maximum at 16:00-18:00 in autumn, and noise decrement presented maximum at 11:00-13:00 in autumn. On Nanzhi Road, dust-capturing capacity presented maximum at 11:00-13:00 in autumn. In the association regularity of ecological effect in different seasons, all the three avenues displayed the optimum overall greening ecological effect in summer. Different avenues had different overall greening ecological effect, and Shangwu Road was most predominance. If the pattern and form of streetgreening were different, the ecological effect of the greening also differed markedly. The composition and structure of street green space had greater effects on the exertion of street’s ecological effect.

Prediction of wheat grain protein yield by canopy hyperspectal remote sensing.

FENG Wei^1,2;ZHU Yan²;TIAN Yong-chao²;CAO Wei-xing²;GUOTian-cai¹;WANG Cheng-yang¹

2008, 27(06):  903-910 . 

Asbtract ( 1869 )   PDF (715KB) ( 879 )  

Three years (2003-2006) field experiment was conducted with different wheat varieties and nitrogen (N) supply, and timecourse measurements were made on the canopy hyperspectral reflectance, plant dry mass and its N content. Based on the technique route of characteristic spectral parameters-leaf N nutrition-grain protein yield, and with leaf N nutrition as a link, the prediction models of wheat grain protein yield based on the canopy hyperspectal parameters at anthesis were constructed. The results showed that the wheat grain protein yield at maturity increased with increasing N supply. Plant N nutritional status, such as leaf N content (LNC) and leaf N accumulation (LNA) at anthesis and leaf N transportation (LNT) after anthesis, could well indicate the grain protein yield at maturity. The regression analysis between existing vegetation indices and leaf N index indicated that some key spectral parameters could accurately estimate the changes in leaf N status across a broad ranges of growth stages, N supply and growing seasons, with unified spectral parameters for each wheat cultivar, such as REPle and mND705 for leaf N content, and SDr/SDb and FD742 for leaf N accumulation. The testing of the prediction models with independent dataset indicated that the spectral indices of REPle, SDr/SDb and FD742 could give accurate grain protein yield estimation, and the R² of REPle, SDr/SDb and FD742 was 0.854, 0.803 and 0.795, with the RE of 16.4%, 18.2% and 14.9%, respectively. Overall, the wheat grain protein yield at maturity could be predicted by the key characteristic spectral indices at anthesis.

The changing trend of organic carbon in black soil under different farming systems: A prediction by using Century model.

GAO Chong-sheng^1,2;YANG Guo-ting²;WANG Jian-guo¹;ZHANG Xing-yi¹

2008, 27(06):  911-915 . 

Asbtract ( 1918 )   PDF (211KB) ( 1192 )  

Century model is one of the main models in predicting the changing trend of soil organic carbon (SOC), and has been used extensively for agricultural and forest ecosystems in recent two decades. In this paper, this model was used to predict the changing trend of organic carbon in black soil under different farming systems. The results showed that Century model was available in predicting the changing trend of organic carbon in farmland black soil. According to the prediction, the annual decrement of SOC content in 2006-2015 would be 0.063 g·kg^-1 under shift farming, 0.027 g·kg^-1 under organic farming, and 0.045 g·kg^-1 under ‘petroleum’ farming. The decreasing trend of the SOC content could be controlled when a combined ‘petroleum’organic farming system was implemented, under which, the SOC content could be maintained at a level of around 34.00 g·kg^-1, being in a balance status.

Theory and application of leaf water potential retrieved from remote sensing.

ZANG Jie¹;ZHANG Qiang¹;ZHAO Hong¹;ZHANG Ping-lan²

2008, 27(06):  916-923 . 

Asbtract ( 1620 )   PDF (588KB) ( 1009 )  

Based on the estimation of transpiration rate by energy balance theory, and combining the estimations of atmospheric water potential and leaf and atmosphere resistance, a leaf water potential model retrieved from remote sensing was built. Some physiological and meteorological parameters observed by CI-301 apparatus were used for testing the retrieval precision of leaf water potential; and the sensitivity of the responses of leaf water potential to physiological and climate drought in arid and semiarid region was analyzed. The results showed that leaf water potential was a good index for reflecting drought, by which, thecharacteristics of physiological and climate drought could be well expressed. The retrieval error of leaf water potential from remote sensing was between 3.2% and 17.3%, indicating that the leaf water potential estimated by remote sensing could be used for monitoring drought and evaluating water stress. In the dry year of 2005 in Gansu, the leaf water potential was between -2 and -3 MPa in May and about -2 MPa in June, and the drought degree was correlated to crop species.

Profile distribution and seasonal variation of soil dissolved organic carbon in natural Castanopsis fabric forest in subtropical China.

WANG Wei^1,2;YANG Yu-sheng¹;CHEN Guang-shui¹;GUO Jian-fen¹; QIAN Wei¹

2008, 27(06):  924-928 . 

Asbtract ( 2013 )   PDF (412KB) ( 1179 )  

The study on the profile (0-100 cm) distribution and seasonal variation of soil dissolved organic carbon (DOC) in a natural Castanopsis fabric forest in Jian’ou of Fujian Province showed that the mean concentration of DOC had a decreasing trend with the increase of soil depth. In 0-5 cm soil layer, the mean concentration of DOC was 55.69 mg·kg^-1, being significantly higher than that in other soil layers (P<0.01). The ratio of DOC to soil organic carbon (SOC) also decreased with increasing soil depth, and its mean value in the profile was about 0.14%. In all seasons, the concentration of DOC in the profile had a decreasing trend with the increase of soil depth, which was most obvious in winter. The seasonal variation of DOC concentration in the profile was in the order of inter>autumn>spring>summer. There was a less variation of DOC/SOC ratio in different soil layers among different seasons. Different soil layers had significant differences in the seasonal variation of DOC, which was most significant in 0-5 cm soil layer (P<0.01).

Acute toxicity of salinity to juvenile Acipenser schrenckii and A. baerii.

ZHAO Feng^1,2;ZHUANG Ping^1,2;LI Da-peng³;ZHANG Long-zhen¹;ZHANG Tao¹

2008, 27(06):  929-932 . 

Asbtract ( 1745 )   PDF (200KB) ( 936 )  

A comparative study was made on the acute toxicity of salinity to juvenile Acipenser schrenckii and A. baerii. The results showed that the 96 h median lethal concentration (LC₅₀) was 14.72 for juvenile A. schrenckiiand 13.08 for juvenileA. baerii. It was deduced from the 96 h LC₅₀ values and salinity response curves that A. schrenckii had higher salinityresistance than A. baerii. The behavioral response of the two species to higher salinities (≥14.70) exhibited five ordinal behaviors, i.e., slow swimming around the tank, manic swimming around the tank, swimming weakly, body imbalance, and movement stopping (dead). Based on the appearance time of specific behavioral response of the two species, A. baerii was more sensitive to the salinity than A. schrenckii.

Effects of thermal water discharged from coastal power plant on distribution of zooplankton.

XU Xiao-qun¹;ZENG Jiang-ning^1,2;ZENG Gan-ning³;CHEN Quan-zhen¹;LIAO Yi-bo¹;GAO Ai-gen¹;SHOU Lu¹

2008, 27(06):  933-939 . 

Asbtract ( 2048 )   PDF (618KB) ( 977 )  

To assess the effects of thermal water discharged from coastal power plant on zooplankton, the sea area near Jiaxing Power Plant located at the coast of Zhejiang Province was selected as a case to investigate the zooplankton distribution during both spring and neap tides in May 2006. The thermal tolerance of Calanus sinicus, Sinocalanus tenellus, Acartiella sinensisand Corycaeus affinis, the common dominant copepods in coastal waters of East China Sea, were also determined by 24 h semilethal temperature. In total, 26 species of zooplankton were identified, among which, 22 species were in spring tide and 23 species in neap tide. The main species identified belonged to neritic low-salinity group, and Tortanus vermiculus and Labidorcera euchaeta were the dominant species. Zooplankton biomass increased from the close to the distant of coastline, while the density was relatively uniform. The biomass distribution was determined by Acanthomysis longirostrisand fish larval, while the density distribution was determined by T. vermiculus and L. euchaeta. No death was observed for the four species when the temperature was raised by 7 centigrade, suggesting that zooplankton had higher thermal tolerance. It was concluded that the thermal water discharged from coastal power plant had larger effects on the distribution of zooplankton species with stronger activities and higher masses near the outfall, but less effects on the species with weaker activities and lower masses.

Observation on the behaviors of wintering waterfowls in artificial wetland at Chongming Dongtan.

SANG Li-li¹;GE Zhen-ming¹;PEI En-le²;XU Xiao-jun¹;JIANG Shan¹, WANG Tian-hou¹

2008, 27(06):  940-945 . 

Asbtract ( 1843 )   PDF (546KB) ( 761 )  

From the beginning of December 2006 to the end of February 2007, observations were made on the daytime (6:30-19:30) behaviors of 7 dominant species of wintering waterfowls in the secondary artificial wetland (fish-crab pond) at Chongming Dongtan. The results indicated that Egretta garzetta, Ardea cinerea and Anas poecilorhyncha mostly showed standing still behavior, accounting for 34.09%, 45.45% and 54.55% of their whole daytime behaviors, respectively. Fulica atra and Phalacrocorax carbo preferred to feeding behavior (32.58% and 35.00%, respectively). Swimming was the major behavior of Tachybaptus ruficollis and Larus argentatus (44.70% and 31.82%, respectively). The waterfowls’ activities were positively correlated with temperature and sunlight, but negatively correlated with wind speed. The relatively constant water level in the wetland had no significant effects on the behaviors of test waterfowls.

Butterfly diversity in different types of habitat in Chongqing urban area.

ZUO Zi-tu^1,2;YUAN Xing-zhong^1,2; LIU Hong¹;LI Xuan¹

2008, 27(06):  946-950 . 

Asbtract ( 4616 )   PDF (337KB) ( 911 )  

An investigation was made on the butterfly diversity in the artificial secondary forest, cropland along stream, mountain cropland, natural secondary forest, and artificial garden in Chongqing urban area from September to November 2006. A total of 529 individuals belonging to 6 families, 16 genera and 20 species were collected, among which, Psedozizeeria maha and Pieris rapae were the dominant species, with their relative dominance being 38.75% and 17.01%, respectively. The diversity indices of butterfly in the five type habitats ranked in order of natural secondary forest>cropland along stream>mountain cropland>artificial secondary forest>artificial garden. Compared with habitat type, human disturbance had more impact on the butterfly diversity. To reserve the remaining agricultural fields in urban area would have positive significance in the conservation of butterfly diversity.

Ecological succession of zooplankton in the treating process of papermaking wastewater.

LIU Na-na; WANG Hai-lei;CHEN Jian-jun;LIU Guo-sheng

2008, 27(06):  951-955 . 

Asbtract ( 1818 )   PDF (279KB) ( 1391 )  

Granular sludge formation and zooplankton succession in the process of domesticating activated sludge and treating papermaking wastewater were investigated with sequencing batch reactor (SBR). The results showed that in the initial stage of sludge domestication, the sludge granularity and the removal capability of COD were low, Mastigophora appeared firstly, and Sarcodina appeared later. In the metaphase, sludge granularity and wastewater treatment capability advanced, and Ciliate dominated. In the stationary phase, wastewater treatment capability reached the maximum, and granular sludge matured. The appearance and increase of Vorticella, a kind of sessile ciliate, symbolized activated sludge maturation. During the running process of the reactor, if the work condition changed, e.g., the appearance of overload, pH abnormity, or nutrition deficiency, the community composition and activities of zooplankton would be changed accordingly.

Effects of phosphorus, copper, and their interaction on seed germination and seedling growth of Trifolium repens L.

CHEN Xue-mei'WANG You-bao;YAO Jing;AN Lei

2008, 27(06):  956-961 . 

Asbtract ( 2031 )  

A solutionculture experiment was conducted to explore the effects of phosphorus application on the seed germination vigor, seedling biomass, photosynthetic pigment content, and electric conductivity of Trifolium repens L. under Cu stress. The results showed that heavy metal Cu²⁺ (0-20 mg·L^-1) inhibited the seed germination and seeding growth of T. repens significantly. After phosphorus application (0.06%), the germination rate suppressed by Cu enhanced markedly, seedling growth was promoted, biomass and photosynthetic pigment content increased, and leaf cell membrane permeability decreased remarkably. Evidently, applying definite amount of phosphorus could alleviate the poisoning of excessive Cu²⁺ to T. repens.

Comparison of growth parameters of sod establishment system with municipal solid waste compost and garden soil as the media.

ZHAO Shu-lan;DUO Li-an

2008, 27(06):  962-967 . 

Asbtract ( 1983 )   PDF (314KB) ( 934 )  

A comparative study was made on the growth parameters of sod establishment system with municipal solid waste compost and garden soil as the media. The results showed that the fibre root numbers of Poa pratensis and Agrostis stolonifera were significantly fewer on compost than on soil medium, and the single plant’s net primary production of turfgrass for Festuca arundinacea and Lolium perenne was significantly higher on compost than on soil medium. For the same cultivar, there was little difference (P>0.05) in the other growth parameters between the two media. The tensile strength of sod was primarily depended on sod netting properties, being about 10 kg for all of test sods. For the four turfgrass cultivars, the sessile state of sod roots with medium and netting had the order of F. arundinacea>L. perenne>P. pratensis>A. stolonifera from strong to weak. In sod laying, there were differences in the ecological cooperativity of cultivar, medium, and netting between the sods on the two different media. The turfgrass growth after sod laying was closely relevant to that in sod culture, i.e., the better in sod culture stage, the better in sod laying stage. After sod laying, the turfgrass with compost as the media had much better- lustrous effect. The synthetical properties of compost medium sod were accorded with sod culture requirement, and some properties were better than those of soil medium sod.

Dynamic changes of ecological footprints in Liaoning Province and its coastal area.

LIU Wei-ling^1,2;ZHU Jing-hai^1,3;HU Yuan-man¹

2008, 27(06):  968-973 . 

Asbtract ( 4558 )   PDF (981KB) ( 1013 )  

This paper calculated the 2003-2005 ecological footprints in Liaoning Province and its six coastal cities (Huludao, Jinzhou, Panjin, Yingkou, Dalian and Dandong), analyzed the dynamic changes and their causes of the footprints, and evaluated the situation of the sustainable development in the study region. It was indicated that in 2003-2005, the ecological footprints in Liaoning Province and its six coastal cities exceeded the corresponding ecological capacity, and the per capita ecological deficit was increased annually. Of the six coastal cities, the per capita ecological deficit in Panjin was the highest, followed by Jinzhou, Huludao, Yingkou, Dandong, and Dalian. The land with fossil energy sources was the main demand of ecological footprint in the study region, while water area had a higher ecological surplus. The GDP per ten thousand yuan in 2003-2005 presented an overall downward trend, indicating that the resource use efficiency in Liaoning Province and its six coastal cities was improved gradually. The measures for reducing the ecological deficit were also proposed.

Evolution of ecological footprints in Hubei Province in last two decades.

TAN Qing¹;WANG Zheng-xiang¹;LEI Yun²;LI Zhong-qiang¹;YU Man¹

2008, 27(06):  974-977 . 

Asbtract ( 1608 )   PDF (325KB) ( 1141 )  

By using ecological footprint model, the ecological footprints in Hubei Province from 1985 to 2004 were measured in temporal sequence. The results showed that from 1985 to 2004, the per capita demand of ecological footprint in Hubei Province surpassed the per capita ecological capacity. The comparison of different scale ecological deficits/surplus in the same periods of time indicated that on provincial and national scales, the ecological footprints in Hubei Province were not in a sustainable development status; but on global scale, they were in a sustainable one. Among all kinds of land types in Hubei Province, farmland had the highest ecological deficit per capita, while forestland was in surplus. Water area had the fastest increasing speed in the demand of per capita ecological footprint, while forestland had the fastest one in the demand of per capita ecological capacity. Overall, the per capita ecological footprint and per capita GDP in Hubei Province kept increasing, while the ecological footprint of ten thousand Yuan GDP presented a downward trend. To control the scale of construction, protect the farmland, and increase the input of new technologies would be the important measures to solve the problems in ecological footprints in this province.

Extent effect of landscape gradient analysis of urban-rural transect.

ZHANG Jing-hua^1,2,3;WU Zhi-feng²;Lü Zhi-qiang^1,2,3;GAO Yang^1,2,3

2008, 27(06):  978-984 . 

Asbtract ( 1738 )   PDF (1379KB) ( 966 )  

With the combination of gradient analysis and quantitative analysis of landscape pattern, and by changing the transect width and research step, the extent effect of landscape gradient analysis of an urban-rural transect were studied. The results showed that the landscape gradient analysis of the urban-rural transect was scale-dependent, and the effect of transect width was greater than that of research step. Research step mainly affected the fluctuation degree of each landscape index along transect, and it was appropriate for the transect to be divided equally into 20 samples. There existed critical values for transect width. When the transect width was beyond the values, the fluctuation trend of each index along transect would be varied. Furthermore, different landscape metrics responded differently to the same transect. The percent coverage and edge density of each class, as well as the Shannon’s diversity index of landscape, showed significant gradient characteristics, while patch density and mean patch fractal dimension were in adverse.

Measurements of plant competition ability and their applications: A review.

JIANG Zhi-lin^1,2;LIU Wan-xue¹;WAN Fang-hao¹;LI Zheng-yue²

2008, 27(06):  985-992 . 

Asbtract ( 2008 )   PDF (325KB) ( 1137 )  

Competition is important for both natural and agricultural plant communities, and being investigated in many settings and for many purposes. Plant competition has several attributes, and can be examined from different perspectives, including importance, intensity, effect, response, and outcome. The selection and use of related indices has an important bearing in the assessment of plant competition, which in turn may condition the inferences drawn from plant competition experiments. Here, three fundamental components of plant competition ability were summarized, and related indices were classified as: (1) indices for quantifying the intensity and importance of competition, (2) indices for quantifying the effects of competition, and (3) indices for quantifying the outcome of competition. Moreover, the functions and applications of different indices were discussed. We hope this essay will make researchers aware of the diversity of the indices that are available, and help them to choose those indices that are suitable to their needs.

Asexual reproduction of moss and its applications.

CHEN Yuan-yuan;GUO Shui-liang;CAO Tong

2008, 27(06):  993-998 . 

Asbtract ( 1590 )   PDF (241KB) ( 968 )  

Various kinds of asexual propagules have been reported from different moss taxa. Asexual reproduction plays important roles in the adaptation of moss to environments, especially to the disturbed, unstable and extreme environments. The asexual propagules of moss can be divided into two main types, i.e., vegetative propagules and specialized asexual reproductive propagules, and the latter includes eight subtypes,i.e., deciduous shoot apices, flagella, caducous branchlets, bulbils, rhizoidal tubers, endogenous gemmae, gemmae, and caducous leaves. This paper summarized the morphological characteristics of propagules and their morphogenesis. The practical and potential applications of asexual propagules of moss in tissue culture, molecular study, and biotic crust formation in relation to dune or desert fixation as well as in garden construction were also introduced.

Interrelations between root herbivore and plant.

LI Xing-peng¹;SONG Li-wen¹;LI Zhi-qing²;LONG Sha²;CHEN Yue-qu¹

2008, 27(06):  999-1004 . 

Asbtract ( 1558 )   PDF (229KB) ( 879 )  

Root herbivore is of the main one that harms plant. The interrelations between root herbivore and plant have attracted extensive attention from scientists. In this paper, the effects of root herbivore on root biomass change, root regeneration and survival, plant physiology, dynamics of plant population, and plant structure, as well as the action mechanisms between plant semiochemicals and other organisms, were discussed, and some research fields that should be further strengthened, e.g., countermeasures of plant for esisting root herbivore, action mechanisms of root herbivore in changing ecosystem C and N cycling, and dynamic changes of ecosystem nutrients when parasitic nematodes exist, were suggested.

Cytological mechanisms of pollutants adsorption by biosorbent.

CAI Jia-liang;HUANG Yi;LI Xiao

2008, 27(06):  1005-1011 . 

Asbtract ( 1991 )   PDF (373KB) ( 1101 )  

Heavy metals and permanent organic pollutants (POPs) are quite stable and harmful, which can endanger human’s life and health directly or indirectly. Nowadays, biosorbents become the hotspot and keystone of the researches on treating heavy metals and POPs. Based on the recent years’ research achievements, this paper made a systematic classification of biosorbents, and expatiated on the mechanisms of heavy metals and POPs adsorption on the outside, surface, and inner cells of the biosorbents, as well as the related affecting factors. Meanwhile, the problems in present researches and future research directions of biosorbents were discussed.

Research advances in wetland landscape pattern and hydrological process.

LI Sheng-nan^1,2;WANG Gen-xu¹;DENG Wei¹

2008, 27(06):  1012-1020 . 

Asbtract ( 1903 )   PDF (426KB) ( 1491 )  

Wetland is the outcome of the interaction between terrestrial and aquatic ecosystems under integrated effects of various ecological processes in different scales, and characterized by prominent spatial heterogeneity. As a main research means, landscape pattern analysis can help us understand the spatial ecological process. Wetland hydrology is the most important determinant of the establishment and maintenance of specific type of wetland, which has a direct effect on the biota in the wetland and makes some changes on landscape ecological pattern. Being a feedback to the wetland hydrological processes and their physical environments, wetland biota can control the hydrology and chemistry of the environments through a variety of mechanisms. The studies on the coupling between wetland ecological pattern and hydrological process would be the keystones in the future research on wetland ecosystem.

A review on radiation use efficiency of the cropland.

TONG Xiao-juan¹;LI Jun²;WANG Ling³

2008, 27(06):  1021-1028 . 

Asbtract ( 1769 )   PDF (332KB) ( 759 )  

Radiation use efficiency (RUE) is one of the most useful parameters in crop growth models, and widely used in the remote sensing estimation of net primary productivity. Due to the effects of environmental factors, RUE varies with crop growth. The inaccurate estimation of RUE will lead to large errors in the simulation of net primary productivity. This paper analyzed the determination methods of cropland RUE and the variation characteristics of RUE, discussed the factors controlling RUE (e.g. solar radiation, temperature, vapor pressure deficit, leaf nitrogen content, and crop species), and pointed out the problems in current RUE studies. It was suggested that when using RUE as a parameter to simulate crop production, the variation of RUE with crop growth should be considered. Further works should be enhanced on the relationship between crop biomass and its intercepted radiation, and hotspot would be the study of RUE variation over short period of time scale (hours or days) by using micrometeorological methods such as the eddy covariance technique to provide reliable parameter for constructing carbon cycle models.

Research progress in fine root decomposition in forest ecosystem.

LIN Cheng-fang^1,2；GUO Jian-feng¹;CHEN Guang-shui^1;YANG Yu-sheng¹

2008, 27(06):  1029-1036 . 

Asbtract ( 1728 )   PDF (303KB) ( 823 )  

Fine root decomposition is one of the major steps of nutrient and energy cycling in forest ecosystem, and also, a complex process including physical (leaching and fragmentation) and soil biochemical processes. In order to understand the carbon balance in forest ecosystem, it is important and necessary to uncover the factors and mechanisms that regulate fine root decomposition. However, the estimated root decomposition rate is challenging, because roots are hidden from view, and occur in an environment that buffers the impact from climatic change. It is difficult to examine the root decomposition without significantly disturbing forest system. This paper reviewed the factors affecting fine root decomposition and related research methods, and brought forward the future research directions, aimed to promote the study of fine root decomposition in forest ecosystem.

Mechanisms of microbial Fe(Ⅲ) respiration: A review.

XU Wei^1,2;HU Pei²;LI Yan-hong²;LI Xiao-min¹;ZHOU Shun-gui¹

2008, 27(06):  1037-1042 . 

Asbtract ( 4135 )   PDF (251KB) ( 1639 )  

Fe(Ⅲ) respiration is an ubiquitous metabolism type of microbes under anaerobic circumstance. Many kinds of archaea and bacteria can respire with Fe(Ⅲ) oxides as terminal electron acceptor. Fe(Ⅲ) is abundant in natural environment, which can provide enough electron acceptors for dissimilatory Fe(Ⅲ)reducing microbes. However, electron transfer is restricted, because most Fe(Ⅲ) is insoluble under natural conditions. This paper introduced the diversity of dissimilatory Fe(Ⅲ)reducing microbes, summarized four mechanisms of Fe(Ⅲ) respiration, i.e., direct cell contact with Fe(Ⅲ) oxides, chelation that solubilizes Fe(Ⅲ), electron shuttling, and bacterial nanowires that serve as the conduits for transferring electrons from cells to mineral surfaces, and proposed future research directions on the mechanisms of microbial-Fe(Ⅲ)- respiration.

Analysis of economic benefits of poplar, maize, soybean, and straw utilization in farmland shelterbelt networks in Jilin Province.

LIANG Wan-jun¹;WANG Fu-wei²;LIN Yu-mei¹;LI Qing-mei¹;CHEN Shi-gang¹;LI Shi-jie

2008, 27(06):  1043-1046 . 

Asbtract ( 2275 )   PDF (152KB) ( 940 )  

In 2005, sampling plots were set up in the farmland shelterbelt networks in Changling County, Songyuan City, Jilin Province to determine the gross caloric and nutrients (C, N and P) content of each component of poplars (Populus × cv. Bailin 2), maize (Zea mays) and soybean (Glycine max), with the annual economic benefits of poplar, maize and soybean as well as the profit of crop straw utilization analyzed. The results showed that the annual economic benefit per hectare was 5 110 yuan (RMB) for maize and 3 965 yuan for soybean. The aboveground parts of maize and soybean straws could generate caloric 113 318 800 kJ·hm^-2 (796 yuan profit) and 61 294 400 kJ·hm^-2 (430 yuan profit), respectively, when they were used to generate electricity, which could increase the profit by 15% for maize and by 10% for soybean. It was estimated that an investment of 1 176 yuan·hm^-2 for maize and 789 yuan·hm^-2 for soybean was needed if compound fertilizer was used to compensate the nutrient loss caused by straw utilization, indicating that such an investment couldn’t match the profit of straw utilization. The annual ecomomic benefit for poplar was 3 690 yuan per nectare, being lower than maize and sybean.

Community structure and diversity of butterfly in Guangzhou City of China.

LI Zhi-gang^1,2;LI Jun¹;ZHANG Bi-sheng¹;GONG Peng-bo³;HAN Shi-chou¹

2008, 27(06):  1047-1050 . 

Asbtract ( 1977 )   PDF (144KB) ( 962 )  

The butterfly resources in Guangzhou City were investigated from May 2005 to December 2006. A total of 73 species belonging to 10 families, 45 genera were recorded. Pieridae had the most abundant individuals, followed by Nymphalidae and Papilionidae. The species richness of Nymphalidae was the highest, with the Margalef richness being 3.87, followed by that of Papilionidae and Satyridae. As for the species diversity, Papiliondae was the highest, followed by Nymphalidae, but Nymphalidae had the highest genera diversity. Papilionidae was the highest in evenness, with the Pielou’s evenness being 0.90, followed by Hesperiidae and Lycaenidae.

Determination and estimation methods of tree transpiration: A review.

DENG Dong-zhou^1,2l FAN Zhi-ping¹;WANG Hong^1,2;SUN Xue-kai¹;GAO Jungang^1,2;ZENG De-hui¹

2008, 27(06):  1051-1058 . 

Asbtract ( 4245 )   PDF (347KB) ( 1288 )  

Evapotranspiration includes soil evaporation and plant transpiration, being an important ecological process in the water vapor exchange between atmosphere and terrestrial ecosystem, by which, terrestrial ecosystem returns its soil water initially charged from precipitation to the atmosphere to balance regional and global water cycling. The tree transpiration in forest ecosystem is an important component of the hydrological budget controlled by canopy architecture and development, soil characteristics, and a variety of in situ environmental variables. Many researchers have determined and estimated tree transpiration by using the methods of rapid weighting (RM), steady-state porometer (SSP), photosynthesis system (PS), wholetree potometer (WP), ventilated chamber (VC), weighting potted-plant (WPP), sap flow measurements (SPM), lysimeter (L), water balance (WB), energy balance (EB), Bowen ratio (BR), eddy covariance (EC), Penman-monteith Method (PMM), and remote sensing (RS). This paper introduced the principles, practices, and application scopes of these methods, and compared their advantages and disadvantages, aimed to provide a systemic support for choosing proper method(s) to estimate the tree transpiration in forest ecosystem.