哈思山油松树轮宽度对气候要素及几种水分指数的响应分析

A tree-ring width chronology developed from Pinus tabulaeformis tree-rings of Hasi Mountain was employed to analyze responses of tree-ring to different climatic metrics. Correlation analyses between tree-ring chronology and precipitation and temperature suggest that tree growth is both limited by precipitation and temperature, and moisture is the principal limiting factor of tree-ring width. To find a suitable moisture index to be reconstructed, three moisture indices considering precipitation and evaporation even water balance are chosen to be analyzed. The results suggest that the PDSI is an appropriate index as predictor of tree-ring width and can be used to reconstruct in this area.     

长白山红松和臭冷杉树轮密度变化特征及其气候响应

本研究建立了长白山红松和臭冷杉的全轮、早晚材密度年表,并分析了2个树种的树轮密度变化特征及其与平均气温、平均最高气温、平均最低气温和降水量的相关关系。结果表明：两树种树轮密度变化具有一致性。红松树轮密度对气候变化更加敏感,而臭冷杉树轮密度变化相对稳定。两树种树轮密度年表与平均气温和平均最低气温整体呈显著正相关,而与平均最高气温和降水量的相关性相对较弱。其中,生长季早期（4—5月）的平均最低气温可能是影响树轮密度变化的主要因素。响应面分析结果表明：随着生长季早期的平均最低气温上升,两树种早材密度与平均最低气温呈现先减弱后增强的响应趋势,而与生长季早期的降水呈现先增强后减弱的响应趋势。滑动相关分析显示：随着气候变暖,两树种树轮密度年表均对生长季晚期（9—10月）平均气温和生长季早晚期平均最低气温的正响应显著增强,而对生长季晚期平均最高气温的正相关减小,与降水的响应相对稳定。臭冷杉的树轮密度年表对上年12月平均最高气温和当年4月平均最低气温的响应出现显著的正负转换现象。     

Monitoring the growth of American beech affected by beech bark disease in Maine using the Kalman filter

The effect of beech bark disease on tree growth was tracked using paired resistant and susceptible American beech trees in two locations in Maine. Within each site, the paired trees were chosen in close proximity and with similar morphological characteristics (e.g. stem diameter and crown class) to minimize environment effects in subsequent analysis. A Kalman filter approach was employed to analyse the yearly time-dependent mean differences between paired susceptible and resistant tree-ring widths using simple structural time series models in state space form. On one site, under the influence of a moderate maritime climate, stand dynamics is hypothesized to account for the 34 year difference in onset of decline of trees in codominant, versus those in the intermediate crown classes. The harsher winter conditions associated with the second, more northerly site and known to limit the insect component of the disease complex, are hypothesized to be more of a factor in the close (six year) difference in decline onset between the two crown classes on this site. Some strengths and cautions in the Kalman filter approach are discussed in relation to the analysis of time-dependent trends in tree-ring series.     

Tree-ring analysis for the assessment of anthropogenic changes and trends

Investigation of Pine (Pinus sylvestris L.)annual radial increment (width of annual tree rings) was carriedout in the surroundings of one of the largest pollution sources inLithuania – Jonava Nitrogen Fertilizers Plant. The main objectiveof investigation was to analyse different sides of anthropogenictransformations of tree-ring series in the polluted environment:changes in tree growth intensity; variance changes in tree-ringseries; changes in the relations with natural external factors.Three different periods of tree reaction to the environmentalpollution were singled out – fertilization period, depressionperiod and recovery period since annual emissions were essentiallyreduced. The variance of tree-ring series has increased severaltimes in the polluted environment. Reaction of trees to the impactof climatic factors (temperature, precipitation) has changedsignificantly in the polluted environment and their sensitivity hasalso increased.     

我国西南地区喀斯特森林树木年轮对气候变化的响应

利用贵州省2个典型喀斯特地区与1个非喀斯特地区的6个优势树种(化香树Platycarya strobilacea为重复树种)的树轮宽度资料,建立了6个树轮宽度年表,研究了不同地区不同树种的树木年轮对近50年来气候变化的响应异同,探讨了影响6个优势树种生长的气候限制因素。结果表明,季风期前的水热条件是喀斯特地区针叶树和阔叶树径向生长的最主要的气候限制因素。季风期前降水减少、月均温升高,导致土壤水分蒸发加快,加强了水分胁迫,不利于喀斯特地区针叶树和阔叶树的生长。帕尔默干旱指数虽表明喀斯特地区未达到干旱胁迫程度,但实际上水分渗漏加剧了喀斯特地区针叶树和阔叶树生长的水分胁迫。非喀斯特地区采样点的高海拔导致的低温,减少了春冬季节土壤水分蒸发。并且非喀斯特地区土壤和地形有利于水分涵养,同时,较高海拔的地形改变了季风期前的降水格局,消除了季风到来前树木生长的降水限制,因此,降水并不是喀斯特地区树木生长的限制因子;但其针叶树的径向生长受到上一年12月的温度控制,产生正响应信号,阔叶树径向生长仅受到生长季温度、降水增加带来的较小促进。     

大别山1846 — 2010年干湿变化记录——来自树轮宽度的证据

中国亚热带地区树轮气候学研究已取得较大进展,但气候重建基本都集中在温度方面,基于树轮宽度的水文气候研究鲜有成果,不利于全面理解亚热带地区历史气候变化特征。本文基于北亚热带大别山地区黄山松树轮宽度年表与气候要素的相关分析,发现树轮宽度指数与上一年4—7月平均相对湿度显著负相关（r=?0.68,p<0.01）。在此基础上,重建了大别山地区1846—2010年4—7月平均相对湿度变化历史。重建序列方差解释量达到46.4%（调整自由度后为45.3%）。在整个重建时段中存在3个湿润期（1891—1903,1905—1921和1950—1993年）和3个干旱期（1868—1890,1922—1934和1994—2005年）。同时,重建序列与采样地周边区域旱涝指数以及天目山的相对湿度重建序列在年代际尺度上高度相关,说明过去165年间中国东南亚热带较大区域范围内的干湿变化在年代际尺度上较为同步。空间分析结果表明重建序列也能够在一定程度上指示研究区及周边较大区域范围内的土壤湿度变化。综上,利用树轮宽度指标重建的大别山的相对湿度变化为研究亚热带地区干湿演化历史提供了参考依据,完善了时间尺度上亚热带地区相对湿度数据,同时也证实了亚热带1990年以后干旱化趋势的出现。     

伊犁地区历史径流深度场的重建

本文利用伊犁地区的树轮年表，首先进行年轮场与流量场的典型相关计算，揭示出两场间的较好相关性；进而重建伊犁地区流量场，分析其主要空间分布型；最后在绘制伊犁地区１８０年来四个径流丰枯阶段径流深度等值线图的基础上，计算各丰枯期的地表水资源量值，并讨论其历史变化，得出了一些有益的结论。     

Reconstructed Stream Flow for the Salt and Verde Rivers From Tree-Ring Data1

ABSTRACT: The Salt and Verde Rivers of central Arizona provide the water supply for metropolitan Phoenix and a considerable acreage of irrigated agriculture. Rapid urbanization has caused concern over future water supply and aggravated flooding in the already flood-prone Salt River Valley. Tree-ring data were used as a proxy source to extend the annual and seasonal runoff records back to A.D. 1580 and thus to determine whether the period of record for annual discharge adequately represents the long term flow characteristics of the two rivers. Results show that several periods of extended low flow have occurred during the past 400 years, many of which were more severe then any comparable period since 1890. The low flow periods appear to have a recurrence interval of about 22 years. Also the gaged records contain an above average number of high seasonal and annual flows when compared to the entire 400 years. The reconstructions contain important implications for future water supply and flood potentials in the Salt River Valley.     

贺兰山油松年轮中稳定碳同位素含量和环境的关系

植物中稳定碳同位素δ¹³C变化和环境关系密切,通过研究贺兰山油松(Pinus tabulacformis)植物纤维素中稳定碳同位素δ¹³C和环境之间的关系,发现该地区树轮纤维素中稳定碳同位素序列和大气中CO₂的含量关系密切,据此可以推算大气中的CO₂浓度的变化情况.研究还发现植物纤维素中稳定碳同位素δ¹³C的变化和生长年1～7月的总降水量显著负相关(r=-0.515,a=0.05),而和当年6～8月的平均气温显著正相关(r=0.427,α=0.05).通过对比树轮纤维素稳定同位素δ¹³C值和太阳黑子之间的关系,发现太阳黑子活动最强的年份往往对应较高的树轮纤维素δ¹³C值.