稳定性碳同位素对植物水分利用效率的指示作用

碳同位素技术已在地质学、生态学和植物学等领域得到广泛应用。文章概述了稳定碳同位素的基本理论,从不同植物类型、空间尺度和抗旱节水植物材料选育等方面对稳定碳同位素对植物水分利用效率的指示作用进行了简要总结,对碳同位素技术进行评价,并就未来发展方向进行展望。碳同位素分辨率与植物水分利用效率高度相关,因而利用碳同位素分辨率来衡量植物水分利用效率必将有广阔的应用前景。     

Carbon isotope discrimination and its relationship to drought resistance under field conditions in genotypes of Eucalyptus globulus Labill.

The aim of this study was to investigate the relationship between carbon isotope discrimination (Δ), survival and growth, to determine the value of Δ for screening for yield improvement under drought conditions. Intra-specific variation in carbon isotope discrimination (Δ) was examined in Eucalyptus globulus. Wood samples were collected from 3 to 7 year-old populations from three different field-sites at Huelva (south-western Spain). Differences between study sites were related to the availability of water resulting from soil physical properties. Average carbon isotope discrimination ranged from 16.7 to 18.1‰. There was a 2.2‰ maximum range in Δ values among different trees of the same age. A strong, positive correlation was observed between average carbon isotope discrimination and average tree diameter at breast height (DBH_ob). Average carbon isotope discrimination was also strongly correlated with survival at the Valdeoscuro site (r²=0.95) and with the percentage of failures in neighbouring trees (r²=0.65) at the San Sebastián site. These results suggest a strong effect of availability of water on Δ values. Implications for the use of carbon isotope discrimination in selecting for better adapted genotypes are discussed.     

Carbon isotope discrimination and oxygen isotope composition in clones of the F(1) hybrid between slash pine and Caribbean pine in relation to tree growth,water-use efficiency and foliar nutrient concentration

The objectives of this study were: (1) to examine how foliar carbon isotope discrimination (Delta) and oxygen isotope composition (delta(18)O) are related to tree growth, ash mineral nutrient concentration and foliar nutrient concentration in 7-year-old clones of the F(1) hybrid between slash pine (Pinus elliottii Engelm.) and Caribbean pine (P. caribaea var. hondurensis Barr. et Golf.) in subtropical Australia; and (2) to evaluate the potential of using foliar Delta, ash mineral nutrient concentration and delta(18)O measurements for selecting F(1) hybrid pine clones with high water-use efficiency (WUE) and growth potential. There were significant differences in tree growth, foliar Delta, delta(18)O and ash mineral nutrient concentration among the eight clones tested. Significant negative linear relationships existed between tree growth and Delta, extrapolating to zero growth at Delta = 24-30 per thousand. There were strong genetic correlations (r = -0.83 to -0.96) between Delta and tree growth, particularly tree height. Significant non-genetic correlations (r = -0.62 to -0.80) existed between Delta and foliar K concentration. Foliar delta(18)O, ash mineral nutrient concentration and foliar nutrient concentration were unrelated to tree growth. In the F(1) hybrid pine clones, variation in tree WUE, as reflected by Delta, was largely attributed to a genetic effect on leaf photosynthetic capacity rather than on stomatal conductance, as reflected by foliar delta(18)O.     

Assessing the performance of woody plants in uptake and utilisation of carbon, water and nutrients: Implications for designing agricultural mimic systems

This article introduces a series of innovative experimental approaches for monitoring current and past performances of woody plant species in utilisation of key resources within ecosystems. We demonstrate how such information might be useful for monitoring the progress of any novel agricultural system which attempts to mimic such natural systems. The experimental data presented principally involve the use of stable isotope techniques coupled to collection and analysis of substances transported in the sap of xylem and phloem. Study species examined are sugar maple (Acer saccharum), tagasaste (Chamaecytisus proliferus), blue gum (Eucalyptus globulus), and acorn banksia (Banksia prionotes). Topics covered include investigations of (a) seasonal changes in water source utilisation using hydrogen stable isotope analyses, (b) water loss from tree roots to the surrounding soil (termed hydraulic lift) using hydrogen stable isotope analyses, (c) relationships between carbon isotope discrimination of plant dry matter and whole-plant water-use efficiency, (d) phloem sap analysis as a means for assessing aspects of a plant's water and nutrient status, (e) carbon isotope ratios of foliage and annual growth rings as they relate to seasonal changes in carbon isotope ratios of phloem translocate, and (f) the composition of simultaneously collected samples of xylem and phloem sap as a means of monitoring current plant performance in uptake and mobilisation of key mineral resources. The chapter concludes with discussion of prospective uses of the above- mentioned techniques in study of managed ecosystems in which woody species play pivotal roles in maintenance of functional stability. This revised version was published online in June 2006 with corrections to the Cover Date.     

杉木不同部位、叶龄针叶净光合效率特征

对6年生杉木人工纯林进行光合作用测定,不同部位针叶单位面积同化CO2净量变化规律是上部〉中部〉下部,不同部位针叶总面积同化CO2净量变化规律是中部〉上部〉下部,不同部位针叶同化CO2能力差异显著。不同叶龄针叶单位面积同化CO2净量变化规律是当年生〉一年生〉二年生〉三年生,不同叶龄针叶间同化CO2能力差异极显著。被测定株间单位面积同化CO2净量差异极显著。下部、中部、上部针叶面积分别为总面积的35．8％、40．0％、24．2％。当年生、一年生、二年生、三年生针叶面积分别为总面积的34．7％、33．9％、20．2％、11．2％。下部、中部、上部针叶同化CO2净量分别为总数的29．8％、38．1％、32．1％;当年生、一年生、二年生、三年生针叶同化CO2净量分别为总数的43．8％、32．7％、16．0％、7．5％。     

稳定碳同位素在森林植物水分利用效率研究中的应用

介绍了植物水分利用效率与稳定碳同位素的相关性,以及影响植物碳同位素丰度值δ13C的主要因子,重点分析几种重要环境因子对林木δ13C的影响,表明降雨量、土壤水分状况、温度、光照和CO₂浓度等因素都会在不同程度上影响植物叶片气孔导度和CO₂的固定,导致植物δ13C发生变化;并从森林抚育间伐措施对δ13C的影响,水分胁迫条件下δ13C的变化,以及δ13C的替代测定方法等方面提出了研究展望。     

油茶光合特性研究进展与高光效育种前景

在综述油茶光合作用和山茶属其他植物光合作用的规律等研究进展的基础上,从高光效株型的选育、生理生化型的选育、杂交育种和基因工程育种等方面论述了油茶高光效育种的主要方法及发展前景。     

Changes in foliar carbon isotope composition and seasonal stomatal conductance reveal adaptive traits in Mediterranean coppices affected by drought

We estimated water-use efficiency and potential photosynthetic assimilation of Holm oak(Quercus ilex L.) on slopes of NW and SW aspects in a replicated field test examining the effects of intensifying drought in two Mediterranean coppice forests. We used standard techniques for quantifying gas exchange and carbon isotopes in leaves and analyzed total chlorophyll, carotenoids and nitrogen in leaves collected from Mediterranean forests managed under the coppice system. We postulated that responses to drought of coppiced trees would lead to differential responses in physiological traits and that these traits could be used by foresters to adapt to predicted warming and drying in the Mediterranean area. We observed physiological responses of the coppiced trees that suggested acclimation in photosynthetic potential and water-use efficiency:(1) a significant reduction in stomatal conductance(p0.01) wasrecorded as the drought increased at the SW site;(2) foliar δ13C increased as drought increased at the SW site(p0.01);(3) variations in levels of carotenoids and foliar nitrogen, and differences in foliar morphology were recorded, and were tentatively attributed to variation in photosynthetic assimilation between sites. These findings increase knowledge of the capacity for acclimation of managed forests in the Mediterranean region of Europe.     

油茶叶片相对电导率与其养分含量的关系

为探求提供一种简捷实用的林木养分测定方法.以油茶为对象,采用常规养分分析和电导率法,分别测定油茶叶片样品的N、P、K养分含量及其相对电导率,建立其相对电导率与养分含量的相关模型,并探索利用根据测定样品的电导率,来快速获得该样品的养分含量.结果表明,油茶叶片样品相对电导率与N、P、K养分含量相关性良好,且均遵循多项式拟合模型,经验证,该预测模型精度达90％以上.     

Genomic DNA methylation of juvenile and mature Acacia mangium micropropagated in vitro with reference to leaf morphology as a phase change marker

Genomic DNA methylation was analyzed in Acacia mangium Willd. microshoots micropropagated in vitro from juvenile and mature explants, and in relation to leaf morphology of the microshoots, which is considered a phase change indicator. Based on high performance liquid chromatography (HPLC) analyses, we found more DNA methylation in microshoots exhibiting juvenile leaf morphology (22.4%) than in microshoots of the mature phyllode morphological type (20.7%), irrespective of the age of the source material. Overall, the degree of DNA methylation in A. mangium microshoots was consistent with values reported for other angiosperms. Complementary investigations based on methylation sensitive amplification polymorphism (MSAP) techniques established that, of 1204 fragments revealed by the different primer pairs used, 49 (i.e., 4.08%) were derived from C(5m)CGG methylated sites. Three of these C(5m)CGG sites were exclusive to the juvenile plant material, and three sites were exclusive to the mature source. No fragments were associated specifically with leaf morphology, rather than with plant age. Thus, although the two age classes could not be distinguished based on a quantitative HPLC measure of DNA methylation, qualitative differences existed, as demonstrated by the six age-specific markers identified by MSAP. The reliability of the MSAP data was confirmed on a larger sample of juvenile plant material, which suggested that the total of six methylation markers detected is probably an underestimation of the age-related differences in DNA methylation that may exist between juvenile and mature plant materials.     

Partition of nocturnal sap flow in Acacia mangium and its implication for estimating the whole-tree transpiration

We analyzed the partition of nocturnal sap flow into refilling of internal water storage and transpiration in Acacia mangium. Sap flow of trees was monitored continuously with Granier’s sensors for estimating the whole-tree transpiration. Possible night transpiration and stomatal conductance at the leaf level in the canopy were measured with a LI-6400 photosynthesis measuring system. For nocturnal leaf transpiration and stomatal conductance were weak, nocturnal sap flow of mature A. mangium trees was mainly associated with water recharge in the trunk. No significant change in night water recharge of the trunk was found at both seasonal and inter-annual scales. Morphological features of trees including diameter at the breast height (DBH), tree height, and canopy size could explain variances of night water recharge. Furthermore, although the contribution of nocturnal sap flow to the total transpiration varied among seasons and DBH classes, the error caused by night water recharge on wholetree transpiration was negligible. __________ Translated from Journal of Plant Ecology (Chinese Version), 2007, 31 (5): 777–786 [译自: 植物生态学报]     

平茬年限对沙冬青光合特性与比叶面积的影响

[目的]为在理论与技术上解决孑遗植物种质资源的保存与修复,探究沙冬青被平茬后更新恢复生长的机理和策略.[方法]利用Li-6400便携式光合仪测定了不同平茬年限沙冬青的光合生理特性,同时分析了不同平茬年限沙冬青比叶面积(SLA)与光合速率(Pn)、水分利用效率(WUE)的关系,从而更好地解释平茬复壮后植物补偿性生长机理与...     

华山松、油松不同叶龄针叶光合特性对林窗式疏伐的响应

[目的]通过对比研究华山松和油松不同叶龄针叶形态、光合速率、叶绿素和叶氮含量对林窗式疏伐的响应,探讨林窗大小、叶龄和树种对林窗式疏伐后叶光合特性响应的影响。[方法]2008年在30年生华山松和油松混交人工林中,设置对照、小林窗(80 m2)和中林窗(110 m2)处理,2013年以对照样地内和林窗边缘华山松和油松为研究对象,测定其当年生、1年生和2年生叶比叶重(LMA)、单位叶面积叶绿素a(Chl a)、叶绿素b含量(Chl b)、氮含量(N)、最大净光合速率(Amax)、光合氮利用效率(PNUE)等指标。[结果]小林窗和中林窗疏伐对叶光合特性影响一致,均对当年生叶影响不显著,但显著改变了1年生和2年生叶绿素含量、N和PNUE,提高了其Amax。华山松叶LMA、叶绿素含量、N、Amax均低于油松,两树种多年生叶对林窗式疏伐的响应也明显不同:林窗边缘华山松1年生和2年生叶LMA和N与对照差异不显著,但叶绿素含量低于对照,PNUE和Amax显著高于对照;林窗边缘油松1年生和2年生叶LMA和PNUE与对照差异不显著,但N和Amax显著高于对照。[结论]80 110 m2林窗疏伐显著改变叶光合特性,提高其光合潜力;林窗疏伐影响1年生和2年生叶光合特性,对当年生叶影响不显著;华山松和油松对林窗式疏伐的响应特征存在差异。     

3种沙地植物光合碳同化对环境因子的生理响应

Physiological responses of the photosynthetic carbon assimilation of one-Year-old seedlings of three sandy plant species to environmental factors were studied. The results showed that ( 1 ) the variati...     

碳氢氧稳定同位素在草地生态系统水循环研究中的应用

碳氢氧稳定同位素是存在于天然水体和植物组织中的良好的示踪剂,具有较高的灵敏度与准确性,可系统和定量地阐明草地生态系统水循环过程及各水体的转化关系、植物水分利用策略以及植被对全球变化的响应机制等。本文概述了稳定同位素的基本概念和原理,总结和分析了草地生态系统水循环的研究方法和现状,重点探讨和综述了氢氧稳定同位素技术在草地生态系统水循环过程（包括大气降水、地表水、土壤水、地下水、植物水、蒸发水等）以及碳稳定同位素技术在植物水分利用效率中应用的国内外研究进展,分析了其存在的问题,展望了这一领域未来的研究方向和应用前景,为我国草地资源保护、合理利用及退化草地生态系统恢复等提供理论依据。     

安吉毛竹春秋季光合特性及碳同化量

在浙江省安吉县利用Li-6400光合作用测定仪测定3年生毛竹当年生叶片在春、秋季的光合特性,并采用相关分析法探讨毛竹叶片在春秋季净光合速率的主要影响因子,最后对其碳同化量进行估算。结果表明:毛竹叶片在春、秋季的净光合速率日变化均表现为不对称的双峰型曲线。秋季的净光合速率的日均值大于春季。毛竹叶片在春、秋季表现出不同的光合特性,其气孔导度(Gs)、胞间CO2浓度(Ci)、光合有效辐射(PAR)、气温(Tair)、叶温(Tleaf)、空气CO2浓度(Ca)、空气相对湿度(RH)和叶温下蒸汽压亏损(VPD)等生理生态因子与净光合速率(Pn)之间存在一定的相关关系。毛竹叶片的固碳能力秋季高于春季。     

碳汇研究及发展探讨

分析了国内外碳汇研究背号,探讨了国内外在低碳发展道路上的应对策略及我国在碳汇研究上所采用的数字化研究方法,为我国在低碳发展道路上实施的方针提供建议。     

An application of data envelopment analysis to investigate the efficiency of lumber industry in northwestern Ontario, Canada

This study aims at exploring the technical efficiency of lumber industry in northwestern Ontario,Canada using data envelopment analysis(DEA).The DEA model analyzes relative technical efficiency of lumber mills with disproportionate inputs and outputs by dividing the 10year time series data,for inputs and outputs of 24 lumber mills,over two periods(1999-2003 and 2004-2008).Four inputs,namely,material(log volume),labour(man-hours),two types of energy(hog-fuel and electricity),and one output(lumber volume) are used in this study.The trend analysis shows an annual reduction of 10%,13% and 13% for lumber output,log consumption(input) and number of employees,respectively,during the period 1999-2008.The results from DEA with two scenarios with energy inputs and without energy inputs,for the two periods are found to be mixed and interesting.While some mills have improved their performance in terms of best use of available scarce inputs in the second period,some have shown negative per cent change in efficiency.In the with energy input and the without energy input scenario,some of the mills show a reduction in efficiency in the second period from the first period,with the highest estimated reductions of-13.9% and-47.6%,respectively.A possible explanation for these negative performances of mills in the latter period is the decline in production in the second period compared to the first period,where these mills were not able to adjust their inputs(mostly labour) as proportional lay-offs might not have been possible.These results provide policy makers and industry stakeholders with an improved understanding of the trends of efficiency and employment as well as reallocation opportunities of future inputs in order to increase benefits from this sector.     

Biomass allocation and assimilation efficiency of natural Tilia amurensis samplings in response to different light regimes

IntroductionAmourIinden(THisamurensiS),animportantcom-ponentofnaturaIIymixedbroad-Ieaved--KoreanpinecommunityineasternmountainareaofNortheastregionofChina,isoneofmainspeciesusedashighqualjtyveneerandcabinetworkingtimber.ButtheamountofnaturallindenresourceswithhighquafitywassharplydecreasedwithIonghistoricaIexpIoita-tionwithoutpIantingsothatlittleIindentimberhavebeenslJppliedintimbermarket.BeIongingtoassociatingspeciesinclimaxcom-munityintheregion,thespecieshasabigfacuIty.Butthegerminat…     

土壤碳现状及其对全球气候变化的响应

本文综述了目前的全球土壤碳储量、密度及其分布规律,从全球升温、大气CO2浓度增加以及气候变化引起土壤侵蚀加剧等几个方面阐述了土壤碳动态对全球气候变化的响应,并介绍了近年来国内外相关的一些研究成果.