scholarly journals Independent Aridity and Drought Pieces of Evidence Based on Meteorological Data and Tree Ring Data in Southeast Banat, Vojvodina, Serbia

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 586 ◽  
Author(s):  
Milivoj B. Gavrilov ◽  
Wenling An ◽  
Chenxi Xu ◽  
Milica G. Radaković ◽  
Qingzhen Hao ◽  
...  
Keyword(s):  
Tree Ring ◽  
Air Temperature ◽  
Meteorological Data ◽  
Ring Width ◽  
Surface Air Temperature ◽  
Aridity Index ◽  
Precipitation Trend ◽  
Positive Temperature ◽  
Tree Ring Width ◽  
Tree Ring Data

In this study, aridity data and tree ring data were collected in Northern Serbia, in Southeast (SE) Banat, a subregion within Vojvodina, and Vojvodina at large. They were each investigated independently. The De Martonne Aridity Index and the Forestry Aridity Index are derived from examining the relationship between precipitation and surface air temperature data sets sourced from seven meteorological stations in SE Banat, and from 10 meteorological stations located in Vojvodina as a whole. Vojvodina is a large territory and used as the control area, for the period 1949–2017. The Palmer Drought Severity Index was derived for the period 1927–2016, for both SE Banat and the totality of Vojvodina. The results of the Tree Ring Width Index were obtained from samples collected in or around the villages of Vlajkovac and Šušara, both located in SE Banat, for the period 1927–2017. These tree ring records were compared with three previous aridity and drought indices, and the meteorological data on the surface air temperature and the precipitation, with the objective being to evaluate the response of tree growth to climate dynamics in the SE Banat subregion. It was noted that the significant positive temperature trends recorded in both areas were too insufficient to trigger any trends in aridity or the Tree Ring Width Index, as neither displayed any change. Instead, it appears that these climatic parameters only changed in response to the precipitation trend, which remained unchanged during the investigated period, rather than in response to the temperature trend. It appears that the forest vegetation in the investigated areas was not affected significantly by climate change in response to the dominant temperature increase.

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.

scholarly journals Forward modelling of tree-ring width and comparison with a global network of tree-ring chronologies

2014 ◽  
Vol 10 (2) ◽  
pp. 437-449 ◽  
Author(s):  
P. Breitenmoser ◽  
S. Brönnimann ◽  
D. Frank
Keyword(s):  
Data Assimilation ◽  
Tree Ring ◽  
Ring Width ◽  
Global Network ◽  
Threshold Temperature ◽  
Tree Ring Width ◽  
Data Set ◽  
Observation Operator ◽  
Tree Ring Data ◽  
Wide Range

Abstract. We investigate relationships between climate and tree-ring data on a global scale using the process-based Vaganov–Shashkin Lite (VSL) forward model of tree-ring width formation. The VSL model requires as inputs only latitude, monthly mean temperature, and monthly accumulated precipitation. Hence, this simple, process-based model enables ring-width simulation at any location where monthly climate records exist. In this study, we analyse the growth response of simulated tree rings to monthly climate conditions obtained from the CRU TS3.1 data set back to 1901. Our key aims are (a) to assess the VSL model performance by examining the relations between simulated and observed growth at 2287 globally distributed sites, (b) indentify optimal growth parameters found during the model calibration, and (c) to evaluate the potential of the VSL model as an observation operator for data-assimilation-based reconstructions of climate from tree-ring width. The assessment of the growth-onset threshold temperature of approximately 4–6 °C for most sites and species using a Bayesian estimation approach complements other studies on the lower temperature limits where plant growth may be sustained. Our results suggest that the VSL model skilfully simulates site level tree-ring series in response to climate forcing for a wide range of environmental conditions and species. Spatial aggregation of the tree-ring chronologies to reduce non-climatic noise at the site level yielded notable improvements in the coherence between modelled and actual growth. The resulting distinct and coherent patterns of significant relationships between the aggregated and simulated series further demonstrate the VSL model's ability to skilfully capture the climatic signal contained in tree-ring series. Finally, we propose that the VSL model can be used as an observation operator in data assimilation approaches to reconstruct past climate.

scholarly journals Cyclic Changes of Climate in Europe During the Last Millenium According to Dendrological Data

2008 ◽  
Vol 13 (1) ◽  
pp. 57-66
Author(s):  
Jerzy Boryczka ◽  
Maria Stopa-Boryczka ◽  
Szymon Bijak
Keyword(s):  
Tree Ring ◽  
Air Temperature ◽  
North Atlantic ◽  
Climate Changes ◽  
Growth Ring ◽  
Ring Width ◽  
Tree Ring Width ◽  
Annual Growth Ring ◽  
Growth Ring Width ◽  
Cyclic Changes

Abstract The paper discusses periodic climate changes in Europe determined on the basis of dendrochronological data dating back one thousand years. In tree-ring width sequences of trees growing in Poland there are approximately 8-, 11-, 100- and 180- year periods. The tree-ring widths of oaks growing in Poland for the last centuries are characterised, without any significant amplitude, by 8- and 11-year periods (Tab. 1). In turn, chronologies of pine, spruce, larch, oak and fir growing in Europe are characterised by 100- and 180-year periods (Tab. 2). Cycles of dendrochronological variables approximate cycles of air temperature and North Atlantic Oscillation NAO as well as those of solar activity. The forecast of annual growth (ring width) for 2001-2100 was calculated by interference of the tree-ring width cycles determined by the sinusoidal regression method. Because of much longer empirical sequences of specific periods, the credibility of forecasts for tree-ring widths is greater than that for air temperature.

scholarly journals Last Millennium Reanalysis with an expanded proxy database and seasonal proxy modeling

2019 ◽  
Vol 15 (4) ◽  
pp. 1251-1273 ◽  
Author(s):  
Robert Tardif ◽  
Gregory J. Hakim ◽  
Walter A. Perkins ◽  
Kaleb A. Horlick ◽  
Michael P. Erb ◽  
...  
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Surface Air Temperature ◽  
Severity Index ◽  
Drought Severity ◽  
Last Millennium ◽  
Tree Ring Width ◽  
Forward Models ◽  
Proxy Records ◽  
Northern Latitudes

Abstract. The Last Millennium Reanalysis (LMR) utilizes an ensemble methodology to assimilate paleoclimate data for the production of annually resolved climate field reconstructions of the Common Era. Two key elements are the focus of this work: the set of assimilated proxy records and the forward models that map climate variables to proxy measurements. Results based on an updated proxy database and seasonal regression-based forward models are compared to the LMR prototype, which was based on a smaller set of proxy records and simpler proxy models formulated as univariate linear regressions against annual temperature. Validation against various instrumental-era gridded analyses shows that the new reconstructions of surface air temperature and 500 hPa geopotential height are significantly improved (from 10 % to more than 100 %), while improvements in reconstruction of the Palmer Drought Severity Index are more modest. Additional experiments designed to isolate the sources of improvement reveal the importance of the updated proxy records, including coral records for improving tropical reconstructions, and tree-ring density records for temperature reconstructions, particularly in high northern latitudes. Proxy forward models that account for seasonal responses, and dependence on both temperature and moisture for tree-ring width, also contribute to improvements in reconstructed thermodynamic and hydroclimate variables in midlatitudes. The variability of temperature at multidecadal to centennial scales is also shown to be sensitive to the set of assimilated proxies, especially to the inclusion of primarily moisture-sensitive tree-ring-width records.

Research on Response of Drought Events in Mountain Area of Haihe River Basin Based on Multi-Source Data

2014 ◽  
Vol 955-959 ◽  
pp. 3026-3031 ◽  
Author(s):  
Jun Yin ◽  
Deng Hua Yan ◽  
Zhi Yong Yang ◽  
Zhe Yuan ◽  
Cai Lian Hao
Keyword(s):  
Tree Ring ◽  
Meteorological Data ◽  
Ring Width ◽  
Haihe River Basin ◽  
Drought Event ◽  
Historical Records ◽  
Tree Ring Width ◽  
Haihe River ◽  
Mountain Area ◽  
Humidity Index

Proxy data, measured data and historical records were assembled to study the drought events response features in the mountain area of Haihe Basin. Tree-ring width data (proxy) and historical records were used to analyze the response features of drought events to proxy. Meteorological data was introduced to calculate relative humidity index to raise the accuracy rate of tree-ring width indexs indication to drought event. Hydrological data was introduced to calculate runoff departure percentage to verify the conclusion that precipitation is the main factor affecting the tree-ring width of Chinese pine in Xiaowutai Mountain.

scholarly journals Tree-ring width wavelet and spectral analysis of solar variability and climatic effects on a Chilean cypress during the last two and a half millennia

2005 ◽  
Vol 1 (1) ◽  
pp. 121-135 ◽  
Author(s):  
N. R. Rigozo ◽  
D. J. R. Nordeman ◽  
E. Echer ◽  
L. E. A. Vieira ◽  
M. P. S. Echer ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Wavelet Analysis ◽  
Tree Ring ◽  
Confidence Level ◽  
Ring Width ◽  
Solar Modulation ◽  
Tree Ring Width ◽  
Enso Events ◽  
Climatic Variations ◽  
Tree Ring Data

Abstract. Spectral and wavelet analysis were performed on a tree ring width time series obtained from a 2500 yr old cypress tree (Fitzroya cupressoides) from Costa del Osorno, Chile. The periods for analysis were selected at 95% confidence level. Both periodicities characteristic of solar activity and climatic variations were found in this tree ring width series. The 11 and 22 years solar cycle periods were present in tree ring data with a confidence level above 98%. This indicates the solar modulation of climatic variations is being recorded by the tree ring grown. However wavelet analysis shows that these are present only sparsely. Short-term variations, between 2-5 years, are also present in tree ring data, and are shown by wavelet maps to be a more permanent characteristic. This time scale is a signature of ENSO events. Long-term variations, above 200 years, are also present in tree ring data. The spectral analysis performed in this work shows that this species has the ability to record solar-ENSO variations that seems to be affecting the local environment of tree growth, and also that this region was influenced by ENSO events at least in the past 2500 yr interval covered by this study.

Early summer temperatures since 1670 A.D. for Central Kamchatka reconstructed based on a Siberian larch tree-ring width chronology

1996 ◽  
Vol 26 (11) ◽  
pp. 2048-2052 ◽  
Author(s):  
Moses Gostev ◽  
Gregory Wiles ◽  
Rosanne D'Arrigo ◽  
Gordon Jacoby ◽  
Peter Khomentovsky
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Siberian Larch ◽  
Kamchatka Peninsula ◽  
Early Summer ◽  
Model Verification ◽  
Tree Ring Width ◽  
Tree Ring Data ◽  
Summer Temperatures ◽  
Larch Tree

A tree-ring width chronology of larch (Larixkurilensis Mayr) has been developed from along the Bystraya River near Esso in the interior valley of the Kamchatka Peninsula, Russia. The chronology, which covers from 1670 to 1992, explains 38% of the variance in May–June temperatures for the Esso meteorological station. This ring-width series is used to develop the first dendroclimatic reconstruction for Kamchatka. We caution that the Esso station record, the closest to the tree-ring site, is only 42 years in length, making model verification difficult. Periods of above-average temperatures are inferred for ca. 1750, 1800, and over the last few decades; colder than average conditions are inferred for 1710–1720, 1760–1770s, and 1860–1880s. The ring-width chronology cross-dates with other larch tree-ring data for Kamchatka and, during certain intervals, with a larch ring-width record from eastern Siberia. Comparison of the two records suggests that the insertion of a missing ring for the year 1816 in the eastern Siberian series is not justified. A birch (Betulaermanii Cham.) chronology from a coastal site near Petropavlovsk-Kamchatskiy correlates with July–August temperatures. Both the larch and more widespread birch species show promise for further dendroclimatic studies in Kamchatka.

scholarly journals The 600-mm precipitation isoline distinguishes tree-ring-width responses to climate in China

2018 ◽  
Vol 6 (2) ◽  
pp. 359-368 ◽  
Author(s):  
Yu Liu ◽  
Huiming Song ◽  
Changfeng Sun ◽  
Yi Song ◽  
Qiufang Cai ◽  
...  
Keyword(s):  
Tree Ring ◽  
Large Scale ◽  
Ring Width ◽  
Severity Index ◽  
Annual Precipitation ◽  
Drought Severity ◽  
Climate Variations ◽  
Tree Ring Width ◽  
Past Climate ◽  
Tree Ring Data

AbstractThe numerous temperature and precipitation reconstructions in China based on tree-ring-width data have played significant roles in furthering the understanding of past climate changes. However, the geographical variability in the responses of trees to climate variations in China remains largely undetermined. Here, we describe an important spatial boundary in the response of trees to climate variations, namely the 600-mm annual precipitation isoline. We found that, to the north of this line, tree-ring widths are usually positively correlated with precipitation and negatively correlated with growing-season temperature. To the south of this line, the tree-ring widths respond positively to temperature, and winter half-year temperatures are the main reconstructed parameters, especially on the third topographical step of China. We also found that precipitation reconstructions based on tree-ring data and the Palmer Drought Severity Index almost exclusively fall in the region of the 200- to 600-mm annual precipitation isolines, not other regions. Our findings indicate that, when using multiple tree-ring-width chronologies for large-scale past climate reconstructions, the climatic signal of each tree-ring-width series should be carefully considered.

scholarly journals Last Millennium Reanalysis with an expanded proxy database and seasonal proxy modeling

2018 ◽  
Author(s):  
Robert Tardif ◽  
Gregory J. Hakim ◽  
Walter A. Perkins ◽  
Kaleb A. Horlick ◽  
Michael P. Erb ◽  
...  
Keyword(s):  
Tree Ring ◽  
Ring Width ◽  
Surface Air Temperature ◽  
Drought Severity ◽  
Last Millennium ◽  
Tree Ring Width ◽  
Forward Models ◽  
Proxy Records ◽  
Skill Scores ◽  
Paleoclimate Data

Abstract. The Last Millennium Reanalysis utilizes an ensemble methodology to assimilate paleoclimate data for the production of annually resolved climate field reconstructions of the Common Era. Two key elements are the focus of this work: the set of assimilated proxy records, and the forward models that map climate variables to proxy measurements. Results based on an extensive proxy database and seasonal regression-based forward models are compared to the prototype reanalysis of Hakim et al. (2016), which was based on a smaller set of proxy records and simpler proxy models formulated as univariate linear regressions against annual temperature. Validation against various instrumental–era gridded analyses shows that the new reconstructions of surface air temperature, 500 hPa geopotential height and the Palmer Drought Severity Index are significantly improved, with skill scores increasing from 10 % to more than 200 %, depending on the variable and verification measure. Additional experiments designed to isolate the sources of improvement reveal the importance of additional proxy records, including coral records for improving tropical reconstructions; tree-ring-width chronologies, including moisture-sensitive trees, for thermodynamic and hydroclimate variables in mid-latitudes; and tree-ring density records for temperature reconstructions, particularly in high northern latitudes. Proxy forward models that account for seasonal responses, and the dual sensitivity to temperature and moisture characterizing tree-ring-width proxies, are also found to be particularly important. Other experiments highlight the beneficial role of covariance localization on reanalysis ensemble characteristics. This improved paleoclimate data assimilation system served as the basis for the production of the first publicly released NOAA Last Millennium Reanalysis.

Tree-ring width and maximum latewood density at the North American tree line: parameters of climatic change

1992 ◽  
Vol 22 (9) ◽  
pp. 1290-1296 ◽  
Author(s):  
Rosanne D. D'Arrigo ◽  
Gordon C. Jacoby ◽  
Rosemary M. Free
Keyword(s):  
Climatic Change ◽  
Tree Ring ◽  
North American ◽  
Ring Width ◽  
Positive Temperature ◽  
Tree Line ◽  
Tree Ring Width ◽  
Maximum Latewood Density ◽  
Latewood Density ◽  
Instrumental Records

In remote subarctic North America, instrumental records are very short and sparsely distributed. Yet a long-term understanding of subarctic climate is critical to studies of global change. Annual tree-ring width and maximum latewood density are complementary, high-resolution parameters with different environmental and physiological controls that can be used to assess recent centuries of climatic change. In this paper we present a comparison of the different temperature information inferred from these parameters for white spruce (Piceaglauca (Moench) Voss), a dominant North American latitudinal tree line species. Ring-width and maximum latewood density chronologies (with a common period from 1720–1977) are shown for five sites along a widely spaced transect of the forest–tundra transition in northern Canada. The positive temperature response of maximum latewood density to year to year local temperatures is more consistent and covers a longer portion of the growing season than does that of ring width. Unlike density, the ring-width data show a preference for cold spring conditions. Some, but not all, of the ring-width and density series display increases during the recent century's large-scale climatic warming trend. It is concluded that both types of parameters are necessary for understanding changes in climate and forest dynamics at the northern tree line.

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