Climate-tree Growth Relationships Research Articles

Street trees in Paris are sensitive to spring and autumn precipitation and recent climate changes

Determining the main factors causing urban tree decline is becoming essential for sustaining their health and survival. Understanding responses of tree growth to urban environments and climate change throughout tree life span is thus necessary. To explore these questions, a dendrochronological study exploring past climate-tree growth relationships was conducted on street and park silver lindens in Paris, according to different DBH classes used as a proxy of tree age, and using climatic data for the 1970–2013 period. Younger urban silver lindens presented high sensitivity to climate with highest growth rate. In comparison with park trees, street trees had higher sensitivity to climate and lower growth rates. Climatic and pointer years analysis pointed out the importance of drought characterization in order to understand its potential impact on tree annual growth and functioning. Urban silver lindens growth is mainly and strongly correlated with precipitations and especially in autumn and spring. Finally, our study on temporal evolution between climatic factors and growth through 1970–2013 periods showed a stronger stability between growth and precipitation only in October and revealed quick climatic changes since 40 years impacting the relation between tree growth and climate. Our study highlights that an optimized irrigation management, specifically in respect of tree phenology, could contribute to maximizing silver linden functioning and survival in Paris under climate change.

Tree growth response of Fokienia hodginsii to recent climate warming and drought in southwest China.

To date, few attempts have been made to assess the influence of climate change on forest ecosystems and on the relationship between tree growth and climate in humid areas of low latitudes. In this paper, we studied the response of tree growth and forest ecosystem to climate change by using Fokienia hodginsii tree-ring cores from the northern Yunnan-Guizhou Plateau, southwest of China. Tree growth correlates the highest (r=-0.64, p<0.01) with mean temperature (July-September), but the coefficients were changing with time as revealed by a moving correlation analysis. Tree growth is significantly (p<0.05) and positively correlated with January-April mean temperature from AD 1961-1987, while correlations with precipitation are insignificant. In contrast, from 1988 to 2014, tree growth correlated negatively with mean temperature of previous summer and positively with precipitation of previous August-September. This indicated that the limiting factors for tree growth have changed under different climate conditions. The meteorological data suggested that from 1961 to 1987 it was cold and wet in the study area and radial growth is limited by winter and spring temperatures. This restriction is weaker if the climate is appropriate in general. However, from 1988 to 2014, the combined effects of recent warming and decreasing precipitation have led to an increasing response of tree-ring width to drought. In addition, a large proportion of mature F. hodginsii mortality occurred from 2007 to 2013, which corresponds with a drastic reduction of radial growth (narrowest in recent 100years). The recent drought, induced by decreasing precipitation and increasing temperature, may have passed the threshold which F. hodginsii could tolerate, causing tree growth reduction, tree growth-climate relationship change, as well as catastrophic tree mortality. All these changes may lead to further responses of the local ecosystem to climate change which should be highly regarded.

Growth responses of Abies spectabilis to climate variations along an elevational gradient in Langtang National Park in the central Himalaya, Nepal

ABSTRACTStudies on tree-growth responses to climatic variations in a subalpine ecoregion of the central Himalaya are limited. The Himalayan silver fir (Abies spectabilis (D. Don) Spach), a dominant tree species in subalpine forest on mesic north-facing slopes, was used to analyse the tree-growth‒climate relationship along an elevational gradient. Tree growth shows sensitive responses to both growing-season and non-growing season temperature and precipitation variability at all elevations. Temperature has a strong influence at the boundaries (highest and lowest elevation) of the forest range. The uppermost tree-limit boundary is strongly associated with summer temperature, and the lowest forest boundary with winter temperature. Autumn temperatures (November, prior to growth year) influence tree growth regardless of elevation. Premonsoon precipitation has a significant influence on growth only at intermediate elevations. As the study describes the response pattern from only a mesic area, more studies covering a range of climate regimes are required to see whether there is a clear pattern of species-specific growth responses to climate variables along an elevational gradient.

Tree growth and its climate signal along latitudinal and altitudinal gradients: comparison of tree rings between Finland and the Tibetan Plateau

Abstract. Latitudinal and altitudinal gradients can be utilized to forecast the impact of climate change on forests. To improve the understanding of how these gradients impact forest dynamics, we tested two hypotheses: (1) the change of the tree growth–climate relationship is similar along both latitudinal and altitudinal gradients, and (2) the time periods during which climate affects growth the most occur later towards higher latitudes and altitudes. To address this, we utilized tree-ring data from a latitudinal gradient in Finland and from two altitudinal gradients on the Tibetan Plateau. We analysed the latitudinal and altitudinal growth patterns in tree rings and investigated the growth–climate relationship of trees by correlating ring-width index chronologies with climate variables, calculating with flexible time windows, and using daily-resolution climate data. High latitude and altitude plots showed higher correlations between tree-ring chronologies and growing season temperature. However, the effects of winter temperature showed contrasting patterns for the gradients. The timing of the highest correlation with temperatures during the growing season at southern sites was approximately 1 month ahead of that at northern sites in the latitudinal gradient. In one out of two altitudinal gradients, the timing for the strongest negative correlation with temperature at low-altitude sites was ahead of treeline sites during the growing season, possibly due to differences in moisture limitation. Mean values and the standard deviation of tree-ring width increased with increasing mean July temperatures on both types of gradients. Our results showed similarities of tree growth responses to increasing seasonal temperature between latitudinal and altitudinal gradients. However, differences in climate–growth relationships were also found between gradients due to differences in other factors such as moisture conditions. Changes in the timing of the most critical climate variables demonstrated the necessity for the use of daily-resolution climate data in environmental gradient studies.

Tree growth-climate relationships in a forest-plot network on Mediterranean mountains

In this study we analysed a novel tree-growth dataset, inferred from annual ring-width measurements, of 7 forest tree species from 12 mountain regions in Greece, in order to identify tree growth – climate relationships. The tree species of interest were: Abies cephalonica, Abies borisii-regis, Picea abies, Pinus nigra, Pinus sylvestris, Fagus sylvatica and Quercus frainetto growing across a gradient of climate conditions with mean annual temperature ranging from 5.7 to 12.6°C and total annual precipitation from 500 to 950mm. In total, 344 tree cores (one per tree) were analysed across a network of 20 study sites. We found that water availability during the summer period (May–August) was a strong predictor of interannual variation in tree growth for all study species. Across species and sites, annual tree growth was positively related to summer season precipitation (PSP). The responsiveness of annual growth to PSP was tightly related to species and site specific measurements of instantaneous photosynthetic water use efficiency (WUE), suggesting that the growth of species with efficient water use is more responsive to variations in precipitation during the dry months of the year. Our findings support the importance of water availability for the growth of mountainous Mediterranean tree species and highlight that future reductions in precipitation are likely to lead to reduced tree-growth under climate change conditions.

Climate—Growth Relationships ofPinus rigida(Mill.) at the Species' Northern Range Limit, Acadia National Park, ME

This study examined climate—tree growth relationships of a G2 globally rare Pinus rigida (Pitch Pine) barren located at the species' northern range limit in Acadia National Park, ME. Our tree-ring chronologies spanned the period 1804–2014 CE and included 50 dated tree-ring series from 33 trees. We found significant (P < 0.05) positive correlations in all chronologies between each year's tree growth and previous October through April temperature, as well as with August precipitation. Additionally, we found negative correlations between our chronologies and previous July precipitation. Moving interval correlation analysis showed temporal instability of all climate—growth relationships except for April temperature and August precipitation for the total width and latewood chronologies. Our results corroborate previous findings that suggest tree species at their northern range limit respond positively to winter temperature. We posit warmer winter temperatures and enhanced late-summer precipitation indicate a maritime influence that positively influenced radial growth at our site.

Elevation Pattern in Growth Coherency on the Southeastern Tibetan Plateau.

It is generally expected that inter-annual changes in radial growth among trees would be similar to the increase in altitude due to the limitation of increasingly harsher climatic factors. Here, we examine whether this pattern exists in alpine forests on the southeastern Tibetan Plateau. Increment cores were collected from mature trees at the lower, middle and upper limits of balfour spruce (Picea likiangensis var. balfouriana (Rehd. et Wils.) Hillier ex Slsvin) forests at the Buze and Yela Mountains in Basu County, Changdu Prefecture of Tibet, China. The treeline elevations are 4320 m and 4510 m a.s.l. for Buze and Yela, respectively. Tree-ring widths were measured, crossdated, and detrended to obtain a sequence of ring-width indices for each individual sample. Annual growth rate, climate sensitivity, growth-climate relationships, and growth synchrony among trees were calculated and compared across altitudes. In Buze Mountain, the annual growth rate of trees has no significant difference across altitudes. The mean sensitivity of trees is lower at the treelines than at lower elevations. Tree growth has stronger correlation with winter temperature at upper elevations than at lower elevations, has significant correlation with moisture, not temperature, in the growing season, and the growth response to moisture is lower at the treeline than at lower elevations. The correlation among individual tree-ring sequences is lower at the treeline than at sites at lower elevation. In Yela Mountain, the characterisitics of annual growth rate, mean sensitivity, tree growth-climate relationships, and inter-serial correlation are similar to those in Buze, but their differences along altitudinal gradients are less significant as those in Buze. Our data do not support the general expectation of growth convergence among individuals with increasing altitude. We conclude that individual heterogeneity and microhabitat diversity are important features for treeline trees that may dampen the growth synchrony in trees. The results obtained in this study expand our knowledge about the pattern of forest growth along altitudinal gradients in high-elevation regions and demonstrate the importance of checking the growth of tree individuals before analyzing the average signal.

Influence of climate on radial growth of Abies pindrow in Western Nepal Himalaya

This study aims to understand the influence of climate on radial growth of Abies pindrow growing in the plateau of mixed forest in Khaptad National Park in Western Nepal Himalaya. Based on the dated tree-ring samples, 362-year long tree-ring width chronology was developed dating back to 1650. The studied taxa of this region was found to have dendroclimatic potentiality that was evident from the chronology statistics calculated. The tree-ring chronology was correlated with climate (temperature and precipitation) data to derive the tree-growth climate relationship. The result showed significant negative relationship with March-May temperature and positive relationship with March-May precipitation. This indicates that the availability of moisture is the primary factor in limiting the tree growth.Banko Janakari, Vol. 23, No. 2, 2013

Predicting softwood quality attributes from climate data in interior British Columbia, Canada

Ongoing and future climate changes are expected to result in fundamental shifts in forest productivity and wood quality over wide regions of interior British Columbia. This study was conducted to investigate the relationships between climate and wood property attributes within Douglas-fir and spruce forests, and to use those relationships to develop a non-invasive approach wood quality attribute prediction. Historical climate station data was correlated to tree-ring samples collected at five sites and climate–tree growth relationships were established to measure and predict wood density, cell-wall thickness, and microfibril angle attributes. Time series models were developed to reconstruct the measured wood properties, and a strong correspondence between the predicted and measured wood attributes was verified. The results confirm that climate parameters provide a useful index for assigning wood quality attributes to forest stands at many sites in BC’s interior. The findings of this research provide insight into the impact future climates may have on wood quality characteristics and could be applied elsewhere to investigate the impacts of climate change on forest fibre supplies.

The climate-tree growth relationships at the evergreen-deciduous broad-leaved forest ecotone in Kannami Primary Forest, Japan

The climate-tree growth relationships at the evergreen-deciduous broad-leaved forest ecotone in Kannami Primary Forest, Japan

Warming-Induced Decline of Picea crassifolia Growth in the Qilian Mountains in Recent Decades.

Warming-induced drought has widely affected forest dynamics in most places of the northern hemisphere. In this study, we assessed how climate warming has affected Picea crassifolia (Qinghai spruce) forests using tree growth-climate relationships and the normalized difference vegetation index (NDVI) along the Qilian Mountains, northeastern Tibet Plateau (the main range of Picea crassifolia). Based on the analysis on trees radial growth data from the upper tree line and the regional NDVI data, we identified a pervasive growth decline in recent decades, most likely caused by warming-induced droughts. The drought stress on Picea crassifolia radial growth were expanding from northeast to southwest and the favorable moisture conditions for tree growth were retreating along the identical direction in the study area over the last half century. Compared to the historical drought stress on tree radial growth in the 1920s, recent warming-induced droughts display a longer-lasting stress with a broader spatial distribution on regional forest growth. If the recent warming continues without the effective moisture increasing, then a notable challenge is developed for Picea crassifolia in the Qilian Mountains. Elaborate forest management is necessary to counteract the future risk of climate change effects in this region.

Do Himalayan treelines respond to recent climate change? An evaluation of sensitivity indicators

Abstract. Climate warming is expected to induce treelines to advance to higher elevations. Empirical studies in diverse mountain ranges, however, give evidence of both advancing alpine treelines and rather insignificant responses. The inconsistency of findings suggests distinct differences in the sensitivity of global treelines to recent climate change. It is still unclear where Himalayan treeline ecotones are located along the response gradient from rapid dynamics to apparently complete inertia. This paper reviews the current state of knowledge regarding sensitivity and response of Himalayan treelines to climate warming, based on extensive field observations, published results in the widely scattered literature, and novel data from ongoing research of the present authors. Several sensitivity indicators such as treeline type, treeline form, seed-based regeneration, and growth patterns are evaluated. Since most Himalayan treelines are anthropogenically depressed, observed advances are largely the result of land use change. Near-natural treelines are usually krummholz treelines, which are relatively unresponsive to climate change. Nevertheless, intense recruitment of treeline trees suggests a great potential for future treeline advance. Competitive abilities of seedlings within krummholz thickets and dwarf scrub heaths will be a major source of variation in treeline dynamics. Tree growth–climate relationships show mature treeline trees to be responsive to temperature change, in particular in winter and pre-monsoon seasons. High pre-monsoon temperature trends will most likely drive tree growth performance in the western and central Himalaya. Ecological niche modelling suggests that bioclimatic conditions for a range expansion of treeline trees will be created during coming decades.

Sensitivity of Nothofagus dombeyi tree growth to climate changes along a precipitation gradient in northern Patagonia, Argentina

Recent variations in climate appear to induce similarities in the responses of N. dombeyi growth along its entire distribution, supporting global convergence in tree growth responses to climate changes. Understanding forest responses to climate variations is urgently needed for anticipating changes in forest composition and biodiversity. We use twelve tree-ring chronologies from Nothofagus dombeyi, the dominant tree at mesic-to-humid sites, to characterize climate–growth relationships along the west-to-east precipitation gradient in Nahuel Huapi National Park, Argentina. A principal components analysis indicates that a large proportion of common variance in tree growth reflects regional-scale influences of climate. Correlation functions between climate and tree-ring indexes show that the critical factor regulating tree growth is spring–summer water deficit induced by above-average temperature and reduced precipitation during the growing season. At high elevations, however, tree growth appears to be less sensitive to water deficit but comparatively more sensitive to warmer conditions. Temporal trends in climate–tree growth relationships supported the occurrence of a dominant large-scale climatic response, but also identify changes in climate–growth relationships over time, primarily at wet and high-elevation sites. These variations in climate–growth relationships are interpreted as a convergence process to similar patterns in tree growth across the entire precipitation gradient, as wet–cool conditions at high-elevation sites turned to be less frequent due to drier and warmer years during the late twentieth century. Sampling along environmental gradients provides a comprehensive view of the potential range of responses of tree growth to climate which is not recorded using traditional dendrochronological sampling at marginal, more climate-sensitive sites. The recent changes in the relationships between climate and growth highlight the vulnerability of N. dombeyi to climate changes across its entire range of distribution in Argentina.

Topography alters tree growth–climate relationships in a semi‐arid forested catchment

Topography and climate play an integral role in the spatial variability and annual dynamics of aboveground carbon sequestration. Despite knowledge of vegetation–climate–topography relationships on the landscape and hillslope scales, little is known about the influence of complex terrain coupled with hydrologic and topoclimatic variation on tree growth and physiology at the catchment scale. Climate change predictions for the semi‐arid, western United States include increased temperatures, more frequent and extreme drought events, and decreases in snowpack, all of which put forests at risk of drought induced mortality and enhanced susceptibility to disturbance events. In this study, we determine how species‐specific tree growth patterns and water use efficiency respond to interannual climate variability and how this response varies with topographic position. We found that Pinus contorta and Pinus ponderosa both show significant decreases in growth with water‐limiting climate conditions, but complex terrain mediates this response by controlling moisture conditions in variable topoclimates. Foliar carbon isotope analyses show increased water use efficiency during drought for Pinus contorta, but indicate no significant difference in water use efficiency of Pinus ponderosa between a drought year and a non‐drought year. The responses of the two pine species to climate indicate that semi‐arid forests are especially susceptible to changes and risks posed by climate change and that topographic variability will likely play a significant role in determining the future vegetation patterns of semi‐arid systems.

Social status-mediated tree-ring responses to climate of Abies alba and Fagus sylvatica shift in importance with increasing stand basal area

The aim of the study was to assess the effects of competition at both stand and tree levels on climate tree-growth relationships of 414 Abies alba and 243 Fagus sylvatica trees growing in 2 contrasting ecological conditions (north- and south-facing) under mountainous continental climate (mean altitude: 886m). Stand level competition was considered through three stand basal area (SBA) modalities (Low: 32m2/ha, Medium: 41 and High: 49) while tree level competition was assessed through three social statuses (SST, Dominant, Codominant and Suppressed trees). A strong specific response to climate was pointed out with different key periods; growth of Abies being mainly driven by previous and current late summer temperatures, while that of Fagus was controlled by April and June ones. No obvious difference between facing sides was evidenced. Competition at stand level prevailed on competition at tree level. In Low and Medium SBA, trees exhibited similar responses to climate whatever their social statuses. On the opposite, sensitivity to summer drought increased with dominancy in high SBA. Inter-specific differences and consequences for forest management are discussed.

Aleppo pine vulnerability to climate stress is independent of site productivity of forest stands in southeastern Spain

Clim ate is the main driver of Aleppo pine radial growth variability irrespective of site pro ductivity, with the climate effects on tree growth more limiting from 1970 onwards. Forest management adaptation to climate change requires identifying the previously most vulnerable stands and the possible climate impacts on forests. This study evaluates whether site index, as an indicator of forest productivity, is related to climate–growth responses and assesses the way in which local site factors modulate climate–tree growth relationships. Tree-ring width series and soil characteristics were obtained from six Pinus halepensis stands with different site indices and similar climate. Dendrochronological methods were used to compare tree climate–growth responses among sites and to study temporal trends in inter-annual growth variability and climate–growth relationships (before and after 1970). The influence of topographic and soil features on tree growth was assessed by means of partial least squares. Stands with low site indices tended to present higher mean sensitivities and greater percentages of missing rings, this relation being modulated mainly by clay percentage and nutrient status in soil. Climate is the major Aleppo pine radial growth driver in the study area with similar growth–climate relationship among sites. Radial growth was mainly influenced by spring temperature and precipitation and previous autumn–winter precipitation. This relationship was stronger after 1970 than before this year, showing also a 2-month advancement of the most influential climate variables after 1970, from May to March. These results and the increasing temporal trend found in mean sensitivity after 1970 highlight the vulnerability of these stands to climate change. Site index was not found to be directly related to stand vulnerability, although local site factors modulate in part the tree-growth response.

Paleoclimatic studies from the tree-ring of Himalayan birch from Langtang National park, central Nepal

Himalayan birch (Betula utilis D Don) is a long live, broadleaf species native to the Himalayas. However, this species has received limited attention for dendroclimatic studies world widely. In order to investigate the dendrochronolgical potential of this species in the central Himalayas, we analyzed 26 cores from 22 trees collected from Langtang National park, central Nepal, in May 2010. Based on these samples, we developed 371-year chronology extending back to 1639 AD. The chronological statistics, such as mean sensitivity and correlation between tree-ring series showed its high potentiality for the dendroclimatological study. In addition, the radial growth of Himalayan birch records clear climatic signals. Precipitation in May and early summer (March-May) plays a significant role (p&lt;0.001) for the growth of this species. However, temperature of the month May have significant (p&lt;0.05) inverse relations with the radial growth. The tree-growth climate relationship indicates the cool and moist condition in the early summer is a favorable condition for the growth of Himalayan birch in the central Himalayan region. In addition, tree ring of Himalayan birch clearly records the local and regional paleoclimatic drought events in 1999, 2000, 1960s, 1950s, 1790s and 1760s.

An Approach for Quantifying and Correcting Sample Size-Related Bias in Population Estimates of Climate-Tree Growth Relationships

Dendroecology is based on the estimation of target population climate sensitivity from a finite number of trees (N). Recent studies showed a sample size-related bias in the estimations of climate-tree growth relationships, decreasing sample size leading to a weakening of the bootstrapped correlation coefficients. The present analysis points out that the bias equals the squared root of the expressed population signal of the growth chronology built from N trees and then proposes a correction factor to accurately estimate the population sensitivity to climate. The interests, limits, and implications of this correction are illustrated from 504 individual growth chronologies of silver fir (Abies alba [Mill.]) sampled in the Jura Mountains (France) along an altitudinal gradient of increasing climate forcing. This data set was split into three groups of 168 trees (low, medium, and high elevation). Our results show that the signal common to all trees strengthened with increasing climate forcing and that the accuracy of the correction slightly decreased with both decreasing sample size and climate forcing. Corrected bootstrapped correlation coefficients still underestimated the strength of the population climate-tree growth relationships when less than 10 trees were used at low elevation against 4 at high altitude. FOR. SCI. ❚❚(❚):000–000.

Climatic signal in tree-ring chronologies of Cedrus deodara from Chitral Hindukush Range of Pakistan

Tree-rings are an important tool for the investigation of paleoclimatic records for regions or periods of time with no instrumental climatic data. However, the responses of different species and sites to various climatic parameters are unusual. In the present study, we developed tree-ring-width chronologies of Cedrus deodara from three different sites of Chitral Hindukush range of Pakistan. The study was conducted to understand tree-growth climate relationship and its applicability in proxy climate investigations. The chronologies covered the past 469 to 595 years, with a mean segment length (MSL) ranging from 148 to 223 years. Climatic data obtained from the three weather stations showed strong correlation and was found useful for tree-ring climate relationships. Correlation Function (CF) and Response Function (RF) analysis showed that spring precipitation (March–May) is a critical limiting factor for tree-ring growth, and temperature prior to November may also play a major role in affecting tree ring-growth. The results exposed that the three sites have continuous relationship indicated that only single species from different locations are affected by the same environmental variables and hence can be used in climate reconstruction in combination. The Cedrus deodara chronologies developed at different locations had several corresponding narrow and wide marker rings indicating a large macroclimatic response to regional climatic conditions. The current study suggests that the tree-rings of Cedrus deodara from the Chitral Hindukush range could be used to develop chronologies for the reconstruction of seasonal climatic variables.

Quantifying the risk of mis-estimating correlation significance of climate–tree growth relationships

In dendroecology, sampling effort has a strong influence of both regional chronology properties and climate–tree growth relationships assessment. Recent studies evidenced that decreasing sample size leads to a weakening of the bootstrapped correlation coefficients (\({\text{BCC}}\)). The present analysis focused on the risk of mis-estimating the significance of population \({\text{BCC}}\,\left( {{\text{BCC}}_{\text{POP}} } \right)\) from a sample of N trees, and then proposed an approach to detect and correct mis-estimations using the properties of the sample. The sample size effect and the limits of the correction were illustrated from 840 individual growth chronologies of Corsican pine (Pinus nigra Arnold ssp. laricio Poiret var. Corsicana) sampled in Western France. The 840 trees were used to assess the population characteristics, and the effect of sampling effort was investigated through a simulation approach based on a resampling procedure of N trees amongst 840 (N Є [5; 50]). Our results evidenced that the risk strongly varied amongst the climatic regressors. The highest risks were evidenced for significant \({\text{BCC}}_{\text{POP}}\), with a percentage of mis-estimation ranging from 25 to 80. On the contrary, small samples allowed providing an reliable estimation of the significance of non-significant \({\text{BCC}}_{\text{POP}}\). To a lesser extent, the risk slightly decreased with increasing N, according to a negative exponential trend. The detection and correction method was found relevant to detect mis-estimation only for significant \({\text{BCC}}_{\text{POP}}\); otherwise, the \({\text{BCC}}_{\text{POP}}\) significance was generally overestimated.