Topographic mediation of growth in high elevation foxtail pine (Pinus balfouriana Grev. et Balf.) forests in the Sierra Nevada, USA

Aim Climate variability is an important mediating agent of ecosystem dynamics in cold, semi‐arid regions such as the mountains of western North America. Climatically sensitive tree‐ring chronologies offer a means of assessing the impact of climate variability on tree growth across temporal scales of years to centuries and spatial scales of metres to subcontinents. Our goal was to bring practices from landscape ecology that highlight the impact of landscape heterogeneity on ecological pattern and processes into a dendroclimatic study that shows that the biophysical setting of target trees affects ring‐width patterns. Location This study was conducted at two sites near alpine treeline in the Sequoia National Park, USA (36°30′ 00′ N, 118°30′ 00′ W). Methods We collected stand information and increment cores from foxtail pines (Pinus balfouriana Grev. et Balf.) for eight tree‐ring chronologies in four extreme biophysical settings at two sites using proxies for soil moisture and radiation derived from a digital elevation model. Results Biophysical setting affected forest age–class structure, with wet and bright plots showing high recruitment after 1900 ad , but had no obvious effect on immature stem density (e.g. seedlings). Biophysical setting strongly affected ring‐width patterns, with wet plots having higher correlation with instrumental temperature records while dry plots correlated better with instrumental precipitation records. Ring‐width chronologies from the wet plots showed strong low‐frequency variability (i.e. hundreds of years) while ring‐width chronologies from the dry plots showed strong variability on multidecadal scales. Main conclusions There was a strong association between biophysical setting and age‐class structure, and with ring‐width patterns in foxtail pine. The mediation of ring widths by biophysical setting has the potential to further the understanding of the expression of synoptic‐scale climate across rugged terrain. When combined with remotely sensed imagery, a priori GIS modelling of tree growth offers a viable means to devise first‐order predictions of climatic impacts in subalpine forest dynamics and to develop flexible and powerful monitoring schemes.     

Climatic signals in tree ring of Picea schrenkiana along an altitudinal gradient in the central Tianshan Mountains, northwestern China

Tree-ring samples of Picea schrenkiana (Fisch. et Mey) were studied along an altitudinal gradient in the central Tianshan Mountains, and ring-width chronologies were developed for three sites at different altitudes: low-forest border (1600–1700 m a.s.l.), interior forest (2100–2200 m a.s.l.), and upper treeline (2600–2700 m a.s.l.). Annual ring-width variations were similar among the three sites but variability was greatest at the low-forest border site. The statistical characters of the chronologies showed that mean sensitivity (MS) and standard deviation (SD) decreased with increasing elevation. In other words, the response of tree growth to environmental changes decreased with increasing altitude. To understand the differing response of trees at different elevations to the environmental changes, response function analysis was used to study the relationships between tree-ring widths and mean monthly temperature and total monthly precipitation from 1961 to 2000. The results showed that precipitation was the most important factor limiting tree radial growth in the arid central Tianshan Mountains, precipitation in August of the prior growth year played an important role on tree's radial growth across the entire altitudinal gradient even at the cold, high-elevation treeline site. It is expected that with increasing altitude air temperature decreased and precipitation increased, the importance of precipitation on tree growth decreased, and the response of tree growth to environmental changes decreased, too. This conclusion may be helpful to understand and research the relationship between climatic change and tree growth in arid and semiarid area.     

Radial Growth of Qilian Juniper on the Northeast Tibetan Plateau and Potential Climate Associations

There is controversy regarding the limiting climatic factor for tree radial growth at the alpine treeline on the northeastern Tibetan Plateau. In this study, we collected 594 increment cores from 331 trees, grouped within four altitude belts spanning the range 3550 to 4020 m.a.s.l. on a single hillside. We have developed four equivalent ring-width chronologies and shown that there are no significant differences in their growth-climate responses during 1956 to 2011 or in their longer-term growth patterns during the period AD 1110–2011. The main climate influence on radial growth is shown to be precipitation variability. Missing ring analysis shows that tree radial growth at the uppermost treeline location is more sensitive to climate variation than that at other elevations, and poor tree radial growth is particularly linked to the occurrence of serious drought events. Hence water limitation, rather than temperature stress, plays the pivotal role in controlling the radial growth of Sabina przewalskii Kom. at the treeline in this region. This finding contradicts any generalisation that tree-ring chronologies from high-elevation treeline environments are mostly indicators of temperature changes.     

Annual Growth Ring Patterns in Brachystegia spiciformis Reveal Influence of Precipitation on Tree Growth1

The availability of exactly dated tree‐ring chronologies is limited in tropical regions. However, these chronologies could contribute widely to studies of the influence of natural and human‐induced factors on tropical forests. We examine the potential for building a chronology based on three sites in the miombo woodland of western Zambia. Brachystegia spiciformis Benth., a dominant species from this vegetation type, is used. Response of the chronology to several climatic factors is examined. All specimens showed very clear growth rings, and cross‐dating between radii of a tree was successful for all trees. Site chronologies could be constructed after cross‐dating of growth ring series of individual trees. The mean growth ring curves of the three sites were significantly similar, allowing for the construction of a regional chronology. Correlation function analysis between the tree‐ring chronology and regional climatic variables revealed that climate at the core of the rainy season, in December and January, has an explicit influence on tree growth. Where precipitation and relative humidity in these months influence tree growth positively, temperature correlates in a negative way. Some 20 percent of the variance in the B. spiciformis tree‐ring chronology is accounted for by wet season rainfall. The successful cross‐dating and correlation between a tree‐ring chronology and climate demonstrated in this study indicate annual ring formation in B. spiciformis trees and sensitivity to climatic conditions.     

芦芽山阳坡不同海拔华北落叶松径向生长对气候变化的响应

为研究树木生长对气候变化的响应状况,选取芦芽山阳坡的3个海拔高度建立了华北落叶松(Larix principis-rupprechtii)的树轮宽度年表。年表的统计参数表明,3条年表均为研究气候信息的可靠资料。结果表明,芦芽山阳坡华北落叶松的径向生长和生长与气候的关系均具有海拔差异,中海拔(2440 m)和高海拔(2540 m)的华北落叶松具有相似年际生长变化,而二者均与低海拔(2330 m)华北落叶松的年际生长不同。低海拔华北落叶松的生长与4月平均气温和上一年11月降水量显著负相关,而中海拔和高海拔的生长均与上一年10月平均气温和6月降水量显著负相关。通过年表与气候因子之间的滑动相关分析发现,3个海拔高度华北落叶松生长与气候因子的关系均不稳定,生长与气温条件之间的显著相关关系是随着气温升高而出现的。气温的升高引起了华北落叶松生长与气温因子关系的海拔差异,以及径向生长的海拔差异。这一结果对于气候变化对植被垂直梯度影响的研究具有一定参考价值。     

Development of tree-ring width chronologies and tree-growth response to climate in the mountains surrounding the Issyk-Kul Lake,Central Asia

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.     

Dendrochronology in Coniferous forests around Lake Rara,West Nepal

In two forest stands, one domonated byAbies spectabilis, and the other byPinus wallichiana-Picea smithiana, 198 cores were taken from 105 conifers in May 1983 and the annual ring widths were measured. The annual ring widths usually had significant similarities between cores taken from the same tree and with cores taken from different trees. these similarities increased with tree size. The climatic change affected the large trees more strongly than it did the small trees. Micro environmental changes, such as canopy gap affected the small trees more strongly. Annual ring widths were also correlated with the annual precipitations at Jumla 30 km south of the plots for a recent 20 year period. A multiple regression analysis between ring width and seasonal precipitation showed that the growth ofA. spectabilis was correlated primarily with the rain from May to August and secondarily with that from September to December in the previous year.     

Recent treeline dynamics are similar between dry and mesic areas of Nepal,central Himalaya

Aims We investigated the treeline dynamics of two environmentally contrasting areas in the Nepalese Himalaya to address the following questions: (i) Does the timing of establishment of the current treeline differ between the two study areas, and can area-specific treeline developments be identified? (ii) Do recruitment patterns and height growth indicate recent climate-driven treeline advance, following the general prediction for the central Himalayan region, in the two study areas?Methods A dry-climate treeline dominated by Pinus wallichiana and a mesic-climate treeline with Abies spectabilis were selected for study. In each area, we sampled the size and age structure of the study species along three elevational transects (20-m wide) from the forest line to the tree species line crossing the treeline. We also sampled treeline trees from within and outside transects to reconstruct past treeline establishment dynamics.Important findings Despite differences in moisture regimes, tree species and recent climate trends, our two study areas showed very similar treeline dynamics over the past six decades. In both areas, the recruitment of treeline trees indicates stationary treelines over the past six decades with the current treelines being dominated by trees that were established around 1990. The mesic area has experienced an overall climatic warming trend, and the stationary Abies treeline is hypothesized to be regulated by non-climatic factors, notably grazing. The dry area has not experienced warming but increased climatic variability and some very cool summers in the recent decades may explain the stationary to weakly receding Pinus treeline, which appears more climatically controlled with decreased recruitment over the past decades and decreased growth towards higher elevations. In both areas, there is a potential for treeline advance, depending on future land use and climate change. Our results highlight the importance of conducting treeline ecotone analyses for several sites or areas, and considering both climatic and non-climatic drivers of the treeline dynamics within each of these areas, for understanding regional treeline dynamics.     

Difference in tree growth responses to climate at the upper treeline: Qilian Juniper in the Anyemaqen Mountains

Three ring-width chronologies were developed from Qilian Juniper (Sabina przewalskii Kom.) at the upper treeline along a west-east gradient in the Anyemaqen Mountains.Most chronological statistics,except for mean sensitivity (MS),decreased from west to east.The first principal component (PC1) Ioadings indicated that stands in a similar climate condition were most important to the variability of radial growth.PC2 Ioadings decreased from west to east,suggesting the difference of tree-growth between eastern and western Anyemaqen Mountains.Correlations between standard chronologies and climatic factors revealed different climatic influences on radial growth along a west-east gradient in the study area.Temperature of warm season (July-August) was important to the radial growth at the upper treeline in the whole study area.Precipitation of current May was an important limiting factor of tree growth only in the western (drier) upper treeline,whereas precipitation of current September limited tree growth in the eastern (wetter) upper treeline.Response function analysis results showed that there were regional differences between tree growth and climatic factors in various sampling sites of the whole study area.Temperature and precipitation were the important factors influencing tree growth in western (drier) upper treeline.However,tree growth was greatly limited by temperature at the upper treeline in the middle area,and was more limited by precipitation than temperature in the eastern (wetter) upper treeline.     

川西亚高山不同年龄紫果云杉径向生长对气候因子的响应

运用树木年轮气候学的基本方法,建立王朗自然保护区紫果云杉在集中分布上限区域的年轮宽度年表,选取差值年表分析不同年龄云杉的径向生长同逐月气候因子的相关及响应关系,结果显示:幼龄组云杉年表的敏感度高于中龄组和老龄组云杉,幼龄组云杉对生长季前及生长季的气温状况显著正相关;中龄组云杉年表仅与当年4月份和7月份的月平均最低气温显著正相关;老龄组云杉的年轮宽度指数同上年生长季(上年8月份)的月平均气温和月平均最低温显著负相关,上年生长季高温的"滞后效应"在老龄组云杉体现的更为突出;幼龄组与中龄组云杉对当年6月份降水持续增加显示出明显的负相关关系,上年12月份的降水会对幼龄组和老龄组云杉径向生长不利。研究表明幼龄组云杉包含的气候信息要优于中龄组和老龄组云杉,在该区域进行相关研究时应根据研究需要选取不同年龄跨度的云杉年表。     

川西米亚罗林区不同海拔岷江冷杉生长对气候变化的响应

为分析青藏高原东缘半湿润区树木生长与气候关系随海拔变化的规律,于川西米亚罗林区分别在高、中、低海拔选取3个采样点,共采集132棵岷江冷杉年轮样芯,建立了最长达170a(1842-2011年)3个海拔高度的差值年表.岷江冷杉年轮指数与气候因子的相关分析表明:随海拔高度降低,温度与生长的负相关呈增加趋势.高海拔岷江冷杉径向生长与前—年冬季最低温呈显著正相关,中低海拔与当年春季均温、最高温和年均最高温呈显著负相关.低海拔岷江冷杉与当年4月降水呈显著正相关,随海拔升高降水与岷江冷杉生长的相关性降低.中低海拔岷江冷杉年表与4、5月帕尔默干旱指数(P DSI)呈显著正相关,表明在中低海拔存在春季干旱胁迫,抑制了岷江冷杉的生长.另外,大龄树木比小龄树木对气候变化的响应更敏感.     

Climate‐driven speedup of alpine treeline forest growth in the Tianshan Mountains,Northwestern China

Forest growth is sensitive to interannual climatic change in the alpine treeline ecotone (ATE). Whether the alpine treeline ecotone shares a similar pattern of forest growth with lower elevational closed forest belt (CFB) under changing climate remains unclear. Here, we reported an unprecedented acceleration of Picea schrenkiana forest growth since 1960s in the ATE of Tianshan Mountains, northwestern China by a stand‐total sampling along six altitudinal transects with three plots in each transect: one from the ATE between the treeline and the forest line, and the other two from the CFB. All the sampled P. schrenkiana forest patches show a higher growth speed after 1960 and, comparatively, forest growth in the CFB has sped up much slower than that in the ATE. The speedup of forest growth at the ATE is mainly accounted for by climate factors, with increasing temperature suggested to be the primary driver. Stronger water deficit as well as more competition within the CFB might have restricted forest growth there more than that within the ATE, implying biotic factors were also significant for the accelerated forest growth in the ATE, which should be excluded from simulations and predictions of warming‐induced treeline dynamics.     

Gradual expansion of moisture sensitive Abies spectabilis forest in the Trans-Himalayan zone of central Nepal associated with climate change

Population structure and tree recruitment dynamics in the natural treeline ecotone of high mountains are strong indicators of vegetation responses to climate. Here, we examined recruitment dynamics of Abies spectabilis across the treeline ecotone (3439–3638 m asl) of Chimang Lekh of Annapurna Conservation Area in the Trans-Himalayan zone of central Nepal. Dendrochronological techniques were used to establish stand age structure by ring counts of adults, and by terminal bud scar count for seedlings and saplings. The results showed abundant seedling recruitment, higher regenerative inertia and colonization with a consistent range shift of the A. spectabilis treeline. The upward expansion of this sub-alpine treeline was found to be driven by a strong dependence of seedling recruitment and radial growth on snowmelt and precipitation as temperatures rise. The radial growth of A. spectabilis at the alpine timberline ecotone (ATE) and closed timberline forest (CTF) showed sensitivity to spring season (March–May) climate. Tree ring indices of CTF showed a strong positive correlation with spring and annual precipitation, and a significant negative correlation with spring and annual temperature, however, moisture sensitivity was less strong at ATE than CTF.     

Tree recruitment above the treeline and potential for climate‐driven treeline change

Questions: How do population structure and recruitment characteristics of Betula saplings beyond the treeline vary among climatic regions, and what is the potential for development into tree‐sized individuals with interacting grazing pressure? Location: Scandes Mountains. Methods: Sapling characteristics of Betula pubescens subsp. tortuosa, their topographic position above the treeline, growth habitat and evidence of recent grazing was investigated in three areas with a long continuous grazing history, along a latitudinal gradient (62‐69°N). Results: Saplings were common up to 100 m above the treeline in all areas. The northern areas were characterised by small (<30 cm) and young (mean 14 years old) saplings in exposed micro‐topographic locations unfavourable to long‐term survival. In the southern area, broad height (2‐183 cm) and age (4‐95 years; mean 32 years) distributions were found in sheltered locations. Age declined with altitude in all areas. Sapling growth rate varied within and between areas, and the age × height interaction was significant only in the southern area. Growth rates decreased from south to north and indicated a considerable time required to reach tree size under prevailing conditions. Conclusions: Regional differences can be attributed to climatic differences, however, interacting biotic and abiotic factors such as micro‐topography, climate and herbivory, mutually affect the characteristics of birch saplings. In view of the long time needed to reach tree size, the generally expected evident and fast treeline advance in response to climate warming may not be a likely short‐term scenario. The sapling pool in the southern region possesses strongest potential for treeline advance.     

昌岭山两个优势树种径向生长对气候变化的响应

在气候变暖背景下,树木径向生长对气候变化的响应存在不稳定性。利用采自祁连山东部余脉昌岭山两个优势树种油松和青海云杉的树轮样芯,建立树轮宽度标准年表,通过分析树轮宽度年表与气候要素的相关关系,探讨两个树种径向生长对气候变化的响应。结果表明：（1）油松年表比青海云杉年表包含更多的气候信息,其平均敏感度、标准差、信噪比和样本对总体的代表性等统计量均高于青海云杉标准年表。（2）气候要素对不同树种径向生长限制程度不同,油松径向生长主要与降水（前一年9月和当年3-8月）和气温（前一年9月）有关,但对降水的响应更为敏感,而青海云杉径向生长则受到气温（当年9月）和降水（前一年9月、当年3月和7月）的共同作用。（3）气温突变后,油松和青海云杉年表与各气温要素的相关性显著增强,而青海云杉年表与气温要素的相关性变化更明显,指示了青海云杉径向生长对气温的响应更不稳定。（4）生长季平均最低气温的升高诱导的干旱胁迫是油松和青海云杉树木径向生长-气温响应变化的主要原因。     

Warming drives a front of white spruce establishment near western treeline,Alaska

Regional warming has led to increased productivity near the boreal forest margin in Alaska. To date, the effects of warming on seedling recruitment have received little attention, in spite of forecasted forest expansion. Here, we used stand structure and environmental data from 95 white spruce (Picea glauca) plots sampled across a longitudinal gradient in southwest Alaska to explore factors influencing spruce establishment and recruitment near western treeline. We used total counts of live seedlings, saplings, and trees, representing five life stages, to evaluate whether geospatial, climate, and measured plot covariates predicted abundance, using current abundance distributions as a surrogate for climate conditions in the past. We used generalized linear models to test the null hypothesis that conditions favorable for recruitment were similar along the environmental gradient represented by longitude, by exploring relationships between per‐plot counts of each life stage and the covariates hypothesized to affect abundance. We also examined the relationship between growing degree days (GDD) and seedling establishment over a period of three decades using tree‐ring chronologies obtained from cores taken at a subset of our sites (n = 30). Our results indicated that seedling, sapling, and tree abundance were positively correlated with temperature across the study area. The response to longitude was mixed, with earlier life stages (seedlings, saplings) most abundant at the western end of the gradient, and later life stages (trees) most abundant to the east. The differential relationship between longitude and life‐stage abundance suggests a moving front of white spruce establishment through time, driven by changes in environmental conditions near the species’ western range limit. Likewise, we found a positive relationship between periods of seedling establishment and GDD, suggesting that longer summers and/or greater heat accumulation might enhance establishment, consistent with the positive relationship we found between life‐stage abundance and temperature.     

Bioclimatology of beech (Fagus sylvatica L.) in the Eastern Alps: spatial and altitudinal climatic signals identified through a tree-ring network

Aim To identify the dominant spatial patterns of Fagus sylvatica radial growth in the Eastern Alps, and to understand their relationships to climate variation and bioclimatic gradients. Location Fourteen beech stands in the Eastern Alps, growing between 200 and 1500 m a.s.l. in Italy, Slovenia and Austria. Methods At each site, trees were sampled using increment borers or by taking discs from felled trees. Cores and discs were processed by measuring and crossdating ring width. Ring width series were standardized, averaged, and prewhitened to obtain site chronologies. Hierarchical Cluster Analysis (HCA) and Principal Components Analysis of prewhitened site chronologies were used to identify spatial and altitudinal growth patterns, related to the bioclimatic position of each stand. Bootstrap correlation and response functions were computed between monthly climatic variables and either principal component scores or composite chronologies from stands associated by HCA. The stability of dendroclimatic signals was analyzed by moving correlation functions (MCF). Correlation analysis (teleconnections) based on a data base of 37 Italian and Slovenian beech tree‐ring chronologies revealed the spatial extent of principal component scores. Results Sampled trees were 200–400 years old, representing the oldest beech trees that have been crossdated for the Alps to date. Maximum age was directly related to altitude and to the presence of historical forms of conservation. Tree‐ring parameters varied according to geographic patterns and the age of sampled trees. Stands were bioclimatically organized according to their location, and with reference to their elevation and distance from the Adriatic Sea. A direct response to winter temperature was found at all elevations. The altitudinal gradient ranged from low‐elevation stands, characterized by a Mediterranean‐type, late spring–summer drought signal, to mountain and high‐elevation stands, characterized by a direct response to growing season temperature plus an inverse response to the previous year’s July temperature. The mountain and high‐elevation signal was evident in Austria, the Central Alps and Slovenia, while the low‐elevation signal was confined to mountains adjacent to the Adriatic Sea. MCF revealed trends in the response to climatic factors affecting tree‐ring formation in mountain and high‐mountain stands linked to climatic warming. Main conclusions Dendroclimatic networks can be used for bioclimatic studies of tree populations. A biogeographical separation emerged between the Alps and the Apennines at the upper elevations, while different degrees of mediterraneity distinguished sites at lower elevations. This information will be useful in assessing any future climate‐related bioclimatic shifts, especially for forests at ecotones and along altitudinal gradients.     

西昆仑山两种针叶树种径向生长及其对气候变化的响应

利用西昆仑山的雪岭云杉和昆仑圆柏树芯样本,建立其树轮宽度年表。通过分析两种针叶树种树木径向生长特征与气候要素的相关关系,探讨了树种间的树木生长气候响应异同及响应关系的稳定性。结果表明：研究区域内的雪岭云杉和昆仑圆柏年表间存在显著正相关。两种针叶树种在1994年气温突变前树轮宽度年表指数和基部断面生长增量（BAI）呈上升趋势,在气温突变后年表和BAI则呈下降趋势,并且昆仑圆柏的树木径向生长速率高于雪岭云杉。与气候要素的相关性分析结果表明,雪岭云杉径向生长与上年生长季（5—6月和8—10月）和当年生长季（3—6月和10月）气温呈显著负相关,而昆仑圆柏径向生长与上年10月和当年生长季前期（4—6月）气温呈显著负相关;两者均与当年春季降水呈显著正相关。滑动相关分析结果显示,上年和当年生长季气温对两个树种树木径向生长的负响应在增强,特别是在当年生长季前期更为显著。此外,当年生长季前期降水对树木径向生长的促进作用也在增强。在有可能的气候突变年份（1994年）之后,两种针叶树种对气温和降水的响应敏感性均有所增强,并且雪岭云杉对气温的响应敏感性强于昆仑圆柏,而对降水响应敏感性要弱于昆仑圆柏。     

Climate Control on Tree Growth at the Upper and Lower Treelines: A Case Study in the Qilian Mountains,Tibetan Plateau

It is generally hypothesized that tree growth at the upper treeline is normally controlled by temperature while that at the lower treeline is precipitation limited. However, uniform patterns of inter-annual ring-width variations along altitudinal gradients are also observed in some situations. How changing elevation influences tree growth in the cold and arid Qilian Mountains, on the northeastern Tibetan Plateau, is of considerable interest because of the sensitivity of the region’s local climate to different atmospheric circulation patterns. Here, a network of four Qilian juniper (Sabina przewalskii Kom.) ring-width chronologies was developed from trees distributed on a typical mountain slope at elevations ranging from 3000 to 3520 m above sea level (a.s.l.). The statistical characteristics of the four tree-ring chronologies show no significant correlation with increasing elevation. All the sampled tree growth was controlled by a common climatic signal (local precipitation) across the investigated altitudinal gradient (520 m). During the common reliable period, covering the past 450 years, the four chronologies have exhibited coherent growth patterns in both the high- and low-frequency domains. These results contradict the notion of contrasting climate growth controls at higher and lower elevations, and specifically the assumption that inter-annual tree-growth variability is controlled by temperature at the upper treeline. It should be stressed that these results relate to the relatively arid conditions at the sampling sites in the Qilian Mountains.     

不同去趋势方法对树轮年表气候信号的影响——以卧龙地区为例

基于川西卧龙地区林线位置岷江冷杉(Abies faxoniana)的树轮宽度数据, 结合地面气象站和空间网格化气象数据, 对不同去趋势年表对气候条件的响应特征进行了比较分析。研究表明: 不同去趋势年表的气候响应特征具有很大的相似性, 具体表现为前一年9月份、当年3月份和7月份的气温, 以及前一年10-12月份的降水、当年4月份和7月份的降水对树木生长的正影响作用; 前一年11月份到当年3月份的相对湿度, 以及当年2-3月份和7-8月份的霜冻频率对树木生长的负影响作用。从不同去趋势方法对气候响应的异质性特征来看, 保守曲线、67%样芯长度步长、60年步长和90年步长的平滑样条函数去趋势年表间具有很强的相关性, 对气候响应也最明显, 特征基本一致。30年步长的平滑曲线去趋势年表与其他去趋势年表的相关性较弱, 与气候要素的相关性也明显较小。另外, 未经去趋势处理的树轮宽度年表统计参量数值要明显高于去趋势年表, 它与气候要素的相关特征也基本反映出川西卧龙地区树木生长对气候响应的基本特征。