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Table of Content
    Volume 40 Issue 12
    10 December 2016

    Mangroves and their reproductive strategies. Three kinds of reproductive strategies in mangrove plants were shown: true-vivipary, crypto-vivipary and non-vivipary with their representative species (Photographed by Wang Wen-Qing). The left picture illustrates the hypocotyls of true-vivipary species Kandelia obovata. The middle picture shows the fruits of crypto-vivipary species Avicennia marina. The right picture presents the fruits of non-vivipary species Sonneratia alba<

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    Research Articles
    Effects of experimental warming on net ecosystem CO2 exchange in Northern Xizang alpine meadow
    Jun-Tao ZHU, Ning CHEN, Yang-Jian ZHANG, Yao-Jie LIU
    Chin J Plan Ecolo. 2016, 40 (12):  1219-1229.  doi:10.17521/cjpe.2016.0186
    Abstract ( 382 )   HTML ( 18 )   PDF (751KB) ( 946 )   Save
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    AimsGlobal warming could have profound effects on ecosystem carbon (C) fluxes in alpine ecosystems. The aim of our study is to examine the effects of gradient warming on net ecosystem carbon exchange (NEE).MethodsIn the Northern Tibetan Grassland Ecosystem Research Station (Nagqu station), Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, we conducted various levels of temperature increasing experiments (i.e., 2 °C and 4 °C increments). The warming was achieved using open-top chambers (OTCs). In total, there were three levels of temperature treatments (control, 2 °C and 4 °C increment), and four replicates for each treatment. The ecosystem NEE was monitored every five days during the growing season in 2015.Important findings Our findings highlight the importance of soil moisture in mediating the responses of NEE to climatic warming in alpine meadow ecosystem. The 4 °C warming significantly stimulated NEE,except for July measurements. The 2 °C warming had no effects on NEE during the growing season. Compared to the 2 °C warming, the 4 °C warming significantly stimulated NEE. The results showed that our targeted ecosystem acts as a carbon sink under 2 °C warming, whereas will act as a net carbon source under 4 °C warming in the future. This study provides basic data and theoretical basis for evaluating the alpine ecosystem’s responses to climate change.
    Effects of simulated warming outdoor on lipid peroxidation and protective enzyme activities in the subtropical species Cunninghamia lanceolata
    Qiu-Fang ZHANG, Chun-Ping LÜ, Zhao-Xian BEI, Jin-Sheng XIE, Mao-Kui LÜ, Wei-Sheng LIN, Yue-Min CHEN, Yu-Sheng YANG
    Chin J Plan Ecolo. 2016, 40 (12):  1230-1237.  doi:10.17521/cjpe.2016.0205
    Abstract ( 411 )   HTML ( 7 )   PDF (507KB) ( 714 )   Save
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    AimsTemperature is often considered as an important limiting factor for plant growth and production. Ecosystems are often affected by the global warming. However, there is little known about the effects of the global climate change to the lipid peroxidation and protective enzyme activities of Cunninghamia lanceolata in subtropical zones.MethodsHeating cables were used to generate a warmed environment in the wild. Two treatments—control and warming (with five replicates each), were used in the study. We sampled fresh leaves of the C. lanceolata to examine the osmotic adjustment substances, inter water use efficiency, protective enzyme activities, and malondialdehyde content.Important findings 1) Warming improved osmotic ability, whereas its effect on lipid peroxidation of C. lanceolata was not obvious; 2) Warming significantly improved inter water use efficiency and carbon sequestration benefits, which indicated that warming decreased the water consumption costs of carbon sequestration; 3) Warming decreased the activity of superoxide dismutase and peroxidase, but significantly increased the activity of catalase and ascorbate peroxidase. These results suggest that warming could protect itself from high temperature through protective enzyme activities (especially catalase and ascorbate peroxidase) of C. lanceolata, which is beneficial to stable cell metabolism. Therefore, more studies are needed about how temperature affects the C. lanceolata under global change in this region.
    Effects of nitrogen and silicon application on leaf nitrogen content and net photosynthetic rate of Elymus nutans in alpine meadow
    Xiao-Lin SI, Wen-Yin WANG, Xiao-Gang GAO, Dang-Hui XU
    Chin J Plan Ecolo. 2016, 40 (12):  1238-1244.  doi:10.17521/cjpe.2015.0398
    Abstract ( 355 )   HTML ( 4 )   PDF (465KB) ( 745 )   Save
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    AimsElymus nutans is one of the dominant plant species in alpine meadow. Purpose of this research was to study the effects of nitrogen and silicon application on leaf nitrogen content and net photosynthetic rate in this species to provide scientific basis for fertilization practice in alpine meadow.MethodFour levels nitrogen combined with four levels silicon was applied to E. nutans plants in the alpine meadow. Leaf nitrogen content and net photosynthetic rate of E. nutans were measured.Important findings The results showed that there was a significant improvement in leaf nitrogen content and net photosynthetic rate of the E. nutans with nitrogen or silicon application alone; However, there was a significant interaction between nitrogen and silicon treatments on leaf nitrogen content and net photosynthetic rate; Combining with the three different levels nitrogen, low level silicon (Si1) application did not increase leaf nitrogen content and net photosynthetic rate, but middle level silicon (Si2) could significantly increase the leaf nitrogen content; Combining with the low (N1) or middle (N2) level nitrogen, middle level silicon (Si2) application could significantly increase the net photosynthetic rate; Compared with that control without fertilization, the middle level nitrogen combined with the same level silicon treatment had the highest average of leaf nitrogen content and net photosynthetic rate, which increased by 119.99% and 85.70%, respectively. This study indicated application of nitrogen combined with silicon application enhanced leaf nitrogen content and net photosynthetic rate of E. nutans, and 8 g·m-2silicon application had the best result among other treatments.
    Changes in normalized difference vegetation index of deserts and dunes with precipitation in the middle Heihe River Basin
    Fang LI, Wen-Zhi ZHAO
    Chin J Plan Ecolo. 2016, 40 (12):  1245-1256.  doi:10.17521/cjpe.2015.0389
    Abstract ( 359 )   HTML ( 3 )   PDF (687KB) ( 710 )   Save
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    AimsPrecipitation is the major water source for desert ecosystems, with its temporal dynamics significantly driving the changes of ecosystem structure and function in desert regions. The objectives of this study are to evaluate the changes in normalized difference vegetation index (NDVI) with seasonal precipitation and different climate years in two cover types (desert and dune).MethodsBased on the daily rainfall dataset of 2000-2012 in the middle Heihe River Basin in Northwest China and the NDVI extracted from the moderate resolution imaging spectroradiometer (MODIS) images, we performed linear regression analysis to examine the correlation of NDVIINT (accumulated NDVI) with precipitation in two cover types (desert and dune). Two measures of the precipitation are Pc (cool-season precipitation from last September to late February) and Pw (warm-season precipitation in between March and August), while NDVI was characterized with NDVIINT-pys (previous-year during the different climate years (dry: 2001-2003, wet: 2004-2007)) and the different periods of a growing season (i.e. whole growing season from May through September, early growing season in between May and June, and late growing season in between July and September).Important findings We found that: (1) the determinants of growing season NDVIINT and their order were NDVIINT-pys > Pc > Pw for the deserts, while the order was Pw > NDVIINT-pys for the dunes. The determinants and their order of NDVIINT in early growing season were NDVIINT-pys > Pc for the desert, while they were NDVIINT-pys > Pc = Pw for the late growing season. However, for the dunes, NDVIINT of the early and late growing season appeared determined by NDVIINT-pys and Pw, respectively. (2) During the dry and wet periods, precipitation was not a significant factor influencing NDVIINT for the desert and dune. However, significant increases in NDVIINTwere observed at dune under wet condition. With the wet years continued, the length of the wet years become an important determinant of NDVIINT at both cove types, particularly at dune. In addition, it appeared that different changes in NDVI with precipitation existed between the two cover types, but with very similar effects of time-lag. These findings provide useful references for further understanding the mechanisms of NDVI changes with precipitation.
    Changes of the relationships between soil and microbes in carbon, nitrogen and phosphorus stoichiometry during ecosystem succession
    Zheng-Hu ZHOU, Chuan-Kuan WANG
    Chin J Plan Ecolo. 2016, 40 (12):  1257-1266.  doi:10.17521/cjpe.2016.0218
    Abstract ( 456 )   HTML ( 0 )   PDF (626KB) ( 1015 )   Save
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    AimsThe carbon (C), nitrogen (N) and phosphorus (P) stoichiometry (C:N:P) of soil profoundly influences the growth, community structure, biomass C:N:P stoichiometry, and metabolism in microbes. However, the relationships between soil and microbes in the C:N:P stoichiometry and their temporal dynamics during ecosystem succession are poorly understood. The aim of this study was to determine the temporal patterns of soil and microbial C:N:P stoichiometry and their relationships during ecosystem succession.MethodsAn extensive literature search was conducted and data were compiled for 19 age sequences of successional ecosystems, including 13 forest ecosystems and 6 grassland ecosystems, from 18 studies published up to May 2016. Meta-analyses were performed to examine the sequential changes in 18 variables that were associated with soil and microbial C, N and P contents and the stoichiometry. Important findings (1) There was no consistent temporal pattern in soil C:N along the successional stages, whereas the soil C:P and N:P increased with succession; the slopes of the linear relationships between soil C:N:P stoichiometry and successional age were negatively correlated with the initial content of the soil organic C within given chronosequence. (2) There was no consistent temporal pattern in microbial C:N:P stoichiometry along the successional stages. (3) The fraction of microbial biomass C in soil organic C (qMBC), the fraction of microbial biomass N in soil total N, and the fraction of microbial biomass P in soil total P all increased significantly with succession, in consistency with the theory of succession that ecosystem biomass per unit resource increases with succession. (4) The qMBC decreased with increases in the values of soil C:N, C:P, or N:P, as well as the stoichiometric imbalances in C:N, C:P, and N:P between soil and microbes (i.e., ratios of soil C:N, C:P, and N:P to microbial biomass C:N, C:P, and N:P, respectively). The C:N, C:P, and N:P stoichiometric imbalances explained 37%-57% variations in the qMBC, about 7-17 times more than that explainable by the successional age, illustrating the importance of soil-microbial C:N:P stoichiometry in shaping the successional dynamics in qMBC. In summary, our study highlights the importance of the theories of ecosystem succession and stoichiometry in soil microbial studies, and suggests that appropriately applying macro-ecological theories in microbial studies may improve our understanding on microbial ecological processes.
    Salt accumulation in vegetative organs and ecological stoichiometry characteristics in typical halophytes in Xinjiang, China
    Yan-Hua YONG, Xia ZHANG, Shao-Ming WANG, Ling WU
    Chin J Plan Ecolo. 2016, 40 (12):  1267-1275.  doi:10.17521/cjpe.2016.0146
    Abstract ( 366 )   HTML ( 1 )   PDF (420KB) ( 785 )   Save
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    AimsStudying salt accumulation in vegetative organs and carbon (C), nitrogen (N), phosphorus (P) stoichiometry in halophytes contributes to understand the adaptive strategy to saline environment and the distribution mechanism of nutrients and salinity of the halophytes.MethodsFour typical dominant species, including three perennial shrubs (Halocnemum strobilaceum, Suaeda microphylla and Kalidium foliatum) and an annual herb (Salicornia europaea) were selected for analyzing the salt accumulation and C, N, P stoichiometry relationships.Important findings 1) The salt accumulation showed “salt island” effect at peak growing stage; Na+, Cl- and electrical conductivity all showed significant positive trends, when salt ions were transported from the root to the shoot of 4 halophytes. 2) P was the limiting growth element of perennial shrubs, while both N and P were limiting factors for the annual herb. 3) Different organs, species and their interactions affected C, N, P stoichiometry and salt icons except Mg2+. 4) C was negatively correlated with N and P, but there was a significant positive correlation between N and P. 5) Electrical conductivity, Na+and K+ were positively correlated with N, N:P ratio, and negatively correlated with C, C:N and C:P ratios, and yet K+, CO32- had significant positive correlation with P. These results implied that there were some kind of mutual promoting relationships between nutrients and salinity in halophytes in the saline environment, and fertilizing with N could promote sodium chloride desalination.
    Effects of decay classes and diameter classes on physico-chemical properties of Pinus koraiensis log in a typical mixed broadleaved-Korean pine forest
    Yu ZHANG, Guang-Ze JIN
    Chin J Plan Ecolo. 2016, 40 (12):  1276-1288.  doi:10.17521/cjpe.2016.0187
    Abstract ( 337 )   HTML ( 0 )   PDF (648KB) ( 516 )   Save
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    AimsLog is an important component for most of forest ecosystems. It plays crucial roles in maintaining soil fertility, sustaining biodiversity and cycling of carbon (C) and nutrient. However, physico-chemical properties of logs vary with decay classes and diameter classes. Our objective was to study effects of decay classes and diameter classes on physico-chemical properties of logs in a typical mixed broadleaved-Korean pine forest in northern China.MethodsIn this study, logs of Pinus koraiensis were chosen as it was the constructive species in the typical mixed broadleaved-Korean pine forest. Logs of P. koraiensis at each decay classes (I-V) were divided into four diameter classes, including diameter class i ≤ 10.0 cm, diameter class ii: 10.1-30.0 cm, diameter class iii: 30.1-50.0 cm, and diameter class iv > 50.0 cm. Then, we explored effects of different decay classes, diameter classes and their interactions on the physico-chemical properties of logs for both the heartwood and sapwood.Important findings The results showed that the physico-chemical properties of heartwood and sapwood generally exhibited similar variations. Their moisture content both increased with an increasing decay class, whereas wood density both decreased with an increased decay class and diameter class. The carbon concentrations of the sapwood showed a trend of gradual increasing during decomposition, and there was an accumulation in nitrogen (N) and phosphorus (P) concentrations of the heartwood and sapwood with an increased decay class, simultaneously. Only N and P concentrations of the heartwood increased and then decreased with an increasing diameter class. The cellulose content decreased with an increasing decay class. In contrast to the cellulose, the lignin content increased with an increased decay class. However, cellulose and lignin contents exhibited no distinct trend among diameter classes. The moisture content of logs had a significant positive correlation with C, N, P concentrations and lignin content (except P concentrations of the heartwood), but had a significant negative correlation with the cellulose content (p< 0.05). The wood density was negatively correlated with C, N, P concentrations and the lignin content, but it was positively correlated with the cellulose content (p< 0.05). Therefore, physico-chemical properties of logs had unique patterns along both decay classes and diameter classes, and the physical properties of logs (the moisture content and wood density) were important factor affecting the variations of their chemical contents.
    Correlation analysis between vein density and stomatal traits of Robinia pseudoacacia in different aspects of Beishan Mountain in Lanzhou
    Bei-Bei DUAN, Cheng-Zhang ZHAO, Ting XU, Hui-Ling ZHENG, Wei FENG, Ling HAN
    Chin J Plan Ecolo. 2016, 40 (12):  1289-1297.  doi:10.17521/cjpe.2016.0215
    Abstract ( 291 )   HTML ( 1 )   PDF (547KB) ( 604 )   Save
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    AimsThe relationship between leaf venation and stomatal traits reflects leaf water potential of plants, and is fundamental to probe the relationship between physiological functions and water use. Our objective was to study the changes in the relationship between venation density and stomatal traits (stomatal density and stomatal length) in Robinia pseudoacacia with the changes in slope aspects.MethodsIn Beishan Mountain of Lanzhou in Gansu Province, China, 20 transects were laid out horizontally along the contour at intervals of 50 m from an elevation of 1550-1750 m in four different slope aspects, and 12 plots were set up along each transect at intervals of 5 m. A handed GPS (global positioning system) was used to measure latitude, longitude and altitude at each plot. Community characteristics, including crown density, tree height and soil moisture, were investigated. Robinia pseudoacacia within all plots were sampled and used for measurements of individual leaf area, venation density, stomatal density and stomatal length in laboratory in each plot. The 240 plots were categorized into groups of southern, eastern, western and northern aspects, and the standardized major axis (SMA) estimation method was then used to examine the relationship between the stomatal density, stomatal length and vein density.Important findings The results showed that with a change of the aspect from south to east, west, and north, the crown density, average tree height and soil moisture of the plant community increased, while leaf net photosynthetic rate (Pn), transpiration rate (Tr), photosynthetically active radiation (PAR), vein density and stomatal density decreased. In addition, stomatal length and individual leaf area increased. Venation density of each aspect of R. pseudoacacia was positively correlated with stomatal density (p < 0.05) and negatively with stomatal length (p < 0.05). These correlations were strongest in south slope (p < 0.01).
    Effects of groundwater salinity on the characteristics of leaf photosynthesis and stem sap flow in Tamarix chinensis
    Qing-Xian KONG, Jiang-Bao XIA, Zi-Guo ZHAO, Fan-Zhu QU
    Chin J Plan Ecolo. 2016, 40 (12):  1298-1309.  doi:10.17521/cjpe.2016.0012
    Abstract ( 392 )   HTML ( 0 )   PDF (570KB) ( 712 )   Save
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    AimsThe objective of this study was to investigate the change pattern of leaves photosynthesis and stem sap flow of Tamarix chinensisin under different groundwater salinity, which can be served as a theoretical basis and technical reference for cultivation and management of T. chinensis in shallow groundwater table around Yellow River Delta.MethodsThree-year-old T. chinensis, one of the dominated species in Yellow River Delta, was selected. Plants were treated by four different salinity concentrations of groundwater—fresh water (0 g∙L-1), brackish water (3.0 g∙L-1), saline water (8.0 g∙L-1), and salt water (20.0 g∙L-1) under 1.2 m groundwater level. Light response of photosynthesis and the diurnal courses of leaf transpiration rate, stem sap flux velocity and environment factors under different groundwater salinity were determined via LI-6400XT portable photosynthesis system and a Dynamax packaged stem sap flow gauge based on stem-heat balance method, respectively.Important findings The result showed that groundwater salinity had a significant impact on photosynthesis efficiency and water consumption capacity of T. chinensis by influencing the soil salt. The net photosynthetic rate (Pn), maximum Pn, transpiration rate, stomatal conductance, apparent quantum yield and dark respiration rate increased first and then decreased with increasing groundwater salinity, while the water use efficiency (WUE) continuously decreased. The mean Pn under fresh water, brackish water and salt water decreased by 44.1%, 15.1% and 62.6%, respectively, compared with that under saline water (25.90 µmol∙m-2∙s-1). The mean WUE under brackish water, saline water and salt water decreased by 25.0%, 29.2% and 41.7%, respectively, compared with that under fresh water (2.40 µmol∙mmol-1). With the increase of groundwater salinity from brackish water to salt water, light saturation point of T. chinensisdecreased while the light compensation point increased, which lead to the decrease of light ecological amplitude and light use efficiency. Fresh water and brackish water treatment helped T. chinensis to use low or high level light, which could significantly improve the utilization rate of light energy. The decrease in Pn of T. chinensis was mainly due to non-stomatal limitation under treatment from saline water to fresh water, while the decrease in Pn of T. chinensis was due to stomatal limitation from saline water to salt water. With increasing groundwater salinity, stem sap flux velocity of T. chinensis increased firstly and then decreased, reached the maximum value under saline water. The mean stem sap flux velocity under fresh water, brackish water and salt water decreased by 61.8%, 13.1% and 41.9%, respectively, compared with that under saline water (16.96 g·h-1). Tamarix chinensis had higher photosynthetic productivity under saline water treatment, and could attained high WUE under severe water deprivation by transpiration, which was suitable for the growth of T. chinensis.
    Photosynthetic characteristics and photosynthesis-light response curve models of summer maize
    Li LI, Xiang-Xing ZHANG, Rui ZHENG, Jian-Qing GUO
    Chin J Plan Ecolo. 2016, 40 (12):  1310-1318.  doi:10.17521/cjpe.2016.0082
    Abstract ( 490 )   HTML ( 11 )   PDF (380KB) ( 853 )   Save
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    Aim The photosynthesis-light response curve is the most commonly used method to explore the relationship between photosynthetically active radiation and the net photosynthetic rate, because it is more effective to reflect the plant photosynthetic characteristics. And it is very meaningful for researchers to choose a suitable summer corn (Zea mays) photosynthetic model and optimal the models of photosynthesis-light response curve by analyzing the differences between simulation and observation in each growth period of some plant. So the object of this paper was to propose some useful suggestions for the choice of summer corn photosynthetic modes and the optimization of the photosynthetic light response curves model in further.Methods In this paper, three typical photosynthetic models were used to fitting the photosynthetic light response curve for upper leaf, leaf at ear of grain and lower leaf of summer corn during bell and milk period. And then the fitting degree of each model was compared to the measured data. Photosynthetic active radiation was divided into three parts, and the fitting residual errors of these three models were analyzed individually.Important findings The photosynthetic characteristic parameters such as maximum net photosynthetic rate (Pnmax), saturated light intensity (Isat) and dark respiration rate (Rd) decreased constantly with a top-down leaf position and the parameters at milk stage were generally lower than the bell stage. Each growth period and leaf position could fit the curve, but some deviation exists for the Pnmax and Isat in the rectangular hyperbolic model and the non-rectangular hyperbolic model. The results of curve fitting residual showed that the simulation values from Ye Zi-Piao model were closest to the actual values, and especially for the high photosynthetically active radiation section.

    Growth metabolism of wheat under drought stress at the jointing-booting stage
    Rui GUO, Ji ZHOU, Fan YANG, Feng LI, Hao-Ru LI, Xu XIA, Qi LIU
    Chin J Plan Ecolo. 2016, 40 (12):  1319-1327.  doi:10.17521/cjpe.2016.0107
    Abstract ( 393 )   HTML ( 2 )   PDF (553KB) ( 754 )   Save
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    AimsThe aim of this study was to investigate the effects of drought stress on primary, secondary metabolites and metabolic pathways in the leaves of wheat, these parameters were evaluated to determine the physiological adaptive mechanisms by which wheat tolerates drought stress at the jointing-booting stage.MethodsA pot experiment was carried out in rain-proof shelter. The relative growth rate, photosynthetic characteristics and metabolism seedlings exposed to stresses lasting 12 days at jointing-booting stage were measured.Important findings The results displayed that the photosynthesis decreased under drought stress, causing the decreases of relative growth rate and dry matter mass. Profiles of 64 key metabolites produced by wheat including organic acids, amino acids, carbohydrates, purine, etc. were examined, 29 of them were changed significantly under drought stress. Principal component analysis (PCA) showed that 64% variations can be explained by the two principal components. One-way ANOVA analysis results revealed that long term drought stress decreased malic acid, citric acid and aconitic acid significantly, indicating inhibited tricarboxylic acid cycle. We further found that prolonged drought stress led to accumulation of progressive amino acids (proline, serine, valine) and carbohydrates (myo-inositol, fructose, clucose) in wheat leaves and depletion of transamination products (asparagine, glutamine, γ-aminobutyric acid). These results imply wheat may enhance its drought tolerance mainly by increasing amino acid biosynthesis and glycolysis under water-deficit conditions. Our findings suggest that drought condition altered metabolic networks including transamination, the tricarboxylic cycle, gluconeogenesis/glycolysis, glutamate-mediated proline biosynthesis, and the metabolisms of choline, pyrimidine and purine. This study provides new insights into the metabolic adaptation of wheat to drought stress and important information for developing drought-tolerant wheat cultivars.
    Reviews
    Progress in the studies of vivipary in mangrove plants
    Xiao-Xuan ZHOU, Ling-Ling CAI, Mei-Ping FU, Li-Wei HONG, Ying-Jia SHEN, Qingshun Quinn LI
    Chin J Plan Ecolo. 2016, 40 (12):  1328-1343.  doi:10.17521/cjpe.2016.0087
    Abstract ( 747 )   HTML ( 13 )   PDF (654KB) ( 833 )   Save
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    Vivipary in plants refers to a phenomenon that sexually reproduced offsprings germinate while still attached to the maternal bodies. This is mostly manifested in mangrove plants, which occur in tropical and subtropical intertidal zones and encounter harsh environmental conditions such as high salinity, high temperatures, waterlogging, hypoxia and tidal waves. Vivipary has long been recognized as one of the most important adaptive features under such a complex environment. Here we discuss four aspects of vivipary: morphological anatomy, physiology and biochemistry, molecular biology and ecological adaptation. We also discuss shortcomings in current studies and prospect of future directions. Differing from regular seed development, viviparous seeds in mangroves are evolved with many special structures, indicating a genetically based process. Hormones play an important role in regulating the process, whilst the dynamics of salt ion concentration during embryo and propagule development seems to be an adaptive feature. The ecological significance of vivipary is fully exhibited in the propagules that can effectively establish themselves on muddy tidal zones. Such a success heavily relies on sound functional features developed on the mother plants. However, the molecular mechanism and the regulation of viviparous seed development in mangroves remain elusive. Systematic studies of vivipary in mangroves not only help to understand the nature and evolutionary process of this distinct adaptive phenomenon, but also provide the foundation for mangrove forest restoration and protection in many parts of the world.

    Applications of functional classification methods for tree fine root biomass estimation: Advancements and synthesis
    Jia-Cun GU, Dong-Nan WANG, Xiu-Xue XIA, Shao-Zhong WANG
    Chin J Plan Ecolo. 2016, 40 (12):  1344-1351.  doi:10.17521/cjpe.2016.0167
    Abstract ( 323 )   HTML ( 2 )   PDF (397KB) ( 801 )   Save
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    The morphology of fine root branching of woody plants is highly variable in their forms and functions. In the past two decades, researchers have increasingly recognized that the root-diameter-based method, using an arbitrary size of root diameter, failed to precisely characterize the physiological and ecological processes involved in finest roots. The number of publications using root-order-based approaches has increased regardless the fact that root trait-measurements based on root order are time-consuming and labor-intensive. A new approach—root functional classification method—was proposed and had been applied in the literature. The functional classification of fine roots separates roots of < 2 mm to absorptive and transport pools, making it more feasible for studies on root biomass and turnover. This new concept redefines fine root guild and has great potentials for future studies. Our literature review of the topic indicates that less is known about the inter-specific differences in estimates of biomass of absorptive and/or transport roots, with a large variation of absorptive roots on global scale. In addition, our review emphasizes the importance in: a) precision estimating of the absorptive biomass of fine roots, and b) proper definition of the range of the transport roots within and among forest ecosystems. Finally, after compare the strengths and weaknesses of the functional classification method, we propose several specific suggestions to improve the applications of this approach.