中国东北地区兴安落叶松林树干呼吸的研究

树干呼吸是森林碳平衡估计中的一个重要项目同时还能够显示树木的活力.对于如何准确估计森林树干呼吸释放CO2总量还存在争论.在本项研究中,2001～2002连续两年在一个33年生的兴安落叶松(Larix gmelini Rupr.)人工林内对树干呼吸进行了测定,同时测定了不同高度树干呼吸、呼吸的日变化、同龄落叶松林内不同个体的树干呼吸以及相关生长状态因子、水分因子和温度因子.结果显示:1)树干上部的呼吸速率在不同季节都高于下部呼吸速率,树干温度的差异能够一定程度上解释这种差异;2)树干呼吸有午间降低的现象,上午的测定结果树干温度与树干呼吸速率紧密相关,而下午则温度依赖性很小,土壤、空气、小枝木质部水势、叶片蒸腾速率和气孔导度都显示下午植物水分亏缺下午较上午严重,呼吸的这种上下午温度相关性的差异可能受这种水分亏缺的影响;3)在同龄林内,树木个体生长状态包括平均生长速率和树冠投影面积与树干呼吸速率有显著相关关系,而树干温度与之相关性很小.幂指数模型和S曲线模型能够产生较好的拟合效果;4)树干呼吸季节变化明显,7月份出现最大值,但同一月份的年间差异较大.自然指数模型能够较好地拟合温度与树干呼吸的季节变化规律.Q10值在2.22(2001年)和3.53(2002年)之间,与以往研究的结果相当.从以上结果可以看出,通过单一的Q10值估计森林树干呼吸总量会产生偏差,要想得到准确的估计,至少应该考虑生长状态的差异和水分状态的差异.     

中国东北地区兴安落叶松林树干呼吸的研究

树干呼吸是森林碳平衡估计中的一个重要项目同时还能够显示树木的活力。对于如何准确估计森林树干呼吸释放CO2总量还存在争论。在本项研究中,2001、2002连续两年在一个33年生的兴安落叶松(Larix gmelini Rupr.)人工林内对树干呼吸进行了测定,同时测定了不同高度树干呼吸、呼吸的日变化、同龄落叶松林内不同个体的树干呼吸以及相关生长状态因子、水分因子和温度因子。结果显示：1)树干上部的呼吸速率在不同季节都高于下部呼吸速率,树下温度的差异能够一定程度上解释这种差异;2)树干呼吸有午间降低的现象,上午的测定结果树干温度与树干呼吸速率紧密相关,而下午则温度依赖性很小,土壤、空气、小枝木质部水势、叶片蒸腾速率和气孔导度都显示下午植物水分亏缺下午较上午严重,呼吸的这种上下午温度相关性的差异可能受这种水分亏缺的影响;3)在同龄林内,树木个体生长状念包括平均生长速率和树冠投影面积与树干呼吸速率有显著相关关系,而树干温度与之相关性很小。幂指数模型和S曲线模型能够产生较好的拟合效果;4)树干呼吸季节变化明显,7月份出现最大值,但同一月份的年间差异较大。自然指数模型能够较好地拟合温度与树干呼吸的季节变化规律。Q10值在2．22(2001年)和3．53(2002年)之间,与以往研究的结果相当。从以上结果可以看出,通过单一的Q10值估计森林树干呼吸总量会产牛偏差,要想得到准确的估计,至少应该考虑生长状态的差异和水分状态的差异。     

3种落叶松幼苗对CO2升高的光合生理响应

采用Li-6400便携式光合作用测定系统研究CO2升高对长白落叶松(Larix olgensisHerry.),日本落叶松(Larix kaempferiCarr.)和兴安落叶松(LarixgmeliniRupr.)当年生和1年生幼苗的光合特性的影响。结果表明:CO2升高使3种落叶松光饱和光合速率(Pmax)和呼吸速率均有不同程度的增加,其中,长白落叶松当年生和1年生幼苗Pmax分别比对照提高了91%和83%,日本落叶松当年生和1年生幼苗Pmax分别比对照提高了71%和94%,而兴安落叶松当年生和1年生幼苗Pmax分别比对照提高了32%和106%。除兴安落叶松外,CO2升高使所有落叶松当年生幼苗的光补偿点(LCP)下降,说明当年生幼苗对CO2浓度升高的反应更敏感。CO2升高使日本落叶松当年生和1年生幼苗光饱和点(LSP)都升高,反映了其光合作用提高的潜力较大。CO2升高条件下,除1年生兴安落叶松外,其他处理的落叶松最大量子效率(AQYmax)均增加。比较分析表明,在未来大气CO2浓度升高条件下,日本落叶松的生长潜能可能最大,具有较强的生态优势,长白落叶松次之,兴安落叶松最小。     

iTRAQ-Based Quantitative Proteomics Suggests Synaptic Mitochondrial Dysfunction in the Hippocampus of Rats Susceptible to Chronic Mild Stress

Mounting studies show that hippocampal synaptic transmission and plasticity are abnormal in depression. It has been suggested that impairment of synaptic mitochondrial functions potentially occurs in the hippocampus. Thus, the synaptic mitochondria may be a crucial therapeutic target in the course of depression. Here, we investigated the potential dysregulation of synaptic mitochondrial proteins in the hippocampus of a chronic mild stress (CMS) rat model. Proteomic changes of hippocampal synaptosomes containing synaptic mitochondria were quantitatively examined using the isobaric tag for relative and absolute quantitation labeling combined with tandem mass spectrometry. 45 Proteins were identified to be differentially expressed, of which 21 were found to be putative synaptic mitochondrial proteins based on gene ontology component and SynaptomeDB analyses. Detailed investigations of protein functions and disease relevance support the importance of hippocampal synaptic mitochondria as a key substrate contributing to impairment in synaptic plasticity of stress-related disorders. Interestingly, eight synaptic mitochondrial proteins were specifically associated to the susceptible group, and might represent part of molecular basis of depression. Further analysis indicated that the synaptic mitochondrial oxidative phosphorylation (OXPHOS) system was heavily affected by CMS in the susceptible rats. The present results provide novel insights into the disease mechanism underlying the abnormal OXPHOS that is responsible for energy-demanding synaptic plasticity, and thereby increase our understanding of the role of hippocampal synaptic mitochondrial dysfunction in depression.     

Carbon Accumulation Patterns During Post-Fire Succession in Cajander Larch (Larix cajanderi) Forests of Siberia

Increased fire activity within boreal forests could affect global terrestrial carbon (C) stocks by decreasing stand age or altering tree recruitment, leading to patterns of forest regrowth that differ from those of pre-fire stands. To improve our understanding of post-fire C accumulation patterns within boreal forests, we evaluated above- and belowground C pools within 17 Cajander larch (Larix cajanderi) stands of northeastern Siberia that varied in both years since fire and stand density. Early-successional stands (<20-year old) exhibited low larch recruitment, and consequently, low density, aboveground larch biomass, and aboveground net primary productivity (ANPP_tree). Mid-successional stands (21- to 70-year old) were even-aged with considerable variability in stand density. High-density mid-successional stands had 21 times faster rates of ANPP_tree than low-density stands (252 vs. 12?g?C?m^?2?y^?1) and 26 times more C in aboveground larch biomass (2,186 vs. 85?g?C?m^?2). Density had little effect on total soil C pools. During late-succession (>70-year old), aboveground larch biomass, ANPP_tree, and soil organic layer C pools increased with stand age. These stands were low density and multi-aged, containing both mature trees and new recruits. The rapid accumulation of aboveground larch biomass in high-density, mid-successional stands allowed them to obtain C stocks similar to those in much older low-density stands (~8,000?g?C?m^?2). If fire frequency increases without altering stand density, landscape-level C storage could decline, but if larch density also increases, large aboveground C pools within high-density stands could compensate for a shorter successional cycle.     

Structure and Composition of Natural Gmelin Larch (Larix gmelinii var. gmelinii) Forests in Response to Spatial Climatic Changes

Background

Many theoretical researches predicted that the larch species would decrease drastically in China under future climatic changes. However, responses of the structural and compositional changes of Gmelin larch (Larix gmelinii var. gmelinii) forests to climatic changes have rarely been reported.

Methodology/Principal Findings

Field survey was conducted to examine the structures and compositions of natural Gmelin larch forests along a climatic gradient. Stepwise linear regression analyses incorporating linear and quadratic components of climatic and non-climatic factors were performed on the structural and compositional attributes of those natural Gmelin larch forests. Isothermality, Max Temperature of Warmest Month (TempWarmestMonth), Precipitation of Wettest Month (PrecipWettestMonth), Precipitation Seasonality (PrecipSeasonality) and Precipitation of Driest Quarter (PrecipDriestQuarter) were observed to be effective climatic factors in controlling structure and composition of Gmelin larch forests. Isothermality significantly affected total basal area of larch, while TempWarmestMonth, PrecipWettestMonth and PrecipSeasonality significantly affected total basal area of Mongolian pine, and PrecipDriestQuarter significantly affected mean DBH of larch, stand density of larch and total basal area of spruce and fir.

Conclusions/Significance

The summer and winter temperatures and precipitations are all predicted to increase in future in Northeast China. Our results showed the increase of total basal area of spruce and fir, the suppression of regeneration and the decrease of stand density of larch under increased winter precipitation, and the decrease of total basal area of larch under increased summer temperature in the region of current Gmelin larch forest. Therefore, we suggest that larch would decrease and spruce and fir would increase in the region of future Gmelin larch forest.     

Molecular phylogeny and biogeography of the spider ants, genus Leptomyrmex Mayr (Hymenoptera: Formicidae)

This study provides the first phylogenetic reconstruction of the ant genus Leptomyrmex Mayr, a prominent endemic component of rain forest and wet sclerophyll forest in Australia, New Guinea and New Caledonia. Five genes are used to reconstruct phylogeny and estimate of ages of diversification in order to test congruence of the history of nuclear and mitochondrial genes: three protein-coding nuclear genes: arginine kinase (argK, 897 bp), long wavelength rhodopsin (LW Rh, 546 bp) and wingless (Wg, 409 bp), as well as the large subunit ribosomal gene 28S (482 bp) and the mitochondrial gene cytochrome oxidase I (COI, 658 bp). Four different partitioning schemes were tested for optimal resolving power; results show that partitioning by gene, translational pattern and codon position were uniformly favoured over less complex partitions. Nuclear markers showed relatively minor sequence divergence and provided strongly supported topology; phylogeny based solely on mtDNA produced somewhat conflicting topology but offered little power to resolve species complexes. Monophyly of the genus Leptomyrmex was recovered, as was the sister-group relationship of 'micro-' and 'macro-'Leptomyrmex species. Divergence dating analyses estimate that Leptomyrmex arose in the Eocene (stem age ～ 44 million years ago (ma)), and that the 'macro-' species diverged from the 'micro-' species in the early Oligocene (～ 31 ma). Diversification of the crown group 'macro-' and 'micro-'Leptomyrmex occurred in the Miocene (～ 15 ma and 7.9 ma, respectively). New Guinean and New Caledonian lineages appear to have diverged from Australian lineages only recently (～ 4.7 ma and 10.3 ma, respectively), and the latter clade is inferred to have reached New Caledonia from Australia via long distance dispersal. These results challenge previous hypotheses of Leptomyrmex classification and assumptions about their historical dispersal, but are in agreement with the current knowledge of the geological history of Melanesia.     

六盘山南坡华北落叶松(Larix principis-rupprechtii)树干直径生长及其对气象因子的响应

2005年6-9月份在宁夏六盘山南侧的西峡林场,应用带状树木径向变化记录仪（Dendrometer）研究了5株华北落叶松树干的直径生长过程,结果表明,在无雨或小雨（日降雨量〈10mm）天气下,树干直径变化呈现出明显的日周期性,可将其划分为3个阶段：收缩阶段、膨胀阶段和生长阶段;在连续降雨（日降雨量≥10mm）及随后的几个晴天中,树干直径变化并不表现出完整的日周期性。基于Deslauriers等人的方法,提出了树干直径日生长量估计的修正公式,并计算了华北落叶松树干直径日生长量和累积生长量,结果表明,各样木树干直径日生长量的季节变化趋势一致,即表现为前快后慢的季节变化格局,6～7月份为快速生长期,其日均生长量在27．0～44．21μm之间;8～9月份为缓慢生长期,其日均生长量在10μm以下;各测定样木的树干直径日生长量具有明显的个体差异,这主要与林木个体大小及其所处林分中的微环境条件差异有关;整个观测期内的树干直径累积生长过程可以较好地用幂函数描述。主分量分析和偏相关分析表明,影响树干径向生长的气象因子可划分为3类,其中日降雨量、日最低气温、日平均太阳辐射和日平均空气饱和差是影响树干径向生长的主要因子。     

Development of the Embryo Sac in Amitostigma kinoshitae (Makino) Schltr. (Orchidaceae)

The embryo sac of Amitostigma kinoshitae was studied. The ovuleis anatropous, bitegmic, and tenuinucellate. The inner integumentalone forms a micropyle. The megaspore of a tetrad nearest tothe chalaza develops into an eight-nucleate embryo sac of thetypical Polygonum-type. Double fertilization takes place normally.     

Profiling of Intracellular Metabolites: An Approach to Understanding the Characteristic Physiology of Mycobacterium leprae

Mycobacterium leprae is the causative agent of leprosy and also known to possess unique features such as inability to proliferate in vitro. Among the cellular components of M. leprae, various glycolipids present on the cell envelope are well characterized and some of them are identified to be pathogenic factors responsible for intracellular survival in host cells, while other intracellular metabolites, assumed to be associated with basic physiological feature, remain largely unknown. In the present study, to elucidate the comprehensive profile of intracellular metabolites, we performed the capillary electrophoresis-mass spectrometry (CE-MS) analysis on M. leprae and compared to that of M. bovis BCG. Interestingly, comparison of these two profiles showed that, in M. leprae, amino acids and their derivatives are significantly accumulated, but most of intermediates related to central carbon metabolism markedly decreased, implying that M. leprae possess unique metabolic features. The present study is the first report demonstrating the unique profiles of M. leprae metabolites and these insights might contribute to understanding undefined metabolism of M. leprae as well as pathogenic characteristics related to the manifestation of the disease.     

Growth in stem diameter of Larix principis-rupprechtii and its response to meteorological factors in the south of Liupan Mountain, China

Research related to daily and seasonal pattern of stem growth of Larix principis-rupprechtii was carried out with the help of a dendrometer from June to September in 2005 in the Liupan Mountain, Ningxia, Northwestern China. The results indicated that daily fluctuation of stem diameter was rhythmic and it could be divided into three continuous phases: contraction, expansion and stem diameter growth when daily rainfall < 10 mm during the measurement period. Comparatively, it showed a different pattern compared with the former when daily rainfall ≥10 mm and in the subsequent days. Based on the work done by Deslauriers et al. a modified method was designed to calculate daily and cumulative stem growth, and it showed that seasonal pattern of cumulative stem growth was similar among five sample trees. From June and July, stem growth rate was quick and the values were in the range 27.0–44.2 μm per day. Relatively, they took on a slow growth rate from August to September, and the values were under 10 μm per day. And it also showed that there existed a significant difference in stem growth among sample trees, which could be as a result of the difference in tree domain and their positions in the stand. The relationship between daily stem growth and meteorological factors was studied by principle component analysis and partial correlation analysis, and the result indicated that the daily rainfall, daily minimum temperature, daily average solar radiation and vapor pressure deficit were four significant factors which determined the daily stem growth.     

An Approach to the Development of Field Studies in Urban Areas

Integrated Science—The Wreake Valley Project D. TINBERGEN and P. THORBURN (Eds) Book 1, 120 pp., illustrated. £1.50. Book 2, 104 pp., illustrated. £1.75. Book 3, 136 pp., illustrated. £2.25. London: Edward Arnold, 1976. Reviewed by John May

Stirling Educational Monographs No. 1. Attitude Goals in Secondary School Science S. BROWN 77 pp. University of Stirling. 1976. £1.75. Reviewed by Clive Carré and Henry Crowther

No. 2. Innovations in Integrated Science in Scottish Secondary Schools S. BROWN, D. McINTYRE, E. DREVER and J. KERI DAVIES 89 pp. University of Stirling, 1976. £1.00. Reviewed by Tessa Carrick

Outline Studies in Biology 64 pp. each, illustrated. London: Chapman and Hall, 1976. £1.30 each. Biological Energy Conservation C. W. JONES Control of Enzyme Activity P. COHEN Metabolic Regulation R. M. DENTON and C. I. POGSON Reviewed by John H. Duffus

Population Genetics L. M. COOK Reviewed by T. J. Crawford

Cytogenetics of Man and other Animals A. McDERMOTT Reviewed by J. A. Beardmore

RNA Biosynthesis R. H. BURDON Protein Biosynthesis A. E. SMITH Reviewed by C. M. Bray

Basic Biology Course Books 3, 5, 8, and 9 London: Cambridge University Press, 1976.

Book 3 Dynamic Aspects of Cells M. A. TRIBE, I. TALLAN, M. R. ERAUT and R. K. SNOOK 119 pp., illustrated. £6.20 boards, £2.90 paper.

Book 5 Cell Membranes M. A. TRIBE, M. R. ERAUT and R. K. SNOOK 79 pp., illustrated. £5.00 boards, £2.50 paper. Super 8 mm film loop (Phagocytosis) £8.00.

Book 8 Metabolism and Mitochondria M. A. TRIBE, M. R. ERAUT and R. K. SNOOK 142 pp., illustrated. £8.00 boards, £3.50 paper. Filmstrip £3.50; cassette £3.80.

Book 9 Protein Synthesis M. A. TRIBE, I. TALLAN, M. R. ERAUT and R. K. SNOOK 103 pp., illustrated. £6.00 boards, £2.75 paper. Reviewed by Colin Stoneman

Population Cytogenetics Studies in Biology, No. 70 B.JOHN 76 pp., illustrated. London: Edward Arnold, 1976. £3.00 boards, £1.50 paper. Reviewed by J. A. Beardmore

Biology Colour Units Helpful and Harmful Organisms M. Sanderson Urban Ecology D. Gilman Co-ordination C. Morgan Movement D. Gray Each 24 pp, illustrated. London: Macdonald Educational, 1977. 75p each. Reviewed by John May

The Natural World : The Mitchell Beazley Joy of Knowledge Library J. MITCHELL (Ed.) 272 pp., illustrated. London: Mitchell Beazley, 1977. £12.50. Reviewed by P. J. Kelly

Human and Social Biology G. USHER 256 pp., illustrated. Plymouth, Devon: Macdonald and Evans, 1977. £1.95. Reviewed by A. Cornwell

Safeguards in the School Laboratory 28 pp., Hatfield, Herts: Association for Science Education, 1976. 35p. Reviewed by Tessa Carrick

A First Science Dictionary D. J. LUCAS, H. I. JAMES, and O. J. SIMPSON 208 pp. London: Edward Arnold, 1976. £1.95. Reviewed by John Feltwell

Introduction to Genetics Third Edition D. G. MACKEAN 42 pp., illustrated. London: John Murray, 1977. £1.40. Reviewed by Tessa Carrick

The Wash water storage feasibility study: a report on the ecological studies 36 pp., illustrated. London: Natural Environment Research Council. Publication series C No. 15, 1976. Free. Reviewed by John A. Barker

Higher Education Film Library Catalogue BRITISH UNIVERSITIES FILM COUNCIL London: BUFC, 1977. £1.00. Reviewed by John A. Barker

Biology: Principles and Issues WILLIAM C. SCHEFLER 370pp., illustrated. London: Addison-Wesley, 1976. £9.10. Reviewed by H. W. Grenville

Guide to Living Mammals J. E. WEBB, J. A. WALLWORK, and J. H. ELGOOD 152 pp., illustrated. London: Macmillan, 1977. £2.95. Reviewed by H. V. Wyatt

Applied Medical Microbiology J. G. COLLEE 121 pp., illustrated. Oxford: Blackwell Scientific, 1976. £2.80. Reviewed by G. E. Mathison

General Microbiology Fourth edition R. Y. STANIER, E. A. ADELBERG and J. L. INGRAHAM 871pp., illustrated. London: Macmillan, 1977. £15.00 boards, £7.95 paper. Reviewed by C. G. Gayford

Fundamentals of Mycology Second edition J. H. BURNETT 673 pp., illustrated. London: Edward Arnold, 1976. £27.50. Reviewed by B. W. Bainbridge

Metals and Metabolism D. A. PHIPPS 134 pp., London: Oxford University Press (Clarendon), 1976. £5.00 boards, £2.50 paper. Reviewed by C. M. Bray

Biochemical Systems Analysis M. A. SAVAGEAU 379 pp., illustrated. London: Addison-Wesley, 1976. £21.20 boards, £13.20 paper. Reviewed by J. H. Parish

The Biochemistry of the Tissues Second edition P. BANKS, W. BARTLEY, and L. M. BIRT 493 pp. Chichester, Sussex: John Wiley, 1976. £14.50 boards, £6.25 paper. Reviewed by John Feltwell

Genetics and Adaptation Studies in Biology, No. 69 E. B. FORD 58 pp., illustrated. London: Edward Arnold, 1976. £2.60 boards, £1.30 paper. Reviewed by R. A. E. Tilney-Bassett

The Comparative Endocrinology of the Invertebrates Second edition K. C. HIGHNAM and L. HILL 357 pp., illustrated. London: Edward Arnold, 1977. £16.00 boards, £8.50 paper. Reviewed by K. Simkiss

Muscles and Movement K. M. BACKHOUSE 48 pp., illustrated. London: Hart Davis, 1976. £1.75. Reviewed by Jackie Hardie

Herbicides: Physiology, Biochemistry, Ecology, Vol. 2 Second edition L. J. AUDUS (Ed.) 564 pp., illustrated. London: Academic Press, 1976. £17.50. Reviewed by Donald S. H. Drennan

Introduction to Ecology R. DAJOZ Translated by A. SOUTH 416 pp., Sevenoaks, Kent : Hodder and Stoughton, 1977. £7.50 boards, £4.45 paper. Reviewed by D. M. Keith-Lucas

Human Sex and Sexuality E. B. STEEN and J. H. PRICE 338 pp., illustrated. Chichester, Sussex: John Wiley, 1977. £7.00. Reviewed by Donald Reid

Rabies : The Facts C. KAPLAN (Ed.) 116 pp., illustrated. Oxford: Oxford University Press, 1977. £1.95 (Also published in paperback by Corgi Books, London. 75p.) Reviewed by W. C. Noble

Introduction to Environmental Remote Sensing E. C. BARRETT and L. F. CURTIS 336 pp., illustrated. London: Chapman and Hall, 1976. £11.00 boards, £5.95 paper. Reviewed by Monical M. Cole

Light and Life L. O. BJÖRN 249 pp., illustrated. London: Hodder and Stoughton, 1976. £3.45 boards, £1.75 paper. Reviewed by John Feltwell     

Changes in Morphology,Anatomy, and Photosynthetic Capacity of Needles of Japanese Larch (Larix kaempferi) Seedlings Grown in High CO2 Concentrations

Photosynthetic traits of two-year-old Japanese larch seedlings (Larix kaempferi Carr.) grown at elevated CO₂ concentrations were studied in relation to structural changes in the needles. Seedlings were grown at two CO₂ concentrations, 360 (AC) and 720 (EC) mol mol^–1 at high and low nutrient supply rates, high N (HN) and low N (LN). The photosynthetic capacity fell significantly in EC+LN, but increased significantly in EC+HN. Since the mesophyll surface area exposed to intercellular space per unit leaf area (A^mes/A) is correlated with the photosynthetic rate, we measured A^mes/A for larch needles growing in EC. Changes of A^mes/A in both EC+HN and EC+LN were very similar to the changes in photosynthetic capacity. This suggests that the changes of A^mes/A in EC probably caused the changes in the photosynthetic capacity. The changes of A^mes/A in EC were attributed to changes in the mesophyll cell size and mesophyll cell number. The photosynthetic capacity in EC can be explained by taking morphological and structural adaptations into account as well as biochemical factors.     

Model of droplet dynamics in the Argentine ant Linepithema humile (Mayr)

The formation of droplets of ants Linepithema humile (Mayr) is observed under certain experimental conditions: a fluctuating aggregate forms at the end of a rod and a droplet containing up to 40 ants eventually falls down. When the flux of incoming ants is sufficient, this process can continue for several hours, leading to the formation and fall of tens of droplets. Previous work indicates that the time series of drop-to-drop intervals may result from a nonlinear low-dimensional dynamics, and the interdrop increments exhibit long-range anticorrelations. A model of aggregation and droplet formation, based on experimental observations, is introduced and shown to reproduce these properties.