Table of Content

18 September 2010, Volume 21 Issue 09

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Articles

Composition and seasonal dynamics of litter falls in a broad-leaved Korean pine(Pinus koraiensis) mixed forest in Changbai Mountains, Northeast China.

2010, 21(09):  2171-2178. 

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In order to understand the composition and spatiotemporal dynamics of the litter falls at community level in a broad-leaved Korean pine mixed forest in Changbai Mountains, litter falls were collected from 150 containers in a 25 hm² permanent plot in 2008. The leaf litters in the containers were from 35 tree species, accounting for 67.3% of the total number (52) of the tree species with DBH≥1 cm in the plot. The litter falls had a weight 29.39 kg, equivalent to 3918.4 kg·hm^-2, among which, broad leaves, miscellany, needle leaves, and branches occupied 61.7%, 18.0%, 11.7%, and 8.6%, respectively. About 83.8% of the broad leaves were from Tilia amurensis, Fraxinus mandshurica, Quercus mongolica, Acer mono, and Ulmus japonica. The litter falls showed an evident seasonal dynamics, with the peaks occurred from 13 September to 10 October, e.g., the litter falls from T. amurensi and Pinus koraiensis peaked in 13-26 September, while those from Q.mongolica, U. japonica, and A. pseudo sieboldianum peaked in 27 September to 10 October. There was a great difference in the mass of the litter falls among the containers, e.g., with 150-200 g litters in 68 containers and >500 g litters in 1 container. The species number of the litter falls in a container was 18 in maximum, and was 12 in common (32 containers). Litter falls mass was positively proportional to the sum of the basal area at breast height of parent trees in the plot, and the amount of the litter falls in the containers was related with the locations of the containers, exhibiting an evident spatial heterogeneity in the plot.

Effects of selective cutting on intra-and interspecies competitions among major tree species in mixed broadleaved-Korean pine forest.

2010, 21(09):  2179-2186. 

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Taking a Korean pine (Pinus koraiensis) forest stand 37 years after selective cutting as test object, this paper studied the effects of selective cutting on the intra- and interspecies competitions among the major tree species in the stand. Selective cutting had significant effects on the population structure, distribution pattern, and competition index of the major species. There was a significant negative correlation between the changes of competition index and tolerance index of the tree species (r=-0.8821). The intra-species competition index had significant linear relationships with the aggregation index and the  number of individuals. Heliophilous species Betula costata and Tilia amurensis  had the largest aggregation index, and their intra-species competitions were stronger than interspecies competitions, being favorable to the coexistence of different species. Selective cutting weakened the competition of  P. koraiensis with its companion tree species, while strengthened the competition of heliophilous species with other tree species. After 37 years of selective cutting, P. koraiensis varied little in its competition stress, being helpful to its regular growth. Because of self-thinning, the dominance of  B. costata and  T.amurensis had somewhat decrease. The competition stress suffered by  Abies nephrolepis was weakened, being beneficial to its regeneration.

Soil nitrogen mineralization and primary productivity in Rhododendron aureum community of snowpacks in alpine tundra of Changbai Mountain.

2010, 21(09):  2187-2193. 

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Based on continuous observation of soil temperature and  in situ  incubation, this paper studied the effects of snow packs on soil temperature, soil nitrogen (N) mineralization, and primary productivity of  Rhododendron aureum community alpine tundra in Changbai Mountain. During the snow-covered period of non-growth season (from last  October to early May), test soil had an increasing N content, and accumulated sufficient mineralized N for plant growth in the coming year. The soil under snow packs in  snow-covered period had a mean temperature -3.0 ℃, and its N mineralization was more vigorous, with available N increased by 3.88 g·m^-2; while the soil with no snowpack had a mean temperature -7.5 ℃, and the available N only increased by 1.21 g·m^-2. During growth lseason (from mid May to late August), soil N content decreased.  In  autumn when plants stopped growing, soil available N content tended to increase. In winter, the soil temperature under snowpacks kept at around 0 ℃ or a little lower, which promoted soil N mineralization, while that with no snowpack was in a frozen status. The difference in soil N mineralization was the key factor resulting in the higher primary productivity of snowpack Rh. aureum community and the driving force for the spatial variation of vegetation.

Coupling effects of water and fertilizer on the biomass of Populus tomentosa seedlings.

2010, 21(09):  2194-2200. 

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Water and fertilizer are the two main factors promoting the fast growth and high-yielding of  Populus tomentosa, and thus, to study their coupling effects on the biomass of P. tomentosa seedlings has important practical significance. Taking the P. tomentosa clone 87 seedlings as test materials, a pot experiment with rotary combination design of square regression of three factors with five levels was conducted in the nursery of Beijing Forestry University from March to October 2008 to study the coupling effects of water, fertilizer N, and fertilizer P on the biomass of the seedlings, and a related regressive mathematical model was established. The results showed that water was the main factor affecting the biomass of P. tomentosa  seedlings, followed by fertilizer N, and fertilizer P. With the increasing input of the three factors, the biomass of the seedlings increased, but when the input was beyond a certain level, the biomass began to decrease. There was a significant positive interactive effect between water and fertilizer N, but a less interactive effect between fertilizer N ,and fertilizer P and between water and fertilizer P. In our case, the optimal combination of water and fertilizer was 73.37% of field capacity＋4.14 g·plant^-1of N fertilization＋1.41 g·plant^-1of P fertilization, under which, the biomass of P. tomentosa seedlings achieved 68.30 g·plant^-1.

Leaf morphological structure and physiological and biochemical characteristics of female and male Hippophae Rhamnoides subsp. sinensis under different soil moisture condition.

2010, 21(09):  2201-2208. 

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A field experiment was conducted to study the leaf morphological structure and physiological and biochemical characteristics of female and male Hippophae rhamnoides subsp. sinensis under  different soil moisture condition. When the soil moisture condition was poorer, the leaf structure of the plants displayed distinct xeromorphic characteristics, being more obvious for the female plants. Comparing with those of male plants, the leaf thickness, thickness of upper and lower epidermis, and the distance between lateral vein bundles of female plants were smaller, while the thickness and density of lower epidermis hairs and the ratio of palisade tissue thickness to sponge tissue thickness were in adverse, indicating that female plants had stronger drought adaptability and greater ecological plasticity. With the decrease of soil moisture content, the leaf dissociative proline, dissoluble sugar, and malonaldehyde (MDA) contents of both male and female plants all increased, but for female plants, the increment of their leaf dissociative proline and dissoluble sugar contents was larger, while that of MDA content was smaller than the male plants. With the changes of soil moisture content, the leaf superoxide dismutase  and catalase  activities of the plants varied greatly, but had no regular pattern. Under the stress of soil drought, the values of multivariate membership function of test parameters were larger for the female than the male plants, suggesting that the female plants of H. rhamnoides subsp. sinensis had stronger physiological regulation capability and greater adaptability to drought stress.

Litter decomposition and nutrient dynamics at different succession stages of typical mixed broadleaved-Korean pine forest in Xiaoxing’an Mountains, China.

2010, 21(09):  2209-2216. 

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Taking the mixed leaf litters in broadleaved-Korean pine forests at different succession stages (secondary birch forest, selective cutting forest, and original mixed forest) and the leaf litters of the dominant tree species (Betula costata, Tilia amurensis, and Pinus koraiensis) in these forests in Xiaoxing’an Mountains, China as test objects, this paper studied their remaining rates and nutrient dynamics in October 2006-November 2008 by using decomposition bag method. For all test leaf litters, their remaining rate had an exponential relationship with time. The annual decomposition constant (k) ranged from 0.137 to 0.328, and the time for decomposing 50% (t_50%) and 95% (t_95%) was 2.340-4.989 years and 9.360-21.796 years, respectively. No significant differences were observed in the decomposition rates of the leaf litters among the forests, but the kvalue of the mixed leaf litters was decreased in the order of original mixed forest > selective cutting forest > secondary birch forest, while that of the dominant tree species leaf litters had no obvious pattern. During decomposition, the elements C, P, and K in leaf litters released continuously, and the release pattern of C followed linear function, while that of P and K followed a function of higher degree. Element N presented different levels of accumulation, but had no clear pattern.

Effects of elevated temperature and CO₂ on desert algal crust photosynthesis.

2010, 21(09):  2217-2222. 

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Taking the 26-and 51-year-old artificial vegetation areas and the natural vegetation area in Shapotou region of southeast Tengger Desert as study sites, this paper measured the net photosynthetic rate (P_n) of algal crusts, and analyzed its relationships with crust water content (>100%, 40%-60%, and <20%), atmospheric CO₂ concentration (360 and 700 mg·L^-1), and air temperature (13 ℃, 24 ℃, and 28 ℃). The P_n of the crusts in the 26-and 51-year-old artificial vegetation areas and natural vegetation area was 3.4, 4.4, and 3.2 μmol·m^-2·s^-1, respectively, and the P_n in 51-year-old other two areas. Crust water content had significant effects on the P_n, which was significantly higher at medium water content (40%-60%) than at low (<20%) and high (>100%) water content. When the CO₂ concentration doubled (700 mg·L^-1), the P_n increased by 1.8-3.3 times at medium and high crust water content but had less change at low crust water content, compared with that under ambient CO₂ concentration (360 mg·L^-1). At medium and high crust water content, the P_n at 24 ℃ and 28 ℃ was 27%-66% higher than that at 13 ℃ (P<0.05), but at low crust water content, no significant difference was observed at the three  temperatures.

Responses of Atriplex triangularis root |permeability and reflection coefficient to salt stress.

2010, 21(09):  2223-2227. 

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Taking hydroponically cultured arrow-leaf saltbush (Atriplex triangularis) seedlings as test materials, and using electrical conductivity detector, atomic spectroscopy, and pressure bomb, this paper studied the effects of salt stress on the seedlings root membrane permeability, ion uptake, and reflection coefficient, and analyzed the salt-resistance characteristics and related mechanisms of A. triangularis. The results showed that with increasing salt stress, the root membrane permeability increased, but the reflection coefficient decreased. Salt stress decreased the total K⁺ uptake and increased the total Na⁺ uptake, but the relative amount of absorbed K⁺ increased while that of absorbed Na⁺ decreased. Under salt stress, A. triangularis roots had a higher regulation capability in their ion uptake, and the reduction of root reflection coefficient was favourable to the water absorption by the roots with moderate negative pressure, and accordingly, reduced the danger of xylem cavitation. All these features could be closely related to the higher salt-resistance of A. triangularis.

Leaf nutrient contents and photosynthetic physiological characteristics of Ulmz us pumila-Robinia pseudocacia  mixed forests.

2010, 21(09):  2228-2234. 

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A field experiment was conducted to study the leaf N, P, and chlorophyll contents, photosynthetic gas exchange parameters, and chlorophyll fluorescence parameters in pure Ulmus pumila orest, pure Robinia pseudoacacia forest, and U. pumila-R. pseudoacacia mixed forests ［1：1 (1B1C), 1:2 (1B2C), and 2:1 (2B1C)］ in different growth periods. From May to September, the plant leaf N and P contents in pure and mixed forests all presented a decreasing trend. By the end of growth period, the leaf N content of U. pumila and the P content of R. pseudoacacia in 1B2C were obviously higher than those in pure forests. In the mixed forests, the chlorophyll content of U. pumila was obviously higher than that of  R. pseudoacacia, and the chlorophyll content of U. pumila in 1B2C reached the highest in July. The photosynthetic rate (P_n) of  U. pumila  and R. pseudoacacia  in mixed forests was higher than that in pure forests, and the P_n of R. pseudoacacia in 1B2C reached the highest (18.54 μmol·m^-2·s^-1) in July. The transpiration rate (T_r) and stomatal conductance (G_s) of R. pseudoacaciam  in mixed forests were higher than those in pure forests, and the T_r and G_s in mixed forests were in the order of 1B2C>1B1C>2B1C. In September, the quantum yield of PSII electron transport (Ф_PSⅡ) of U. pumila  in mixed forests was obviously higher than that in pure forest. The photochemical quenching coefficients (q_P) of U. pumila and  R. pseudoacacia  in pure and mixed forests had no significant difference, but the nonphotochemical quenching coefficient (NPQ) of the two tree species in 1B2C was significantly lower than that in corresponding pure forests. It was suggested that mixed planting  U. pumila  and R. pseudoacacia  could significantly improve the leaf nutrient contents and photosynthetic capacity of the two tree species, and the optimum mixed ratio of  U. pumila and  R. pseudoacacia was 1: 2.

Litter fall production and carbon return in Cunninghamia lanceolata, Schima superba, and their mixed plantations.

2010, 21(09):  2235-2240. 

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From March 2005 to April 2007, an investigation was made on the litter fall production and carbon return of  Cunninghamia lanceolata, Schima superba, and their mixed plantations in the Jian’ou Science and Education Park of Soil and Water Conservation, Fujian. In these three plantations, the mean annual litter fall production was from 2470.85 kg·hm^-2·a^-1 to 4285.99 kg·hm^-2·a^-1, and dominated by leaf litter, accounting for 68.62%-87.26% of the total production. In C. lanceolata plantation, the litter fall production peaked in April-May, July, and December; while in S. superba and mixed plantations, this production only peaked in March. Comparing with pure plantations, mixed plantation had a higher litter fall production per tree of broadleaved S. superba while a lower litter fall production per tree of coniferous C. lanceolata. Leaf litter in the three plantations was the main body of the litter falls carbon return, and the total amount of the carbon return was the largest (2.12 t C·hm^-2·a^-1) in mixed plantation and the smallest (1.19 t C·hm^-2·a^-1) in C. lanceolata plantation, which was in accordance with the annual litter fall production of the plantations. This study demonstrated that comparing with pure coniferous or broadleaved plantation, coniferous-broadleaved mixed plantation had higher annual litter fall production and carbon return, and thus, higher potential of C sequestration.

Carbon losses from forest fire in Jiangxi Province, China in 1950-2008.

2010, 21(09):  2241-2248. 

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The annual occurrence of forest fire in Jiangxi Province of China in 1950-2008 was averaged 762 times and covering 1.578×10.4 hm². Based on the forest fire statistic data, meteorological data, forest inventory data, and other parameters, this paper analyzed the characters of forest fire in the province, and estimated its carbon release and transfer. In the province, the total forest biomass loss from forest fire in 1950-2008 was about 61.155 Tg, and the biomass carbon loss was about 30.993 Tg C, accounting for 15.92% of the vegetation carbon pool in the whole province. Before the 1970s, the biomass carbon loss occupied 74.3% of the total loss in 1950-2008, but after the 1990s, this loss decreased rapidly, with an annual average carbon loss less than 0.097 Tg C. The released CO₂, CH₄, and CO from the forest fire were about 5.408 Tg, 0.047 Tg, and 0.486 Tg, respectively, and led to 22.436 Tg of biomass carbon transferred into soil carbon. The  snow and ice disaster in the beginning of 2008 resulted in high frequency forest fire, and led to a 0.463 Tg biomass carbon loss, which was 2.56 times of the average value (0.181 Tg) in 2003-2007.

Spatiotemporal heterogeneity and its formation causes of soil physical properties in karst peak-cluster depression area of northwest Guangxi, China.

2010, 21(09):  2249-2256. 

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Soil samples were collected from the grassland, shrub land, secondary forest, and original forest on the hill slope in a typical karst peak-cluster depression area of northwest Guanxi, with the spatiotemporal heterogeneity of soil physical properties investigated by classical statistics, and the formation causes of the heterogeneity analyzed by redundancy analysis (RDA). In 0-15 cm soil layer, the clay (<0.002 mm) and silt (0.002-0.05 mm) contents of shrub land and original forest had significant differences  with those of grassland and  secondary forest, respectively, but the clay, silt, and sand (0.05-2.0 mm) contents had no significant differences between grassland and  secondary forest. No significant difference was observed in the soil sand content among the four land types, but the soil bulk density of grassland was significantly different from that of other three land types. The soil clay content of grassland increased with increasing elevation, while that of the other three land types was the highest on medium slope, and had no significant differences for the same land types  among different slope locations. The soil clay content in different layers of 0-30 cm had a greater variation extent in original forest (14.55%) than in grassland (7.12%), shrub land (11.24%), and secondary forest (13.77%), and the soil particle size composition was greatly affected by the disturbance of human activities. Soil organic carbon (SOC) and vegetation type were the dominant factors affecting the soil physical properties, and the bare rock ratio had greater effects on soil sand content.

Microbial community and its activities in canopy- and understory humus of two montane forest types in Ailao Mountains, Northwest China.

2010, 21(09):  2257-2266. 

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Mid-montane moist evergreen broadleaved forest (MMF) and top-montane dwarf mossy forest (DMF) are the two major natural forest types in subtropical mountainous area of Ailao Mountains, Northwest China. In this paper, a comparative study was made on the microbial composition, quantity, biochemical activity, metabolic activity, and their seasonal dynamics in the canopy-and understory humus of the two forest types. The composition, quantity, and metabolic activity of the microbes in the canopy humus of dominant tree species in MMF and DMF were also analyzed. In the canopy humus of the two forest types, the amounts of fungi and actinomycetes,  microbial biomass C and N, and intensities of nitrogen fixation and cellulose decomposition were significantly higher than those in understory humus. Meanwhile, the amount of cellulose-decomposing microbes (ACDM), cellulose decomposition intensity, microbial biomass C and N, and metabolic activity in the canopy humus of MMF were significantly higher than those of DMF. The amounts of bacteria, fungi, and aerobic nitrogen-fixing bacteria (ANFB) and the metabolic activity in the canopy humus of MMF and DMF were significantly higher in wet season than in dry season, while a contradictory trend was observed on the amount of actinomycetes. No significant difference was observed on the amount of ACDM between wet season and dry season. For the two forest types, the amounts of microbes and their biochemical activities in canopy humus had a larger seasonal variation range than those in understory humus. There was a significant difference  in the amounts of the microbes in canopy humus among the dominant tree species in MMF and DMF, especially in wet season. The microbes in canopy humus played important roles in maintaining the biodiversity of epiphytes in the canopy, and in supplying the needed nutrients for the vigorous growth of the epiphytes.

Effects of microbial agents on litter decomposition in urban protective greenbelts of arid zone.

2010, 21(09):  2267-2272. 

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In order to explore the ways for promoting litter decomposition in urban protective greenbelts of arid zone, litter falls were collected from the protective greenbelts in north suburb of Karamay, Xinjiang, and a composting experiment with the inoculation of three kinds of microbial agents, i.e., Qingzhu, Jiegan, and Sufu, was carried out for 198 days in late October 2007. At the early stage (0-30 d) of composing, inoculating microbial agents promoted the decomposition of the litter falls, and the effect of Sufu agent was significant, compared with CK. The N, P, and Ca concentrations in the composing litter falls increased persistently with time. By the end of the experiment, the nutrient concentrations in the composed litter falls were 14.2%-252.9% higher than their initial values. During the whole composing process, the decomposition rate of the litter falls organic C increased continuously, and the C/N ratio decreased gradually. It was suggested that inoculating microbial agents could accelerate the composting process, and increase the nutrient concentrations in composted litter falls. Among the three test microbial agents, Jiegan agent was the best one.

Soil soluble organic matter, microbial biomass, and enzyme activities in forest plantations in degraded red soil region of Jiangxi Province, China.

2010, 21(09):  2273-2278. 

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Taking the adjacent 18-year-old pure Pinus massoniana pure forest (Ⅰ), P. massoniana, Liquidamber fomosana, and Schima superba mixed forest (Ⅱ), S. superba pure forest (Ⅲ), L. fomosana  (Ⅳ) pure forest, and natural  restoration fallow land (CK) in Taihe County of Jiangxi Province as test sites, a comparative study was made on their soil soluble organic carbon (SOC) and nitrogen (SON), soil microbial biomass C (MBC) and N (MBN), and soil urease and asparaginase activities. In 0-10 cm soil layer, the pool sizes of SOC, SON, MBC, and MBN at test sites ranged in 354-1007 mg·kg^-1, 24-73 mg·kg^-1, 203-488 mg·kg^-1, and 24-65 mg·kg^-1, and the soil urease and asparaginase activities were 95-133 mg·kg^-1·d^-1 and 58-113 mg·kg^-1·d^-1, respectively. There were significant differences in the pool sizes of SOC, SON, MBC, and MBN and the asparaginase activity among the test sites, but no significant difference was observed in the urease activity. The pool sizes of SOC and SON were in the order of Ⅳ> CK> Ⅲ>Ⅰ>Ⅱ, those of MBC and MBN were in the order of CK>Ⅳ> Ⅲ >Ⅰ> Ⅱ, and asparaginase activity followed the order of Ⅳ>CK>Ⅲ>Ⅱ>Ⅰ.With the increase of soil depth, the pool sizes of SOC,SON, MBC, and MBN and the activities of soil asparaginase and urease decreased. In 0-20 cm soil layer, the SOC, SON, MBC, MBN, total C, and total N were highly correlated with each other, soil asparaginase activity was highly correlated with SOC, SON, TSN, total C, total N, MBC, and MBN, and soil urease activity was highly correlated with SON, TSN, total C, MBC and MBN.

Characteristics of soil organic carbon and total nitrogen under different land use types in Shanghai.

2010, 21(09):  2279-2287. 

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By the methods of field sampling and laboratory analysis, this paper studied the variations of soil organic carbon (SOC) and total nitrogen (TN) contents and SOC density under different land use types in Shanghai. Significant differences were observed in the test parameters among- different land use types. The SOC density was the highest in paddy field (3.86 kg·m^-2), followed by in upland (3.17 kg·m^-2), forestland (3.15 kg·m^-2), abandoned land (2.73 kg·m^-2), urban lawn ( 2.65 kg·m^-2), garden land (2.13 kg·m^-2 ), and tidal flat (1.38 kg·m^-2). The assessment on the effects of three types of land use change on the test parameters showed that the conversion of paddy field into upland resulted in a significant decrease of SOC and TN contents and SOC density；the abandonment of farmland was not an effective way in improving SOC storage in the Yangtze Delta region with abundant water and heat resources, high soil fertility, and high level of field management; while the 4-5 years conversion of paddy field into artificial forestland decreased the SOC and TN contents and SOC density, suggesting that in a short term, the soil carbon sequestration effect of the conversion from paddy field to forestland was at a low level, due to the limitation of vegetation productivity.

Passive nighttime warming （PNW）system, its design and warming effect.

2010, 21(09):  2288-2294. 

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Based on the technique of passive nighttime warming (PNW), a convenient and energy-saving PNW facility was designed for a rice-wheat cropping system in Danyang, Jiangsu Province. The facility could guarantee 15.75 m² effective sampling area, with a homogeneous amplitude of increased temperature, and making the nighttime canopy temperature during whole rice growth season increased averagely by 1.1 ℃ and the nighttime canopy temperature and 5 cm soil temperature during whole winter wheat growth period increased averagely by 1.3 ℃ and 0.8 ℃, respectively. During the operation period of the facility, the variation trends of the canopy temperature and 5 cm soil temperature during the whole growth periods of rice and winter wheat in the warming plots were similar to those of the control. Though the facility slightly decreased the soil moisture content during winter wheat growth period, wheat growth was less impacted. The application of this facility in our main production areas of rice and winter wheat showed that the facility could advance the initial blossoming stages of rice and winter wheat averagely by 3 d and 5 d, respectively. In despite of the discrepancy in the warming effect among different regions and seasons, this energy-saving facility was reliable for the field research on crop responses to climate warming, when the homogeneity of increased temperature, the effective area, and the effects on crop growth period were taken into comprehensive consideration.

Application of biotope mapping model integrated with vegetation cover continuity attributes in urban biodiversity conservation.

2010, 21(09):  2295-2303. 

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Based on the biotope classification system with vegetation structure as the framework, a modified biotope mapping model integrated with vegetation cover continuity attributes was developed, and applied to the study of the greenbelts in Helsingborg in southern Sweden. An evaluation of the vegetation cover continuity in the greenbelts was carried out by the comparisons of the vascular plant species richness in long-and short-continuity forests, based on the identification of woodland continuity by using ancient woodland indicator species (AWIS). In the test greenbelts, long-continuity woodlands had more AWIS. Among the forests where the dominant trees were more than 30-year-old, the long-continuity ones had a higher biodiversity of vascular plants, compared with the short-continuity ones with the similar vegetation structure. The modified biotope mapping model integrated with the continuity features of vegetation cover could be an important tool in investigating urban  biodiversity, and provide corresponding strategies for future urban biodiversity conservation.

Effects of applying controlled-release compound fertilizer on Platycodon grandiflorum growth.

2010, 21(09):  2304-2308. 

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A pot experiment was conducted in 2008 to study the effects of applying controlled-release compound fertilizer (N：P₂O₅：K₂O = 14:14：14) on the growth of Platycodon grandiflorum in the medicinal herbal farm of Shandong Agricultural University. Comparing with the application of common compound fertilizer (N：P₂O₅：K₂O=15：15：15), applying equivalent amount of the controlled-release fertilizer increased the leaf chlorophyll content, root volume, root activity, and root diameter of P. grandiflorum at the late growth stage, but decreased the root length. When the N application rate was 0.24 and 0.32 g·kg^-1soil, applying the controlled-release compound fertilizer increased the root yield by 26.78% and 22.50%, and the root soluble sugar, protein, and total saponin contents by 9.77% and 6.99%, 11.38% and 2.20%, and 8.85% and 5.47%, respectively, compared with applying the common compound fertilizer. More nitrogen application made the root soluble sugar content decreased  but the total saponin content increased. Under our experimental condition, applying the controlled-release compound fertilizer with an application rate of 0.24 g N·kg^-1soil could obtain the best effect for P. grandiflorum.

Effects of controlled-release N and K fertilizers on N, P, and K use efficiency of mauls (Malus- robusta).

2010, 21(09):  2309-2316. 

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A pot experiment was conducted to study the effects of controlled-release N and K fertilizers on mauls seedlings growth, their P and K use efficiency, and the N balance in soil-plant system. The results showed that the nutrient release from controlled-release fertilizers accorded well with the nutrient requirement of mauls seedlings. Controlled-release N fertilizer significantly increased the K use efficiency, and controlled-release K fertilizer significantly increased the N use efficiency. Under the same K application rate, the plant height and stem diameter under the application of controlled-release N fertilizer (CN) and controlled-release N and K fertilizers (NK) had no significant difference, while those under the application of common fertilizer (SF) were all higher. The plant dry mass and the P and K use efficiency were in the order of NK＞CN＞SF. Under the application of NK, the application rate of K had no significant effects on the plant height and stem diameter, but significantly affected the plant dry mass. The P use efficiency increased with increasing application rate of controlled-release K fertilizer, but was less affected by application rate common K fertilizer. The K use efficiency decreased with increasing application rate of K. The N use efficiency was in the order of NK＞CN＞SF, while the N-loss rate was in adverse. The residual rate of NK and CN had no significant difference, but was higher than that of SF. The application rate of controlled-release K fertilizer had significant effects on the N use efficiency and N loss rate, but no significant effects on N residual rate.

Effects of grafting on cucumber rhizospheric soil microbial characteristics and enzyme activities under copper stress.

2010, 21(09):  2317-2322. 

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A pot experiment with cucumber (taking Cucurbita ficifolia B. as the rootstock) was conducted to study the effects of grafting on the microbial population, microbial biomass, and enzyme activities in rhizospheric soil under copper stress. Under the stress of copper, the microbial biomass C and N in grafted and self-rooted cucumber rhizospheric soils all decreased significantly, while the basal respiration and metabolic quotient were in adverse. In grafted cucumber rhizospheric soil, the microbial biomass C and N were significantly higher than those in self-rooted cucumber rhizospheric soil, whereas the basal respiration and metabolic quotient were significantly lower. Under copper stress, the quantities of actinomyces and nitrogen-fixing bacteria in rhizospheric soils decreased and that of fungi increased significantly, whereas the quantity of bacteria had less change. In grafted cucumber rhizospheric soil, the quantities of bacteria, actinomyces, and nitrogen-fixing bacteria were significantly higher than those in self-rooted cucumber rhizospheric soil, but the quantity of fungi was in opposite. The urease, phosphatase, sucrase, and catalase activities were significantly higher in grafted than in self-rooted cucumber rhizospheric soil. All the results suggested that grafting could mitigate the impact of copper stress on the microbial micro-environment and enzyme activities in cucumber rhizospheric soil, and as a result, improve the adaptability of cucumber to copper stress.

Soil microbial biomass and respiration rate under effects of different planting patterns of peanut.

2010, 21(09):  2323-2328. 

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A field experiment with randomized design was conducted to study the effects of six planting patterns of peanut, i.e., spring sowing and plastic film mulching, spring sowing and open cultivation, summer sowing and plastic film mulching, summer sowing and open cultivation, intercropped in wheat field, and control of intercropped in wheat field, on soil microbial biomass C, soil active microbial biomass, and soil respiration rate. The results showed that the growth stage and planting pattern of peanut had significant effects on soil microbial biomass and respiration rate. With the prolonged time after anthesis, soil microbial biomass C, active microbial biomass, and respiration rate increased gradually, peaked at pod-setting stage, and decreased then. Open cultivation enhanced soil microbial biomass C and respiration rate but reduced soil active microbial biomass, being unfavorable to soil nutrient transformation and nutrient availability, while plastic film mulching increased soil active microbial biomass, and consequently, promoted soil nutrient transformation and nutrient availability. Comparing with intercropped in wheat field and open cultivation, intercropped in wheat field and plastic film mulching increased soil microbial biomass C, active microbial biomass, and respiration rate, which immobilized more soil nutrients and was not conducive to peanut growth.

Effects of bagging on light use efficiency of tomato fruit photosystem Ⅱ.

2010, 21(09):  2329-2334. 

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In a greenhouse experiment, white laminating bags were applied to bag the tomato cultivar ‘Baoluota’ fruits, with the absorption spectra and chlorophyll fluorescence parameters of the fruits measured by optical spectrometer and Mini-Imaging-Pam after different bagging time, aimed to investigate the effects of bagging on the light use efficiency of photosystem Ⅱ of the fruits. In the first 20 days of bagging, no significant effects of bagging were observed on the chlorophyll a (Chl a) content and the maximum quantum yield of PSⅡ (F_v/F_m) of the fruits, but the relative absorption coefficient (A_670/780) and the effective quantum yield of PS Ⅱ （Y_Ⅱ) were reduced, compared with the control. In this period, the regulatory energy dissipation of PSⅡ played an important role. After then, the Chl a and Chl b contents of bagged fruits decreased markedly, but the F_v/F_m,Y_Ⅱ, and A_670/780 had no significant differences with the control. On the 40th day of bagging, the Chl a and Chl b contents of bagged fruits decreased by 35.2% and 52.8%, but theF_v/F_m and Y_Ⅱ increased by 24.5% and 35.4%, respectively, suggesting that at this time, the PSⅡof bagged tomato fruits had a higher light use efficiency, which provided energy foundation for the earlier ripening of the bagged fruits via further reducing the quantum yield of non-regulatory energy dissipation (Y_NO).

Effects of applying different nitrogen form on cherry tomato nitrogen metabolism during fruit development.

2010, 21(09):  2335-2341. 

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A hydroponic experiment  was conducted to study the effects of applying 100% NO₃^--N,100% NH₄⁺-N, and 75% NO₃^--N＋25% NH₄⁺-N on the nitrogen metabolism and the nitrate reductase (NR) and glutamine synthetase (GS) gene expression of cherry tomato during its fruit development. Applying 75% NO₃^--N＋25% NH₄⁺-N slightly increased the single fruit mass, and increased the fruit NH₄⁺-N, total amino acid, and total N contents and N accumulation significantly, compared with applying 100% NO₃^--N. In treatments 100% NO₃^--N and 75% NO₃^--N＋25% NH₄⁺-N, the fruit NR activity and its gene expression had no significant difference, but were higher than those in treatment 100% NH₄⁺-N. The fruit GS activity was significantly higher in treatment 75% NO₃^--N＋25% NH₄⁺-Nthan in treatment 100% NO₃^--N. In the three treatments, isozyme GS1 (Cytosolic type GS) and GS2 (Chloroplast type GS) expression was inconsistent with GS activity, suggesting that the effects of applied N on GS activity could be mainly reflected at posttranscriptional level.

Effects of nitrogen fertilization on wheat leaf photosynthesis under elevated atmospheric CO₂ concentration.

2010, 21(09):  2342-2346. 

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In this paper, the effects of nitrogen (N) fertilization on the wheat leaf photosynthesis under long-term elevated atmospheric CO₂ concentration (760 μmol·mol^-1) was studied, based on the measurements of photosynthetic gas exchange parameters and light intensity-photosynthetic rate response curves at jointing stage. Under the long-term elevated atmospheric CO₂ concentration, applying sufficient N could increase the wheat leaf photosynthetic rate (P_n), transpiration rate (T_r), and instantaneous water use efficiency (WUE_i). Comparing with those under ambient atmospheric CO₂ concentration, the P_n and WUE_i under the elevated atmospheric CO₂ concentration increased, while the stomatal conductance (G_s) and intercellular CO2 concentration (C_i) decreased. With the increase of light flux intensity, the P_n and WUE_i under the elevated atmospheric CO₂ concentration were higher those under ambient atmospheric CO₂ concentration, G_s was in adverse, while C_i and T_r had less change. At high fertilization rate of N, the G_s was linearly positively correlated with P_n, T_r, and WUE_i, and the G_s and C_i had no correlation with each other under the elevated atmospheric CO₂ concentration but negatively correlated under ambient atmospheric CO₂ concentration. At low fertilization rate of N, the G_s had no correlations with P_n and WUE_i but linearly positively correlated with C_i and T_r. It was suggested that under the elevated atmospheric CO₂ concentration, the wheat leaf P_n at low N fertilization rate was limited by non-stomatal factor.

Effects of high concentration ozone on soybean growth and grain yield.

2010, 21(09):  2347-2352. 

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By using open top chambers (OTCs), soybean plants were grown in pots, and exposed to charcoal-filtered air (［O₃］<10 μg·kg^-1) and elevated O₃(80 μg·kg^-1) after anthesis, aimed to investigate the responses of soybean’s agronomic characters, leaf area, chlorophyll content, antioxidant system, and grain yield to elevated O₃. Under elevated O₃, the leaf area and chlorophyll content decreased significantly (P<0.05), and the leaf catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) activities had a significant increase(P<0.01) first but a gradual decrease then, compared with those under charcoal-filtered air. Elevated O₃ decreased the leaf soluble protein and ascorbate content (AsA) contents while increased the leaf malonaldehyde (MDA) content (P<0.05), suggesting that the leaf membrane lipid peroxidation was accelerated. The dry mass per plant, effective pod number, grain number, 100-grains weight, and grain yield under elevated O₃ had somewhat decreased, among which, grain yield decreased significantly, with the decrement reached to 47% (P<0.01).

Effects of combined application of biogas residues and chemical fertilizers on greenhouse tomato’s growth and its fruit yield and quality.

2010, 21(09):  2353-2357. 

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With randomized block design, a field experiment was conducted in greenhouse to study the effects of combined application of biogas residues and chemical fertilizers on the tomato growth and its fruit yield and quality. The combined application of biogas residues and chemical fertilizers benefited the tomato growth and its fruit yield and quality. The yield of  the combined application of 60% biogas residues and 40% chemical fertilizers were higher than the other treatments. The fruit quality under the application of 60% biogas residue and 40% chemical fertilizers also improved significantly, with the Vc content (91.09 mg·kg^-1) and total sugar content being 21.32 mg·kg^-1and 2.13% higher than the control, respectively. Among the test fertilization combinations, 60% biogas residue combined with 40% chemical fertilizers was the best one for greenhouse tomato’s growth and its fruit yield and quality.

Responses of Nicotiana tabacum morphology and photosynthetic physiology to reduced ultraviolet-B radiation.

2010, 21(09):  2358-2366. 

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By the method of canopy film-covering to reduce UV-B radiation, this paper studied the responses of the morphology and photosynthetic physiology of Nicotiana tabacum cultivar K326 at its physiological, technical, and physiological-technical transitional maturity stages in high -elevation tobacco-growing area of Yunnan. Three treatments were installed, i.e., reducing 75.74% (T₁), 70.08% (T₂), and 30.39% (T₃) of natural solar UV-B radiation. Reducing UV-B radiation increased the stem height and the internode distance of K326 significantly, with the larger values in T₂. Comparing with those under natural UV-B radiation condition, the leaf net photosynthetic rate (P_n), assimilation capacity (AC), water use efficiency (WUE), intrinsic water
use efficiency (WUE_i), photosynthetic pigments (PP) and flavonoids (FL) contents, and specific leaf mass (SLM) in T₁ and T₂ all decreased, with larger decrement in T₂. The factors affecting the P_n in T₁ and T₂ were stomatal and non-stomatal, and the latter was the main one. The major reason of the lower WUE in T₁ and T₂ was due to the increase of transpiration rate (T_r) caused by low stomatal regulation capability. In T₃, the P_n,AC, WUE, WUE_i, and PP increased but the FL and PP decreased to the lowest levels at physiological and transitional maturity stages, and the PP degradation rate was faster at the technical maturity stage.

Community structure of soil fauna in Eucalyptus grandis plantations at different slope locations.

2010, 21(09):  2367-2374. 

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To understand the effects of slope location on the community structure of soil fauna in Eucalyptus grandis plantation, an investigation was made in the soil fauna in 3 E.grandis plantations at different slope locations in the hilly area of Sichuan Province from January to October 2009. A total of 392762 individuals were observed, belonging to 146 groups, 7 phyla, 16 classes, and 31 orders. The community composition, trophic group, diversity, and seasonal dynamics of soil fauna in the plantations all varied with slope. The abundance of macro-fauna, xeric meso- and micro-fauna, saprophagous macro-fauna, and omnivorous xeric meso-and micro-fauna increased with the decrease of slope, indicating that soil fauna had sensitive responses to the soil environmental factors affected by slope. Significant differences in the diversity of soil saprophagous macro-fauna and hygrophilous meso- and micro-fauna were observed at different slope locations, suggesting that these two faunal groups could be used as the indicators of the habitat heterogeneity of E. grandis plantations at different slope. Overall, slope location had definite effects on the community structure and distribution of soil fauna in the E. grandis plantations, but the effects were not statistically significant.

Darkling beetle community structure and its relations with environmental factors in Sidunzi of Yanchi, Ningxia, China.

2010, 21(09):  2375-2382. 

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From March to October 2009, a field survey was conducted on the darkling beetle community structure and related environmental factors in the desert grasslands with different vegetation cover and human disturbance intensity in Sidunzi of Yanchi, Ningxia, China. By using diversity index and canonical correspondence analysis (CCA), the relationships between the beetle community structure and related environmental factors were analyzed. A total of 5431 individuals were collected, belonging to 20 species and 10 genera. Blaps femoralis femoralis, Microdera kraatzi kraatzi, and Platyope mongolica were the dominant species, accounting for 47.30%, 39.90%, and 3.59% of the total, respectively. CCA explained 100% of the correlations between the beetle species and related environmental factors, suggesting that the occurrence of the beetle species had close relations to the changes of related environmental factors. Among the environmental factors, the Shannon diversity index of plant community (HP), plant biomass (BP), and soil water content (SW) affected the beetle species occurrence most. The occurrence frequency of Mantichorula semenowi, Anatolica amoenula, A. sternalis, and A. gravidula was negatively correlated with BP and plant coverage (CP), and that of B. gobiensis, Cyphogenia chinensis, Gonocephalum reticuluatum, and Crypticus rufipes was positively correlated with plant density (DP) and SW. The distribution of P. mongolica, M. kraatzi kraatzi, Scytosoma pygmaeum, and B. kiritshenkoi showed a positive correlation to HP, and that of Eumylada oberbergeri, B. femoralis femoralis, and B. davidea showed a positive correlation to BP and CP. There was a significant positive correlation (r=0.943, P=0.005) between the beetle activity density and SW. The CCA ordination showed that the darkling beetles had different demands for multidimensional ecological resources in desert and semi-desert ecosystems.

Anti-erosion effect of hedgerows in hillside croplands of Danjiangkou based on the evaluation with water erosion prediction project (WEPP) model.

2010, 21(09):  2383-2388. 

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Based on the data of field experiments on the hillside croplands of Danjiangkou, Hubei Province of China, the input files of crop characters, management measures, slope gradient and length, and soil properties for running WEPP model (Hillslope version) were established. Combining with the local weather data, a simulation study with the model was made on the runoff and soil loss of the croplands protected by four kinds of hedgerows (Amorpha fruticosa, Lonicera japonica, Hemerocallis fulva, and Poa sphondylodes) in Danjiangkou area. The resulted showed that WEPP model could accurately simulate the anti-erosion effect of hedgerows in hillside farmlands in the study area. Using this model not only reduced test number, but also saved time and effort, being able to provide scientific basis for the popularization and application of hedgerows. Among the four hedgerows, Amorpha fruticosa had the best anti-erosion effect. According to the simulation, the optimal planting density of A. fruticosa hedgerows in the farmlands was 1 m×15 m at slope gradient 5°, 1 m×10 m at slope gradient 15°, and 1 m×3 m at slope gradient 25°.

Impacts of uncertainty in data processing on estimation of CO₂ flux components.

2010, 21(09):  2389-2396. 

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Based on the eddy covariance observations at 4 sites (2 forested sites and 2 grassland sites) in Chinese Terrestrial Ecosystem Flux Research Network (ChinaFLUX), this paper analyzed the effects of three data processing methods, i.e., spike detection, threshold (u^*_c) determination of nocturnal friction velocity (u^*), and gap-filling model selection, on the estimation of CO₂ flux components. All the three methods had significant impacts on the estimation of annual net ecosystem exchange (NEE), and the determination of (u^*_c) was an important factor affecting the annual NEE estimation. The estimation deviation of the annual NEE caused by spike detection, determination of (u^*_c), and gap-filling model selection was 0.62-21.31 gC·m^-2·a^-1 (0.84%-65.31%), 4.06-30.28g C·m^-2·a^-1(3.76%-21.58%), and 0.69-27.73 g C·m^-2·a^-1(0.23%-55.62%), respectively. Comparing with that of forested ecosystem, the NEE estimation of grassland ecosystem was more sensitive to the parameter setting of data processing method, and the relative estimation deviation of annual gross ecosystem exchange and ecosystem respiration induced by the uncertainty in data processing was 3.88%-11.41% and 6.45%-24.91%, respectively.

Distribution characteristics of heavy metals in soil profile of facility vegetable fields.

2010, 21(09):  2397-2402. 

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Taking the facility vegetable fields having been planted for 1-12 years and the adjacent wheat land in Shouguang City of Shandong Province as test objects, this paper studied the distribution characteristics of arsenic (As), cadmium (Cd), copper (Cu), zinc (Zn), chromium (Cr), and nickel (Ni) in their soil profiles (0-150 cm). With the increase of soil depth, the test heavy metals contents in the soil profiles all had a decreasing trend, and in the same soil layers, the contents were obviously higher in facility vegetable fields than in wheat land. Comparing with those in the same soil layers of wheat land, the average contents of As, Cd, Cu, Zn, Cr, and Ni in 0-20 and 120-150 cm soil layers of facility vegetable fields were 35.0%, 146.2%, 65.6%, 36.4%, and 21.5%, and 10.6%, 178.5%, 19.4%, 20.2%, 15.2%, and 9.3% higher, respectively, and the average contents of the heavy metals in 20-120 cm soil layer of facility vegetable fields were also higher in some degree. In the 0-20 cm soil layer of facility vegetable fields, the Cd, Cu, and Zn contents had significant positive correlations with planting years (P<0.05), with the accumulation rates of Cd, Cu, and Zn being 0.027, 1.153, and 2.830 mg·kg^-1·a^-1, respectively. In facility vegetable fields, the test six heavy metals contents were significantly positively correlated with the contents of soil organic carbon and total nitrogen, and the Cd, Cu, Zn, and Cr contents were significantly correlated with the content of soil total phosphorus (P<0.01). Applying organic fertilizer could induce the heavy metals accumulation in the soils of facility vegetable fields to some extent.

Variations of fish species diversity, faunal assemblage, and abundances in Daya Bay in 1980-2007.

2010, 21(09):  2403-2410. 

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Based on the 2004-2005 otter trawl survey data and the 1980-2007 relevant historical records, this paper analyzed the variations of fish species composition, faunal assemblage, diversity indices, dominant species, and abundance in Daya Bay. In the 2004-2005 trawl survey, a total of 107 fish species were recorded, belonging to 50 families and 13 orders, among which, meso-demersal fish were predominant, with 48 species recorded, and followed by pelagic and demersal fishes, with 37 and 21 species, respectively. The fishes in the Bay belonged to tropical and subtropical fauna, with the dominance of warm water fishes (97 species) and warmtemperate water fishes (10 species). The diversity index was the highest in summer (3.82), followed by in winter (3.37) and autumn (3.00), and the lowest in spring (2.40). The seasonal variation of Pielou evenness index mimicked that of diversity index. In 1980-2007, the characteristics of fish community in the Bay changed obviously. The species number reduced from 157 species in the 1980s to 110 species in the 1990s and to 107 species in 2004-2005, and the dominant species shifted from the high-value fishes such as hairtail and pomfret in the 1980s to low-value fishes such as sardine fish, anchovy, and juvenile porgy. A non-linear regression model composed of inter-annual trend and seasonal cycle was used to simulate the changes of fish stock density in 1980-1999 and 1990-2007, and the results indicated that in the two periods, the fish stock density in the Bay all showed a decreasing trend, but the decrement was larger in 1990-2007 than in 1980-1999. The seasonal variation of the stock density in 1980-1999 was relatively small, with an amplitude being 0.099, while that in 1990-2007 was relatively larger, with the amplitude being 0.420, illustrating that the fish abundance in the Bay had a larger seasonal fluctuation in 1990-2007.

Effects of salinity on haematological biochemistrical indices and liver tissue in juvenile Oncorhynchus keta.

2010, 21(09):  2411-2417. 

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In order to simulate the catadromous migration environment of the juvenile salmon (Oncorhynchus keta), five experimental groups containing different salinities (0, 5, 10, 15 and 20) were set up. The juvenile salmons with average body mass of (26.57±6.32) g and average full length of (14.44±1.05) cm were cultured for 130 days, and then the haematological biochemistrical indices was analyzed and the structure of liver tissue was observed to investigate the changes in physiological indices during the catadromous migration of juvenile salmon. The results showed that serum osmolality and the concentration of Na⁺, Cl^- illustrated the same tendency with water salinity variation. Specifically, the serum Na⁺, Cl^- and Mg²⁺ levels in the salinities of 15, 20 were significantly different from those in the salinity 5 and the freshwater and serum K⁺ in different salinities were all obviously lower than that in the freshwater . Also, the blood glucose level in salinity 10 was significantly higher than that in salinity 5 and 20, whereas total serum protein (TP), albumin (ALB) and globulin (GLB) levels all declined with the increase of salinity and the serum TP and GLB content in the freshwater group was remarkably higher than those in the salinity 15 and 20. There also existed an obvious discrepancy on total bile acids in freshwater group and the
other salinity groups. The alanine aminotransferase (ALT) activity and aspartate aminotransferase (AST) activity in fresh water group were far different from those of the high salinity groups. Furthermore, in the low salinities (0 and 5), the liver cells of juvenile chum salmon partly broke down, and liver tissue was serious vacuolization. Collectively, the growth and survival rate had no significant difference in all groups and according to the physiological and biochemical indices, the appropriated salinity for juvenile chum salmon ranged from 10 to 20 during the catadromous migration.

Heavy metals cycling and its regulation in China cropland ecosystems.

2010, 21(09):  2418-2426. 

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This paper analyzed the current situation of heavy metal contamination in  cropland soils in China, and discussed the input, output, and balance of heavy metals in  cropland ecosystems. It was considered that heavy metals had definite accumulation in cropland ecosystems, but overall speaking, this accumulation had relatively small environmental risk, and only some plants, especially vegetables, accumulated heavy metals over the standards. In mining areas, adjacent areas of smelting plants, and the farming areas using larger amounts of related wastes, the heavy metals content in plants and soils was at least ten times higher than that in normal croplands, existing larger environmental risk. Aiming at the current situation of heavy metal contamination of farmland soils in China, some effective regulation measures for the heavy metal cycling in the cropland ecosystems were proposed, and the further research prospects in related fields were discussed.

Methods for determining plant water source in thin soil region: A review.

2010, 21(09):  2427-2433. 

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Plant water source depends on the distribution of available water in the environment, and the capability of plants in capturingwater. In dry season, the soil water in thin soil region cannot satisfy the demand of normal plant growth, and whether the plants can use the water stored in weathered bedrock is the key for them to maintain their normal water consumption. This paper reviewed the research methods for determining the plant water source in thin soil region, including investigating and analyzing the characteristics of root growth and distribution, monitoring the changes of water content at various depths below ground surface, monitoring and analyzing the seasonal variation of plant water status, and identifying the plant water source by stable isotope techniques. The advantages and disadvantages of these methods and their potential applications in tracing plant water source in karst region of Southwest China were discussed.

Research advances in the effects of host plant volatiles on Cydia pomonella behaviors and the application of the volatiles in pest control.

2010, 21(09):  2434-2440. 

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Codling moth (Cydia pomonella) is a worldwide pest of stone fruit trees, and an important quarantine target in China. Its occurrence, damage, and potential expansion in this country should be seriously concerned. Host plant volatiles, the species-specific attractants of C. pomonella, have attracted extensive attention. This paper reviewed the researches on the interactions between host plant source volatiles and C. pomonella, with the focus on the effects of the volatiles on the behaviors of C. pomonella, e.g., host orientation, courting and mating, and spawning, etc., the changes of the volatile components released by the host plants after fed by C. pomonella larvae, and the impacts of the volatiles on the sex pheromone of C. pomonella. The research progress and field application of plant source pear ester were also introduced, aimed to provide a reference for the prevention and control of C. pomonella in China.

Interrelationships between soil fauna and soil environmental factors in China: Research advance.

2010, 21(09):  2441-2448. 

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Soil fauna has close relations with various environmental factors in soil ecosystem. To explore the interrelationships between soil fauna and soil environmental factors is of vital importance to deep understand the dynamics of soil ecosystem and to assess the functioning of the ecosystem. The environmental factors affecting soil fauna can be classified as soil properties and soil external environment. The former contains soil basic physical and chemical properties, soil moisture, and soil pollution. The latter includes vegetation, land use type, landform, and climate, etc. From these aspects, this paper summarized the published literatures in China on the interrelationships between soil fauna and soil environmental factors. It was considered that several problems were existed in related studies, e.g., fewer researches were made in integrating soil fauna’s bio-indicator function, research methods were needed to be improved, and the studies on the multi-environmental factors and their large scale spatial-temporal variability were in deficiency. Corresponding suggestions were proposed, i.e.,more work should be done according to the practical needs, advanced experiences from abroad should be referenced, and comprehensive studies on multienvironmental factors and longterm monitoring should be conducted on large scale areas.