Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  
Keyword(s):  
Tree Growth ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Southwestern China ◽  
Maximum Temperature ◽  
Driving Mechanism ◽  
Western Sichuan ◽  
Relationship Analysis ◽  
Decadal Scale ◽  
Thermal Variability

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

scholarly journals Trees tell of past climates: but are they speaking less clearly today?

1998 ◽  
Vol 353 (1365) ◽  
pp. 65-73 ◽  
Author(s):  
K. R. Briffa ◽  
F. H Schweingruber ◽  
P. D. Jones ◽  
T. J. Osborn ◽  
I. C. Harris ◽  
...  
Keyword(s):  
Climate Variability ◽  
Tree Growth ◽  
Growth Rates ◽  
Large Scale ◽  
Scale Effects ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Past Climate ◽  
Tree Ring Data ◽  
Past Climate Variability

The annual growth of trees, as represented by a variety of ring–width, densitometric, or chemical parameters, represents a combined record of different environmental forcings, one of which is climate. Along with climate, relatively large–scale positive growth influences such as hypothesized ‘fertilizationrsquo; due to increased levels of atmospheric carbon dioxide or various nitrogenous compounds, or possibly deleterious effects of ‘acid rain’ or increased ultra–violet radiation, might all be expected to exert some influence on recent tree growth rates. Inferring the details of past climate variability from tree–ring data remains a largely empirical exercise, but one that goes hand–in–hand with the development of techniques that seek to identify and isolate the confounding influence of local and larger–scale non–climatic factors. By judicious sampling, and the use of rigorous statistical procedures, dendroclimatology has provided unique insight into the nature of past climate variability, but most significantly at interannual, decadal, and centennial timescales. Here, examples are shown that illustrate the reconstruction of annually resolved patterns of past summer temperature around the Northern Hemisphere, as well as some more localized reconstructions, but ones which span 1000 years or more. These data provide the means of exploring the possible role of different climate forcings; for example, they provide evidence of the large–scale effects of explosive volcanic eruptions on regional and hemispheric temperatures during the last 400 years. However, a dramatic change in the sensitivity of hemispheric tree–growth to temperature forcing has become apparent during recent decades, and there is additional evidence of major tree–growth (and hence, probably, ecosystem biomass) increases in the northern boreal forests, most clearly over the last century. These possibly anthropogenically related changes in the ecology of tree growth have important implications for modelling future atmospheric CO 2 concentrations. Also, where dendroclimatology is concerned to reconstruct longer (increasingly above centennial) temperature histories, such alterations of ‘normal’ (pre–industrial) tree–growth rates and climate–growth relationships must be accounted for in our attempts to translate the evidence of past tree growth changes.

Evidence of volcanic activity in the growth rings of trees at the Tacaná volcano, Mexico–Guatemala border

2020 ◽  
Vol 50 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Teodoro Carlón Allende ◽  
José Luis Macías ◽  
Manuel E. Mendoza ◽  
José Villanueva Díaz
Keyword(s):  
Tree Growth ◽  
Volcanic Activity ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Growth Rings ◽  
Growth And Survival ◽  
Ash Layer ◽  
Tacaná Volcano ◽  
First Time ◽  
Santa Maria

Volcanic activity can have a significant effect on the growth and survival of trees. The objective of our research was to analyze the effects of the 1855–1856 eruption of the Tacaná volcano and the ashfall from the 1902 eruption of the Santa María volcano, Guatemala, on the radial growth of trees at Tacaná. Dendrochronological sampling was carried out on sites covered by Pinus hartwegii Lindl., and a ring-width chronology was built using 102 increment cores from 75 trees. The ring-width chronology shows two statistically significant suppression events. One of these events occurred from 1857 to 1868 and was potentially caused by the historic eruption of Tacaná (1855–1856). The second suppression event occurred from 1903 to 1908, during which tree growth was affected 1 year after the ashfall caused by the 1902 eruption of Santa María. The growth suppression did not have the same magnitude in all sampled trees and may be related to the thickness of the ash layer deposited around each tree. For the first time, we show that tree growth at Tacaná is reduced by ashfall from volcanic eruptions. Our results may contribute to the evaluation of risks associated with the volcanic activity of the Tacaná volcano.

scholarly journals Climate-Growth Relations of Abies georgei along an Altitudinal Gradient in Haba Snow Mountain, Southwestern China

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1569
Author(s):  
Mei Sun ◽  
Jianing Li ◽  
Renjie Cao ◽  
Kun Tian ◽  
Weiguo Zhang ◽  
...  
Keyword(s):  
Tree Growth ◽  
Interval Analysis ◽  
Climatic Factors ◽  
Function Analysis ◽  
Ring Width ◽  
Maximum Temperature ◽  
Subalpine Forest ◽  
Moisture Condition ◽  
Monthly Total Precipitation ◽  
Main Component

Climate warming has been detected and tree growth is sensitive to climate change in Northwestern Yunnan Plateau. Abies georgei is the main component of subalpine forest in the area. In this study, A. georgei ring width chronologies were constructed at four sites ranging from 3300 to 4150 m a.s.l. in Haba Snow Mountain, Southeastern edge of Tibetan Plateau. We analyzed the relationship between four constructed chronologies and climatic variables (monthly minimum temperature, monthly mean temperature, monthly maximum temperature, monthly total precipitation, the Standardized Precipitation-Evapotranspiration Index, and monthly relative humidity) by using response function analysis, moving interval analysis, and redundancy analysis. Overall, the growth of A. georgei was positively affected by common climatic factors (winter moisture conditions, autumn temperature, and previous autumn precipitation). At low and middle-low sites, May moisture condition and previous December precipitation controlled its radial growth with positive correlations. At middle-high and high sites, previous November temperature was the key factor affecting tree growth. The result of moving interval analysis was consistent with correlation analyses, particularly for May moisture at low altitudes.

Tree growth across the Nepal Himalaya during the last four centuries

2017 ◽  
Vol 41 (4) ◽  
pp. 478-495 ◽  
Author(s):  
UK Thapa ◽  
S St. George ◽  
DK Kharal ◽  
NP Gaire
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Environmental Changes ◽  
Ring Width ◽  
High Elevation ◽  
Forest Growth ◽  
Tree Ring Width ◽  
Early 19Th Century ◽  
Tree Ring Data ◽  
Instrumental Records

The climate of Nepal has changed rapidly over the recent decades, but most instrumental records of weather and hydrology only extend back to the 1980s. Tree rings can provide a longer perspective on recent environmental changes, and since the early 2000s, a new round of field initiatives by international researchers and Nepali scientists have more than doubled the size of the country’s tree-ring network. In this paper, we present a comprehensive analysis of the current tree-ring width network for Nepal, and use this network to estimate changes in forest growth nation-wide during the last four centuries. Ring-width chronologies in Nepal have been developed from 11 tree species, and half of the records span at least 290 years. The Nepal tree-ring width network provides a robust estimate of annual forest growth over roughly the last four centuries, but prior to this point, our mean ring-width composite fluctuates wildly due to low sample replication. Over the last four centuries, two major events are prominent in the all-Nepal composite: (i) a prolonged and widespread growth suppression during the early 1800s; and (ii) heightened growth during the most recent decade. The early 19th century decline in tree growth coincides with two major Indonesian eruptions, and suggests that short-term disturbances related to climate extremes can exert a lasting influence on the vigor of Nepal’s forests. Growth increases since AD 2000 are mainly apparent in high-elevation fir, which may be a consequence of the observed trend towards warmer temperatures, particularly during winter. This synthesis effort should be useful to establish baselines for tree-ring data in Nepal and provide a broader context to evaluate the sensitivity or behavior of this proxy in the central Himalayas.

A millennium-long perspective on high-elevation pine recruitment in the Spanish central Pyrenees

2018 ◽  
Vol 48 (9) ◽  
pp. 1108-1113 ◽  
Author(s):  
Gabriel Sangüesa-Barreda ◽  
J. Julio Camarero ◽  
Jan Esper ◽  
J. Diego Galván ◽  
Ulf Büntgen
Keyword(s):  
Ring Width ◽  
High Elevation ◽  
Upward Migration ◽  
Scale Temperature ◽  
Decadal Scale ◽  
History Of ◽  
Climatic Drivers ◽  
Individual Trees ◽  
Central Pyrenees

Long-term fluctuations in forest recruitment, at time scales well beyond the life-span of individual trees, can be related to climate changes. The underlying climatic drivers are, however, often understudied. Here, we present the recruitment history of a high-elevation mountain pine (Pinus uncinata Ram.) forest in the Spanish central Pyrenees throughout the last millennium. A total of 1108 ring-width series translated into a continuous chronology from 924 to 2014 CE, which allowed estimated germination dates of 470 trees to be compared against decadal-scale temperature variability. High recruitment intensity mainly coincided with relatively warm periods in the early 14th, 15th, 19th, and 20th centuries, whereas cold phases during the mid-17th, early 18th, and mid-19th centuries overlapped with generally low recruitment rates. In revealing the importance of prolonged warm conditions for high-elevation pine recruitment in the Pyrenees, this study suggests increased densification and even possible upward migration of tree-line ecotones under predicted global warming.

Bristlecone pine tree rings and volcanic eruptions over the last 5000 yr

2007 ◽  
Vol 67 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Matthew W. Salzer ◽  
Malcolm K. Hughes
Keyword(s):  
Tree Ring ◽  
Ice Core ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Pine Tree ◽  
Tree Ring Data ◽  
Pinus Longaeva ◽  
Bristlecone Pine ◽  
Ice Core Record ◽  
Pinus Aristata

AbstractMany years of low growth identified in a western USA regional chronology of upper forest border bristlecone pine (Pinus longaeva and Pinus aristata) over the last 5000 yr coincide with known large explosive volcanic eruptions and/or ice core signals of past eruptions. Over the last millennium the agreement between the tree-ring data and volcano/ice-core data is high: years of ring-width minima can be matched with known volcanic eruptions or ice-core volcanic signals in 86% of cases. In previous millennia, while there is substantial concurrence, the agreement decreases with increasing antiquity. Many of the bristlecone pine ring-width minima occurred at the same time as ring-width minima in high latitude trees from northwestern Siberia and/or northern Finland over the past 4000–5000 yr, suggesting climatically-effective events of at least hemispheric scale. In contrast with the ice-core records, the agreement between widely separated tree-ring records does not decrease with increasing antiquity. These data suggest specific intervals when the climate system was or was not particularly sensitive enough to volcanic forcing to affect the trees, and they augment the ice core record in a number of ways: by providing confirmation from an alternative proxy record for volcanic signals, by suggesting alternative dates for eruptions, and by adding to the list of years when volcanic events of global significance were likely, including the mid-2nd-millennium BC eruption of Thera.

scholarly journals What can be learned about carbon cycle climate feedbacks from the CO<sub>2</sub> airborne fraction?

2010 ◽  
Vol 10 (16) ◽  
pp. 7739-7751 ◽  
Author(s):  
M. Gloor ◽  
J. L. Sarmiento ◽  
N. Gruber
Keyword(s):  
Land Use ◽  
Fossil Fuel ◽  
Carbon Sink ◽  
Volcanic Eruptions ◽  
Atmospheric Co2 ◽  
Anthropogenic Emissions ◽  
Term Trend ◽  
Decadal Scale ◽  
Long Term Trend

Abstract. The ratio of CO2 accumulating in the atmosphere to the CO2 flux into the atmosphere due to human activity, the airborne fraction AF, is central to predict changes in earth's surface temperature due to greenhouse gas induced warming. This ratio has remained remarkably constant in the past five decades, but recent studies have reported an apparent increasing trend and interpreted it as an indication for a decrease in the efficiency of the combined sinks by the ocean and terrestrial biosphere. We investigate here whether this interpretation is correct by analyzing the processes that control long-term trends and decadal-scale variations in the AF. To this end, we use simplified linear models for describing the time evolution of an atmospheric CO2 perturbation. We find firstly that the spin-up time of the system for the AF to converge to a constant value is on the order of 200–300 years and differs depending on whether exponentially increasing fossil fuel emissions only or the sum of fossil fuel and land use emissions are used. We find secondly that the primary control on the decadal time-scale variations of the AF is variations in the relative growth rate of the total anthropogenic CO2 emissions. Changes in sink efficiencies tend to leave a smaller imprint. Therefore, before interpreting trends in the AF as an indication of weakening carbon sink efficiency, it is necessary to account for trends and variations in AF stemming from anthropogenic emissions and other extrinsic forcing events, such as volcanic eruptions. Using atmospheric CO2 data and emission estimates for the period 1959 through 2006, and our simple predictive models for the AF, we find that likely omissions in the reported emissions from land use change and extrinsic forcing events are sufficient to explain the observed long-term trend in AF. Therefore, claims for a decreasing long-term trend in the carbon sink efficiency over the last few decades are currently not supported by atmospheric CO2 data and anthropogenic emissions estimates.

scholarly journals How Do Volcanic Eruptions Influence Decadal Megadroughts over Eastern China?

2020 ◽  
Vol 33 (19) ◽  
pp. 8195-8207 ◽  
Author(s):  
Liang Ning ◽  
Kefan Chen ◽  
Jian Liu ◽  
Zhengyu Liu ◽  
Mi Yan ◽  
...  
Keyword(s):  
Asian Summer Monsoon ◽  
Eastern China ◽  
Volcanic Eruptions ◽  
Internal Variability ◽  
Last Millennium ◽  
Decadal Scale ◽  
Community Earth System Model ◽  
Sea Surface Temperature Anomalies ◽  
Asian Summer ◽  
The Western Pacific

AbstractThe influence and mechanism of volcanic eruptions on decadal megadroughts over eastern China during the last millennium were investigated using a control (CTRL) and five volcanic eruption sensitivity experiments (VOLC) from the Community Earth System Model (CESM) Last Millennium Ensemble (LME) archive. The decadal megadroughts associated with the failures of the East Asian summer monsoon (EASM) are associated with a meridional tripole of sea surface temperature anomalies (SSTAs) in the western Pacific from the equator to high latitudes, suggestive of a decadal-scale internal mode of variability that emerges from empirical orthogonal function (EOF) analysis. Composite analyses further showed that, on interannual time scales, within a decade after an eruption the megadrought was first enhanced but then weakened, due to the change from an El Niño state to a La Niña state. The impacts of volcanic eruptions on the magnitudes of megadroughts are superposed on internal variability. Therefore, the evolution of decadal megadroughts coinciding with strong volcanic eruptions demonstrate that the impacts of internal variability and external forcing can combine to influence hydroclimate.

scholarly journals Different Wood Anatomical and Growth Responses in European Beech (Fagus sylvatica L.) at Three Forest Sites in Slovenia

2021 ◽  
Vol 12 ◽  
Author(s):  
Domen Arnič ◽  
Jožica Gričar ◽  
Jernej Jevšenak ◽  
Gregor Božič ◽  
Georg von Arx ◽  
...  
Keyword(s):  
Tree Ring ◽  
Climatic Factors ◽  
Ring Width ◽  
European Beech ◽  
Growing Season ◽  
Climatic Conditions ◽  
Maximum Temperature ◽  
Tree Ring Width ◽  
Vessel Area ◽  
Temperature And Precipitation

European beech (Fagus sylvatica L.) adapts to local growing conditions to enhance its performance. In response to variations in climatic conditions, beech trees adjust leaf phenology, cambial phenology, and wood formation patterns, which result in different tree-ring widths (TRWs) and wood anatomy. Chronologies of tree ring width and vessel features [i.e., mean vessel area (MVA), vessel density (VD), and relative conductive area (RCTA)] were produced for the 1960–2016 period for three sites that differ in climatic regimes and spring leaf phenology (two early- and one late-flushing populations). These data were used to investigate long-term relationships between climatic conditions and anatomical features of four quarters of tree-rings at annual and intra-annual scales. In addition, we investigated how TRW and vessel features adjust in response to extreme weather events (i.e., summer drought). We found significant differences in TRW, VD, and RCTA among the selected sites. Precipitation and maximum temperature before and during the growing season were the most important climatic factors affecting TRW and vessel characteristics. We confirmed differences in climate-growth relationships between the selected sites, late flushing beech population at Idrija showing the least pronounced response to climate. MVA was the only vessel trait that showed no relationship with TRW or other vessel features. The relationship between MVA and climatic factors evaluated at intra-annual scale indicated that vessel area in the first quarter of tree-ring were mainly influenced by climatic conditions in the previous growing season, while vessel area in the second to fourth quarters of tree ring width was mainly influenced by maximum temperature and precipitation in the current growing season. When comparing wet and dry years, beech from all sites showed a similar response, with reduced TRW and changes in intra-annual variation in vessel area. Our findings suggest that changes in temperature and precipitation regimes as predicted by most climate change scenarios will affect tree-ring increments and wood structure in beech, yet the response between sites or populations may differ.

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