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Large earthquakes can increase the amount of water feeding stream flows, raise groundwater levels, and thus grant plant roots more access to water in water‐limited environments. We examine growth and photosynthetic responses of Pine plantations to the Maule Mw 8.8 earthquake in headwater catchments of Chile's Coastal Range. We combine high‐resolution wood anatomic (lumen area) and biogeochemical (δ13C of wood cellulose) proxies of daily to weekly tree growth sampled from trees on floodplains and close to ridge lines. We find that, immediately after the earthquake, at least two out of six tree trees on valley floors had increased lumen area and decreased δ13C, while trees on hillslopes had a reverse trend. Our results indicate a control of soil water on this response, largely consistent with models that predict how enhanced postseismic vertical soil permeability causes groundwater levels to rise on valley floors, but fall along the ridges. Statistical analysis with boosted regression trees indicates that streamflow discharge gained predictive importance for photosynthetic activity on the ridges, but lost importance on the valley floor after the earthquake. We infer that earthquakes may stimulate ecohydrological conditions favoring tree growth over days to weeks by triggering stomatal opening. The weak and short‐lived signals that we identified, however, show that such responses are only valid under water‐limited, rather than energy‐limited tree, growth. Hence, dendrochronological studies targeted at annual resolution may overlook some earthquake effects on tree vitality. Plain Language Summary: Earthquakes deform and shake Earth's surface and the ground below. These changes may affect groundwater flow. Groundwater level may rise in the valley bottom and drop along higher elevated ridges. Trees depend on such groundwater resources, particularly in dry climates. Hence, we expect contrasting responses of trees after earthquakes: at higher elevations, access to groundwater may be impeded, but enabled in the valley bottoms. Thus, earthquake‐enhanced tree growth should be pronounced only on valley floors, with opposite responses happening along ridges. We test this hypothesis in pine forest plantations that were affected by the 2010 Maule earthquake, Chile. We find that tree growth increased following the earthquake because of enhanced photosynthesis on valley floors, but decreased on upper hillslopes due to increased water stress. Overall, these responses are small but measurable. Our study is the first to combine state‐of‐the‐art isotopic and wood anatomic proxies that we quantified at the cellular scale. Our results provide novel insights into the impacts of earthquakes on soil water and tree growth at an unprecedented daily to weekly resolution. Key Points: Earthquakes may stimulate tree growth by promoting photosynthesisDirection of tree growth change depends on local topographic positionFirst dendroecohydrological study to explore earthquake‐water‐vegetation interactions at scale of cells [ABSTRACT FROM AUTHOR]

Aim: The aim was to decipher Europe‐wide spatio‐temporal patterns of forest growth dynamics and their associations with carbon isotope fractionation processes inferred from tree rings as modulated by climate warming. Location: Europe and North Africa (30‒70° N, 10° W‒35° E). Time period: 1901‒2003. Major taxa studied: Temperate and Euro‐Siberian trees. Methods: We characterize changes in the relationship between tree growth and carbon isotope fractionation over the 20th century using a European network consisting of 20 site chronologies. Using indexed tree‐ring widths (TRWi), we assess shifts in the temporal coherence of radial growth across sites (synchrony) for five forest ecosystems (Atlantic, boreal, cold continental, Mediterranean and temperate). We also examine whether TRWi shows variable coupling with leaf‐level gas exchange, inferred from indexed carbon isotope discrimination of tree‐ring cellulose (Δ13Ci). Results: We find spatial autocorrelation for TRWi and Δ13Ci extending over a maximum of 1,000 km among forest stands. However, growth synchrony is not uniform across Europe, but increases along a latitudinal gradient concurrent with decreasing temperature and evapotranspiration. Latitudinal relationships between TRWi and Δ13Ci (changing from negative to positive southwards) point to drought impairing carbon uptake via stomatal regulation for water saving occurring at forests below 60° N in continental Europe. An increase in forest growth synchrony over the 20th century together with increasingly positive relationships between TRWi and Δ13Ci indicate intensifying impacts of drought on tree performance. These effects are noticeable in drought‐prone biomes (Mediterranean, temperate and cold continental). Main conclusions: At the turn of this century, convergence in growth synchrony across European forest ecosystems is coupled with coordinated warming‐induced effects of drought on leaf physiology and tree growth spreading northwards. Such a tendency towards exacerbated moisture‐sensitive growth and physiology could override positive effects of enhanced leaf intercellular CO2 concentrations, possibly resulting in Europe‐wide declines of forest carbon gain in the coming decades. [ABSTRACT FROM AUTHOR]

Abstract: In forests, the increase in atmospheric CO2 concentrations (Ca) has been related to enhanced tree growth and intrinsic water‐use efficiency (iWUE). However, in drought‐prone areas such as the Mediterranean Basin, it is not yet clear to what extent this “fertilizing” effect may compensate for drought‐induced growth reduction. We investigated tree growth and physiological responses at five Scots pine (Pinus sylvestris L.) and five sessile oak (Quercus petraea (Matt.) Liebl.) sites located at their southernmost distribution limits in Europe for the period 1960–2012 using annually resolved tree‐ring width and δ13C data to track ecophysiological processes. Results indicated that all 10 natural stands significantly increased their leaf intercellular CO2 concentration (Ci), and consequently iWUE. Different trends in the theoretical gas‐exchange scenarios as a response to increasing Ca were found: generally, Ci tended to increase proportionally to Ca, except for trees at the driest sites in which Ci remained constant. Ci from the oak sites displaying higher water availability tended to increase at a comparable rate to Ca. Multiple linear models fitted at site level to predict basal area increment (BAI) using iWUE and climatic variables better explained tree growth in pines (31.9%–71.4%) than in oak stands (15.8%–46.8%). iWUE was negatively linked to pine growth, whereas its effect on growth of oak differed across sites. Tree growth in the western and central oak stands was negatively related to iWUE, whereas BAI from the easternmost stand was positively associated with iWUE. Thus, some Q. petraea stands might have partially benefited from the “fertilizing” effect of rising Ca, whereas P. sylvestris stands due to their strict closure of stomata did not profit from increased iWUE and consequently showed in general growth reductions across sites. Additionally, the inter‐annual variability of BAI and iWUE displayed a geographical polarity in the Mediterranean. [ABSTRACT FROM AUTHOR]

The comprehensive procedure of wood sample preparation, including tree-ring dissection, cellulose extraction, homogenization and packing for stable isotope analysis, is labour intensive and time consuming. Based on a brief compilation of existing methods, we present a methodological approach from pre-analyses considerations to wood sample preparation, semi-automated chemical extraction of cellulose from tree-ring cross-sections, and tree-ring dissection for stable isotope ratio mass spectrometry: the Cross-Section Extraction and Dissection (CSED) guideline. Following the CSED guideline can considerably increase efficiency of tree-ring stable isotope measurement compared to classical methods We introduce a user-friendly device for cellulose extraction, allowing simultaneous treatment of wood cross-sections of a total length of 180 cm (equivalent to 6 increment cores of 30 cm length) and thickness of 0.6–2.0 mm. After cellulose extraction, tree-ring structures of 10 tree species (coniferous and angiosperm wood) with different wood growth rates and tree-ring boundaries, largely remained well identifiable. Further, we demonstrate that tree rings from cellulose cross-sections can be dissected at annual to intra-seasonal resolution, utilizing simple manual devices as well as sophisticated UV-laser microdissection microscopes in a way that sample homogenization is no longer necessary in most cases. We investigate seasonal precipitation signals in high-resolution intra-annual δ 18 O cellulose values from African baobab, performed by using UV-laser microdissection microscopes. [ABSTRACT FROM AUTHOR]

UV-laser-based microscopic systems were utilized to dissect and sample organic tissue for stable isotope measurements from thin wood cross-sections., We tested UV-laser-based microscopic tissue dissection in practice for high-resolution isotopic analyses (δ13C/δ18O) on thin cross-sections from different tree species. The method allows serial isolation of tissue of any shape and from millimetre down to micrometre scales. On-screen pre-defined areas of interest were automatically dissected and collected for mass spectrometric analysis., Three examples of high-resolution isotopic analyses revealed that: in comparison to δ13C of xylem cells, woody ray parenchyma of deciduous trees have the same year-to-year variability, but reveal offsets that are opposite in sign depending on whether wholewood or cellulose is considered; high-resolution tree-ring δ18O profiles of Indonesian teak reflect monsoonal rainfall patterns and are sensitive to rainfall extremes caused by ENSO; and seasonal moisture signals in intra-tree-ring δ18O of white pine are weighted by nonlinear intra-annual growth dynamics., The applications demonstrate that the use of UV-laser-based microscopic dissection allows for sampling plant tissue at ultrahigh resolution and unprecedented precision. This new technique facilitates sampling for stable isotope analysis of anatomical plant traits like combined tree eco-physiological, wood anatomical and dendroclimatological studies. [ABSTRACT FROM AUTHOR]

Tree-ring chronologies of Pinus sylvestris L. from latitudinal and altitudinal limits of the species distribution have been widely used for climate reconstructions, but there are many sites within the temperate climate zone, as is the case in northeastern Germany, at which there is little evidence of a clear climate signal in the chronologies. In this study, we developed long chronologies of several cell structure variables (e.g., average lumen area and cell wall thickness) from P. sylvestris growing in northeastern Germany and investigated the influence of climate on ring widths and cell structure variables. We found significant correlations between cell structure variables and temperature, and between tree-ring width and relative humidity and vapor pressure, respectively, enabling the development of robust reconstructions from temperate sites that have not yet been realized. Moreover, it has been shown that it may not be necessary to detrend chronologies of cell structure variables and thus low-frequency climate signals may be retrieved from longer cell structure chronologies. The relatively extensive resource of archaeological material of P. sylvestris covering approximately the last millennium may now be useful for climate reconstructions in northeastern Germany and other sites in the temperate climate zone. [ABSTRACT FROM PUBLISHER]

We investigated the tree growth and physiological response of five pine forest stands in relation to changes in atmospheric CO concentration ( c) and climate in the Iberian Peninsula using annually resolved width and δC tree-ring chronologies since 1600. C discrimination (Δ≈ c/ c), leaf intercellular CO concentration ( c) and intrinsic water-use efficiency (iWUE) were inferred from δC values. The most pronounced changes were observed during the second half of the 20th century, and differed between stands. Three sites kept a constant c/ c ratio, leading to significant c and iWUE increases (active response to c); whereas a significant increase in c/ c resulted in the lowest iWUE increase of all stands at a relict Pinus uncinata forest site (passive response to c). A significant decrease in c/ c led to the greatest iWUE improvement at the northwestern site. We tested the climatic signal strength registered in the δC series after removing the low-frequency trends due to the physiological responses to increasing c. We found stronger correlations with temperature during the growing season, demonstrating that the physiological response to c changes modulated δC and masked the climate signal. Since 1970 higher δC values revealed iWUE improvements at all the sites exceeding values expected by an active response to the c increase alone. These patterns were related to upward trends in temperatures, indicating that other factors are reinforcing stomatal closure in these forests. Narrower rings during the second half of the 20th century than in previous centuries were observed at four sites and after 1970 at all sites, providing no evidence for a possible CO'fertilization' effect on growth. The iWUE improvements found for all the forests, reflecting both a c rise and warmer conditions, seem to be insufficient to compensate for the negative effects of the increasing water limitation on growth. [ABSTRACT FROM AUTHOR]

Abstract: δ 13C and δ 18O of tree rings contain time integrated information about the environmental conditions weighted by seasonal growth dynamics and are well established as sources of palaeoclimatic and ecophysiological data. Annually resolved isotope chronologies are frequently produced by pooling dated growth rings from several trees prior to the isotopic analyses. This procedure has the advantage of saving time and resources, but precludes from defining the isotopic error or statistical uncertainty related to the inter-tree variability. Up to now only a few studies have compared isotope series from pooled tree rings with isotopic measurements from individual trees. We tested whether or not the δ 13C and the δ 18O chronologies derived from pooled and from individual tree rings display significant differences at two locations from the Iberian Peninsula to assess advantages and constraints of both methodologies. The comparisons along the period 1900–2003 reveal a good agreement between pooled chronologies and the two mean master series which were created by averaging raw individual values (Mean) or by generating a mass calibrated mean (MassC). In most of the cases, pooled chronologies show high synchronicity with averaged individual samples at interannual scale but some differences also show up especially when comparing δ 18O decadal to multi-decadal variations. Moreover, differences in the first order autocorrelation among individuals may be obscured by pooling strategies. The lack of replication of pooled chronologies prevents detection of a bias due to a higher mass contribution of one sample but uncertainties associated with the analytical process itself, as sample inhomogeneity, seems to account for the observed differences. [Copyright &y& Elsevier]

A tree ring oxygen isotope (δ 18 O TR ) chronology developed from one species ( Cedrela odorata ) growing in a single site has been shown to be a sensitive proxy for rainfall over the Amazon Basin, thus allowing reconstructions of precipitation in a region where meteorological records are short and scarce. Although these results suggest that there should be large-scale (> 100 km) spatial coherence of δ 18 O TR records in the Amazon, this has not been tested. Furthermore, it is of interest to investigate whether other, possibly longer-lived, species similarly record interannual variation of Amazon precipitation, and can be used to develop climate sensitive isotope chronologies. In this study, we measured δ 18 O in tree rings from seven lowland and one highland tree species from Bolivia. We found that cross-dating with δ 18 O TR gave more accurate tree ring dates than using ring width. Our “isotope cross-dating approach” is confirmed with radiocarbon “bomb-peak” dates, and has the potential to greatly facilitate development of δ 18 O TR records in the tropics, identify dating errors, and check annual ring formation in tropical trees. Six of the seven lowland species correlated significantly with C. odorata , showing that variation in δ 18 O TR has a coherent imprint across very different species, most likely arising from a dominant influence of source water δ 18 O on δ 18 O TR. In addition we show that δ 18 O TR series cohere over large distances, within and between species. Comparison of two C. odorata δ 18 O TR chronologies from sites several hundreds of kilometres apart showed a very strong correlation ( r = 0.80, p < 0.001, 1901–2001), and a significant (but weaker) relationship was found between lowland C. odorata trees and a Polylepis tarapacana tree growing in the distant Altiplano ( r = 0.39, p < 0.01, 1931–2001). This large-scale coherence of δ 18 O TR records is probably triggered by a strong spatial coherence in precipitation δ 18 O due to large-scale controls. These results highlight the strength of δ 18 O TR as a precipitation proxy, and open the way for temporal and spatial expansion of precipitation reconstructions in South America. [ABSTRACT FROM AUTHOR]

Abstract: Climatic hazards, such as severe droughts and floods, affect extensive areas across monsoon Asia and can have profound impacts on the populations of that region. The area surrounding Indonesia, including large portions of the eastern Indian Ocean and Java Sea, plays a key role in the global climate system because of the enormous heat and moisture exchange that occurs between the ocean and atmosphere there. Here, we evaluate the influence of rainfall variability on multiple tree-ring parameters of teak (Tectona grandis) trees growing in a lowland rain forest in Central Java (Indonesia). We assess the potential of, annually resolved, tree-ring width, stable carbon (δ13C) and oxygen (δ18O) isotope records to improve our understanding of the Asian monsoon variability. Climate response analysis with regional, monthly rainfall data reveals that all three tree-ring parameters are significantly correlated to rainfall, albeit during different monsoon seasons. Precipitation in the beginning of the rainy season (Sep–Nov) is important for tree-ring width, confirming previous studies. Compared to ring width, the stable isotope records possess a higher degree of common signal, especially during portions of the peak rainy season (δ13C: Dec–May; δ18O: Nov–Feb) and are negatively correlated to rainfall. In addition, tree-ring δ18O also responds positively to peak dry season rainfall, although the δ18O rainy season signal is stronger and more time-stable. The correlations of opposite sign reflect the distinct seasonal contrast of the δ18O signatures in rainfall (18OPre) during the dry (18O-enriched rain) and rainy (18O-depleted rain) seasons. This difference in 18OPre signal reflects the combination of two signals in the annual tree-ring δ18O record. Highly resolved intra-annual δ18O isotope analyses suggest that the signals of dry and rainy season can be distinguished clearly. Thereby reconstructions can improve our understanding of variations and trends of the hydrological cycle over the Indonesian archipelago. [Copyright &y& Elsevier]

• Evaluating trees' responses to climate change can be challenging. • We propose the use of correlation networks to aid the integration of wood traits. • Trees coordinate carbon and water related traits along a tropical climate gradient. • Correlation networks revealed trade-offs that reflects carbon metabolic pathways. • Cell-wall xylose and mannose are central in trees responses to climate variability. Tropical forests uptake more atmospheric CO 2 and transpire more water than any other forest in the world and are critical components of the global carbon and hydrological cycles. Both cycles depend to a great extent on the carbon and water balance of individual trees. Such adjustments are usually evaluated through well-established and newly-emerging traits but integrating them for a systemic understanding of trees' responses to climate change can be challenging. We propose using complex correlation networks to integrate and understand how trees coordinate water- and carbon-related traits under changing climate conditions. We built a correlation network based on 20 traits measured in the wood of Hymenaea courbaril (Leguminosae) trees, a species known for its extreme anisohydric water-use strategy, sampled along a climate gradient in Southeastern Brazil. Intercellular to ambient CO 2 concentrations ratio (c i /c a , estimated from tree-ring δ13C) is a central network trait for being coordinated with several hydraulic and carbon allocation traits. Trees of H. courbaril coordinate these traits along the climate gradient, favoring high c i /c a under warm and dry conditions. A high c i /c a is only possible through a consistent water supply provided by wider vessels together with the investment on soluble sugars, at the detriment of starch, likely for hydraulic maintenance. Trees also favor heat resistance by investing in cell-wall xylose, another central network trait, from xyloglucans and xylans, at the expense of mannose from glucomannans. Such trade-offs within, and between, structural and non-structural carbon allocation reflect well-known metabolic pathways in plants. In summary, this systemic approach confirms previously reported patterns on leaf physiology, stem hydraulics and carbon adjustments while bringing to light the previously unreported role of cell-wall composition and its fine adjustments to cope with climate change. [ABSTRACT FROM AUTHOR]

Abstract: We present the first and longest (413 years) dataset on stable carbon isotope ratios in tree-ring cellulose (δ 13C), tree-ring width (TRW), and maximum latewood density (MXD) obtained from larch trees growing on permafrost under continental climate in the Suntar Khayata mountain ridge in Eastern Siberia (Russia). With this first study we calibrate tree-ring parameters against climate quantities, and based on these results assess the potential added value of MXD and especially of δ 13C complementing TRW analysis for future climate reconstruction purposes. δ 13C chronologies were corrected for human induced changes in atmospheric CO2 since AD 1800. Two different approaches were compared i) a correction referring merely to the decline in atmospheric δ 13C (δ 13Catm) and ii) a correction additionally accounting for the increase in atmospheric partial pressure of CO2. δ 13C chronologies are characterized by strong signal strength with only 4 trees representing the population signal at the site (mean inter-series correlation=0.71 and EPS=0.90). δ 13C variation shows low similarity to TRW and MXD, while correlation between TRW and MXD is highly significant. Correlation analysis of tree-ring parameters with gridded instrumental data (Climate Research Unit, CRU TS 2.1) over the AD 1929–2000 calibration period demonstrates that TRW and MXD react as reported from other sites at cold and humid northern latitudes: precipitation plays no significant role, but strong dependencies on monthly mean, maximum and minimum temperatures, particularly of the current summer (June to August), are found (up to r =0.60, p <0.001). Combining instrumental data to a summer season mean (JJA) and TRW and MXD to a growth parameter mean (TRW+MXD), clearly shows the importance of the number of frost days and minimum temperatures during summer (r =0.67, p <0.001) to dominate tree growth and highlights the potential for climate reconstruction. Carbon isotope fixation in tree rings is obviously less controlled by temperature variables. In particular, the frost days and minimum temperature have a much smaller influence on δ 13C than on tree growth. δ 13C strongly reacts to current-year July precipitation (r =−0.44, p <0.05) and June–July maximum temperature (r =0.46, p <0.001). All significant (p <0.05) correlation coefficients are higher when using the corrected δ 13C chronology considering an additional plant physiological response on increasing atmospheric CO2 concentration, than using the chronology corrected for δ 13Catm changes alone. Spatial distribution of correlations between tree-ring data and climate variables for Eastern Siberia indicates that the summer temperature regime in the studied region is mostly influenced by Arctic air masses, but precipitation in July seems to be brought out from the Pacific region. Both the combined TRW+MXD record and the δ 13С record revealed a high reconstruction potential for summer temperature and precipitation, respectively, particularly on decadal and longer-term scales. [Copyright &y& Elsevier]