32 results on '"Bräuning, Achim"'
Search Results
2. Precipitation dominates the growth of common hornbeam (Carpinus betulus L.) and stinking juniper (Juniperus foetidissima Willd) in Arasbaran forests of northwestern Iran.
- Author
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Emaminasab, Mohammad, Oladi, Reza, Pourtahmasi, Kambiz, Bräuning, Achim, and Shirvany, Anoushirvan
- Abstract
Key message: European hornbeam has a great potential for tree-ring based research when using a combination of conventional dendrochronological techniques and fluorescent microscopy. Arasbaran forests are among the most important ecological areas in Iran, but they have been studied less extensively in comparison to the famous Hyrcanian forests. For the first time, the potential of two dominant species in these forests, i.e. hornbeam (Carpinus betulus) and stinking juniper (Juniperus foetidissima) to study the climate-growth relations was evaluated using a dendroecological approach. Difficulties in distinguishing ring-width boundaries of hornbeam were overcome using fluorescence microscopy. The statistics used to evaluate the chronologies of both species confirmed their capability to study climate–growth relationships and their potential for developing regional climate reconstruction. Hornbeam and juniper showed similar climate-growth relationships. Across all sampling sites, the growth index displayed a positive correlation with precipitation and SPEI drought index, and a negative correlation with temperature. Precipitation in spring and early autumn played a significant role in stimulating the radial growth of the species. However, topography and microclimate could affect the relationship between growth and regional climate, as the highest elevation site receives abundant moisture input from frequent fog events. Our initial study highlights the potential of hornbeam as a widely spread but neglected species in the Northern Hemisphere for dendroecological studies. Furthermore, we conclude that despite some variance in the microclimate of different sites (ranging from cold, sub-humid to warm, semi-arid) within the Arasbaran region, trees of different species in the entire study area show a common response to climatic change, mainly affected by water availability. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. HYDRO-CLIMATIC VARIABILITY IN SOUTHERN ECUADOR REFLECTED BY TREE-RING OXYGEN ISOTOPES
- Author
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Volland, Franziska, Pucha, Darwin, and Bräuning, Achim
- Published
- 2016
4. Inter-annual and intra-annual tree-ring oxygen isotope signals in response to monsoon rainfall in northwestern Thailand.
- Author
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Preechamart, Sineenart, Pumijumnong, Nathsuda, Bräuning, Achim, Muangsong, Chotika, Cai, Binggui, and Buajan, Supaporn
- Subjects
RAINFALL ,TREE-rings ,MONSOONS ,TEAK ,STABLE isotopes ,OXYGEN isotopes ,MOISTURE - Abstract
We present a new teak (Tectona grandis L.f.) tree-ring stable oxygen isotope (δ
18 OTR ) chronology from Mae Tuen (MT) site, Tak province, northwestern Thailand at inter-annual (167-year, A.D.1850–2016) and intra-annual (A.D.2006–2016) timescales. The inter-annual δ18 OTR chronology showed a significant negative correlation (r = −0.678, p < 0.01) with the May–October amount of regional rainfall obtained from CRU TS4.03. We established a linear regression model that explained 46.0% of the actual rainfall variance and reconstructed monsoon season rainfall back to A.D.1850. The seasonal variations in moisture conditions were reflected in inter-annual δ18 OTR variability. The rainfall amount and δ18 O in precipitation (δ18 Op ) mainly controlled intra-annual variations in teak δ18 OTR . These results show that the variation in Thai teak δ18 OTR is dominated by rainfall, highlighting the strength of δ18 OTR as a monsoon rainfall proxy. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
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5. Climatic Control of Radial Growth of Cedrela Montana in a Humid Mountain Rainforest in Southern Ecuador
- Author
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Bräuning, Achim, Volland-Voigt, Franziska, Burchardt, Iris, Ganzhi, Oswaldo, Nauss, Thomas, and Peters, Thorsten
- Published
- 2009
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6. Growth-Ring Variations of Dwarf Shrubs Reflect Regional Climate Signals in Alpine Environments Rather than Topoclimatic Differences
- Author
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Bär, Annette, Pape, Roland, Bräuning, Achim, Löffler, Jörg, and Linder, Peter
- Published
- 2008
- Full Text
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7. Reduced Temperature Sensitivity of Maximum Latewood Density Formation in High-Elevation Corsican Pines under Recent Warming
- Author
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Römer, Philipp, Hartl, Claudia, Schneider, Lea, Bräuning, Achim, Szymczak, Sonja, Huneau, Frédéric, Lebre, Sébastien, Reinig, Frederick, Büntgen, Ulf, Esper, Jan, Buentgen, Ulf [0000-0002-3821-0818], and Apollo - University of Cambridge Repository
- Subjects
Pinus nigra ,climate change ,Meteorology. Climatology ,tree-ring density ,ddc:550 ,France ,dendroclimatology ,Mediterranean ,QC851-999 ,climate signals - Abstract
Maximum latewood density (MXD) measurements from long-lived Black pines (Pinus nigra spp. laricio) growing at the upper treeline in Corsica are one of the few archives to reconstruct southern European summer temperatures at annual resolution back into medieval times. Here, we present a compilation of five MXD chronologies from Corsican pines that contain high-to-low frequency variability between 1168 and 2016 CE and correlate significantly (p <, 0.01) with the instrumental April–July and September–October mean temperatures from 1901 to 1980 CE (r = 0.52−0.64). The growth–climate correlations, however, dropped to −0.13 to 0.02 afterward, and scaling the MXD data resulted in a divergence of >, 1.5 °C between the colder reconstructed and warmer measured temperatures in the early-21st century. Our findings suggest a warming-induced shift from initially temperature-controlled to drought-prone MXD formation, and therefore question the suitability of using Corsican pine MXD data for climate reconstruction.
- Published
- 2021
8. On the Problem of Possible Last-Glacial Forest-Refuge-Areas within the Deep Valleys of Eastern Tibet (Zum Problem der Existenz letzteiszeitlicher Waldrefugien in den tiefen Tälern Osttibets)
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Frenzel, Burkhard, Bräuning, Achim, and Adamczyk, Sonja
- Published
- 2003
9. Spring Season in Western Nepal Himalaya is not yet Warming: A 400-Year Temperature Reconstruction Based on Tree-Ring Widths of Himalayan Hemlock (Tsuga dumosa)
- Author
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Aryal, Sugam, Gaire, Narayan Prasad, Pokhrel, Nawa Raj, Rana, Prabina, Sharma, Basant, Kharal, Deepak Kumar, Poudel, Buddi Sagar, Dyola, Nita, Fan, Ze-Xin, Grießinger, Jussi, and Bräuning, Achim
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climate variability ,pre-monsoon temperature ,ddc:55 ,past climate ,manang ,lcsh:Meteorology. Climatology ,Naturwissenschaftliche Fakultät ,dendroclimatology ,lcsh:QC851-999 - Abstract
The Himalayan region has already witnessed profound climate changes detectable in the cryosphere and the hydrological cycle, already resulting in drastic socio-economic impacts. We developed a 619-yea-long tree-ring-width chronology from the central Nepal Himalaya, spanning the period 1399−2017 CE. However, due to low replication of the early part of the chronology, only the section after 1600 CE was used for climate reconstruction. Proxy climate relationships indicate that temperature conditions during spring (March−May) are the main forcing factor for tree growth of Tsuga dumosa at the study site. We developed a robust climate reconstruction model and reconstructed spring temperatures for the period 1600−2017 CE. Our reconstruction showed cooler conditions during 1658−1681 CE, 1705−1722 CE, 1753−1773 CE, 1796−1874 CE, 1900−1936 CE, and 1973 CE. Periods with comparably warmer conditions occurred in 1600−1625 CE, 1633−1657 CE, 1682−1704 CE, 1740−1752 CE, 1779−1795 CE, 1936−1945 CE, 1956−1972 CE, and at the beginning of the 21st century. Tropical volcanic eruptions showed only a sporadic impact on the reconstructed temperature. Also, no consistent temperature trend was evident since 1600 CE. Our temperature reconstruction showed positive teleconnections with March−May averaged gridded temperature data for far west Nepal and adjacent areas in Northwest India and on the Southwest Tibetan plateau. We found spectral periodicities of 2.75−4 and 40−65 years frequencies in our temperature reconstruction, indicating that past climate variability in central Nepal might have been influenced by large-scale climate modes, like the Atlantic Multi-decadal Oscillation, the North Atlantic Oscillation, and the El Niño-Southern Oscillation.
- Published
- 2020
10. Dendrochronology for the last 1400 Years in Eastern Tibet
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Bräuning, Achim
- Published
- 1994
11. Tree-ring based December–February precipitation reconstruction in the southern Zagros Mountains, Iran.
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Arsalani, Mohsen, Pourtahamsi, Kambiz, Azizi, Ghasem, Bräuning, Achim, and Mohammadi, Hosein
- Abstract
We developed the first tree-ring width chronology from Quercus brantii Lindel for the period 1796–2015 in the southern Zagros Mountains, Iran, using standard dendrochronological procedures. Climate-growth relationships revealed that DecemberöFebruary precipitation has strong positive effects (r = 0.66; P < 0.01) on the species’ growth while mean temperature during the growing season has strong negative effects. Spatial correlations with Palmer Drought Severity Index (PDSI) and gridded precipitation data revealed that the chronology contains regional climate signals and tree growth variations may represent precipitation fluctuations over large areas of the Middle East. The linear regression model accounts for 44% of the actual DecemberöFebruary precipitation variance. The reconstructed precipitation revealed that over the period 1850–2015 extreme dry years occurred in 1870-71, 1898, 1960 and 1963-64, and extreme wet years occurred in 1851, 1885, 1916 and 1921 in the southern Zagros region. The longest dry period lasted 16 years and occurred from 1958 to 1973. Two-year consecutive wet and dry events showed the highest frequencies and the average length of dry and wet events were 2.9 and 3.6 years over the reconstructed period. Correlations between the long-term reconstructed precipitation and the North Atlantic Oscillation (NAO), Southern Oscillation Index (SOI), and Pacific Decadal Oscillation (PDO) confirmed the effects of teleconnection patterns on precipitation in the southern Zagros region. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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12. Relationships betweenWood Formation and Cambium Phenology on the Tibetan Plateau during 1960-2014.
- Author
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He, Minhui, Yang, Bao, Shishov, Vladimir, Rossi, Sergio, Bräuning, Achim, Ljungqvist, Fredrik Charpentier, and Grießinger, Jussi
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CAMBIUM ,PHENOLOGY ,TREE growth ,DENDROCLIMATOLOGY - Abstract
The variability of tree stem phenology plays a critical role in determining the productivity of forest ecosystems. Therefore, we aim to identify the relationships between the timings of cambium phenology, and forest growth in terms of tree-ring width over a long-term scale. A meta-analysis was performed that combined the timings of xylem formation, which were calculated by a tree-ring formation model of the VS (Vaganov-Shashkin)-oscilloscope during the period 1960-2014, and a tree-ring width series at 20 composite sites on the Tibetan Plateau. Both the start and length of the growing season significantly affected the formation of wood at 70% of the 20 composite sites within the study region. A wider tree ring probably resulted from an earlier start and a longer duration of the growing season. The influence of ending dates on tree-ring width was less evident, and more site-dependent. Weak relationships were identified between the start and end of the growing season at 85% of the composite sites. Compared to the monitoring results, which could only detect the relationships between cambium phenology and xylem cell production from a limited number of trees and years, our long-term relationships deepened such connections, and therefore should be used to improve mechanism models for the accurate evaluating and predicting of wood production and carbon sequestration in forest ecosystems under current and future climate change. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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13. Multi-century tree-ring precipitation record reveals increasing frequency of extreme dry events in the upper Blue Nile River catchment.
- Author
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Mokria, Mulugeta, Gebrekirstos, Aster, Abiyu, Abrham, Van Noordwijk, Meine, and Bräuning, Achim
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CLIMATE change ,RAINFALL ,TREE-rings ,DENDROCLIMATOLOGY - Abstract
Climate-related environmental and humanitarian crisis are important challenges in the Great Horn of Africa ( GHA). In the absence of long-term past climate records in the region, tree-rings are valuable climate proxies, reflecting past climate variations and complementing climate records prior to the instrumental era. We established annually resolved multi-century tree-ring chronology from Juniperus procera trees in northern Ethiopia, the longest series yet for the GHA. The chronology correlates significantly with wet-season ( r = .64, p < .01) and annual ( r = .68, p < .01) regional rainfall. Reconstructed rainfall since A.D. 1811 revealed significant interannual variations between 2.2 and 3.8 year periodicity, with significant decadal and multidecadal variations during 1855-1900 and 1960-1990. The duration of negative and positive rainfall anomalies varied between 1-7 years and 1-8 years. Approximately 78.4% (95%) of reconstructed dry (extreme dry) and 85.4% (95%) of wet (extreme wet) events lasted for 1 year only and corresponded to historical records of famine and flooding, suggesting that future climate change studies should be both trend and extreme event focused. The average return periods for dry (extreme dry) and wet (extreme wet) events were 4.1 (8.8) years and 4.1 (9.5) years. Extreme-dry conditions during the 19th century were concurrent with drought episodes in equatorial eastern Africa that occurred at the end of the Little Ice Age. El Niño and La Niña events matched with 38.5% and 50% of extreme-dry and extreme-wet events. Equivalent matches for positive and negative Indian Ocean Dipole events were weaker, reaching 23.1 and 25%, respectively. Spatial correlations revealed that reconstructed rainfall represents wet-season rainfall variations over northern Ethiopia and large parts of the Sahel belt. The data presented are useful for backcasting climate and hydrological models and for developing regional strategic plans to manage scarce and contested water resources. Historical perspectives on long-term regional rainfall variability improve the interpretation of recent climate trends. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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14. Tree rings reveal recent intensified spring drought in the central Himalaya, Nepal.
- Author
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Panthi, Shankar, Bräuning, Achim, Zhou, Zhe-Kun, and Fan, Ze-Xin
- Subjects
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DENDROCLIMATOLOGY , *DROUGHT forecasting , *TREE-rings , *OCEAN temperature , *METEOROLOGICAL precipitation , *ATLANTIC multidecadal oscillation - Abstract
To better understand long-term drought variations in the central Himalaya, we developed new tree-ring width chronologies of Himalayan spruce ( Picea smithiana (Wall.) Boiss.) from three sites in the north-western Nepal. The local site chronologies showed high cross correlations and similar growth-climate responses to regional spring drought variability. We thus combined all site chronologies into a regional composite (RC) standard chronology that spans 516 years (1498–2013 CE). The RC chronology showed significant positive (negative) correlations with spring (March–May) precipitation (temperature) variability. Meanwhile, RC chronology showed the highest correlation with spring self-calibrating Palmer drought severity index (scPDSI, r = 0.652, p < 0.001), indicating that radial growth of P. smithiana is strongly limited by spring moisture availability. Using RC chronology, we reconstructed the spring drought variability for the period 1725–2013, which explained 42.5% variance of the actual scPDSI during the calibration period 1957–2012. Our reconstructed spring drought variability in the central Himalaya showed consistent wet-dry episodes with other regional drought and precipitation reconstructions from the Himalaya and nearby regions. Spectral peaks and spatial correlation analysis indicate that spring drought variability in the central Himalaya may be linked to large scale climatic drivers, mainly Atlantic Multidecadal Oscillation activities due to sea surface temperatures variation in the Atlantic Ocean. Our reconstruction revealed a continuous shift toward drier conditions in the central Himalaya since early 1980s that coincide with continental-scale warming and reduced spring precipitation in the central Himalaya. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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15. Dendroclimatic reconstruction of May-June maximum temperatures in the central Zagros Mountains, western Iran.
- Author
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Arsalani, Mohsen, Azizi, Ghasem, and Bräuning, Achim
- Subjects
LANDFORMS ,HILLSIDE architecture ,CLIMATOLOGY ,TEMPERATURE - Abstract
Long-term instrumental records that provide estimates about the natural range of long-term climate fluctuation are lacking in Iran. Ring-width chronologies were developed from two oak sites in the central Zagros Mountains, dating back to 1705 A.D. Due to high correlations between the local site chronologies, a mean regional chronology ( RC) was calculated. Correlations with regionalized climate data showed significant negative correlations with maximum temperature in December of the previous year and February, May, June and August of the current year. However, May-June maximum temperatures of the current growing season showed the highest negative correlation coefficient with regional tree growth patterns. Based on this relationship, maximum temperature of May-June was reconstructed over the last 170 years (1840-2010). The average length of cold periods was shorter than that of warm periods. Further sampling may allow the analysis of long-term climatic trends in this region. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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16. Tree-ring based evidence of the multi-decadal climatic oscillation during the past 200 years in north-central China.
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Shuyuan Kang, Bräuning, Achim, and Hongyuan Ge
- Subjects
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TREE-rings , *METEOROLOGICAL precipitation , *CLIMATE change , *PRINCIPAL components analysis , *DROUGHTS , *ARID regions - Abstract
As the northern fringe of the Asian summer monsoon region, north-central China (hereafter NCC) is highly sensitive to climate change. It is important to understand drought variability and the associated mechanisms in this region since precipitation changes have direct impacts on human society in this semiarid-arid area. In this study, a new tree ring-width based drought reconstruction (AD 1804-2010) was established in the Songmingyan Nature Reserve, which lies in NCC. This reconstruction illustrates the severe drought periods occurring in the 1860s, 1928-1932 and 1991-2000, with recurring drought intervals being about 60 years. The first principal component of the five chronologies from NCC shows strongly coherent drought variability with the other single-site records and can thus be used as an indicator of regional moisture variations. Combining the Monsoon Asia Drought Atlas (hereafter MADA) dataset and the dry-wet index (hereafter DWI) dataset from eastern China, the spatial distribution of moisture variability for three selected drought events is mapped. It is found that northern China and Mongolia experienced dry conditions during the three severe drought periods, whereas wet conditions prevailed in the middle and lower reaches of the Yangtze River. The Pacific Decadal Oscillation (hereafter PDO) might have been one of the possible causes responsible for multi-decadal drought variability over NCC, with the PDO warm phases being associated with drought conditions and the cold phases corresponding to wet conditions over NCC. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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17. Rainfall history for the Hexi Corridor in the arid northwest China during the past 620 years derived from tree rings.
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Bao Yang, Chun Qin, Bräuning, Achim, Burchardt, Iris, and Jingjing Liu
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RAINFALL ,REGRESSION analysis ,METEOROLOGICAL precipitation ,PRECIPITATION anomalies ,CLIMATE change ,HISTORY - Abstract
We present a 620-year long ring width record from the middle Qilian Mountains, where it is presently controlled by the Westerlies. The chronology was developed from Qilian juniper ( Sabina przewalskii) growing at sites near the western distribution limit of the species in the northern Qilian Mountains, Gansu Province, China. A linear regression model between ring width and annual (July to June) precipitation accounts for 34.9% of the observed instrumental precipitation variance during the period 1952 to 2007. Spatial correlation analyses between the reconstruction and gridded precipitation data shows that the annual precipitation reconstruction captures regional climatic variations over the Qilian Mountains and the nearby Hexi Corridor. We also show the scaled standard chronology adjusted to the mean and variance of the instrumental data. Relatively wet periods are identified for AD 1390-1413, 1425-1450, 1530-1649, 1792-1920, 1937-1949 and 1980-1985. Dry conditions prevailed during AD 1414-1424, 1451-1529, 1650-1791, 1921-1936, 1950-1979 and 1986-2007. In comparison with the regression-based reconstruction, the scaled reconstruction indicates considerably wetter conditions during 1390-1413, 1425-1450, 1570-1630 and 1790-1920. The interval AD 1451-1529 was the most intense and longest drought epoch in the Hexi Corridor over the past six centuries. This drought was not only recorded in the Qilian Mountains but also occurred in northern and eastern China. It might be caused by a substantial weakening of the Asian summer monsoon induced by the joint effects of solar and volcanic activities at that time. Our results also suggest that the Hexi Corridor was under the control of the Asian monsoon circulation on inter-decadal to centennial timescales in the past centuries. Copyright © 2010 Royal Meteorological Society [ABSTRACT FROM AUTHOR]
- Published
- 2011
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18. Tree ring recorded May–August temperature variations since A.D. 1585 in the Gaoligong Mountains, southeastern Tibetan Plateau
- Author
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Fan, Ze-Xin, Bräuning, Achim, Tian, Qin-Hua, Yang, Bao, and Cao, Kun-Fang
- Subjects
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TEMPERATURE , *CLIMATE change , *TREE-rings , *DENDROCLIMATOLOGY , *SEASONS , *LARCHES - Abstract
Abstract: High-resolution proxy data are still scarce in the southeastern Tibetan Plateau, which limit our understanding of climatic variability before instrumental records. In this study, we developed 595-year tree ring-width chronology from Larix speciosa near the timberlines of the Gaoligong Mountains, southeastern Tibetan Plateau. Ring-width site chronologies and a well-replicated regional chronology (RC) showed significant positive correlations with warm season temperatures from May to August. Using RC as predictor, we reconstructed mean May–August temperature for the study region that extends back to A.D. 1585. Cold conditions prevailed during the periods 1600s, 1620–30, 1640–50s, 1700s, 1730–40s, 1760s, 1810–20s, 1850s, 1900–10s and 1955–70. Warm episodes occurred during 1610s, 1660–1680s, 1710–20s, 1750s, 1780–90s, 1820–40, 1920–50 and 1980–present. Spatial correlations with gridded land surface temperatures revealed that our reconstruction represents regional temperature signal for the southern Tibetan Plateau. Comparison with other tree ring-based temperature reconstructions from surrounding areas implies a high degree of confidence for our reconstruction. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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19. Growth–climate responses of high-elevation conifers in the central Hengduan Mountains, southwestern China.
- Author
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Fan, Ze-Xin, Bräuning, Achim, Cao, Kun-Fang, and Zhu, Shi-Dan
- Subjects
VEGETATION & climate ,PLANT growth ,CONIFERS ,FOREST ecology ,CLIMATE change ,DENDROCLIMATOLOGY ,TREE-rings ,PRINCIPAL components analysis - Abstract
Abstract: Improved understanding of tree-growth responses to climate is needed to model and predict forest ecosystem responses to current and future climatic variability. We applied dendroclimatological techniques to assess the effects of inter-annual climate variations on radial growth of high-elevation conifers in the central Hengduan Mountains, southwestern China. Eight tree-ring width chronologies of the major tree genera Abies and Picea that are aligned along an elevation gradient from 3200 to 4200m a.s.l. were developed. Correlation and principal component analyses for the eight chronologies identified three groups of sites, representing different patterns of growth–climate relationships. Correlation and redundancy analyses with regional climate data revealed that radial growth of fir growing at high-elevation sites is enhanced by normal or warm summer temperatures (June and July) during the current growing season. In addition, radial growth of trees growing from high to middle elevations is sensitive to low temperatures during winter season. At low-elevation sites, trees display low sensitivity to temperature variation. However spring moisture availability becomes crucial for radial growth regardless of tree species. High- to middle-elevation conifers in the central Hengduan Mountains may benefit from the current climate warming, especially from rising winter temperatures. [Copyright &y& Elsevier]
- Published
- 2009
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20. Tree ring density-based summer temperature reconstruction for the central Hengduan Mountains in southern China
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Fan, Ze-Xin, Bräuning, Achim, Yang, Bao, and Cao, Kun-Fang
- Subjects
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EFFECT of temperature on plants , *SPRUCE , *VARIATION in wood , *DENDROCLIMATOLOGY , *STATISTICAL correlation ,WOOD density - Abstract
Abstract: Variations in ring width and wood density of Picea brachytyla were used to develop high-resolution climate proxy data to extend the existing climate record in the central Hengduan Mountains, north-western Yunnan Province, China. Growth–climate response analyses showed that the total ring width (TRW) and maximum latewood density (MXD) in the sub-alpine zone are mainly influenced by summer temperature variability. Based on a MXD regional chronology derived from two high elevation sites, we developed a warm season (April–September) temperature reconstruction for the period A.D. 1750–2006. The climate/tree-growth model accounts for 41% of the instrumental temperature variance during the period 1958–2004. Warm summers occurred during 1750s, 1820–50s, 1880–1890s, 1930–1950s and 1990–present; while the periods of 1790–1810s, 1860–1870s, 1900–1920s, and 1960–1985 were relatively cold. Spatial climate correlation analyses with gridded land surface data revealed that our warm season temperature reconstruction contains a strong regional temperature signal for the Hengduan Mountain ranges. Our reconstruction successfully captured recent abrupt climatic changes and agreed in general with other tree ring-based temperature reconstructions from nearby regions on a decadal timescale. In addition, reconstructed summer temperature variations were consistent with recorded glacier fluctuations in the surrounding high mountains. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
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21. Tree-ring based drought reconstruction in the central Hengduan Mountains region (China) since A.D. 1655.
- Author
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Ze-Xin Fan, Bräuning, Achim, and Kun-Fang Cao
- Subjects
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TREE growth , *TREE-rings , *DROUGHTS , *CHRONOLOGY , *METEOROLOGICAL precipitation , *HUMIDITY , *TEMPERATURE - Abstract
The article discusses a tree ring-based drought reconstruction in the central Hengduan Mountains in north-western Yunnan, China. The study involved developing four tree ring-width chronologies of three species. It was found that there are correlations existing among the chronologies, and that the first principal component makes up 60.5% of total variance in 1655-2005. Also, radial growth was observed to be affected by precipitation and relative humidity and Palmer drought severity index (PDSI), whereas tree growth is negatively affected by temperature in March.
- Published
- 2008
- Full Text
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22. Annual temperature reconstruction in the central Hengduan Mountains, China, as deduced from tree rings.
- Author
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Fan, Ze-Xin, Bräuning, Achim, and Cao, Kun-Fang
- Subjects
DENDROCLIMATOLOGY ,TEMPERATURE ,TREE-rings ,SPRUCE ,FIR ,REGRESSION analysis - Abstract
Abstract: We developed five tree ring-width chronologies from one fir (Abies georgei) and four spruce (Picea brachytyla) stands near the upper treeline in the central Hengduan Mountain, northwestern Yunnan, China. Similar growth patterns and significant correlations are embodied among the five chronologies. A principal component analysis for the four spruce chronologies indicated that the first component accounts for 54.8% of the total variance over the period 1750–2003. Climate–growth response analysis revealed that radial growth is mainly controlled by temperature variations, especially in the winter season. The first principal component of the spruce chronology network accounts for 43% of the annual mean temperature (from previous October until September) variance during the common period 1959–2003. By using a linear regression approach, we reconstructed annual mean temperature for the past 250 years. The reconstruction shows that the central Hengduan Mountain experienced some cool episodes during the 1810s, 1860s, and during 1960–1980. Warm intervals occurred during the 1780s, 1850s, 1940–1960 and in the past two decades. These general patterns are in general accordance with other records from nearby regions. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
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23. Tree-ring evidence of 'Little Ice Age' glacier advances in southern Tibet.
- Author
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Bräuning, Achim
- Subjects
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ATMOSPHERIC temperature , *GLACIAL landforms , *GLACIERS , *CLIMATE change , *MORAINES , *JUNIPERS ,HOLOCENE paleohydrology - Abstract
The history of late Holocene glacier fluctuations in eastern Tibet was studied by determining the ages of trees growing on glacier deposits. Maximum tree ages yield minimum ages of AD 1760 and 1780 for moraine formation at the maximum extent of the 'Little Ice Age' glacier advances in two glacier forefields. Subsequent moraines could be dated to the beginning of the nineteenth and the beginning of the twentieth century. Larch trees from a third glacier forefield in southeastern Tibet show evidence of glacier activity from 1580 to 1590, from the end of the eighteenth to the beginning of the nineteenth century and from 1860 to 1880. One glacier at Mt Gyalaperi recently advanced in both 1951 and 1987. Periods of glacier advances can partly be correlated with periods of growth reductions in chronologies of total ring width and maximum latewood density derived from trees growing on slopes above the glacier valleys. Correlation functions with meteorological data suggest that maximum latewood density of subalpine Picea balfouriana, Larix griffithii and Abies delavayi var. motouensis is positively correlated with summer temperature, while ring width of these species and of subalpine Juniperus tibetica is also sensitive to winter conditions prior to the growing season. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
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24. Ring widths of Rhododendron shrubs reveal a persistent winter warming in the central Himalaya.
- Author
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Panthi, Shankar, Fan, Ze-Xin, and Bräuning, Achim
- Abstract
• We developed a new ring-width chronology (227 years) of shrub Rhododendron (R. campanulatum) from the central Himalaya. • Minimum winter temperature is the most important factor that determines radial growth of Rhododendron shrubs. • Cool-warm episodes in the central Himalaya coincide with other regional temperature records from the Himalaya and vicinities. • Winter temperature in the central Himalaya is teleconnected with the December-February India-Burma trough. • The shift in winter temperature during recent decades coincides with continental-scale warming. Himalayan Mountains provide unique opportunities for the extension of shrub-ring based dendroclimatology beyond the upper tree limit. However, little is known about limiting climate factors of shrub growth under harsh environmental conditions. We established a new ring-width chronology of a Himalayan shrub rhododendron (Rhododendron campanulatum D. Don) at the upper Krummholz treeline in the Mt. Gaurishankar massif, central Himalaya, Nepal. Bootstrapped correlation analysis showed positive relationships between radial growth and temperatures of all months from previous November to current October. Correlations were the highest with winter (December-February) minimum temperature (r = 0.781, p < 0.001), indicating that radial growth of R. campanulatum is strongly sensitive to winter minimum temperature. The linear regression model explained 61 % of the actual winter minimum temperature variance during the calibration period 1960–2013. Periods of low and high minimum winter temperatures in the central Himalaya were consistent with cool and warm episodes found by other regional winter temperature reconstructions from the Himalayas and the Tibetan Plateau. Spatial correlation analysis with land surface temperatures revealed the spatial representativeness of our reconstruction for a larger geographical territory over the Himalayas and the Tibetan Plateau. Furthermore, winter temperature in the central Himalaya is teleconnected with the December-February India-Burma trough. The persistent increasing winter temperature in recent decades in the central Himalaya coincides with continental-scale warming. Alpine vegetation in humid regions of the Himalayas may benefit from winter warming via an earlier start and extension of the growing season, as long as moisture availability is sufficient. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
25. Evaluation of Different Pooling Methods to Establish a Multi-Century δ18O Chronology for Paleoclimate Reconstruction.
- Author
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Foroozan, Zeynab, Grießinger, Jussi, Pourtahmasi, Kambiz, and Bräuning, Achim
- Subjects
TREE-rings ,DENDROCHRONOLOGY ,PALEOCLIMATOLOGY ,STABLE isotopes ,CLIMATE extremes ,CLIMATE sensitivity - Abstract
To develop multi-century stable isotope chronologies from tree rings, pooling techniques are applied to reduce laboratory costs and time. However, pooling of wood samples from different trees may have adverse effects on the signal amplitude in the final isotope chronology. We tested different pooling approaches to identify the method that is most cost-efficient, without compromising the ability of the final chronology to reflect long-term climate variability as well as climatic extreme years. As test material, we used δ
18 O data from juniper trees (Juniperus polycarpus) from Northern Iran. We compared inter-tree and shifted 5-year blocks serial pooling of stable isotope series from 5 individual trees and addition of one single series to a shifted serial pooled chronology. The inter-tree pooled chronology showed the strongest climate sensitivity and most synchronous δ18 O variations with the individual tree ring analyses, while the shifted block chronologies showed a marked decline in high-frequency signals and no correlations with climate variables of the growth year. Combinations of block-pooled and single isotope series compensated the high-frequency decline but added tree-individual climatic signals. Therefore, we recommend pooling calendar synchronous tree rings from individual trees as a viable alternative to individual-tree isotope measurements for robust paleoclimate reconstructions. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
26. Recent advances in dendroclimatology in China.
- Author
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He, Minhui, Yang, Bao, Bräuning, Achim, Rossi, Sergio, Ljungqvist, Fredrik Charpentier, Shishov, Vladimir, Grießinger, Jussi, Wang, Jianglin, Liu, Jingjing, and Qin, Chun
- Subjects
- *
TREE-rings , *OXYGEN isotopes , *STABLE isotopes , *CARBON isotopes , *TREE growth ,WOOD density - Abstract
Considerable progress has been made in dendroclimatological research in China during the period 2000–2017, including a significant increase in the spatial coverage of tree-ring chronologies developed for paleoclimatic research. New tree-ring sampling sites have been established across the Tibetan Plateau, as well as the northeastern and sub-tropical eastern parts of China. Most of the studies use coniferous trees, although different plant functional types (e.g., broadleaf species and shrubs) have also been increasingly investigated. Tree-ring chronologies longer than 600 years, however, are mostly found on the Tibetan Plateau, with the longest one extending back to 2637 BCE (before Common Era). Most tree-ring records in the eastern parts of China are <400 years long. Tree-ring width is the most commonly studied parameter, although stable isotope ratios and wood density data have also been obtained for specific sites. Stable oxygen isotope data frequently shares a common hydroclimate signal, whereas the climate or environmental signals remain inconsistent for the few available stable carbon isotope records. In general, tree-ring width-based temperature reconstructions originate from higher elevation sites (i.e., treeline) compared to hydroclimate reconstructions. Precipitation or drought reconstructions are mainly obtained from regions with an annual precipitation of <800 mm. Most of the tree-ring reconstructions are based on individual site or local-scale chronologies, although a limited number of regional-scale and field reconstructions have been produced. The most prominent identified characteristics of the recent advances in dendroclimatological research for China have manifested in aspects such as an expanded network of sampling sites, improved climate reconstruction methodology, and improved uncertainty estimations in the latter. Furthermore, the traditional statistical-based tree growth–climate relationships have been supplemented by monitoring and modeling approaches. Based on the progress from 2000 to 2017, and on the research potential of the country in this field, we expect additional widening of the dendroclimatological investigations in China during the coming years. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
27. Precipitation variations in the central Zagros Mountains (Iran) since A.D. 1840 based on oak tree rings.
- Author
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Azizi, Ghasem, Arsalani, Mohsen, Bräuning, Achim, and Moghimi, Ebrahim
- Subjects
- *
METEOROLOGICAL precipitation , *OAK , *CLIMATE change , *DENDROCHRONOLOGY , *DATA analysis , *REGRESSION analysis - Abstract
Abstract: We established three tree-ring width chronologies from oak species in the central Zagros Mountains, Iran, where instrumental climate data only cover a short period (1951–2010). Due to high similarity of the individual ring-width series, we included all studied sites in a regional chronology covering 306years. Correlation functions with regional climate data revealed significant positive correlations (p<0.01) with total precipitation from previous October to current May. Thus, we reconstructed regional precipitation variability over the period 1840–2010 based on linear regression between regional tree growth and climate data. Dry conditions prevailed in the 1840s, 1850, 1870s, 1880s, 1900s, 1920s, 1940s, 1960s, 1980s and 1999–2003. In comparison to wet periods, the number and the intensity of dry periods have increased during the 1840–2010 study period. Many of the reconstructed wet years coincided with major El Niño events. Inverse association between the Southern Oscillation Index (SOI) and the reconstructed precipitation during the common period (1877–2010) revealed that the Southern Oscillation Index (SOI) plays an important role in regional precipitation variability. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
28. Regional extreme climate events on the northeastern Tibetan Plateau since AD 1450 inferred from tree rings
- Author
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Qin, Chun, Yang, Bao, Bräuning, Achim, Sonechkin, Dmitry M., and Huang, Kai
- Subjects
- *
CLIMATOLOGY , *JUNIPERS , *TREES , *SLOPES (Physical geography) , *GEOLOGICAL time scales , *METEOROLOGICAL precipitation , *GLOBAL warming - Abstract
Abstract: Qilian juniper (Juniperus przewalskii Kom.) is a widely distributed tree species growing on south-facing slopes in the northeastern Tibetan Plateau in arid northwestern China. We established a tree-ring width network based on two new chronologies and four previously published chronologies. Correlation and response function analyses demonstrate that precipitation positively influences radial growth. Despite of minor differences in local climate–growth relations, precipitation for the annual window between previous July and current June shows consistent positive correlations with ring width at all study sites. Similar to the so called ‘pointer year’ approach, ‘anomalous’ growth years were defined to extract extreme climate events for the period AD 1450–2006. We defined a dryness–wetness grade series with five grades of climate events inferred from anomalous year analysis. During the last 50years, the frequency of wet events increased and that of drought events decreased noticeably, implying that the probability of occurrence of dry years in the northeastern Tibetan Plateau will further decrease in the future if regional warming continues. Combining our proxy records with a historical dryness–wetness record from eastern China, we mapped dryness–wetness patterns over large parts of China. By analyzing the atmospheric pressure patterns at the 850hPa level over China for selected extreme event years, we found that the confluence of cold and hot air is a precondition for a flood event in the northeastern Tibetan Plateau. Thus, a counter-clockwise atmospheric circulation centered in south of Lake Baikal only occurs in flood event years. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
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29. Tree rings in Tsuga dumosa reveal increasing drought variability in subtropical southwest China over the past two centuries.
- Author
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Yin, Yun-Li, Zaw, Zaw, Peng, Xin-Hua, Zhang, Hui, Fu, Pei-Li, Wang, Wen-Li, Bräuning, Achim, and Fan, Ze-Xin
- Subjects
- *
TREE-rings , *DROUGHTS , *SUMMER , *CLIMATE change , *STATISTICAL correlation , *REGRESSION analysis - Abstract
High-resolution palaeoclimate proxy records have been lacking for the subtropical region of southwest China. To gain insights into hydroclimate variability in central Yunnan Province, we constructed a tree ring-width chronology of Tsuga dumosa from the Wuliang Mountain area. Correlation analysis shows that moisture availability is predominantly the limiting factor on radial growth, particularly during the spring-early summer season. Using a well-calibrated regression model (R2 = 0.36, p < 0.001), we reconstructed the March–June Standardized Precipitation-Evapotranspiration Index (SPEI) for the period from 1826 to 2020 CE. Eleven extreme drought years (1860, 1897, 1958, 1960, 1979, 1984, 1987, 2006, 2010, 2013, and 2019) were identified, with most of them confirmed by historical evidence. The reconstruction series shows inter-annual to inter-decadal variations and an increasing occurrence of severe dry or wet events in the recent past, particularly during the last 50 years. Our drought reconstruction series shows high frequency cycle of 2–8 years. Spatial correlations indicate that our drought reconstruction captures hydrological signals over a larger area. In line with this, the reconstructed dry periods exhibit broad consistency with other tree-ring based drought reconstructions conducted in nearby regions. Our findings demonstrate the potential of tree-ring proxies for hydroclimate reconstruction in the subtropical areas of southwest China and provide crucial information for evaluating long-term climate change in this region. • Radial growth of T. dumosa in central Yunnan is mainly limited by spring-early summer moisture availability. • The two-century SPEI reconstruction identified eleven extreme drought years that align with historical records. • There has been a notable increase in the occurrence of severe dry or wet events in recent decades. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. Drought (scPDSI) reconstruction of trans-Himalayan region of central Himalaya using Pinus wallichiana tree-rings.
- Author
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Gaire, Narayan Prasad, Dhakal, Yub Raj, Shah, Santosh K., Fan, Ze-Xin, Bräuning, Achim, Thapa, Uday Kunwar, Bhandari, Sanjaya, Aryal, Suman, and Bhuju, Dinesh Raj
- Subjects
- *
DROUGHTS , *TREE-rings , *PALEOENVIRONMENTAL studies , *ECOSYSTEMS - Abstract
Abstract Knowledge of the long-term frequency and intensity of drought events in an area is crucial since drought has adverse effects on natural ecosystems, food security, economy, society, and civilization. We developed a 405-year long (1611–2015C.E.) tree-ring chronology of Pinus wallichiana (Blue pine) from the Dolpo area of the trans–Himalayan region in Nepal to reconstruct drought variability in this remote region. Correlation analysis revealed significant positive relationships with February–August precipitation, but negative correlations with temperature. High positive correlations with the self-calibrated Palmer drought severity index (scPDSI) confirmed that moisture availability during the early growing season and full growing season is the primary limiting factor for Blue pine tree growth in the trans–Himalayan region. We used a linear regression model between our tree-ring record and regional climate data to reconstruct a 319-year long (1697–2015C.E.) February–August scPDSI series. This reconstruction accounts for 39.4% of the total variance in actual scPDSI over the calibration period (1957–2015C.E.). The reconstruction showed that the area was under slightly dry conditions for most of the reconstructed period, with below normal scPDSI values. An extreme drought was observed in the year 1707. Also, the years 1705, 1706, 1784, 1786, 1809, 1810, 1813, 1821, 1849, 1858, 1861, 1909, 1967, 2006, and 2009 experienced severe drought conditions. Consecutive years with moderate drought were 1702–1706, 1783–1789, 1796–1798, 1812–1814, 1816–1827, 1846–1848, 1856–1864, 1873–1877, 1879–1882, 1899–1901, 1908–1911, and 1967–1968. Three historic mega-drought events that occurred in Asia were also captured in our reconstruction: Strange Parallels drought (1756–1768), the East India drought (1790–1796), and the late Victorian Great Drought (1876–1878). Very few wet years (1776–1979, 1989, 1991, and 2003) were observed during the reconstruction period. Power spectrum analysis revealed drought variability at frequencies of 2.0–2.5, 3.0, 12.0, and 128 years, suggesting that drought in the region might be linked to broad-scale atmospheric-oceanic variabilities such as the El Niño-Southern Oscillation (ENSO) and the Atlantic Multidecadal Oscillation (AMO). The results not only improve our understanding on regional drought variability, but are also helpful to make decisions on adaptation measures for protecting the marginal communities of the trans–Himalayan region from the anticipated adverse impacts of future droughts. Highlights • Radial growth of Pinus wallichiana is mainly limited by moisture availability. • February-August scPDSI during 1697–2015 C.E. was reconstructed for trans-Himalaya region • The trans-Himalayan region experienced prolonged drought during 19th and 20th century. • Drought variability in the trans-Himalayan regions has teleconnections with ENSO and AMO. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
31. Application of dendroclimatic methods in assessment of climate change impacts on the annual growth of Schrenk spruce in the Ile River basin, southeastern Kazakhstan
- Author
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Zubairov, Bulat, Schröder, Hilmar, Bräuning, Achim, and Rost, Karl Tilman
- Subjects
Kasachstan ,dendrochronologie ,ddc:915 ,915 Geografie Asiens und Reisen in Asien ,TK 1045 ,dendroklimatologie ,dendrochronology ,RQ 70507 ,RQ 70438 ,dendroclimatology ,Kazakhstan ,Schrenks Fichte ,Schrenk spruce - Abstract
Wälder stellen wichtige Ökosystemleistungen und -güter bereit und tragen damit maßgeblich zur Lebensgrundlage der Menschen bei. Sie unterliegen jedoch vielseitigen Bedrohungen, welche die volle Funktionsfähigkeit des Ökosystems gefährden und deren Entwicklung beeinträchtigen. Inwiefern sich diese auf die Funktionsweise und die Walddynamik in Kasachstan äußert, ist aufgrund der wenigen durchgeführten dendroklimatischen Untersuchungen im Detail unklar. Hinzu kommt, dass für die qualitative Bewertung der Klima-Wachstums-Beziehungen diese Studien in ihrer räumlichen und zeitlichen Abdeckung unzureichend sind. Zu den bereits verfügbaren Informationen fehlen zur Einschätzung gemeinsamer Muster und Unterschiede hinsichtlich der Reaktion des Baumwachstums auf das Klima qualitative Analysen. Hierfür wurden alle verfügbaren Publikationen zu den dendroklimatischen Untersuchungen in Kasachstan analysiert. Diese Analyse ermöglichte nicht nur die Zusammenfassung der verfügbaren Informationen zu den Beziehungen zwischen Klima und Wachstum, sondern lieferte zudem konkrete Informationen zu vorhandenen Forschungslücken. Einige dieser Lücken wurden durch die Untersuchungen der variierenden Klima-Wachstums-Beziehungen der Schrenks Fichte im Einzugsgebiet des Ile-Flusses geschlossen. Die durchgeführte Studie verdeutlicht unterschiedliche Reaktion von Früh-, Spätholz und Gesamtringbreite auf den Klimawandel. Der starke Einfluss des Klimawandels wurde durch die Abnahme des Temperatursignals um die 1970er-Jahre beobachtet. Eine erkennbare Periodizität bei Schwankungen der Baumringindizes lässt auf einen Einfluss bestimmter Klimaindizes, z. B. der Nordatlantischen Oszillation u. a. schließen. Die im Rahmen dieser Dissertation durchgeführten Untersuchungen tragen zur Entwicklung eines Baumring-Netzwerkes in Kasachstan bei. Die erhoben Daten sind für die Bewertung möglicher Auswirkungen des Klimawandels auf die Wälder der Schrenks Fichte in Kasachstan hilfreich. Forests are very important for people’s livelihood. They provide important ecosystem services and goods. However there are many threats that interfere with the normal functioning and development of forest ecosystems. The influence of climate change processes on functioning and dynamics of forests in Kazakhstan is understudied, and is observed in the relatively small number of dendroclimatic studies. Additional limitations in understanding of climate-growth relationships arise from insufficient spatial and temporal coverage of those studies and the absence of a qualitative analysis of already available information for identification of common patterns and differences in the impacts of tree growth on climate. The main research goal of this thesis was accordingly to address these limitations. An analysis of all available publications on dendroclimatic studies in Kazakhstan was performed. This analysis not only summarized the available information on climate-growth relationships, but also provided certain information about existed research gaps. Some of those gaps were addressed by an investigation of variation of climate-growth relationships of Schrenk spruce in the Ile River basin. The study revealed certain differences in reaction of earlywood, latewood and total ring width on climate in four mountain ranges of the Ile River basin. The strong influence of climate change was observed in a decreasing temperature signal around the 1970s. Revealed periodicities in the fluctuation of tree-ring indices suggested an influence of certain climate indices such as North Atlantic Oscillation and the Tropospheric Biennial Oscillations. Collectively, the analysis in this dissertation contributes to development of the tree-ting network of Kazakhstan. Obtained information should help in assessment of possible impacts of climate change on Schrenk spruce forests in Kazakhstan.
- Published
- 2020
32. Multi-centennial reconstruction of drought events in South-Western Iran using tree rings of Mediterranean cypress (Cupressus sempervirens L.).
- Author
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Arsalani, Mohsen, Grießinger, Jussi, Pourtahmasi, Kambiz, and Bräuning, Achim
- Subjects
- *
TREE-rings , *CYPRESS , *LITTLE Ice Age , *ARID regions , *PRECIPITATION variability , *PRECIPITATION gauges - Abstract
Semi-arid regions are among the most vulnerable areas prone to the negative impacts of climate change. Long-term high-resolution proxy climate data will enable us to put the recent climate trends into a long-term context of natural climate variability. We developed the hitherto first regional ring-width chronology (1450–2015C.E.) from Cupressus sempervirens L. in the Zagros Mountains, western Iran and reconstructed precipitation variability for the semi-arid region during the period 1560–2015C.E. Climate-growth relationships revealed that precipitation and minimum temperatures are positively correlated with radial growth, whereas maximum temperatures reveal negative impacts. Spatial correlations with gridded precipitation data, Palmer drought severity index (PDSI), and standardized precipitation-evapotranspiration index (SPEI 01) further indicate that the climate signals contained in tree-ring width variations capture the precipitation variability in the Near East and other eastern Mediterranean regions. The southern Zagros Mts. experienced multiple megadroughts during the reconstructed period. The longest dry period occurred from 1956 to 1971 and the highest frequency of dry events occurred in the 20th century. In addition, documented famines in Iran occurred within prolonged droughts. The southern Zagros Mts. has experienced high frequency of extreme/severe dry events and long dry phases during the Little Ice Age (1560–1850C.E.). The reconstructed dry and wet events occurred irregularly, and one-year and two-year drought/wet events showed the highest frequency during the reconstructed period, highlighting the importance of sustainable water management strategies for the semi-arid southern Zagros region. • Mediterranean cypress are reliable proxies for climate reconstructions in SW Iran. • C. sempervirens growth is mainly limited by precipitation and maximum temperatures. • High frequencies of extreme dry and wet events have occurred in the 20th century. • One-year and two-year drought/wet years showed the highest frequencies. • Large-scale climate indices have strong influence on rainfall patterns in SW Iran. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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