川西亚高山森林岷江冷杉树轮碳稳定同位素对气候要素的响应

利用四川卧龙亚高山暗针叶林岷江冷杉树木年轮样本资料,建立树轮宽度年表,对比宽度年表,提取树木年轮(简称树轮)碳稳定同位素(δ13C)序列和去趋势序列(DS),研究岷江冷杉树轮碳稳定同位素序列对气候要素的响应关系.结果表明:岷江冷杉(1904-2009年)树轮碳稳定同位素变化范围为-23.33‰～-26.31％‰,平均值为-24.91‰,变异系数为-0.025;相关分析表明,岷江冷杉δ13C序列(DS)与前一年11月和当年1月的月平均气温显著正相关(P≤0.05),与前一年1月和当年2,11月的月平均气温极显著正相关(P≤0.01),冬季平均气温对岷江冷杉树轮碳稳定同位素的响应最为敏感,是研究过去环境变化的良好载体,与当年1月降水量显著正相关(P≤0.05),与全年的月平均相对湿度相关性不显著(P≥0.05).     

杉木北缘产地林木径向生长与气候因子的关系研究

摘要：杉木是中国南方湿润地区的主要造林树种之 一 。研究杉木生长与气候响应关系,对预测未来气候变化背景下杉 木的生长特点具有重要意义 。本研究以安徽霍山县茅山林场现存百年杉木林为研究对象,利用人工钻取的 58支杉木树轮 样芯,基于树轮交叉定年技术,构建了杉木树轮标准化年表,分析树轮宽度与气候要素间的关系,以探讨杉木分布北缘林木 径向生长对气候的响应关系 。结果表明:杉木年轮宽度与当年 4 月 降水量以及 9 月 日 照 时数均呈正相关关系 。 多元线性 回归及优势度分析得出,当年 4月 降水和 9月 日 照时数分别贡献了杉木生长的 9.6%和 12.1% 。 由上可知,杉木北缘产地 的杉木在生长季早期生长主要依赖于水分供应,而在生长季晚期则主要依赖于光照。     

帽儿山地区不同种源樟子松树轮对气候因子的响应

[目的]为了进一步了解不同种源的樟子松在帽儿山地区的生长差异,研究该地区气候因子对樟子松径向生长的影响,本文建立了来自于阿尔山、高峰、红花尔基、卡伦山、图强罕达盖和金山等7个种源樟子松树轮年表。[方法]通过年轮-气候响应分析、相关分析、主成分分析,探讨了不同种源樟子松径向生长与气候因子的响应差异。[结果]表明:7个种源地樟子松树轮年表整体变化趋势基本相似,但局部也有不同之处,除图强种源外,其余6个种源地樟子松在生长初期年轮宽度呈增加趋势。阿尔山、高峰、红花尔基和卡伦山种源地樟子松径向生长与当年2月平均温度显著正相关,罕达盖种源地樟子松径向生长与前一年4月平均温度显著正相关;高峰、图强、卡伦山种源地樟子松径向生长与当年6月降水显著正相关,阿尔山、高峰、金山、卡伦山、红花尓基、图强种源樟子松的径向生长主要与前一年8月降水显著负相关。[结论]多数种源的樟子松在初期径增长较快,与当年2月份的温度和6月份的降水量有正相关的响应性,而与前一年8月份的降水量有负相关的响应性。     

云阳马尾松树轮宽度年表特征研究

利用采自重庆市云阳县马尾松分布上限和下限的树轮样芯材料,分别建立了树轮宽度年表.结果表明:分布上限的马尾松树轮宽度指数变化幅度大于下限,且上限树轮样本的信噪比、样本总体代表性均比下限的高;总体来讲,上限树木的生长对环境的敏感性比下限的高.进一步分析表明:上限马尾松的生长受前一年气温和降水的影响,而下限马尾松的生长只与当年降水量有关,这表明云阳分布在上限的马尾松和分布在下限的马尾松生长与气候因子之间的关系不同;气候因子对分布在上限的马尾松生长的影响存在滞后效应.     

峨眉山不同海拔冷杉径向生长对气候变化的响应

【目的】研究峨眉山不同海拔冷杉Abies fabri径向生长对气候变化的响应规律。【方法】以冷杉为研究对象,用树轮生态学的方法对峨眉山不同海拔的冷杉进行年轮采样、处理与分析,比较不同海拔冷杉径向生长特征及其与各气候因子之间的关系。【结果】年表统计数据表明,4个年表均具有较高的可靠性,可以用于树木生长与气候关系的研究。不同海拔冷杉径向生长与气候的关系具有明显的海拔差异,海拔2 400 m处冷杉径向生长与当年7月的温度呈显著正相关;海拔2 800 m处冷杉径向生长与当年4-9月的帕尔默干旱指数(PDSI)呈显著正相关;海拔2 900 m处冷杉径向生长与前一年9月和当年4月的温度呈显著负相关,与当年1-9月的PDSI均呈显著正相关;海拔3 000 m处冷杉径向生长和当年3-4月温度呈显著负相关,与当年6-7月的PDSI和当年4月平均相对湿度呈显著正相关。【结论】峨眉山高海拔的冷杉包含有更多的环境信息,对气候变化的响应也更为敏感;高海拔区域冷杉径向生长受到水分的强烈限制,而低海拔区域冷杉径向生长主要受温度影响;冷杉衰亡与气候因子的变化密切相关,随着区域气候的变暖,高海拔地区冷杉可能会进一步衰退。该研究揭示了峨眉山不同海拔冷杉生长动态及其对气候变化响应的敏感性差异,为全球气候变化背景下冷杉林的保护与适应性管理提供科学参考。     

人工林红松生长轮宽度对气候变化的响应

应用响应函数分析方法研究了东北地区人工林红松生长轮宽度对月平均气温等气候因素变化的响应,结果表明：前一年4月到当年9月的气候变化对人工林红松生长轮宽度径向变异可产生40.8%的影响;温度是影响红松生长轮宽度径向变异最主要的气候因素,其中,前一年9月平均地温的影响最大,回归系数达到0.441。     

四川红杉径向生长对气候变化的响应研究

为了解青藏高原东缘四川红杉径向生长对气候变化的响应规律,于四川马尔康海拔3940 m采集四川红杉木年轮样芯,建立标准年表,对年轮宽度指数与前一年1月至当年12月的月平均最高温、最低温、平均温和降水量进行了相关分析。结果表明：四川红杉径向生长与当年9月降水量呈显著正相关,与当年12月份的最低气温呈显著负相关,其生长季降水增多可能有利于高海拔四川红杉的生长。     

间伐与气候对长白落叶松树轮宽度的影响

【目的】研究间伐及气候因子对长白落叶松树轮宽度的影响,以期了解全球气候变化背景下,树木生长对气候变化的响应,及人类营林措施对树木生长的影响。【方法】以长白落叶松为对象,建立以树轮宽度指标为因变量、包含间伐效应及气候因子的非线性混合模型。样地数据为20块人工林起源经自然演替形成的长白落叶松云冷杉针阔混交林间伐区组试验样地1987—2012年的调查数据。利用Lintab 6树轮宽度测量仪测量树轮宽度并通过COFECHA程序交叉定年后,共保留231条长白落叶松年轮条的年轮宽度数据。气候数据为样地附近多个气象站1964—2010年的线性插值数据。综合各部分数据的重叠时间段,选用1987—2010年的数据进行建模。【结果】形成层年龄、林分密度、单木竞争、间伐和气候因子均对长白落叶松树轮宽度指标有显著影响;第1次间伐时间在林龄20年左右,重度间伐(40%)后树轮宽度指标增量最大,中度间伐(30%)次之,轻度间伐(20%)的影响不显著,树轮宽度指标增长量在伐后1~2年达到峰值,并持续至伐后4年;第2次间伐时间在林龄26年左右,中度、轻度间伐均显著引起树轮宽度指标增加,其中中度间伐效果弱于轻度间伐,树轮宽度指标的增加在伐后4~5年达到峰值,并持续至伐后15年;气候因子中有7个变量对长白落叶松树轮宽度指标表现出显著影响,其中,7月最高气温和生长季大于5℃积温对树轮宽度指标影响最大,夏季热湿指数次之,冬季降水量、9月最低气温、4月平均温和5月降水量对树轮宽度指标影响较小;将样地与树木个体水平的随机效应引入模型后,模型决定系数相比只有固定效应时大幅提高,从0.37提高至0.73。【结论】对林龄20年的长白落叶松云冷杉混交林进行中高强度的间伐,能显著促进伐后4年内长白落叶松保留木的生长;低海拔长白落叶松生长受到显著的气候影响,最主要的限制因子是7月最高气温和生长季大于5℃积温;为精确预估全球气候变化背景下的树木生长,有必要建立气候敏感的树轮宽度模型。     

板栗年轮结构对北京地区气候因子的响应分析

以北京地区板栗为材料,建立板栗年轮宽度、早材宽度和晚材宽度3项年轮结构指标的标准化年表和差值年表,分析板栗径向生长与气候因子间的相关关系和响应,并对可重建的气候因子进行筛选。结果表明：板栗年轮宽度和晚材宽度的年表质量明显好于早材宽度年表,其中差值年表优于标准化年表,其样本总体代表性达到93%,第1主成分方差解释量达到40%。差值年表与气候因子的相关分析和响应分析结果表明：年轮宽度、早材宽度和晚材宽度与各项气候因子间响应关系不同,在将来重建过去气候时,可利用年轮宽度和晚材宽度重建当年6月的温度,晚材宽度还可以重建当年7月的降水,早材宽度重建当年3月和4月的温度。     

江苏农博园湿地松径向生长对气候变化的响应

依据树木年代学方法，以江苏农博园湿地松人工林作为研究对象，获取年轮宽度资料，建立年轮宽度年表，探讨影响该树种径向生长的主要气候限制因子。结果表明：湿地松径向生长对气候因子的响应比较敏感，适合用于年轮气候学研究；相关函数分析表明，湿地松径向生长与上年和当年5月平均气温呈显著负相关，与上年5月降水量呈显著正相关。滑动相关进一步表明，升温导致的干旱胁迫是限制湿地松生长的主要原因，如果未来全球气温进一步升高，将对湿地松生长产生不利的影响。     

Tree-ring response of Larix chinensis on regional climate and sea-surface temperature variations in alpine timberline in the Qinling Mountains

Tree-ring width chronologies of Larix chinensis were developed from the northern and southern slopes of the Qinling Mountains in Shaanxi Province,and climatic factors affecting the tree-ring widths of L.chinensis were examined.Correlation analysis showed that similar correlations between tree-ring width chronologies and climatic factors demonstrated that radial growth responded to climate change on both slopes.The radial growth of L.chinensis was mainly limited by temperature,especially the growing season.In contrast,both chronologies were negatively correlated with precipitation in May of the previous year and April of the current year.Spatial climate-correlation analyses with gridded land-surface climate data revealed that our tree-ring width chronologies contained a strong regional temperature signal over much of northcentral and eastern China.Spatial correlation with seasurface temperature fields highlights the influence of the Pacific Ocean,Indian Ocean,and North Atlantic Ocean.Wavelet coherence analysis indicated the existence of some decadal and interannual cycles in the two tree-ring width chronologies.This may suggest the influences of El Nin˜o-Southern Oscillation and solar activity on tree growth in the Qinling Mountains.These findings will help us understand the growth response of L.chinensis to climate change in the Qinling region,and they provide critical information for future climate reconstructions based on this species in semi-humid regions.     

Larix olgensis growth-climate response between lower and upper elevation limits:an intensive study along the eastern slope of the Changbai Mountains,northeastern China

Larix olgensis is a dominant tree species in the forest ecosystems of the Changbai Mountains of northeast China.To assess the growth response of this species to global climate change,we developed three tree-ring width and biomass chronologies across a range of elevations in the subalpine forests on the eastern slope of the Changbai Mountains.We used dendroclimatic analyses to study key factors limiting radial growth in L.olgensis and its variation with elevation.The statistical characteristics of chronologies suggested that elevation is a determinant of tree growth patterns in the study area.Response function analysis of chronologies with climate factors indicated that climate–growth relationships changed with increasing elevation:tree growth at high elevation was strongly limited by June temperatures of the previous year,and as elevation decreases,the importance of temperature decreased;tree radial growth at mid-elevation was mainly controlled by precipitation towards the end of the growing season of the current year.Biomass chronologies reflected a stronger climatic signal than tree-ring width chronologies.Spatial correlation with gridded climate data revealed that our chronologies contained a strong regional temperature signal for northeast China.Trees growing below timberline appeared to be more sensitive to climate,thus optimal sites for examining growth trends as a function of climate variation are considered to be just below timberline.Our study objective was to provide information for more accurate prediction of the growth response of L.olgensis to future climate change on the eastern slope of the Changbai Mountains,and to provide information for future climate reconstructions using this tree species in humid and semi humid regions.     

Growth–climate responses of high-elevation conifers in the central Hengduan Mountains,southwestern China

Improved understanding of tree-growth responses to climate is needed to model and predict forest ecosystem responses to current and future climatic variability. We applied dendroclimatological techniques to assess the effects of inter-annual climate variations on radial growth of high-elevation conifers in the central Hengduan Mountains, southwestern China. Eight tree-ring width chronologies of the major tree genera Abies and Picea that are aligned along an elevation gradient from 3200 to 4200 m a.s.l. were developed. Correlation and principal component analyses for the eight chronologies identified three groups of sites, representing different patterns of growth–climate relationships. Correlation and redundancy analyses with regional climate data revealed that radial growth of fir growing at high-elevation sites is enhanced by normal or warm summer temperatures (June and July) during the current growing season. In addition, radial growth of trees growing from high to middle elevations is sensitive to low temperatures during winter season. At low-elevation sites, trees display low sensitivity to temperature variation. However spring moisture availability becomes crucial for radial growth regardless of tree species. High- to middle-elevation conifers in the central Hengduan Mountains may benefit from the current climate warming, especially from rising winter temperatures.     

Climatic signal from <Emphasis Type="Italic">Pinus leucodermis</Emphasis> axial resin ducts: a tree-ring time series approach

Developing long-term chronologies of tree-ring anatomical features to evaluate climatic relationships within species might serve as an annual proxy to explore and elucidate the climatic drivers affecting xylem differentiation. Pinus leucodermis response to climate was examined by analyzing vertical xylem resin ducts in wood growing at high elevation in the Apennines of peninsular Southern Italy. Early- and latewood tree-ring resin duct chronologies, spanning the 1804–2010 time period, were constructed. We analyzed the relationships between resin duct chronologies and climate over the last century using correlation and response function analyses. Overall, results showed that ring width and resin duct relationships differed between early- and latewood, which indicated conditions affecting growth were not associated with resin duct production. Results also revealed differential responses to climate between early- and latewood resin duct chronologies. A notable observation was a positive and stable relationship between latewood resin duct number chronology and July maximum temperature throughout the twentieth century. This result suggested resin ducts might be a suitable proxy to evaluate P. leucodermis response to climate in the study area.     

Relationships between climate and tree radial growth in interior British Columbia,Canada

Climate is a main driving factor of the formation of annual tree-rings, but which climatic variables are the most influential on radial growth may vary among species and sites. To explore these interactions, tree-ring chronologies along a major elevation gradient were examined for three tree species in southern interior British Columbia (Canada): Pseudotsuga menziesii, Pinus contorta, and Picea glauca × engelmannii. We used correlations and linear and multiple regressions to explore the relationships between tree-ring radial growth and climate variables in the area from 1922 to 1997. All correlation coefficients between ring chronologies and monthly climatic variables were medium to low (from −0.3 to 0.4); nevertheless, moderate but significant trends could be identified. Multivariate models explained up to 53%, 43% and 32% of radial growth variability for P. contorta, P. menziesii and P. glauca × engelmannii, respectively. All three species showed similar radial growth–climate patterns across the elevational gradient, but they had different details that made ring width–climate relationships species-specific. Precipitation-related variables were more related to radial growth at low-elevations, changing into temperature-related variables at high-elevations. Tree-ring width for all three species was primarily and significantly affected by climate variables from the year previous to the growing season and only secondly by current year conditions, but the critical months varied for different species and altitudes. Winter precipitation also affected radial growth, either as a source of water or as a possible agent of physical damage. Although our work showed significant climate influences on breast height tree radial growth, our results also indicated that other site factors such as microclimate or stand dynamics can be as or more important than climate variability.     

Radial growth variations of black pine along an elevation gradient in the Cazorla Mountains (South of Spain) and their relevance for historical and environmental studies

In southern Spain, the Cazorla Mountains (500–2,100 m a.s.l.) have supplied construction timber from black pine (Pinus nigra Arn.) for buildings and ships since at least the Middle Ages. To establish the age and provenance of wooden cultural heritage originating from this area, well-replicated long-span chronologies are needed. Old-living trees occur at high elevations, whereas many historical timbers originated from lower altitudes; hence, crossdating possibilities were questionable. To assess the potential of this species for the development of a multi-millennia tree-ring data set with living trees and historical timbers for the western Mediterranean, we developed four ring-width chronologies along the circa 1,000 m altitudinal range of black pine in these mountains and examined crossdating patterns and climate–growth responses along with altitude and through time. Teleconnections with other Iberian and Mediterranean tree-ring data were also tested. A well-replicated chronology spanning AD 1331–2009 was obtained at the upper site, while lower elevations delivered shorter chronologies. Similarity among chronologies and responses to climate were dependent on elevation. Tree-ring width was negatively related to temperature in previous late summer and positively to February–March, whereas precipitation had an opposite effect; some negative influence of early summer temperature was also observed. However, growth responses were rather unstable throughout the twentieth century. These chronologies showed good tele- and heteroconnections with conifer chronologies from Iberia, northern Morocco and Turkey, evidencing the existence of a common macroclimatic signal, which also varied along with elevation. The relevance of these results for dendrohistorical studies is discussed.     

Size-mediated climate-growth relationships in temperate forests: A multi-species analysis

In most dendrochronological studies, climate-growth relationships are established on dominant trees to minimize non-climatic signals. However, response to environmental factors may be affected by tree-size, which begs the question of the representativeness of dominant trees on the stand level. To highlight the variations in climate-growth relationships among sizes and species, under a wide range of ecological conditions (climate and soil properties), 61 pure even-aged stands were sampled across France. At each stand, two tree-ring chronologies were established from 10 big- to 10 small-diameter trees. Our objectives were, (1) to assess variations in climate sensitivity between the two size-diameter classes, and (2) to investigate the role of species and ecological conditions on these variations. The climate-growth relationships were evaluated from 122 tree-ring chronologies (1 220 trees) through extreme growth years and correlation function analyses. Sensitivity to climate of shade-intolerant and moderately shade-tolerant species (Picea abies (L.) Karst., Pinus sylvestris L. and Quercus petraea (Matt.) Liebl.) remained constant between the size-diameter classes for both temperature and hydric balance, while the shade-tolerant species Abies alba Mill. and Fagus sylvatica L. displayed significant differences, with larger trees being more sensitive to summer drought than smaller trees. This difference increased with increasing climatic xericity. Our results suggest that, for shade-tolerant species, (1) big trees could be more sensitive to climatic change especially under xeric climate, and (2) future tree ring studies should include trees stratified by size to produce unbiased estimation of sensitivity to climate.     

Climatic responses of tree-ring widths of <Emphasis Type="Italic">Larix gmelinii</Emphasis> on contrasting north-facing and south-facing slopes in central Siberia

An analysis was performed on the climatic responses of the radial growth of Larix gmelinii (Rupr.) Rupr. on contrasting north-facing and south-facing slopes in Tura, central Siberia. We developed chronologies of tree-ring width for four plots, designated as north-upper, northlower, south-upper, and south-lower. Both residual and standard chronologies of tree-ring widths exhibited a significant positive correlation with temperature from the end of May until early June in all four plots. The chronologies of ring width did not reveal any major difference in the response to temperature among the four plots. The standard chronologies of ring widths on the north-facing slope were negatively correlated with precipitation during the winter (October–April) and in early and mid-May, whereas the residual chronologies did not reveal clear relationships with precipitation during the winter and May. The significant correlation between ring width and temperature from the end of May until early June indicates that temperatures in springtime play a significant role in the radial growth of L. gmelinii. The negative correlations between standard chronologies of tree-ring width and precipitation in the winter and in May on the north-facing slope indicate that lowfrequency fluctuations in snowfall have negative effects on the radial growth. However, these effects vary and depend on the microscale topography. Part of this report was presented at the 55th Annual Meeting of the Japan Wood Society, March 2005, Kyoto     

三峡库区秭归县不同海拔马尾松径向生长对气候的响应

利用采自三峡库区秭归县不同海拔高度的马尾松树轮样芯,分别建立树木年轮宽度年表.包括标准年表和差值年表,并对2种年表进行比较.运用相关函数及单年分析等树木年轮学方法,研究秭归县马尾松在不同海拔高度处的径向生长与气候变化的关系.最后通过多元回归得出不同海拔高度处马尾松年轮指数与气候因子的关系模型.结果表明:在正常的气候条件下,海拔300 m处马尾松生长受上年6和10月份降雨量和湿润指数的影响,与当年气候因子的关系不显著;海拔600 m处马尾松生长与上年6月份温度呈显著相关,还受当年7月份的月平均降雨量和湿润指数的影响;海拔900 m处马尾松生长不仅与当年2月份温度呈显著相关,还受当年12月份月平均降雨量和湿润指数的影响,单年分析进一步印证了这种关系.     

Ecological and climatological signals in tree-ring width and density chronologies along a latitudinal boreal transect

Shifts in the climate sensitivity of trees throughout the twentieth century might indicate climate change effects in the boreal forest ecosystem. We here evaluated such potential changes by analyzing six tree-ring width (TRW) and maximum latewood density (MXD) chronologies from northern, central and southern boreal forests in Finland (60°N–69°N). Besides latitudinal effects, differing micro-sites (lakeshore and inland) were considered to evaluate the influence of ground water access on twentieth-century tree-ring formation and climate sensitivity. Overall, the boreal MXD chronologies appeared less affected by micro-site conditions compared to the TRW chronologies. Along the boreal transect, mean growth rates decrease with increasing latitude, but the ratio of earlywood-to-latewood (～70%/～30%) remains stable. However, latewood is slightly denser at the dry inland micro-sites. The correlations with climate data showed that TRW and MXD at all sites are positively related with summer temperature. The MXD chronologies are also negatively correlated with precipitation, a feature that is largely missing in TRW. A recent trend toward wetter and cloudier conditions in the study region coincides with a shift of the MXD signal from a distinct temperature limitation toward an additional sensitivity to precipitation, which in turn stimulated the trees’ competition for sunlight.