Table of Content

10 October 2016, Volume 35 Issue 10

Previous Issue    Next Issue

Effect of grassland utilization pattern on spatial heterogeneity of Stipa grandis population in a typical steppe.

CHEN Wan-jie, XUE Wen-jie, GU Chen, DU Yu-fan, WANG Xi, ZHAO Meng-li*

2016, 35(10):  2569-2574. 

Asbtract ( 397 )   PDF (1408KB) ( 218 )  

Spatial distribution heterogeneity of Stipa grandis population at small scale in a typical steppe in Xilinhot, Inner Mongolia under two utilization ways (mowing and grazing) and exclosure (control) was studied by using semivariance analysis, fractal analysis and Kriging interpolated analysis based on field investigation data. The results showed that the highest population density of S. grandis was observed in the mowing plots, followed by the grazing plots, and the control plots had the lowest population density (P<0.05). The population structure ratio of S. grandis in the exclosure plots was 95.3%, indicating a strong spatial autocorrelation; while the population structure ratios of S. grandis in the mowing plots and grazing plots were 70.2% and 62.5% respectively, indicating a medium degree spatial autocorrelation. The spatial heterogeneity of S. grandis population was in order of mowing plots > grazing plots > exclosure plots. The optimal models of S. grandis population spatial distribution for exclosure, mowing and grazing plots were Gaussian model, spherical model and spherical model, according to fitting semivariogram. The spatial variation of S. grandis in the exclosure plots was affected by structural factors and trended to a simple distribution pattern, while the spatial variation of S. grandis in the mowing plots and grazing plots was affected by both structural factors and random factors, and showed a mosaic distribution pattern of high density patches and low density patches.

Interspecific association of dominant species in Taxus chinensis var. mairei community of Lingchuan in Shanxi.

WANG Xia1, TIE Jun2,3*, LI Yan-fen1, LIU Ze-yu1

2016, 35(10):  2575-2582. 

Asbtract ( 347 )   PDF (628KB) ( 215 )  

To provide basis for effective utilization and protection of endangered plant Taxus chinensis var. mairei resources in Shanxi, this paper studied interspecific associations among 300 species pairs of 25 dominant species in T. chinensis var. mairei community by using χ² test, Pearson correlation and Spearman rank analysis in Lingchuan Nature Reserve in Shanxi. Moreover, the detrended correspondence analysis was used to carry out the division of ecological species groups of dominant species. The results showed that the number of negatively correlated pairs was greater than that of the positively correlated pairs for the dominant species of T. chinensis var. mairei community, indicating that dominant species in T. chinensis var. mairei community in Lingchuan Nature Reserve did not correlate with each other significantly. The community maturity was lower and structure stability was poorer. Thus, the community was still at the early or middle stage of succession. The correlation among most species in T. chinensis var. mairei community did not reach a significant level and the independence of species was relatively strong, which may be related to habitat heterogeneity, and the different biological characteristics and ecological needs of the different species. According to the adapting ways of the dominant populations in T. chinensis var. mairei community and the leading ecological factors in the help of DCA ordination, the 25 dominant species in the T. chinensis var. mairei community could be classified into three ecological species groups.

Spatial pattern and spatial association of Myricaria bracteata and Tamarix ramosissima in Zhangye wetland.

FENG Wei, ZHAO Cheng-zhang*, HAN Ling, XU Ting, ZHENG Hui-ling, DUAN Bei-bei

2016, 35(10):  2583-2591. 

Asbtract ( 490 )   PDF (801KB) ( 123 )  

The spatial patterns and spatial association of plant populations are the results of coordinated adaptation of plants to environment. The spatial distribution and spatial association of Myricaria bracteata and Tamarix ramosissima were studied by using the methods of community survey and point pattern analysis. Four types of soil texture plots were chosen, including gravelly soil (Ⅰ), half naked gravel soil (Ⅱ), coarse sand (Ⅲ), and silty sand (Ⅳ) in the floodplain wetland of middle reaches of the Heihe River. The results showed that, with the size fraction of soil changing from coarse to fine, the M. bracteata plant height decreased firstly and then increased, twig number, branch density and the proportion of small bunch declined, while the T. ramosissima plant height and twig number increased, branch density and the proportion of small bunch increased firstly and then decreased. At the plots Ⅰ, Ⅱ and Ⅲ, the M. bracteata population showed a clumped distribution on different scales, which shifted from a larger scale to a smaller scale, while it showed a random distribution on all scales at the plot Ⅳ. At the plots Ⅰ, Ⅱ and Ⅲ, the T. ramosissima population showed a clumped distribution but with an opposite variation trend, while it showed a random distribution on all scales at the plot Ⅳ. At the plots Ⅰ and Ⅲ, the spatial association between M. bracteata and T. ramosissima showed a negative correlation or no significant correlation; at the plot Ⅱ, the spatial association transferred from significantly negative to significantly positive; at the plot Ⅳ, the spatial association shifted from significantly negative to not significantly. With the effects of environmental heterogeneity in the floodplain wetland, the plants’ asymmetric competition caused the change of dominant position of plant population and the scale transformation of spatial patterns, reflecting the strategy of plant’s adaptation to environment.

Floral syndrome and breeding system of Gymnocarpos przewalskii Maxim.

LI Xin-rong*， TANG Xin, FU Wen-jie

2016, 35(10):  2592-2598. 

Asbtract ( 433 )   PDF (1940KB) ( 158 )  

Gymnocarpus przewalskii, a rare Tertiary relict species in the desert region of Central Asia, is a vital constructive species that constitutes the stony desert vegetation community, and its natural population is declining due to human interference. In the present study, based on field observations and artificial pollination experiments, we investigated the floral characteristics and breeding system of G. przewalskii, which are highly important for revealing its life history characteristics, discussing factors that affect the success of its reproduction, and developing conservation and management strategies. G. przewalskii is a plant with bisexual flowers that are small and apetalous. Each flower has 1 ovule and 10 stamens, with the 5 outerwhorl stamens being abortive. During anthesis, the flower has a small amount of nectar with strong unpleasant odor. During this period, there is a 46hour overlap between pollen viability and stigma receptivity and the incomplete female becomes mature first; in addition, the stigma does not come in contact with the anthers when the uniflorous florescence of most flowers ends. Thus, G. przewalskii flowers mainly exhibit herkogamy and adapt to crosspollination with a pollen/ovule (P/O) ratio of 1371.67 ± 236.21 and outcrossing coefficient of 3. Pollen from different sources (natural pollination, selfpollination, geitonogamy, and xenogamy) can all germinate on the stigma, but the growth rates of the pollen tubes vary. In geitonogamy and xenogamy, the pollen tubes grow faster, while in selfpollination, the growth is slowest, with growth ceasing in part of the pollen tube (43%) as it approaches the ovary, thereby it is not able to reach the ovule. The experimental results of artificial bagging show that G. przewalskii is apogamous and has few naturally born seeds, and the number of the seeds of naturally pollinated flowers is much lower than that of artificial xenogamous flowers, indicating the existence of pollination restriction caused by the insufficiency of crosspollinators. Partial protogyny and herkogamy in G. przewalskii are a floral mechanism adopted by the bisexual flowers to avoid the functional overlap of males and females and to promote outcrossing. The breeding system of G. przewalskii is facultatively xenogamous and it requires pollinators. The success of its sexual reproduction is mainly affected by two factors, partial selfincompatibility and pollination restriction.

Leaf functional traits of main plants in a mixed evergreen and deciduous broad-leaved forest in Mt. Gongga.

PENG A-hui1,2, WANG Gen-xu1, LUO Ji1, YANG Yang1, RAN Fei1, YANG Yan1*

2016, 35(10):  2599-2605. 

Asbtract ( 488 )   PDF (856KB) ( 174 )  

Five main species of a mixed evergreen and deciduous broad-leaved forest in Mt. Gongga were employed to investigate their plant functional traits including specific leaf area (SLA), leaf dry weight (LDW), leaf carbon (C), nitrogen (N) and phosphorus (P) concentrations, and leaf isotope (δ¹³C, δ¹⁵N). Our aims were to explore the difference of the leaf functional traits of the main species and their interrelations, and reveal the relationship between nutrient use efficiency and water use efficiency of these species and how such relationship may affect the growth and nutrient cycles of these species. The results showed that a significant difference in SLA was found between evergreen and deciduous species. Leaf C concentration was negatively related with leaf N and P concentrations. Significant positive relationships between leaf N and P concentrations and between C∶N and C∶P were observed. In addition, leaf SLA increased with increasing leaf N concentration and N∶P ratio, but decreased with increasing C concentration, δ¹³C, and C∶N ratio. No relationship between δ¹³C and C∶N ratio was detected in the study. Moreover, our results showed that plants with the higher SLA exhibited the higher leaf N, but the lower leaf C concentration, nitrogen use efficiency and water use efficiency. There was no tradeoff between WUE and NUE for the main species in the mixed evergreen and deciduous broad-leaved forest, indicating that the water and nitrogen coupling mechanism was not employed in the humid environment. The relict plants (Indigofera souliei and Cercidiphyllum japonicum) took a different nutrient use strategy compared with other non-relict tree species, and formed niche differentiation thus co-existing in the community.

Response of photosynthetic characteristics and antioxidant system in needles and bark chlorenchyma of Korean pine to drought stress and rehydration.

ZHANG Dan, REN Jie, WANG Hui-Mei*

2016, 35(10):  2606-2614. 

Asbtract ( 483 )   PDF (860KB) ( 128 )  

The effects of drought stress and rehydration on photosynthetic characteristics and antioxidant enzyme activities of needles and bark chlorenchyma of Korean pine were studied. The results showed that the total chlorophyll content and chlorophyll a/b of needles and bark chlorenchyma decreased significantly under drought stress, reducing the PSII antenna to capture light energy and thus the risk of photoinhibition. The main reason for restricting net photosynthetic rate (P_n) of needles was nonstomatal limitation and the main reason for restricting P_n of bark chlorenchyma was stomatal limitation. Nonphotochemical quenching (NPQ) of needles and bark chlorenchyma were significantly increased under drought stress, indicating that thermal dissipation is an important photoprotection mechanism. Malondialdehyde (MDA) contents in needles and bark chlorenchyma were significantly increased under drought stress, resulting in oxidative stress. Increased SOD activity played an active role in drought stress defense of pine. After rehydration, P_n of needles and bark chlorenchyma recovered to the level of the control. Chlorophyll fluorescence parameters and antioxidant enzyme activities also recovered to varying degrees. These results suggest that needles and bark chlorenchyma of Korean pine can stabilize the photosynthetic apparatus function by enhancement of thermal dissipation and antioxidant enzyme activity, and that Korean pine has a good recovery after rehydration and strong adaptability to drought stress.

Rhizome and root competitive effects of bamboo in Phyllostachys edulis and Ph. prominens mixed forest.

GUO Zi-wu1, CHEN Shuang-lin1*, JIANG Zhi-biao2, YANG Qing-ping1, LI Ming-liang2, HU Jun-jing3

2016, 35(10):  2615-2620. 

Asbtract ( 435 )   PDF (457KB) ( 178 )  

Mixed forests of Phyllostachys edulis and Phyllostachys prominens are developing due to their mutual invasion in the adjacent distribution regions of these two bamboo species. To compare the plasticity and competition of Ph. edulis and Ph. prominens, a field experiment was conducted to explore the adaptive features of rhizome and roots of Ph. edulis and Ph. prominens in the pure and mixed forests. The results showed that rhizome diameter and node length, specific root length, densities of root length, surface area and volume, rhizome biomass, root biomass and total rhizome and root biomass of Ph. prominens were all lower than those of Ph. edulis, while an opposite pattern was found for the specific rhizome length, and densities of rhizome length and rhizome node. No differences in root diameter and fractal dimension between the two bamboos were found. Morphological character and biomass allocation for rhizomeroot system of Ph. edulis and Ph. Prominens changed after mutual invasion. Rhizome diameter of Ph. edulis and rhizome node length of the two bamboos increased, but densities of rhizome length and node of the two bamboos, specific rhizome length of Ph. edulis all decreased remarkably. Density of root length, surface area and volume, biomass of rhizome, root and total rhizome and root biomass of Ph. edulis and Ph. Prominens all decreased greatly, while specific root length and allocation proportion of rhizome for the two bamboos increased obviously. The relative yield for the two bamboos was significantly less than 1, and competitive balance index (Ph. prominens/Ph. edulis) was less than 0. Furthermore, the competitive balance index of rhizome and root was significantly higher than that of rhizome. All those results indicated that rhizomeroot system of Ph. edulis was more plastic than that of Ph. prominens. There was intense interspecific competition among the two bamboos in the mixed forest, and Ph. edulis was more competitive than Ph. prominens, and rhizome root system played a leading role in competition between Ph. edulis and Ph. prominens.

Likelihood and influencing factors of tree cavities in tropical forest in Xishuangbanna, Southwest China.

LIU Jun-yan1,2, ZHENG Zheng2, NIU Yan-fen3, DONG Ting-fa1*

2016, 35(10):  2621-2626. 

Asbtract ( 521 )   PDF (622KB) ( 178 )  

Hollow-bearing trees (HBT) are important components in forest ecosystems, playing a crucial role in maintaining animal diversity. To quantify the probability and influencing factors of tree cavities in tropical forests, we conducted a groundbased observation in a 20hm² tropical forest community in Xishuangbanna, Southwest China. We used Logistic models to study the relationship between the probability of tree cavities and the diameter at breast height (DBH). The results showed that the probability of tree cavities was positively related with DBH, and varied across different tree species. The four species with the highest probability of tree cavities were Castanopsis hystrix (21.23%), Diospyros hasseltii (13.53%), Sloanea tomentosa (12.06%) and C. echidnocarpa (11.99%). In an optimal fitting model, tree cavities were strongly correlated with DBH, slope and aspect of the tree location. Our results indicate that tree cavities are related with tree traits and topographic factors, and therefore have implication for the conservation and management of biodiversity in tropical forests.

Cold injury symptoms and physiological responses of mango seedlings under low temperature stress.

TANG Li-sheng1, WANG Hua1*, HU Fei2, XIONG Xian-zi2

2016, 35(10):  2627-2636. 

Asbtract ( 457 )   PDF (4213KB) ( 241 )  

One-year-old mango (Mangifera indica L. cv. Tainong 1) graft seedlings were experimented in climate growth chambers, in which six daily minimum temperatures (T_min) were set as 2, 1, 0, -1, -2 and -3 ℃, with the daily range of 15 ℃ and 6 ℃ for 1, 2 or 3 d. The subsequent observation was conducted on the changes of leaves, and the relevant physiological indexes, including superoxide dismutase  activity, soluble sugars, proline, soluble proteins, and ion leakage, MDA concentrations in leaves of mango seedlings, were determined. The chilling injury index of mango seedlings was established based on the injury symptoms and the physiological indexes in relation to T_min and its duration. Then a more precise index for short-term cold injury was procured with five geographical displacement experiments, in which mango seedlings were exposed to natural low temperature. The result showed that the mango seedlings were killed when low temperature was below -1 ℃, but they grew normally when low temperature was above 3 ℃ (≤3 d). When low temperature was between 3 and 5 ℃ for 9 days, mango seedlings showed no injury symptoms at all. The results provide reference for regionalization, introduction and extension of mango plants.

Analysis of stable carbon and nitrogen isotope compositions of Acanthus ilicifolius in the Pearl River estuary.

TAO Wen-qin, MIAO Shen-yu*, ZENG Qing-chang, LONG Lian-di, CHEN Wei-lin, CHEN Jian-hui, CHEN Xue-mei

2016, 35(10):  2637-2642. 

Asbtract ( 449 )   PDF (674KB) ( 186 )  

Compositions of stable carbon and nitrogen in plants to some degree can reflect habitat changes. Stable carbon and nitrogen isotope ratios and carbon and nitrogen contents in mangrove plant Acanthus ilicifolius and in sediment from the Pearl River estuary (Qi’ao of Zhuhai, and Nansha of Guangzhou) were measured. The results showed that there were no significant differences in the contents of carbon and nitrogen in both sediment and plant root from the two sampling sites; however, there were significant differences in nitrogen content and carbon to nitrogen ratio (P<0.01) in stem (P<0.05) and leaf (P<0.05). The δ¹³C values detected in root, stem and leaf of A. ilicifolius, a C₃ plant, from both sampling sites showed a decrease, and the δ¹³C values of samples from Qi’ao were significantly higher than that of Nansha, which may be due to the higher salinity of the sediment at Qi’ao. The δ¹⁵N values of root, stem and leaf from both sites showed some increase, with the δ¹⁵N values of all samples from Qi’ao being higher than that of Nansha. There were significant differences in δ¹⁵N values of sediment, stem, and leaf between the two sampling sites, but no significant difference in δ¹⁵N values of root from the two sampling sites, which was in accordance to the variations of nitrogen content in root, stem and leaf. Overall, there was no significant correlation between the δ¹³C, and δ¹⁵N values in plant and those in sediment.

Effects of mixed sewage sludge and garden waste compost on germination and growth of Festuca arundinacea L.

SI Li-qing1, CHEN Li-min2, ZHENG Jing-ming1*, ZHOU jin-xing1, PENG xia-wei1

2016, 35(10):  2643-2650. 

Asbtract ( 319 )   PDF (740KB) ( 257 )  

To assess the effects of sewage sludge and garden waste compost on plant growth, a potbased experiment was conducted in Beijing, with the two types of compost mixed at four volume ratios (1∶0, 1∶3, 1∶1, and 0∶1), and applied at five levels (0%, 25%, 50%, 75%, and 100% compost mixture). Germination rate and height growth of Festuca arundinacea were recorded during the experiment. The results showed that germination of F. arundinacea seeds was impacted negatively by the compost addition at the early stage, and the germination rate reached the highest value when sewage sludge and garden waste mixed at volume ratio of 1∶1 and applied at 25%. Addition of sewage and garden waste significantly increased the plant height during the experiment period compared to the control (P<0.05), especially during the late growing period. Increasing the addition amount of compost mixture greatly decreased the aboveground biomass except for the addition of sewage sludge compost only. Both aboveground and belowground biomasses after compost mixture addition were higher than those of the control, and the highest value appeared in the treatment with sewage sludge and garden waste mixed at 1∶1 volume ratio. Generally, the mixture of sewage sludge and garden waste played a more important role in promoting the growth of F. arundinacea than applying garden waste only and the control. Additionally, the effect of mixture addition varied from acceleration to inhibition with increasing input amount. It was proved that the mixture of sewage sludge and garden waste compost at 1∶1 volume ratio had the greatest effect when added at 25%.

Amelioration of soil contaminated by Mg-rich dusts and maize growth assessment.

YANG Dan1, ZENG De-hui2*

2016, 35(10):  2651-2658. 

Asbtract ( 362 )   PDF (687KB) ( 128 )  

According to the characteristics of high pH, low nutrient concentration and large soluble Mg²⁺/Ca²⁺ ratio in soil contaminated by Mg-rich dusts around magnesite regions, a pot experiment was conducted, in which different proportions of furfural residue and phosphogypsum were added to soil contaminated by Mgrich dusts. Effects of furfural residue and phosphogypsum addition on physicochemical properties of soil and growth of maize seedlings were analyzed. The results showed that furfural residue significantly decreased the contaminated soil pH and increased organic matter concentration. When its addition proportion was 5% to 30%, soil pH decreased from 9.34 to 8.96-7.61, and organic matter concentration increased by 1.19-13.19 times. Phosphogypsum significantly increased soil soluble Ca²⁺, and adjusted Mg²⁺/Ca²⁺ in soil. When its addition proportion was 5% to 30%, soil soluble Mg²⁺/Ca²⁺ ratio decreased by 92.4%-94.9%. Moreover, soil microbial biomass C (MBC), microbial biomass N (MBN), and growth characteristics of maize seedlings were more enhanced under phosphogypsum addition than under furfural residue addition with the same proportions. When 5% to 15% of furfural residue and phosphogypsum was added, soil MBC, MBN, the maximum root length, plant height, biomass and chlorophyll concentration of maize seedlings obviously increased, but gradually declined as the addition proportion increased from 15% to 30%. In 15% of furfural residue and phosphogypsum addition treatments, soil MBC increased by 2.02 and 2.27 times, MBN increased by 4.75 and 5.54 times, the maximum root length of maize seedlings increased by 1.05 and 1.14 times, the plant height increased by 1.15 and 1.34 times, the biomass increased by 1.47 and 1.58 times. Furthermore, the catalase (CAT) and peroxidase (POD) activities were higher than in the other treatments. Therefore, furfural residue and phosphogypsum were potential materials for improving physicochemical properties of the contaminated soil around magnesite regions, and their amendment at 15% showed a better remediation effect under the condition of greenhouse experiment.

Revision on meteorological indices of spring frost disaster for Camellia sinensis in Zhejiang Province.

LI Ren-zhong1, JIN Zhi-feng1*, YANG Zai-qiang2, WANG Zhi-hai1, YAO Yi-ping1

2016, 35(10):  2659-2666. 

Asbtract ( 531 )   PDF (759KB) ( 184 )  

Revision on meteorological indices of frost disaster for Camellia sinensis can provide more scientific and proper criteria for the prevention and evaluation of the spring frost disaster. Taking 4 main varieties of C. sinensis in Zhejiang Province as study objects, changes of physiological indices in C. sinensis leaves were observed in 6 groups of different low temperature and duration time in artificial climate box (15 ℃/3 ℃, 12 ℃/2 ℃, 10 ℃/1 ℃, 10 ℃/0 ℃, 10 ℃/-1 ℃, 10 ℃/-2 ℃, with higher temperature lasting 12 h while lower lasting 4 h; 25 ℃ as control). Thereby, semilethal temperature of C. sinensis was determined by the application of Logistic function. The results showed that happening of frost disaster was closely related with low temperature intensity and duration, and the semilethal temperatures of the 4 varieties were Fortin white tea (-1.5 ℃) < Wuniuzao (-1.3 ℃) < Jiukeng (-1.2 ℃) < Longjing43 (-0.7 ℃). Accordingly, a new rating standard of frost disaster for C. sinensis was put forward by combining historical disaster with hourly temperature data of tea gardens. The rating standard included three parts, namely meteorological index, symptom and frost damage percentage of new spring shoots. Among them, the meteorological index referred to hourly minimum air temperature and its duration during the growth period of C. sinensis. The validation by two frost disasters in the spring of 2013 indicated that the monitoring results of the new rating standard were consistent with the actual situation, with 41.7% higher percentage of accuracy than that of the original standard. This study provides important technique support for quantitative tea meteorological services.

Emergy benefit analysis of different maize and soybean planting patterns.

XU Min1, SONG Chun1,2*, CHEN Yu-liang1, ZHANG Teng1, XU feng1, ZHAO wei1, YANG Wen-yu2*

2016, 35(10):  2667-2675. 

Asbtract ( 393 )   PDF (755KB) ( 65 )  

Proper field arrangements are essential for sustainable agricultural ecosystem. Using emergy theory and method, this paper analyzed the differences of emergy input and output, environmental loading rate and emergy sustainability index under four cultivation modes: 2∶2 cornsoybean strip intercropping (M/S1), cornsoybean traditional intercropping 1∶1 (M/S2), maize monoculture (M) and soybean monoculture (S), in order to provide reference for optimized arrangement of farmlands. The results showed that the emergy inputs were in order of M/S2>M/S1>M>S. Fertilizer input accounted for a large proportion of subsidiary industrial emergy, and labor input accounted for a large proportion of renewable organic emergy. The emergy outputs were in order of M/S1>M/S2>S>M. Compared with maize, soybean had higher energy output, lower energy input, lower environmental load rate, higher emergy sustainability index. Economic benefits of M/S1, M/S2 and M were higher than that of mode S. In order to further optimize M/S1, we should reduce fertilizer input, especially phosphorus and potassium fertilizer, reduce the frequency and depth of farming, and increase the density of soybean, reduce density of maize, reduce environmental load rate and improve the emergy sustainability index.

Effect of simulated atmospheric nitrogen deposition on soil microbial community structure in a temperate forest.

XU Ke, WANG Chun-mei*, ZHANG Yi, YANG Xin-tong, LIU Wei-min

2016, 35(10):  2676-2683. 

Asbtract ( 519 )   PDF (724KB) ( 229 )  

Atmospheric nitrogen (N) deposition is a serious threat to global ecosystems. Soil microbes are sensitive to environmental changes. Investigating the effects of N deposition on soil microbial community structure may provide theoretical basis for scientific management of forest ecosystems. A manipulative field experiment was conducted to investigate the effects of different forms (NH₄NO₃, (NH₄)₂SO₄, NaNO₃) and different levels (0, 50, 150 kg N·hm^-2·a^-1) of N addition on the microbial community structure in a temperate forest soil. Soil microbial community structure was measured using the method of phospholipid fatty acid analysis (PLFA) after three consecutive years of N addition treatments. Our results showed that the amounts of total PLFA, bacterial PLFA, G⁺ bacterial PLFA, G^- bacterial PLFA and fungal PLFA in N addition plots were significantly higher than that in control plots, and N addition increased the amount of microbial PLFA significantly in the order of high N addition > low N addition > control. The amounts of total PLFA, bacterial PLFA, fungal PLFA and actinomyces PLFA in NH₄NO₃N addition plots were generally higher than that in NaNO₃N addition and (NH₄)₂SO₄N addition plots at the same N addition level. Principal component analysis (PCA) showed that microbial community structures were changed in all Nadded plots except the low (NH₄)₂SO₄N addition plots. Overall, these results suggested that N addition would increase soil microbial biomass and change soil microbial community structure in forest soils when N addition level reaches a threshold, at least over the short term.

Effects of mixed Fraxinus mandshurica and Larix olgensis plantation on the function diversity of soil microbial community.

DENG Jiao-jiao, ZHOU Yong-bin, YANG Li-xin, ZHANG Song-zhu, LI Hui, WEI Ya-wei, DENG Ji-feng, QIN Sheng-jin, ZHU Wen-xu*

2016, 35(10):  2684-2691. 

Asbtract ( 325 )   PDF (915KB) ( 166 )  

In order to evaluate the effect of afforestation mode on soil physical and chemical properties and the function diversity of microbial community, we studied soil pH, nutrient content and metabolism function diversity of soil microorganisms in three plantation forests, including pure coniferous forest (Larix olgensis), pure broadleaf ash forest (Fraxinus mandshurica), and their mixed forest (F. mandshurica + L. olgensis) in Douling, Xinbin of Liaoning Province. The results showed that, compared to the coniferous forest, the concentrations of total N, available N, total P and available P in the mixed forest increased by 37.1%, 35.6%, 9.5% and 12.9%, respectively. Total carbon source utilization capacity (AWCD) by soil microbial communities was in the order of F. mandshurica forest > mixed forest > L. olgensis forest, indicating that soil microbial metabolic activity in L. olgensis forest was the lowest. There were differences in microbial utilization rate of six major carbon sources among the three forests. The mixed forest had significantly higher microbial utilization rates in L-arginine, Lasparagine, pyruvic acid methyl ester, putrescine, N-acetylD-glucosamine, D-galacturonic acid, D-glucosaminic acid, and 4-hydroxybenzoic acid (eight kinds of carbon source) than the coniferous forest. Principal component analysis showed that carbohydrate and amino acids were important factors affecting soil metabolic activity. There was no significant difference in Simpson’s diversity index of soil microbes among the three forests. The Shannon’s index was in order of F. mandshurica forest > mixed forest > L. olgensis forest. Our results demonstrated that planting F. mandshurica and L. olgensis trees together can improve soil fertility and promote soil microbial activity.

Negative priming effect of maple roots reduced heterotrophic respiration and its temperature sensitivity.

QU Gui-fang1,2, XU Wen-hua1, WANG Hui1,2, PENG Bo1,2, GAO De-cai1,2, SUN Jian-fei1,2, ZHENG Jun-qiang1, JIANG Ping1, BAI Edith1*

2016, 35(10):  2692-2698. 

Asbtract ( 508 )   PDF (559KB) ( 180 )  

Soil respiration (R_s) comprises autotrophic (R_a) and heterotrophic (R_h) respiration. The difference in temperature sensitivity (Q₁₀) between R_a and R_h is still under debate. Rhizosphere priming effect (RPE) plays an important role in affecting the temperature sensitivity of R_h, which makes the issue more complex. Here we used the ¹³C natural abundance method by planting Acer mono (C₃ plant) in microcosms with maize soil (soil with cultivation of C₄ maize for 23 years) to investigate the responses of R_a and R_h to temperature change and the role of RPE. An overall negative RPE was observed in the growing season, which reduced R_h and its Q₁₀ value by 34.3% and 27.0%, respectively. The Q₁₀ value of R_a (3.89) was 2.5 times higher than that of R_h (1.51). Our results highlight the importance of plant roots in regulating the response of R_s to temperature, which should be considered in models of soil respiration in the future.

Effect of nitrogen addition and litter manipulation on soil physicochemical properties of a Pinus sylvestris var. mongolica plantation.

ZHAO Xin-ran1,2, ZHAO Qiong1*, WANG Wei-wei1, YANG Dan3, ZHENG Lin-lin1,2, AI Gui-yan1, ZENG De-hui1

2016, 35(10):  2699-2706. 

Asbtract ( 511 )   PDF (831KB) ( 205 )  

Nitrogen (N) deposition and litterfall variation are main pathways by which global change impacts forests, but how they interact to change belowground processes is poorly known. To explore these interactions, we conducted a field manipulative experiment under nitrogen addition (control and N addition as 10 g N·m^-2·a^-1) and litter manipulation (ambient litterfall, litter removal and litter doubling) in a Pinus sylvestris var. mongolica plantation in Keerqin Sandy Land. We measured soil properties such as available N and P concentrations and basal respiration rate in dry and wet seasons (May and August) 3 years after manipulation. The results showed that impacts of litter manipulation on soil variables differed greatly in the control and N addition plots. In the control plots, both litter removal and doubling greatly elevated soil basal respiration, while generally did not change available P and N concentrations. In N addition plots, both litter removal and doubling did not change basal respiration and available P concentration, but greatly decreased available N concentration. Impacts of N addition and litter manipulation were more obvious in wet season than in dry season. Nitrogen addition alone significantly reduced basal respiration and available P concentration in August, while litter doubling effectively lessened the depression of respiration and enhanced P limitation caused by N addition.

Soil organic carbon distribution and its influencing factors of Beijing Songshan natural Chinese pine forests.

GAO Jie, GUO Zi-jian, LIU Yan-hong*

2016, 35(10):  2707-2713. 

Asbtract ( 467 )   PDF (1201KB) ( 84 )  

With the change of global climate, forest soil organic carbon, as an important part of the carbon pool, has become one of the key research topics of forest carbon cycle. We studied soil organic carbon, carbon density and their influencing factors of eight natural Chinese pine forests with different ages in Songshan, Beijing using the variance analysis and variance decomposition method. We found that (1) the average soil carbon content of the pine forests in the studied area was 20.61 g·kg^-1. The soil carbon density was 153.67 t·hm^-2, which was lower than the average value of Chinese forest ecosystems (193.55 t·hm^-2). At the same aged stands, the soil organic carbon content decreased with the increase of soil depth significantly (P<0.05). (2) In the 0-50 cm soil layers, there existed significant differences in soil organic carbon content among different aged stands (P<0.05). However, in the 50-100 cm soil layer, the difference was not significant (P>0.05). As the stand age increased, soil carbon density increased significantly (P<0.05). Soil organic carbon in the shallow surface layers (0-30 cm) accounted for 81.1%, 83.6%, 82.5%, and 81.7% of total soil organic carbon in middleaged forest, nearmature forest, mature forest, and overmature forest, respectively. (3) The carbon content and carbon density of each layer were significantly positively correlated with soil water content (P<0.001, P<0.05), and the carbon content of each layer was significantly negatively correlated with soil bulk density (P<0.05). The average carbon content (ACC), and average carbon density (ACD) of various soil layers in each plot were significantly correlated with topographic factors, stand characteristic factors and soil factors. Terrain model, stand characteristic model, and soil model explained the degree of variance of ACD and ACC differently. Overall, the stand characteristic model can explain the ACD variance well, while the terrain factor model and the soil factor model can not. The stand characteristic model and the soil model together can explain the variance of ACC well, while the terrain factor model can not.

Effects of tillage on inorganic carbon in upper soil profiles in arid zone.

NIU Zi-ru1,2,3, WANG Yu-gang1,2*, DENG Cai-yun1,2,3, LI Yan1,2

2016, 35(10):  2714-2721. 

Asbtract ( 565 )   PDF (689KB) ( 190 )  

In order to understand the effects of land reclamation on soil inorganic carbon in 0-50 cm soil layer in arid zone, an investigation was carried out at a typical inland river basin namely the Sangong River watershed in Xinjiang, northwest China. The soil inorganic carbon content and storage in 0-20 cm and 20-50 cm soil layers were determined in crop growth season (from May to October) under different reclamation durations \[0 (non-reclaimed land), 5, 20, 50 and 100 years\]. The results showed that there was a similar change trend in soil inorganic carbon content for all reclamation durations, which was increased before June, and then followed by a decrease during crop growth season. For different soil layers, accumulation of soil inorganic carbon in the old oasis region was higher in non-reclaimed land than that in reclaimed land, but it showed an opposite trend for soil inorganic carbon accumulation in the new oasis region, with an increased carbon accumulation in 0-20 cm soil layer of nonreclaimed land and in 20-50 cm soil layer of reclaimed land, and a decreased inorganic accumulation in 20-50 cm soil layer of non-reclaimed land and 0-20 cm soil layer of reclaimed land. pH value decreased with the increase of reclamation duration after 5 years (P<0.05). The soil inorganic carbon content and storage increased from early reclamation before 20 years, and then decreased, being 1.8 times in 20 years as that in 100 years with soil inorganic carbon storage of 66.80 kg·m^-2 in 0-50 cm soil layers. In conclusion, soil inorganic carbon content and storage in the 0-50 cm soil layers began to decrease 20 years after reclamation.

Impact of fertilization on soil organic carbon and enzyme activities in a Cunninghamia lanceolata plantation.

LI Yan-peng1,2, HE Tong-xin1,2, WANG Qing-kui1,3*

2016, 35(10):  2722-2731. 

Asbtract ( 453 )   PDF (680KB) ( 247 )  

A fertilization experiment was conducted in a 5-year-old Chinese fir (Cunninghamia lanceolata) plantation in Huitong, Hunan Province, China, to study effects of fertilization on soil organic carbon and enzymatic activity. In this experiment, four treatments were: no fertilization as control (CK); 200 kg N·hm^-2·a^-1 (N); 50 kg P·hm^-2·a^-1 (P); and 200 kg N·hm^-2·a^-1and 50 kg P·hm^-2·a^-1 (NP). The results showed that sucrase and catalase activities in 0-10 cm soil layer were decreased in NP treatment by 40.2% and 36.5% compared to the CK treatment. In 0-10 cm soil layer, β-glucosidase activity was decreased by 31.1% in NP treatment than in P treatment. In 10-20 cm soil layer, urease activity was significantly decreased in N treatment compared with the CK. Sucrase activity in 10-20 cm soil layer was significantly decreased by 46.9%, 37.8%, and 42.4% in N, P and NP treatments, respectively. Catalase activity in 10-20 cm soil layer was decreased by 22.6% in NP treatment than in P treatment. The concentration of dissolved  organic carbon in 0-10 cm soil layer was significantly decreased in the N and P treatments by 24.1% and 29.4% compared to the CK treatment, respectively. In addition, soil microbial biomass carbon in 0-10 cm layer was significantly lower in the NP treatment than in the CK treatment. The effects of fertilization on labile organic carbon were mainly found in 0-10 cm soil layer. Labile organic carbon in 0-10 cm soil layer was higher than in 10-20 cm soil layer. Correlation analysis showed that sucrase activity had a significant negative correlation with nitrate nitrogen content, indicating that the increasing nitrate nitrogen content by NP treatment suppressed the activity of sucrase. Dissolved  organic carbon was positively related to urease activity. There were positive relationships between soil microbial biomass carbon and urease, catalase, β-glucosidase activities. Our findings suggest that the release of soil carbon to the atmosphere is probably suppressed by decreasing soil microbial biomass carbon, dissolved  organic carbon content and soil enzyme activities, thus enhancing the potential of carbon sequestration in forest ecosystems.

Effect of simulated nitrogen deposition on litter quality in a temperate grassland.

LI Ying-bin1,3, LI Qi1, YANG Jun-jie1*, Lv Xiao-tao1, LIANG Wen-ju1, HAN Xing-guo1,2

2016, 35(10):  2732-2737. 

Asbtract ( 482 )   PDF (545KB) ( 226 )  

Based on a 6-year simulation N deposition experiment, we investigated the effects of N deposition on the litter quality in a temperate grassland. Mixed and monospecific litter from four N treatments, including control (0 g N·m^-2·a^-1), low nitrogen (5 g N·m^-2·a^-1), medium nitrogen (10 g N·m^-2·a^-1), and high nitrogen (15 g N·m^-2·a^-1) were collected. The basic properties of litter quality (concentrations of cellulose, hemicellulos, lignin, C, N and P) were measured. The results indicated that N deposition decreased the concentration of cellulose, hemicellulos and lignin in litter, while increased the N and P concentration. The effect of N deposition on the concentration of C was not significant. The ratios of C/N and C/P were decreased by N deposition. Our results suggest that the litter decomposition rate may be stimulated by simulated N deposition due to the increase of N and P concentration and decrease of structural carbohydrate and lignin in plant litter.

Effects of lead stress on tolerance and uptake of different wetland plant species.

YANG Jun-xing1, HU Jian1, GUO Qing-jun1, WAN Xiao-ming1, SONG Bo2, GAO Meng3*, GU Song-pu1, GUO Jun-mei1, LI Zhen-li4, LU Yi-fu4, CAO Liu4

2016, 35(10):  2738-2744. 

Asbtract ( 406 )   PDF (463KB) ( 158 )  

In a constructed wetland system, appropriate choice of plant species is a key factor affecting metal removal from metal-contaminated soils, sediments and wastewaters. A hydroponic experiment was conducted to compare lead (Pb) tolerance indices and uptake among 18 emergentrooted wetland plants under 0, 10 and 20 mg·L^-1 Pb exposures. The results indicated that Pb translocation from root to shoot was generally low in all species tested. There were significant differences among the 18 wetland plants in their Pb tolerance indices and also Pb uptake under the same Pb treatment. Some wetland plants with higher Pb tolerance indices and Pb concentrations in shoot suggested that the detoxification system in plant may play an important role in alleviating Pb toxicity. Under the 20 mg·L^-1 Pb exposure, Veronica serpyllifolia had the highest accumulation of Pb in shoots (8226 mg Pb·kg^-1), while Fimbristylis monostachya had the lowest accumulation of Pb in shoots (50 mg Pb·kg^-1). In addition, Alternanthera philoxeroides having higher accumulation of Pb in shoots still did not show any severe symptoms of Pb toxicity. The data obtained should help in future species selection in designing wetlands in Pbcontaminated environments.

Species diversity and distribution characters of wood-decaying fungi in Fenglin Nature Reverse.

ZHANG Li-yan1,2, WEI Yu-lian1

2016, 35(10):  2745-2751. 

Asbtract ( 536 )   PDF (1891KB) ( 209 )  

Wood-decaying fungi are an important group in the forest ecosystem. They can improve the material cycling by decomposing cellulose, semi-cellulose and lignin of wood into nutrition that can be absorbed easily by themselves and other organisms. An investigation about the distribution characters of wood-decaying fungi was carried in three forest types in the Fenglin Nature Reserve. Nine hundred and sixty-six specimens were collected and identified to 122 species, belonging to 49 genera, 17 families and 7 orders. The majority of the polypores in Fenglin are north temperate element and cosmopolitan element, showing a distinct north temperate character. By comparing the fungal community composition of the three forest types, we found that the number of brown rotting fungi in the broad leaved-Korean pine mixed forest was greater than that of the poplarbirch forest and fir forest, accounting for 29.9% of the whole individuals. The white rotting fungi were the major group in the other two forests with 93.6% and 90.6% of the whole individuals, respectively. The fungal biodiversity in the broad leavedKorean pine mixed forest was the highest, with Shannon diversity index 4.60, Simpson index 0.99 and Pielou evenness index 0.99. Most of the wood-decaying fungi of Fenglin Nature Reserve preferred growing on the fallen wood with decaying degrees 2 and 3. Forest type, decaying degree and diameters of host wood were the main reasons affecting fungal community. Even growing on the same species of host, the fungal species were different in the different forest types.

Effects of largescale riceduck farming on rice plant architecture and yield formation.

LIANG Yu-gang1,2,3, HUANG Huang1,2,3*, LI Jing-yi1,2,3, ZHANG Qi-fei1

2016, 35(10):  2752-2758. 

Asbtract ( 390 )   PDF (583KB) ( 133 )  

An experiment was conducted to assess whether large-scale rice-duck farming could improve the plant architecture of rice, which in turn influences the yield and yield components. Three treatments including large-scale rice-duck farming, normal rice-duck farming and direct sowing were established to investigate plant architecture at late tillering and fullheading stages and grain yield of rice. The result showed that, compared with the traditional rice-duck farming, largescale rice-duck farming decreased the actual grain yield and the number of effective ears. There were no significant differences among the various aspects of the plant architecture. However, compared with direct sowing, large-scale rice-duck farming could optimize the plant architecture. It decreased the stem basal width and increased the canopy range at the late tillering stage and fullheading stage, giving plants certain looseness. The opening angel, drooping angle and leaf length of the flag leaves and second leaves saw an increase and the third leaves and fourth leaves declined, making the upper leaves flatter and lower leaves more erect than the control treatment. The leaf areas of the flag leaf, second leaf and third leaf increased, enabling the upper part of the plant to contain more leaf area. Large-scale rice-duck farming enhanced the growth of rice roots, and increased the basal leaf height and SPAD value of different phyllotaxises, which could slow down the aging of leaves. Therefore, large-scale rice-duck farming optimized the rice plant architecture, which improved the photosynthetic efficiency of rice, increased dry matter accumulation, thus ensuring a high grain yield.

Micro-habitat use of water birds in Poyang Lake and its response to water level during non-breeding period.

SHAO Ming-qin1*, JIANG Jian-hong1,2, DAI Nian-hua3

2016, 35(10):  2759-2767. 

Asbtract ( 366 )   PDF (6877KB) ( 36 )  

In order to find out the micro-habitat use of water birds in Poyang Lake and its response to water level, a survey on the number of water birds and the use of microhabitat was carried on with a fixed-radius point count method in 52 locations of 5 regions of Poyang area from October, 2014 to April, 2015. The results showed that 8 species such as tundra swan (Cygnus columbianus), spotted redshank (Tringa erythropus) and Eurasian spoonbill (Platalea leucorodia) mostly inhabited in shallow water. Bean goose (Anser fabalis), swan goose (A. cygnoides) and ruddy shelduck (Tadorna ferruginea) mostly inhabited in grassland and shallow water. Greater whitefronted goose (A. albifrons) and common crane (Grus grus) mostly inhabited in grassland. Common coot (Fulica atra) and great crested grebe (Podiceps cristatus) mostly inhabited in deep water. Blackheaded gull (Larus ridibundus) and little grebe (Tachybaptus ruficollis) mostly inhabited in both deep and shallow water. According to the analysis of the relationship between water birds’ number and the water level of Xingzi hydrological station, the total amount of water birds in Lake Poyang was negatively correlated with the water level. The numbers of water birds peaked at the water level of 8 m in Wucheng area of Poyang Lake National Nature Reserve, Duchang Migratory Birds Provincial Nature Reserve and Jinxian area, while they peaked at the level of 10-12 m in Hengfeng area of Poyang Lake National Nature Reserve, Nanji Wetland National Nature Reserve and East Poyang Lake National Wetland. Generally, a negative correlation was found between the water level in each region and the number of water birds of different families and species, whereas there existed a significant positive correlation between the water level and the number of Podicipediformes birds in some regions because Podicipediformes birds dived for foraging demanding for certain depth of water level.

Effects of feeding RbCl with different dosages on Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) and marking efficiency.

LI Guo-ping1, CUI Jian-xin2, HUANG Jian-rong1, TIAN Cai-hong1, FENG Hong-qiang1*, ZHONG Jing1, HUANG Bo1, SONG Guo-jing1

2016, 35(10):  2768-2773. 

Asbtract ( 530 )   PDF (566KB) ( 147 )  

Marking insects with Rb is a low cost, easy to use and environmentally safe technique in entomological research for understanding the insect population dynamics, migration, dispersal, mating competition, feeding behavior, and other ecological interactions. The ideal marker should persist without inhibiting the insect’s “normal” biology. The present study investigated the influence of Rb incorporated into larvae diet on the marking efficiency and life parameters of cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae). Feeding 1000-4000 mg·L^-1 RbCl in artificial diet effectively marked the adults without any negative effect on the survival, development and flight. Rb could be detected in the adults for at least 10 days. Furthermore, Rb was also detected in the unmarked (not fed RbCl) females when they mated with males feeding on a diet containing RbCl. Therefore, 1000-4000 mg·L^-1 are the suitable RbCl concentrations for marking cotton bollworm.

The aquatic organism communities of the Panjiakou-Daheiting Reservoir and the bioassessment of water quality.

ZHANG Min1, QU Xiao-dong1*, CHEN Yong1, ZHANG Rui-hao2, XIE Ying1, ZHANG Hai-ping1, YU Yang1

2016, 35(10):  2774-2782. 

Asbtract ( 484 )   PDF (1193KB) ( 180 )  

Panjiakou and Daheiting reservoirs (known as Pan-Da Reservoir) serve as the important drinking water source for the Beijing-Tianjin-Hebei area. The status of the reservoir ecosystem is an important indicator to water supply security. Based on field investigations of phytoplankton, zooplankton and macroinvertebrates, we analyzed the community composition and evaluated the status of the aquatic ecosystem and water environment. The results showed that phytoplankton community was dominated by Bacillariophyta and Chlorophyta, while the density was mainly contributed by Chrysophyta and Cyanophyta. The maximum density of phytoplankton in the reservoir was up to 14.45×10⁷ ind·L^-1, showing a algalbloom status. Zooplankton community was mainly composed of Rotifer, Cladocera and Copepoda, and their spatial difference was not identified. Rotifer dominated the community, while Cladocera dominated the density. The Shannon diversity index (H) of zooplankton ranged from 2.31 to 2.50. Macroinvertebrate community was dominated by Chironomidae and Tubificidae. Their densities showed significant difference in spatial distribution; the highest value was up to 14400 ind·m^-2, mainly contributed by Tubificidae indicating severe organic pollution. H of macroinvertebrates of all sites was lower than 0.40, except a value of 0.92 for one site in the most upper reach. Bioassessment of phytoplankton and macroinvertebrates indicated that the reservoir suffered serious pollution in the study period.

Spatial pattern analysis of ecosystem services based on InVEST in Heihe River Basin.

WANG Bei1, ZHAO Jun1*, HU Xiu-fang1,2

2016, 35(10):  2783-2792. 

Asbtract ( 485 )   PDF (4770KB) ( 287 )  

Ecosystem services of Heihe River Basin including water conservation, soil retention, water purification, biodiversity sustaining, carbon storage and food supply in 2011 were estimated based on InVEST. Furthermore, the distribution of cold and hot zones, the spatial differentiation characteristics, and the comprehensive hotspots of these ecosystem services were calculated by the spatial statistical methods. The results showed that these ecosystem services presented spatially differential characteristics. Firstly, the upper reaches were the major water supply area, while the other ecosystem services were mainly concentrated in the middle reaches. In addition, the water supply and water purification services were much lower in the lower reaches than in the middle reaches. Among the main ecosystem types, grassland played the main role in providing ecosystem services. Secondly, the spatial pattern of hotspots presented the characteristic of “lowvalue zone located at the north and the downstream, while high-value zone mostly distributed at the south and the upstream, midstream of the basin”. The spatial differentiation of various types of ecosystem services mainly exhibited as lowlow and lowhigh types. This study provided a basis for determining the goal of watershed ecological protection and construction, and also supplied a significant reference for other river basins to carry out spatial evaluation of ecosystem services.

Distributions of sulfur forms and sulfate-reducing bacteria in yellow soil of small karst catchment.

ZHANG Wei1,2*, ZHANG Li-li2,3

2016, 35(10):  2793-2803. 

Asbtract ( 281 )   PDF (1560KB) ( 30 )  

We analyzed the contents of total sulfur (S), SO₄^2-S, total reduced inorganic sulfur (TRIS), organic S, and sulfatereducing bacteria (SRB) groups and quantities in yellow soil to examine the distribution patterns of sulfur forms and SRBs in soils under acid deposition in the karst areas of Southwest China. The results showed that organic sulfur was the major sulfur form, and SO₄^2- was the major inorganic sulfur form in yellow soil. DesulfovibrioDesulfomicrobium was detected at different soil depths, indicating that DesulfovibrioDesulfomicrobium is the dominant SRB group in yellow soil. The soil depths of increasing SRB quantity and TRIS contents corresponded well to the depths of decreasing SO₄^2--S contents, indicating that dissimilatory SO₄^2- reduction occurred in yellow soil with TRIS as the main product. The residual SO₄^2- after biological S retention was firstly adsorbed and then desorbed; desorbed SO₄^2- could transport downward and was subsequently re-adsorbed and accumulated in deep soil layers. This explained the increasing SO₄^2-S contents in bottom layers of yellow soil profiles. The deposited SO₄^2- was retained as organic sulfur and adsorbed SO₄^2- in yellow soil, then yellow soil may release more S into rivers by organic sulfur mineralization and desorption of the adsorbed SO₄^2- in a long period after a large decrease in annual sulfur deposition rate. Therefore, the environmental implications such as changes of soil properties and chemical compositions of river water in southwest China should be investigated in the future.

Water-rock effect analysis on the impact factors of groundwater chemistry of Huludao City, West Liaoning Province.

LI Xiao1*, CHAI Lu1, WANG Hong-yan2, DU Ji-zhong1, WANG Xiao-guang1, CUI Jian1

2016, 35(10):  2804-2813. 

Asbtract ( 306 )   PDF (2063KB) ( 194 )  

In order to find out the shallow groundwater quality and contamination situation of Huludao City, the groundwater samples were analyzed with the fuzzy comprehensive evaluation and hierarchy ladder methods. Based on the evaluation results, some main indicators affecting the water quality and pollution status were chosen. The hydrogeochemical simulation method was then adopted to analyze the genetic mechanism of various indicators. The results showed that, from the inland mountain foothills to coastal alluvial plain, the shallow groundwater chemical type changed from HCO₃ to HCO₃·SO₄ and HCO₃·Cl gradually. Groundwater quality levels of Ⅰ-Ⅲ, Ⅳ and Ⅴ accounted for 44%, 4% and 52% of the total, respectively. Moderately, heavy and severely heavy polluted water samples accounted for 48%, 36% and 16% of the total, respectively. It was concluded that Na⁺, K⁺, Ca²⁺, Mg²⁺, HCO₃^-, SO₄^2-, Cl^-, Br, NH₄⁺, NO₃^- and Pb were impact indicators of the groundwater quality and contamination status. The genetic mechanism mainly included cation exchange adsorption, transpiration, evaporation, and redox reaction. Regional agricultural production, mining activities and seawater intrusion were the major factors leading to the quality deterioration and contamination severity of the shallow groundwater.

Emergy analysis of straw biogas project based on different biogas manure use scenarios: A case study in Gengguantun, Qingxian County, Hebei Province.

WANG Hong-yan, WANG Ya-jing, WANG Dao-long, GAO Chun-yu, WANG Lei, SUN Ning, BI Yu-yun*

2016, 35(10):  2814-2823. 

Asbtract ( 344 )   PDF (600KB) ( 18 )  

This study aims to conduct an emergy analysis of different biogas manure use patterns of straw biogas project for central gas supply, and evaluate ecoeconomic benefit and sustainability. Taking the biogas project in Gengguantun, Qingxian County, Hebei Province as an example, a comparative analysis of emergy input, output and emergy evaluation indices of this straw biogas project was made under 3 scenarios, normal scenario (Scenario 1), real scenario (Scenario 2) and hypothetical scenario (Scenario 3), which were designed on the basis of different biogas manure use patterns. The results showed that the emergy yield ratios of Scenario 1, Scenario 2 and Scenario 3 were 1.0023, 1.0020 and 1.0029, the emergy investment ratios were 441.45, 497.93 and 341.61, and the emergy sustainability indices were 1.08, 0.80 and 0.61, respectively. The straw biogas project has both ecological and economic benefits of energy production and crop straw dealing. With the increase of biogas residue and slurry use, the straw biogas project is more dependent on purchased emergy resource input, and the sustainability decreases. The economic reproduction characteristics of this project system are continuously strengthened, and the overall development direction is “high inputhigh output”.

Rediscussion on Chinese translation of the term “Ecological Restoration”.

MENG Wei-qing1,3, LI Hong-yuan2*

2016, 35(10):  2824-2830. 

Asbtract ( 743 )   PDF (484KB) ( 381 )  

Ecological restoration has become a very popular field of applied ecology in recent years, but the use and understanding of the term “ecological restoration” has been obscured in Chinese. Thus, the translation and scientific use of the term “ecological restoration” should be further discussed. Based on the definition analysis of the Society for Ecological Restoration (SER), the rational use of the scientific term “ecological restoration” in Chinese was determined to include the reason for damaged ecosystem, measures, theory, practice application, public using. It is found that Chinese scholars are all basically in agreement with the definition from SER about the term “ecological restoration.” As the understanding of and research on ecological restoration were not systematic, and there is no accurate corresponding vocabulary in Chinese, the term “ecological restoration” was translated into different Chinese expressions. Our opinion is that in determining a suitable Chinese translation and use of the term “ecological restoration”, theoretical basis and academic development should be considered besides etymological meaning and Chinese conventional expression habits. But above all, the basic principle for a suitable Chinese translation of the term “ecological restoration” must be consistent with the definition of SER.

Research progress on pepper mild mottle virus. 

LI Xiao-dong, WU Yuan-hua*

2016, 35(10):  2831-2837. 

Asbtract ( 889 )   PDF (532KB) ( 227 )  

Pepper mild mottle virus (PMMoV), which belongs to Tobamovirus, is one of the most important viruses on Capsicum frutescens and widely threatens pepper production throughout the world. So far many researches have been done on PMMoV, including virus detection, pathogenic gene and disease control. In this paper, the virus biological characteristics, genome structure, virus detection and disease control of PMMoV were summarized. Meanwhile, we also summed up the latest research advances on the influence and application of PMMoV on ecological environment and human health. Finally, the existing problems in virus detection and prevention, ecological environment security and medical application of PMMoV were explored, and some perspectives on future researches were put forward, with an attempt to provide reference for further study of PMMoV through multidisciplinary coordination.

Impact of genetically modified crops on soil invertebrates.

GUO Jia-hui1,2, KONG Yun1,3, LI Gang1, ZHAO Jian-ning1, YANG Dian-lin1, YAN Feng-ming2*, XIU Wei-ming1,2,3*

2016, 35(10):  2838-2844. 

Asbtract ( 366 )   PDF (495KB) ( 127 )  

With the rapid development of biotechnology, the introduction of a large number of genetically modified (GM) crops into agricultural ecosystems has raised environmental concerns over ecological impacts of these crops on soil ecosystems. As the decomposers in food webs, soildwelling invertebrates play an essential role in soil ecosystems. The number and diversity of soildwelling invertebrates are directly related to the health and quality of soil. Soildwelling invertebrates as potential indicators of soil quality have become an important part of the ecological risk assessment of GM crops. This article first summarizes residue of exotic gene expressing products of GM crops in soil, and then reviews the recent research advances on the impact of GM crops on main soil invertebrate groups, including nematodes, springtails, mites and earthworms. Generally, information available so far indicates that plantation of GM crops has had no significant sideeffects on diversity and community of soil invertebrates, with only variations in numbers and composition of some environmentally sensitive species. Current research results of GM crops on soil invertebrates are unable to compare one to the other due to differences in investigation methods, crops and soils, so it is suggested that establishment of standard methods and criteria in ecological assessment of GM crops on soil invertebrates should be speeded up for conducting reliable ecological evaluation of GM crops, so as to promote development and commercialization of GM crops as well as to minimize sideeffects of GM crops on ecosystems in China.

Automation for measuring tree ring width and its correction based on photogrammetry.

LUO Chun-wang1, YU Jian1,2, LIU Qi-jing1*, XU Qian-qian1,3, ZHANG Guo-chun1,4

2016, 35(10):  2845-2851. 

Asbtract ( 320 )   PDF (846KB) ( 143 )  

Tree-ring width measurement is the key operation in studies of dendroclimatology, tree growth pattern and forest productivity; its bias magnitude directly affects the final results. Although specialized measurement systems or software are reliable tools for dendrochronology and tree growth analysis, it is inconvenient for labs without such devices. The purpose of this study was to develop a tree ring measuring algorithm which is easy to apply while keeping desired accuracy, especially for labs without the aforementioned conditions. Based on imagery scanned from sample cores, tree ring widths were automatically positioned with an image processor that was commonly used in remote sensing. The extracted widths were corrected with a simple program based on triangle principle for inclined rings. After scanning, the imagery was measured with remote sensing software PCI Geomatica, for which the geocorrection module was used. Results indicated that the final values under the high resolution were highly consistent with instrumentmeasured ones, showing the effectiveness of the method. The method proposed in this paper was simple to operate, convenient for popularization. In addition, it was both time and costeffective, especially when specialized instruments were not available.

Stability evaluation of different accumulated temperature models: A case of spring maize in Northeast China.

ZHAO Qian1, GUO Jian-ping1,2*

2016, 35(10):  2852-2860. 

Asbtract ( 456 )   PDF (905KB) ( 228 )  

In this study, the field observation data of spring maize varieties including “Danyu 13”, “Longdan 13” and “Sidan 19” in Northeast China were used to fit three nonlinear accumulated temperature models proposed by Shen Guoquan, Gao Liangzhi and Yin Xinyou respectively, and to obtain the model parameters. Precision and stability of the simulation results were assessed, and compared with that of the commonly used accumulatedtemperature method. The results showed that the simulation result of Gao Liangzhi model was the best during the period from emergence to maturity. The three nonlinear accumulated temperature models had the similar results in fitting effective accumulated temperature during the period from emergence to jointing. During the jointingheading and headingmaturity stages, Gao Liangzhi model performed best, followed by Yin Xinyou model and Shen Guoquan model. On the analysis of variation coefficient and relatively extreme value of the effective accumulated temperature calculated by the four methods, the stability of the three nonlinear accumulated temperature models was consistently superior to the commonly used method during the whole growth period. During the emergencejointing stage, Shen Guoquan model had better stability. During the jointingheading stage, the stability of Shen Guoquan and Yin Xinyou models was the best. The stability of the four methods was similar during the period from heading to maturity. However, a parameter validity problem was found in the process of fitting the three accumulated temperature nonlinear models. In conclusion, Shen Guoquan model could be selected during the period from emergence to jointing. From jointing to heading stage, Yin Xinyou model was the best. Gao Liangzhi model was suitable for the whole growth period. Our results can provide theoretical basis and technical support for spring maize development and yield prediction in Northeast China.

Three-dimensional interpolation of dimethylbenzene distribution in soil at a petroleum-contaminated site in China.

SHI Guang1, JING Yao-dong1, QIN Ming-xing1, LIU Geng2*

2016, 35(10):  2861-2866. 

Asbtract ( 353 )   PDF (1140KB) ( 59 )  

A petroleum-contaminated site was selected to determine the contamination boundary and volume of soil contaminated with dimethylbenzene. We compared the efficiency and precision of three 3D interpolation models (Kriging, IDW, and Nearest Neighbor) in determining the site contamination boundary. Employing a cross validation method, we found that the results of the IDW model were more accurate than the other two models in predicting the actual pollution conditions of the contaminated site. The mean error (ME) and root mean square error (RMSE) of IDW were 4.94, and 14.11, respectively. With a view towards remediation, the contaminated soil volume calculated by the IDW interpolation model was 666.2 m³. Different prediction models had uncertain influences on determining the contamination boundary. This study provides a contribution towards determining pollutant distribution and making decision for remediation of contaminated sites.