共查询到20条相似文献，搜索用时 62 毫秒
1.
树木的生长与立地环境密切相关并受气候变化的影响,树木年轮宽度作为反映气候与环境变化的一个重要参数,已被广大生态学家所重视并应用。本文综述了树木年轮宽度与温度(当年初春温度、前一年的夏季高温和冬季低温)、降水(生长季的降水和生长季前的降水)、太阳辐射、CO2浓度等气候因子的关系及其在古气候环境研究、环境预测等领域中的应用,并对该研究的量测方法和数据处理分析方法的进展作了概述。针对我国树木年轮宽度研究的现状,提出了扩大取样范围、拓宽研究领域、改善取样和分析方法、建立完善的树轮年表体系、加强与国外树轮研究工作者的信息交流等建议,为我国树木年轮宽度研究的进一步发展提供了理论参考。 相似文献
2.
长白山北坡落叶松年轮年表及其与气候变化的关系 总被引：8，自引：0，他引：8
运用相关函数及单年分析等树木年轮气候学方法,研究了长白山北坡落叶松径向生长与气候变化的关系.结果表明,落叶松的生长对环境变化相当敏感,温度是影响其生长的主要因子.但不同海拔的落叶松对温度的响应明显不同.高海拔分布的落叶松只与当年6月的温度指标显著相关,而低海拔的落叶松与环境的关系相对复杂,除当年的4、5月外,上一年的6、9月温度以及上年9月的湿润指数都显著影响其生长.这说明不同环境梯度上的同一树种对气候变化的响应不尽相同. 相似文献
3.
4.
5.
论述了湖南省桑植县氵娄水河地区的柏木生长年轮特点。根据柏木年轮资料分析得知 ,氵娄水河近百年间曾有过 1 9次冷期阶段和 1 9次暖期阶段 ,文中表 2显示了近百年氵娄水河地区气候冷、暖阶段 2～ 3年循环变化的周期规律 ;通过年轮宽度指数与气候因子的相关性分析 ,为氵娄水河地区柏木生长的历史气候变化及环境变化提供了基础研究资料。 相似文献
6.
大兴安岭库都尔地区兴安落叶松年轮宽度年表及其与气候变化的关系 总被引：5，自引：0，他引：5
基于建立的大兴安岭库都尔地区兴安落叶松树轮宽度年表,分析了兴安落叶松树轮宽度年表与该区温度、降水和帕尔默干湿指数(PDSI)等主要气候因子之间的关系.结果表明:研究区5月和7月的温度与兴安落叶松年轮宽度变化呈极显著负相关关系(P0.01);虽然降水与年轮宽度变化没有表现出显著的相关关系,但6—8月PDSI与年轮宽度变化显著相关(P0.05),说明兴安落叶松的生长明显受区域水热条件共同控制,且以5月和7月最显著.兴安落叶松树轮宽度年表与诸如太平洋年代际振荡(PDO)等大尺度气候系统波动的低频系数和高频系数之间呈显著相关,说明太平洋气候系统的波动对该区树木径向生长具有显著影响. 相似文献
7.
江垭水库树木年轮与氵娄水河近百年间气候变化 总被引：1，自引：0，他引：1
论述了湖南省桑植县氵娄水河地区的柏木生长年轮特点.根据柏木年轮资料分析得知,氵娄水河近百年间曾有过19次冷期阶段和19次暖期阶段,文中表2显示了近百年氵娄水河地区气候冷、暖阶段2～3年循环变化的周期规律;通过年轮宽度指数与气候因子的相关性分析,为氵娄水河地区柏木生长的历史气候变化及环境变化提供了基础研究资料. 相似文献
8.
树木年轮—环境气候的档案 总被引：1，自引：0，他引：1
本世纪初期,美国有一位天文学家常手执锯斧等工具,穿行在美国西南部干旱区,尤其是土著印第安人集居地的山林之中,风餐露宿;同时还冒着被人误解和危险,仔细观察着树木的年轮。经过十几年奋斗,他揭示出树木年轮生长与降水之间的对应关系,建立起比较完整的树木年轮学原理及方法,创立了从公元700年至1929年连续的年轮宽度年表及世界上最早的树木年轮研究实验室,被后人誉为“树木年轮学之父”,他就是A. E. 道格拉斯。年轮,又称生长轮,指的是树木茎或根次生木质部中的生长层,因为通常每年形成一轮,故称之为年轮。 相似文献
9.
灌木往往分布在树线以上或以北的高海拔和高纬度地区以及干旱、半干旱区,是把传统上以乔木为主的树轮研究扩展至森林分布界限以外的唯一选择.尽管灌木具有以上研究潜力,迄今用于树木年代学研究的灌木种类仅有30种左右.介绍了灌木年轮研究方法,综述了过去几十年来环北极高纬度地区,干旱、半干旱区以及高海拔地区的灌木年轮研究的主要进展.主要研究进展如下:(1)发掘一些灌木的树木年代学潜力;(2)揭示限制灌木生长的主要环境因子,并尝试利用灌木年轮宽度等指标重建过去区域气候变化历史;(3)探讨全球变暖的背景下,灌木的生长或分布范围的变化;(4)通过人为控制增温来揭示变暖对灌木生理特征和生长的影响.这些研究展示了灌木在扩展传统乔木树轮研究网络方面的潜力,也是树木年代学研究中最有前景的研究方向之一.目前的灌木年轮学研究多集中于环北极苔原带.作为地球的第三极,青藏高原具有广泛的高山灌木分布,具有把青藏高原边缘区以乔木为主的树木年轮网络扩展至更高海拔和高原内部的潜力.青藏高原高山灌木的年轮学研究并没有引起足够的重视.青藏高原高山灌木的生长是如何适应极端环境条件的,全球变暖的背景下,青藏高原高山灌木的分布和生长正在发生哪些变化等,都有待深入研究. 相似文献
10.
树木年轮火灾学作为树木年轮学和林火生态学的一个重要交叉学科, 主要利用树轮火疤准确确定火灾发生年代, 从而研究过去和现在的火灾变化规律。树轮火灾学以其定年准确、分辨率高和时间久远等特点在森林火灾研究中具有极其重要的作用。该文对树木年轮火历史国内外 研究现状进行了简要评述, 国内树木年轮火历史研究尚处在起步阶段, 国外树木年轮火历史研究主要集中在以下几个方面:1) 火历史的时空格局特征, 主要包括林火发生的时间间隔、空间范围、强度、林火发生的时空关联、林火发生与立地条件的关系、林火发生与物种演替以及树轮火疤与其他方法相结合的火灾判 断等内容;2) 火灾历史与全球气候变化的关系, 主要包括火灾与温度和降水关系, 如一般在当年干旱而前几年相对湿润时火灾发生;火灾发生与大尺度气候事件也有一定的关联, 火灾一般发生在厄尔尼诺 (ElNiño) 向拉尼娜 (LaNiña) 转换的年代, 而且相位组合比单个事件更容易引发火灾;3) 火历史与人为活动及土地利用的关系, 战争和人口增加容易引发火灾, 而放牧活动却降低火灾发生频率, 20世纪以来的森林火抑制降低了火灾发生频率却增加了大火发生的可能性。最后对树木年轮火历史的未来进行了展望, 主要包括火灾时空格局的尺度效应、火历史变化的气候与人为驱动机制以及火历史研究方法的拓展等内容。 相似文献
11.
《Dendrochronologia》2014,32(3):230-236
Three tree-ring width chronologies were developed from 75 Picea schrenkiana trees ranging from low- to high-elevation in the mountains surrounding the Issyk-Kul Lake, Northeast Kyrgyzstan. The reliable chronologies extend back to the mid-18th and late-19th centuries. Spatial correlation analysis indicates that the chronologies for the relatively high-elevation trees contain large-scale climatic signals, while the chronology at relatively low elevation may reflect the local climate variability. The results of the response of tree growth to climate show that these chronologies contain an annual precipitation signal. Furthermore, the influence of temperature indicates mainly moisture stress that is enhanced with rising elevation. The tree-ring records also captured a wetting trend in eastern Central Asia over the past decades. These new tree-ring width chronologies provide reliable proxies of precipitation variability in Central Asia and contribute to the International Tree-Ring Data Bank. 相似文献
12.
Riparian forests in natural desert oases are extremely vulnerable to water shortages; of late these shortages have been associated with climate change and with increased human-led water allocation. This study covers a hundred-year history (1876–2017) of riparian forest growth at the Ejina Oasis, which is located in the lower reaches of the Heihe River basin of northwestern China. We collected tree cores from Populus euphratica, which is the major tree species found in the Ejina riparian forests. These samples allowed us to chart variations in riparian forest growth and to examine correlations between tree growth and local precipitation, temperature, drought indices, groundwater depth, and runoff volume from the middle reaches of the river. We found that groundwater depth (groundwater being mainly recharged by runoff) is the major factor limiting tree-stem radial growth. We compared runoff reconstruction series from upper reaches and P. euphratica radial growth in the lower reaches. We found a period of greatly decreased growth (1942–1951); which seems to have been due to human water diversion. We note that mountain runoff increased after 2000, but that riparian forest growth didn’t increase in tandem; the water that would otherwise have supported the forests had been diverted. Our study provides a warning for future water resource planning and suggests the desirability of policies that will balance the needs of natural ecosystems (riparian forests) with the requirements of artificial ecosystems (croplands). 相似文献
13.
Tree-ring width (TRW) chronologies have been widely and long-time used to reconstruct past climate variations in the Andes in South America. The use of tree-ring isotopic chronologies is still not widespread in this region although they have proved to be very efficient climate proxies. Araucaria araucana (Molina) K. Koch is a conifer tree species with some multi-century-old individuals that offers an excellent opportunity to measure stable carbon (δ13C) and oxygen (δ18O) isotopes in cellulose from long tree-ring records. Here, we explore whether current or stored carbohydrates are used for A. araucana radial growth and we assess the potential of a tree-ring isotopic record of to study past climate variability. Eleven A. araucana cores from a dry and high-elevation forest at the northern border of Patagonia, Argentina (38°55’S, 70°44’W) were selected for stable isotopes analyses. The strong correlation between the isotopic composition of the first and second parts of the same ring, but also the strong relationships between δ13C and δ18O records with climate parameters of the current growing season such as temperature, show that tree-rings are built mostly with carbohydrates produced during the current growing season with little or no supply from storage or reserves. This finding leads to reconsidering the interpretation of the legacy effect (i.e. ecological memory effects) based on the previously described strong negative correlation between A. araucana TRW chronologies and previous growing season temperature and suggests a dependence of radial tree growth on the level of development of organs. Regarding climate sensitivity, the A. araucana tree-ring δ13C chronology is strongly related to current summer temperature (r = 0.82, p < 0.001), vapour pressure deficit (VPD; r = 0.79, p < 0.001), precipitation (r = −0.53, p < 0.001) and SPEI2 (r = −0.73, p < 0.001). These strong relationships support the use of δ13C of A. araucana tree-ring cellulose to reconstruct past temperature variations at regional scale in relation with large-atmospheric drivers of climate variability such as the Southern Annular Mode. The A. araucana tree-ring δ18O chronology is also correlated with temperature (r = 0.42, p < 0.01) and VPD (r = 0.45, p < 0.01) of the winter preceding the growing season. This suggests that trees are using water from precipitation infiltrated in the soil during the previous recharge period (autumn-winter). The weak correlations of δ18O with current summer atmospheric conditions and the decoupling between δ18O and δ13C, may be due to a high rate of oxygen exchange between sugars and xylem water (Pex) during cellulose synthesis, which dampens evaporative isotopic fractionation. 相似文献
14.
树木年轮 (简称树轮 ) 气候学是监测与重建全球气候变化的重要方法之一。针叶树树轮的生长能反馈出气温的变化, 在高纬度地带尤为明显。该文分析了生长在我国最北部的兴安落叶松 (Larixgmelinii) 与樟子松 (Pinussylvestrisvar.mongolica) 的树轮密度和宽度的特性。落叶松最大密度、晚材平均密度、早晚材宽度和轮宽都远高于樟子松。樟子松的所有密度变量的样本方差都明显高于兴安落叶松, 宽度变量的样本方差却明显低于兴安落叶松。两树种密度变量的差值年表显著相关, 宽度变量之间没有显著相关关系。落叶松与樟子松的晚材密度的形成受 7、8月的最高温控制。另外, 樟子松的晚材还与生长季节的长短相关。落叶松的年轮宽度对生长季节开始前的温度敏感, 而樟子松的轮宽对气候变量没有很好的响应。结果表明, 落叶松与樟子松的树轮最大密度都与生长季后期的温度显著相关, 两树种的树轮信息对气候变化的重建有很大的潜力。 相似文献
15.
We test the application of parametric, non-parametric, and semi-parametric calibration models for reconstructing summer (June–August) temperature from a set of tree-ring width and density data on the same dendro samples from 40 sites across Europe. By comparing the performance of the three calibration models on pairs” of tree-ring width (TRW) and maximum density (MXD) or maximum blue intensity (MXBI), we test whether a non-linear temperature response is more prevalent in TRW or MXD (MXBI) data, and whether it is associated with the temperature sensitivity and/or autocorrelation structure of the dendro parameters. We note that MXD (MXBI) data have a significantly stronger temperature response than TRW data as well as a lower autocorrelation that is more similar to that of the instrumental temperature data, whereas TRW exhibits a redder” variability continuum. This study shows that the use of non-parametric calibration models is more suitable for TRW data, while parametric calibration is sufficient for both MXD and MXBI data – that is, we show that TRW is by far the more non-linear proxy. 相似文献
16.
Tree rings are a natural archive containing valuable information about environmental changes. Among the most sensitive ecosystems to such changes are high-mountain forests. Tree-ring series from such locations are exceptionally valuable both for climate reconstructions and for studying the effects of climate changes on forest ecosystems.The objective of our study is to present new long tree-ring width chronologies of Pinus peuce Griseb. from several locations at Pirin Mountains in southwestern Bulgaria, to explore their correlation with monthly temperatures and precipitation in the research area and to assess their potential for climate reconstruction.We built three long-term index chronologies for the radial increment of P. peuce from treeline locations in the study region. The longest chronology spans 675 years. We studied the impact of monthly air temperature and precipitation on its growth for the past 86 years using multiple regression analysis. Our analysis shows that P. peuce growth is positively influenced by high temperatures at the end of the previous growing season, especially at the two sites in Banderitsa valley until the middle of the 1970s, and negatively affected by cold winters. In some of the sample plots its growth was also positively correlated with high summer temperatures. However, even at these high altitudes in some of the locations on steep slopes P. peuce showed signs of negative impact of drought during the hottest summer months (especially in August).Our chronologies contribute to the paleoclimatic record for southwestern Bulgaria, which could provide baseline information about past climate variability and improve our understanding of current and future environmental changes. 相似文献
17.
This study concerns dendrochronology and dendroclimatology of yew growing in Poland. The yew (Taxus baccata L.), a long-lived, slow-growing tree, is regarded as a species threatened with extinction. The eastern boundary of its range transects Poland. The analyses were performed on 34 yew populations which are protected as parts of nature reserves, as nature monuments, or which are planned to be protected. Samples were collected using Pressler borer from a total of 774 trees yielding 1307 profiles. Classical dating techniques (including cross-dating method) were subsequently used to reconstruct 34 local chronologies. Average tree-ring width was 0.84 mm and ranged from 0.27 to 1.47 mm. For most stands, the age of the yew trees is overestimated. The studied populations most frequently are 100–200 years old, and the oldest yew trees in Poland are growing in the KS population (age estimated at 500–600 years). Average tree-ring width was found to be strongly dependent on the chronology length/tree age. The 674 pointer years calculated for the local chronologies served as a basis for determining pointer years for the entire study area. Negative years include: 1862, 1865, 1917, 1927, 1940, 1947, 1956, 1963, 1969, 1976, 1979, 1993, 1996, and 2003. Positive years are: 1884, 1914, 1916, 1965, 1977, 1988, 1997, and 2007. Analysis of weather conditions in those years demonstrated a strong relationship between tree-ring width and air temperature in winter, pre-spring, and early spring. Higher-than-average temperatures during those seasons correlate positively with yew tree-ring width. Response function analysis performed for local and regional chronologies point to a dominant role of air temperature in December of the year preceding growth and in January, February, and March of the current year (linear relationships). June precipitation is an additional factor affecting tree-ring width in some areas of northern and northwestern Poland: the higher the precipitation, the wider the tree-rings. The results obtained, particularly those concerning growth-climate relationships and dendroclimatic regionalisation, can be used in the on-going programme of yew restitution in Poland. 相似文献
18.
The mountain forest steppe and taiga in northern Mongolia have experienced a forest decline in area and quality since the end of the last century. Changes in land use, climate, fire frequency and pest occurrence are considered to be the main drivers of this vegetation shift and desertification. Because this region is the source for major rivers, is home to a unique flora and fauna and represents an important source of timber for Mongolia, the ability of different tree species to respond to these changes and regenerate is of increasing interest. Our contribution focuses on the climate-growth relationship of old and young birch trees from two valleys in the Mongolian province of Selenge Aimag.The research site Bugant, located in the Western Khentey Mountains, was the most important logging centre in Mongolia during socialist times. Today, the vegetation is dominated by succession forests of light taiga. The research site Altansumber, on the border of the Sant and Khushat soum, is dominated by light taiga and mountain forest steppe. Traditional nomads who depend on these forests for different reasons inhabit this area.Wood cores were sampled and chronologies of young and old birch trees at Bugant and Altansumber were created. Climate data were obtained from the Eroo station, which is known in the region for its long and reliable climate record. We analysed the climate-growth relationships of the chronologies from 1962 to 2009. At both sites and in both age classes, correlations with temperature were predominantly negative, particularly in April (Bugant, south- and east-facing slopes) and May (Altansumber, north-facing slopes). Precipitation of the late summer of the previous year (August/September) positively correlated with the growth of birch at Altansumber. We assume that the significant negative correlation between winter precipitation (December/January) and the growth of old birches at both sites is due to positive effects of snow cover on the survival rate of herbivorous insect populations. Our results indicate that during the early vegetation period, younger birch trees are more dependent on water availability than older ones. Negative pointer years were characterized by below-average precipitation during the current summer period and above-average spring temperatures. For the old trees, positive pointer years were characterized by above-average summer precipitation. We conclude that water availability is the most crucial factor for the growth of white birch in northern Mongolia. 相似文献
19.
Although it has been widely recognized that tree-ring response to climate drivers may change over recent decades, often due to anthropogenic environment changes, there are fewer reports of such changes in earlier pre-warming periods. In this paper we report on the pre-1930 unstable relationship between climate and tree-ring width (TRW) of Pinus taiwanensis Hayata in southeastern China based on reliable long-term temperature data. TRW of P. taiwanensis is strongly controlled by temperatures in two seasons, previous spring to summer (March to August, mainly June to July) and previous winter to current spring (December to March). However, TRW are insensitive to previous spring to summer temperature between 1890 and 1930. Reduced summer temperature variability, changing regimes of spring-summer temperature and precipitation, and complicated tree physiological processes behind the complex growth-climate relationship are the more likely causes of this phenomenon. This study adds to the body of knowledge that lower climate sensitivity of tree rings is not specific to the most recent decades. 相似文献
20.
Precise knowledge how tree growth will respond to future climate change is essential for the adapted management of forest ecosystems. By conducting sensitivity tests, tree-ring process-based cambial growth models can provide an innovative way to better understand wood formation under different climate change scenarios. As a case study in semi-arid north central China, we used artificially increased or decreased daily climatic data as input to the Vaganov-Shashkin dynamic growth model to investigate the response of wood formation to climatic change. By calibrating the tree-ring model using daily climate data over the period 1951–2010, we found that 81% of radial growth was driven by soil moisture, while 13% of growth was controlled by temperature. During the main growing season June–August, significant differences in the integral growth rate occurred after changing precipitation by ± 30% or by decreasing temperature by 3.0 °C (p < 0.05). However, increasing temperature showed only modest effects on tree radial growth rate. During the past 60 years, a significant advancement of the starting dates of growth was detected, whereby non-significant variability was found for the ending dates of growth. Contemporaneously, the effect of previous winter temperature (previous December to current January) on cambial growth initiation declined after 1980. Significant differences in the growth onset dates only occurred when temperature was reduced by 4.5 °C or increased by 5.5 °C. Moreover, both the onset and ending dates of growth in the study region were more sensitive to cooling rather than to warming. If temperature will increase by 2°C and precipitation will increase by 30% at the end of this century as predicted by some Earth system models, tree radial growth might increase by 19% in the study region, compared to the average during the period 1952–2010. Consequently, tree stem radial growth is expected to increase under a warming and wetting climatic scenario, but will decrease under drying conditions. 相似文献