Career:

• since 2009 Senior Scientist, Head of Dendrolaboratory, Section 4.6 Geomorphology, German Centre for GeoSciences GFZ

• 2008 Scientist at the Institute for Chemistry and Dynamics of the Geosphere, ICG-3 Phytosphere, Helmholtz Centre Jülich, 52428 Jülich, Germany   

• 2005-2008 Group Leader “Tree-ring stable isotopes” at the Institute for Chemistry and Dynamics of the Geosphere, ICG-4 Sedimentary Systems, Helmholtz Centre Jülich

• 2000-2005 Research Group Leader and Co-Ordinator of the young researchers network project  “ TRICE – Tree-Rings, Isotopes, Climate and Environment”, at the Institute for Chemistry and Dynamics of the Geosphere, ICG-4 Sedimentary Systems, Helmholtz Centre Jülich, funded by the German Federal Ministry for Education and Research (BMBF) within the German Climate Research Programme DEKLIM

• 1998-2000 PostDoc at the Institute for Chemistry and Dynamics of the Geosphere, ICG-4 Sedimentary Systems (Prof. Dr. G.H. Schleser), Helmholtz Centre Jülich, Germany (special leave from MünsterUniversity)

• 1997-1998 Assistant lecturer at the Chair of Palaeontology (Prof. F. Strauch), University of Münster, Germany    

• 1997 Young scientist at the Chair of Palaeontology, Institute for Geology & Palaeontology, University of Tübingen, Germany

Education:

• 1997 Dissertation (Dr. rer. nat.) in Geosciences, Department 14: GeoSciences, University of Münster, Germany Title: "Hochauflösende intra-annuelle Kohlenstoff-Isotopenuntersuchungen an Baumjahresringen"

• 1994 Diploma in Geology & Palaeontology, Department 14: GeoSciences, University of Münster,  Germany

Research Boards and Committees:

since 2012 Member of the board of Association for Tree-ring Research (ATR) (treasurer)

2001 Founding Member of the Association for Tree-ring Research (ATR)

2013 – 2016 Introduction to Dendrochronology. Lecture and practical training course.

FU Berlin, Geological Sciences, Palaeontology

Seit 2016 Introduction to Dendroclimatology. Lecture and practical training course.

FU Berlin, Geological Sciences, Palaeontology

since 2017 Introduction to Dendroclimatology. Lecture and practical training course.
FU Berlin, Geological Sciences, Palaeontology

Research Interests:  

• Stable isotope techniques with focus on invention and optimization of methodologies for high-resolution and high-throughput isotope analysis of tree-rings
• Climate signal and stable isotope transfer from atmosphere, soil and leaves into tree-rings
• Natural climate variability of the late Glacial/early Holocene period as well as the Common Era, i.e. the last 2000 years
• Stable isotope variability in tropical timber (Tropical dendroclimatology)
• Stable Isotope Dendroclimatology of South America (in cooperation with Pontifical Catholic University of Valparaíso, Chile and IANIGLA-CCT CONICET-Mendoza, Argentina)

Patents:

"Verfahren zur thermischen Umsetzung von Probenmaterial in Messgas". DE102010001677.2; WO2011/095639A1

2024

• Álvarez, C., Christie, D. A., González-Reyes, Á., Veblen, T. T., Helle, G., LeQuesne, C., Rodriguez-Caton, M., Szejner, P., Flores-Sáez, F., Gipoulou-Zúñiga, T., Suazo-Álvarez, M., Muñoz-Salazar, T., Aliste, D., Morales, M. S., Muñoz, A., Villalba, R. (2024): Hydroclimate variability in the Tropical Andes recorded by δ18O isotopes from a new network of Polylepis tarapacana tree-rings. - Global and Planetary Change, 239, 104503. https://doi.org/10.1016/j.gloplacha.2024.104503
• Nagavciuc, V., Michel, S. L. L., Balting, D. F., Helle, G., Freund, M., Schleser, G. H., Steger, D. N., Lohmann, G., Ionita, M. (2024): A past and present perspective on the European summer vapor pressure deficit. - Climate of the Past, 20, 3, 573-595. https://doi.org/10.5194/cp-20-573-2024
• Treydte, K., Liu, L., Padrón, R. S., Martínez-Sancho, E., Babst, F., Frank, D. C., Gessler, A., Kahmen, A., Poulter, B., Seneviratne, S. I., Stegehuis, A. I., Wilson, R., Andreu-Hayles, L., Bale, R., Bednarz, Z., Boettger, T., Berninger, F., Büntgen, U., Daux, V., Dorado-Liñán, I., Esper, J., Friedrich, M., Gagen, M., Grabner, M., Grudd, H., Gunnarsson, B. E., Gutiérrez, E., Hafner, P., Haupt, M., Hilasvuori, E., Heinrich, I., Helle, G., Jalkanen, R., Jungner, H., Kalela-Brundin, M., Kessler, A., Kirchhefer, A., Klesse, S., Krapiec, M., Levanič, T., Leuenberger, M., Linderholm, H. W., McCarroll, D., Masson-Delmotte, V., Pawelczyk, S., Pazdur, A., Planells, O., Pukiene, R., Rinne-Garmston, K. T., Robertson, I., Saracino, A., Saurer, M., Schleser, G. H., Seftigen, K., Siegwolf, R. T. W., Sonninen, E., Stievenard, M., Szychowska-Krapiec, E., Szymaszek, M., Todaro, L., Waterhouse, J. S., Weigl-Kuska, M., Weigt, R. B., Wimmer, R., Woodley, E. J., Vitas, A., Young, G., Loader, N. J. (2024): Recent human-induced atmospheric drying across Europe unprecedented in the last 400 years. - Nature Geoscience, 17, 58-65. https://doi.org/10.1038/s41561-023-01335-8

2023

• Freund, M., Helle, G., Balting, D., Ballis, N., Schleser, G. H., Cubasch, U. (2023): European tree-ring isotopes indicate unusual recent hydroclimate. - Communications Earth and Environment, 4, 26. https://doi.org/10.1038/s43247-022-00648-7
• Helle, G., Brauer, A., Heinrich, I. (2023): Stable oxygen isotope ratios of tree-ring cellulose from oak (Quercus robur) at Lake Tiefer See, Mecklenburg Lake District, Northeastern Germany. https://doi.org/10.5880/tereno.trsi.2023.002
• Helle, G., Brauer, A., Heinrich, I. (2023): Stable carbon isotope ratios of tree-ring cellulose from oak (Quercus robur) at Lake Tiefer See, Mecklenburg Lake District, Northeastern Germany. https://doi.org/10.5880/tereno.trsi.2023.001
• ISONET Project Members, Schleser, G. H., Andreu-Hayles, L., Bednarz, Z., Berninger, F., Boettger, T., Dorado-Liñán, I., Esper, J., Grabner, M., Gutiérrez, E., Helle, G., Hilasvuori, E., Jugner, H., Kalela-Brundin, M., Krąpiec, M., Leuenberger, M., Loader, N. J., Masson-Delmotte, V., Pawełczyk, S., Pazdur, A., Pukienė, R., Rinne-Garmston, K. T., Saracino, A., Sauerer, M., Sonninen, E., Stiévenard, M., Switsur, V. R., Szychowska-Krąpiec, E., Szczepanek, M., Todaro, L., Treydte, K., Vitad, A., Waterhouse, J. S., Weigl-Kuska, M., Wimmer, R. (2023): Stable carbon isotope ratios of tree-ring cellulose from the site network of the EU-Project ‘ISONET’. https://doi.org/10.5880/GFZ.4.3.2023.002
• ISONET Project Members, Schleser, G. H., Andreu-Hayles, L., Bednarz, Z., Berninger, F., Boettger, T., Dorado-Liñán, I., Esper, J., Grabner, M., Gutiérrez, E., Helle, G., Hilasvuori, E., Jugner, H., Kalela-Brundin, M., Krąpiec, M., Leuenberger, M., Loader, N. J., Masson-Delmotte, V., Pawełczyk, S., Pazdur, A., Pukienė, R., Rinne-Garmston, K. T., Saracino, A., Saurer, M., Sonninen, E., Stiévenard, M., Switsur, V. R., Szychowska-Krąpiec, E., Szczepanek, M., Todaro, L., Treydte, K., Vitas, A., Waterhouse, J. S., Weigl-Kuska, M., Wimmer, R. (2023): Stable oxygen isotope ratios of tree-ring cellulose from the site network of the EU-Project ‘ISONET’. https://doi.org/10.5880/GFZ.4.3.2023.001

2022

• Baker, J. C. A., Cintra, B. B. L., Gloor, M., Boom, A., Neill, D., Clerici, S., Leng, M. J., Helle, G., Brienen, R. J. W. (2022): The Changing Amazon Hydrological Cycle—Inferences From Over 200 Years of Tree‐Ring Oxygen Isotope Data. - Journal of Geophysical Research: Biogeosciences, 127, 10, e2022JG006955. https://doi.org/10.1029/2022JG006955
• Brauer, A., Heinrich, I., Schwab, M. J., Plessen, B., Brademann, B., Köppl, M., Pinkerneil, S., Balanzategui, D., Helle, G., Blume, T. (2022): Lakes and trees as climate and environment archives: the TERENO Northeastern German Lowland Observatory. - DEUQUA Special Publications, 4, 41-58.https://doi.org/10.5194/deuquasp-4-41-2022
• Brienen, R., Helle, G., Pons, T., Boom, A., Gloor, M., Groenendijk, P., Clerici, S., Leng, M., Jones, C. (2022): Paired analysis of tree ring width and carbon isotopes indicates when controls on tropical tree growth change from light to water limitations. - Tree Physiology, 42, 6, 1131-1148. https://doi.org/10.1093/treephys/tpab142
• Chakraborty, T., Reif, A., Matzarakis, A., Helle, G., Faßnacht, F., Saha, S. (2022): Carbon and oxygen dual-isotopes in tree rings indicate alternative physiological responses opted by European beech trees to survive drought stress. - Scandinavian Journal of Forest Research, 37, 5-8, 295-313. https://doi.org/10.1080/02827581.2022.2155236
• Kwiecien, O., Braun, T., Brunello, C. F., Faulkner, P., Hausmann, N., Helle, G., Hoggarth, J. A., Ionita, M., Jazwa, C. S., Kelmelis, S., Marwan, N., Nava-Fernandez, C., Nehme, C., Opel, T., Oster, J. L., Perşoiu, A., Petrie, C., Prufer, K., Saarni, S. M., Wolf, A., Breitenbach, S. F. (2022): What we talk about when we talk about seasonality – A transdisciplinary review. - Earth-Science Reviews, 225, 103843. https://doi.org/10.1016/j.earscirev.2021.103843
• Vitali, V., Martínez-Sancho, E., Treydte, K., Andreu-Hayles, L., Dorado-Liñán, I., Gutierrez, E., Helle, G., Leuenberger, M., Loader, N. J., Rinne-Garmston, K. T., Schleser, G. H., Allen, S., Waterhouse, J. S., Saurer, M., Lehmann, M. M. (2022): The unknown third – Hydrogen isotopes in tree-ring cellulose across Europe. - Science of the Total Environment, 813, 152281. https://doi.org/10.1016/j.scitotenv.2021.152281
• Zuidema, P. A., Babst, F., Groenendijk, P., Trouet, V., Abiyu, A., Acuña-Soto, R., Adenesky-Filho, E., Alfaro-Sánchez, R., Aragão, J. R. V., Assis-Pereira, G., Bai, X., Barbosa, A. C., Battipaglia, G., Beeckman, H., Botosso, P. C., Bradley, T., Bräuning, A., Brienen, R., Buckley, B. M., Camarero, J. J., Carvalho, A., Ceccantini, G., Centeno-Erguera, L. R., Cerano-Paredes, J., Chávez-Durán, Á. A., Cintra, B. B. L., Cleaveland, M. K., Couralet, C., D’Arrigo, R., del Valle, J. I., Dünisch, O., Enquist, B. J., Esemann-Quadros, K., Eshetu, Z., Fan, Z.-X., Ferrero, M. E., Fichtler, E., Fontana, C., Francisco, K. S., Gebrekirstos, A., Gloor, E., Granato-Souza, D., Haneca, K., Harley, G. L., Heinrich, I., Helle, G., Inga, J. G., Islam, M., Jiang, Y.-m., Kaib, M., Khamisi, Z. H., Koprowski, M., Kruijt, B., Layme, E., Leemans, R., Leffler, A. J., Lisi, C. S., Loader, N. J., Locosselli, G. M., Lopez, L., López-Hernández, M. I., Lousada, J. L. P. C., Mendivelso, H. A., Mokria, M., Montóia, V. R., Moors, E., Nabais, C., Ngoma, J., Nogueira Júnior, F. d. C., Oliveira, J. M., Olmedo, G. M., Pagotto, M. A., Panthi, S., Pérez-De-Lis, G., Pucha-Cofrep, D., Pumijumnong, N., Rahman, M., Ramirez, J. A., Requena-Rojas, E. J., Ribeiro, A. d. S., Robertson, I., Roig, F. A., Rubio-Camacho, E. A., Sass-Klaassen, U., Schöngart, J., Sheppard, P. R., Slotta, F., Speer, J. H., Therrell, M. D., Toirambe, B., Tomazello-Filho, M., Torbenson, M. C. A., Touchan, R., Venegas-González, A., Villalba, R., Villanueva-Diaz, J., Vinya, R., Vlam, M., Wils, T., Zhou, Z.-K. (2022): Tropical tree growth driven by dry-season climate variability. - Nature Geoscience, 15, 269-276. https://doi.org/10.1038/s41561-022-00911-8
• Helle, G., Pauly, M., Heinrich, I., Schollaen, K., Balanzategui, D., Schürheck, L. (2022): Stable isotope signatures of wood, its constituents and methods of cellulose extraction. - In: Siegwolf, R. T. W., Brooks, J. R., Roden, J., Saurer, M. (Eds.), Stable Isotopes in Tree Rings, (Tree Physiology book series ; 8), Cham : Springer International Publishing, 135-190. https://doi.org/10.1007/978-3-030-92698-4_5
• Rinne-Garmston, K. T., Helle, G., Lehmann, M. M., Sahlstedt, E., Schleucher, J., Waterhouse, J. S. (2022): Newer developments in tree-ring stable isotope methods. - In: Siegwolf, R. T. W., Brooks, J. R., Roden, J., Saurer, M. (Eds.), Stable Isotopes in Tree Rings, (Tree Physiology book series  ; 8), Cham : Springer International Publishing, 215-249. https://doi.org/10.1007/978-3-030-92698-4_7

2021

• Balting, D. F., Ionita, M., Wegmann, M., Helle, G., Schleser, G. H., Rimbu, N., Freund, M. B., Heinrich, I., Caldarescu, D., Lohmann, G. (2021): Large-scale climate signals of a European oxygen isotope network from tree rings. - Climate of the Past, 17, 3, 1005-1023. https://doi.org/10.5194/cp-17-1005-2021
• Macieira, B. P. B., Locosselli, G. M., Buckeridge, M. S., Jardim, V. C., Krottenthaler, S., Anhuf, D., Helle, G., Cuzzuol, G. R. F., Ceccantini, G. (2021): Will climate change shift carbon allocation and stem hydraulics? Insights on a systemic view of carbon- and water-related wood traits in an anysohydric tropical tree species (Hymenaea courbaril, Leguminosae). - Ecological Indicators, 128, 107798. https://doi.org/10.1016/j.ecolind.2021.107798
• Mohr, C. H., Manga, M., Helle, G., Heinrich, I., Giese, L., Korup, O. (2021): Trees Talk Tremor—Wood Anatomy and δ13C Content Reveal Contrasting Tree‐Growth Responses to Earthquakes. - Journal of Geophysical Research: Biogeosciences, 126, 10, e2021JG006385. https://doi.org/10.1029/2021JG006385
• Müller, C., Hennig, J., Riedel, F., Helle, G. (2021): Quantifying the impact of chemicals on stable carbon and oxygen isotope values of raw pollen. - Journal of Quaternary Science, 36, 3, 441-449. https://doi.org/10.1002/jqs.3300
• Pauly, M., Turney, C. S. M., Palmer, J. G., Büntgen, U., Brauer, A., Helle, G. (2021): Kauri tree‐ring stable isotopes reveal a centennial climate downturn following the Antarctic Cold Reversal in New Zealand. - Geophysical Research Letters, 48, 2, e2020GL090299. https://doi.org/10.1029/2020GL090299
• Slotta, F., Wacker, L., Riedel, F., Heußner, K.-U., Hartmann, K., Helle, G. (2021): High-resolution 14C bomb peak dating and climate response analyses of subseasonal stable isotope signals in wood of the African baobab – a case study from Oman. - Biogeosciences, 18, 12, 3539-3564. https://doi.org/10.5194/bg-18-3539-2021
• 2020
• Müller, C., Hethke, M., Riedel, F., Helle, G. (2020): Inter- and intra-tree variability of carbon and oxygen stable isotope ratios of modern pollen from nine European tree species. - Plos One, 15, 6, e0234315.
• https://doi.org/10.1371/journal.pone.0234315
• Pauly, M., Helle, G., Büntgen, U., Wacker, L., Treydte, K., Reinig, F., Turney, C., Nievergelt, D., Kromer, B., Friedrich, M., Sookdeo, A., Heinrich, I., Riedel, F., Balting, D., Brauer, A. (2020): An annual-resolution stable isotope record from Swiss subfossil pine trees growing in the late Glacial. - Quaternary Science Reviews, 247, 106550. https://doi.org/10.1016/j.quascirev.2020.106550
• Reinig, F., Sookdeo, A., Esper, J., Friedrich, M., Guidobaldi, G., Helle, G., Kromer, B., Nievergelt, D., Pauly, M., Tegel, W., Treydte, K., Wacker, L., Büntgen, U. (2020): Illuminating IntCal during the Younger Dryas. - Radiocarbon, 62, 4, 883-889. https://doi.org/10.1017/RDC.2020.15GFZPublicVolltext (PDF)
• Sookdeo, A., Kromer, B., Büntgen, U., Friedrich, M., Friedrich, R., Helle, G., Pauly, M., Nievergelt, D., Reinig, F., Treydte, K., Synal, H.-A., Wacker, L. (2020): Quality dating: a well-defined protocol implemented at ETH for high-precision 14C-Dates tested on late glacial wood. - Radiocarbon, 62, 4, 891-899. https://doi.org/10.1017/RDC.2019.132

2019

Paper (SCI/Scopus journals)

• Andreu-Hayles, L., Levesque, M., Martin-Benito, D., Huang, W., Harris, R., Oelkers, R., Leland, C., Martin-Fernández, J., Anchukaitis, K. J., Helle, G. (2019): A high yield cellulose extraction system for small whole wood samples and dual measurement of carbon and oxygen stable isotopes. - Chemical Geology, 504, pp. 53-65. DOI: http://doi.org/10.1016/j.chemgeo.2018.09.007
• Arco Molina, J. G., Helle, G., Hadad, M. A., Roig, F. A. (2019): Variations in the intrinsic water-use efficiency of north Patagonian forests under a present climate change scenario: tree age, site conditions and long-term environmental effects. - Tree Physiology, 39, 4, pp. 661-678. DOI: http://doi.org/10.1093/treephys/tpy144
• Brunello, C. F., Andermann, C., Helle, G., Comiti, F., Tonon, G., Tiwari, A., Hovius, N. (2019): Hydroclimatic seasonality recorded by tree ring δ18O signature across a Himalayan altitudinal transect. - Earth and Planetary Science Letters, 518, pp. 148-159. DOI: http://doi.org/10.1016/j.epsl.2019.04.030
• Grießinger, J., Bräuning, A., Helle, G., Schleser, G., Hochreuther, P., Meier, W., Zhu, H. (2019): A Dual Stable Isotope Approach Unravels Common Climate Signals and Species-Specific Responses to Environmental Change Stored in Multi-Century Tree-Ring Series from the Tibetan Plateau. - Geosciences, 9, 4, 151. DOI: http://doi.org/10.3390/geosciences9040151
• Shestakova, T. A., Voltas, J., Saurer, M., Berninger, F., Esper, J., Andreu‐Hayles, L., Daux, V., Helle, G., Leuenberger, M., Loader, N. J., Masson‐Delmotte, V., Saracino, A., Waterhouse, J. S., Schleser, G. H., Bednarz, Z., Boettger, T., Dorado‐Liñán, I., Filot, M., Frank, D., Grabner, M., Haupt, M., Hilasvuori, E., Jungner, H., Kalela‐Brundin, M., Krąpiec, M., Marah, H., Pawełczyk, S., Pazdur, A., Pierre, M., Planells, O., Pukienė, R., Reynolds‐Henne, C. E., Rinne‐Garmston (Rinne), K. T., Rita, A., Sonninen, E., Stiévenard, M., Switsur, V. R., Szychowska‐Kra̧piec, E., Szymaszek, M., Todaro, L., Treydte, K., Vitas, A., Weigl, M., Wimmer, R., Gutiérrez, E., Hickler, T. (2019): Spatio‐temporal patterns of tree growth as related to carbon isotope fractionation in European forests under changing climate. - Global Ecology and Biogeography, 28, 9, pp. 1295-1309. DOI: http://doi.org/10.1111/geb.12933

Paper (Other journals)

• Heinrich, I., Balanzategui, D., Bens, O., Blume, T., Brauer, A., Dietze, E., Gottschalk, P., Güntner, A., Harfenmeister, K., Helle, G., Hohmann, C., Itzerott, S., Kaiser, K., Liebner, S., Merz, B., Pinkerneil, S., Plessen, B., Sachs, T., Schwab, M. J., Spengler, D., Vallentin, C., Wille, C. (2019): Regionale Auswirkungen des Globalen Wandels: Der Extremsommer 2018 in Nordostdeutschland. - System Erde, 9, 1 DOI: http://doi.org/10.2312/GFZ.syserde.09.01.6

2018

Paper (SCI/Scopus journals)

• Balanzategui, D., Knorr, A., Heussner, K., Wazny, T., Beck, W., Slowinski, M., Helle, G., Buras, A., Wilmking, M., Van Der Maaten, E., Scharnweber, T., Dorado-Liñán, I., Heinrich, I. (2018): An 810-year history of cold season temperature variability for northern Poland. - Boreas, 47, 2, pp. 443-453. DOI: http://doi.org/10.1111/bor.12274
• Martínez-Sancho, E., Dorado-Liñán, I., Gutiérrez Merino, E., Matiu, M., Helle, G., Heinrich, I., Menzel, A. (2018): Increased water-use efficiency translates into contrasting growth patterns of Scots pine and sessile oak at their southern distribution limits. - Global Change Biology, 24, 3, pp. 1012-1028. DOI: http://doi.org/10.1111/gcb.13937
•  Meyer, M., Krabel, D., Kniesel, B., Helle, G. (2018): Inter-annual variation of tree-ring width, δ13C and δ18O in juvenile trees of five plantation poplar cultivars (Populus spp.). - Dendrochronologia, 51, pp. 32-39. DOI: http://doi.org/10.1016/j.dendro.2018.07.002
• Pauly, M., Helle, G., Miramont, C., Büntgen, U., Treydte, K., Reinig, F., Guibal, F., Sivan, O., Heinrich, I., Riedel, F., Kromer, B., Balanzategui, D., Wacker, L., Sookdeo, A., Brauer, A. (2018): Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas. - Scientific Reports, 8, 13980. DOI: http://doi.org/10.1038/s41598-018-32251-2
• Reinig, F., Nievergelt, D., Esper, J., Friedrich, M., Helle, G., Hellmann, L., Kromer, B., Morganti, S., Pauly, M., Sookdeo, A., Tegel, W., Treydte, K., Verstege, A., Wacker, L., Büntgen, U. (2018): New tree-ring evidence for the Late Glacial period from the northern pre-Alps in eastern Switzerland. - Quaternary Science Reviews, 186, pp. 215-224. DOI: http://doi.org/10.1016/j.quascirev.2018.02.019
• Turney, C. S. M., Palmer, J., Maslin, M. A., Hogg, A., Fogwill, C. J., Southon, J., Fenwick, P., Helle, G., Wilmshurst, J. M., McGlone, M., Bronk Ramsey, C., Thomas, Z., Lipson, M., Beaven, B., Jones, R. T., Andrews, O., Hua, Q. (2018): Global Peak in Atmospheric Radiocarbon Provides a Potential Definition for the Onset of the Anthropocene Epoch in 1965. - Scientific Reports, 8, 3293. DOI: http://doi.org/10.1038/s41598-018-20970-5

2017

Paper (SCI/Scopus journals)

• Andreu-Hayles, L., Ummenhofer, C. C., Barriendos, M., Schleser, G. H., Helle, G., Leuenberger, M., Gutiérrez, E., Cook, E. R. (2017): 400 Years of summer hydroclimate from stable isotopes in Iberian trees. - Climate Dynamics, 49, 1, pp. 143-161. DOI: http://doi.org/10.1007/s00382-016-3332-z
• Ben, T., Hart, P. J., Helle, G. (2017): Towards establishing a new environmental archive – Annual growth periodicity, stable carbon isotope variability and reconstruction potential of 'Akoko (Euphorbia olowaluana), a native Hawaiian tree with C4 photosynthetic pathway. - Erdkunde, 71, 1, pp. 77-92. DOI: http://doi.org/10.3112/erdkunde.2017.01.05
• Brienen, R. J. W., Gloor, E., Clerici, S., Newton, R., Arppe, L., Boom, A., Bottrell, S., Callaghan, M., Heaton, T., Helama, S., Helle, G., Leng, M. J., Mielikäinen, K., Oinonen, M., Timonen, M. (2017): Tree height strongly affects estimates of water-use efficiency responses to climate and CO2 using isotopes. - Nature Communications, 8, 288. DOI: http://doi.org/10.1038/s41467-017-00225-z
• Grießinger, J., Bräuning, A., Helle, G., Hochreuther, P., Schleser, G. (2017): Late Holocene relative humidity history on the southeastern Tibetan plateau inferred from a tree-ring δ18O record: Recent decrease and conditions during the last 1500 years. - Quaternary International, 430, pp. 52-59. DOI: http://doi.org/10.1016/j.quaint.2016.02.011
• Martínez-Sancho, E., Dorado-Liñán, I., Heinrich, I., Helle, G., Menzel, A. (2017): Xylem adjustment of sessile oak at its southern distribution limits. - Tree Physiology, 37, 7, pp. 903-914. DOI: http://doi.org/10.1093/treephys/tpx036
• Saracino, A., Rita, A., Rossi, S., Andreu-Hayles, L., Helle, G., Todaro, L. (2017): Climatic signal from Pinus leucodermis axial resin ducts: a tree-ring time series approach. - European Journal of Forest Research, 136, 1, pp. 27-36. DOI: http://doi.org/10.1007/s10342-016-1005-4
• Schollaen, K., Baschek, H., Heinrich, I., Slotta, F., Pauly, M., Helle, G. (2017): A guideline for sample preparation in modern tree-ring stable isotope research. - Dendrochronologia, 44, pp. 133-145. DOI: http://doi.org/10.1016/j.dendro.2017.05.002
• Slotta, F., Helle, G., Heußner, K., Shemang, E., Riedel, F. (2017): Baobabs on Kubu Island, Botswana – A dendrochronological multi-parameter study using ring width and stable isotopes (δ13C, δ18O). - Erdkunde, 71, 1, pp. 23-43. DOI: http://doi.org/10.3112/erdkunde.2017.01.02

Paper (Other journals)

• Plessen, B., Helle, G. (2017): Vom Monitoring zum Klimaarchiv : Sauerstoffisotope in der Paläoklimatologie . - System Erde, 7, 1 DOI: http://doi.org/10.2312/GFZ.syserde.07.01.2

Report

• Wistuba, M., Cedro, A., Malik, I., Helle, G., Gärtner, H.(2017): Proceedings of the DENDROSYMPOSIUM 2016 : May 11th - 15th, 2016 in Białowieża, Poland, (Scientific Technical Report STR ; 17) , 15th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) (Białowieża, Poland 2016), GFZ German Research Centre for Geosciences : Potsdam, 133 p. DOI: http://doi.org/10.2312/GFZ.b103-17040

2016

Paper (SCI/Scopus journals)

• Buras, A., van der Maaten-Theunissen, M., van der Maaten, E., Ahlgrimm, S., Hermann, P., Simard, S., Heinrich, I., Helle, G., Unterseher, M., Schnittler, M., Eusemann, P., Wilmking, M., Guralnick, R. (2016): Tuning the Voices of a Choir: Detecting Ecological Gradients in Time-Series Populations. - Plos One, 11, 7. DOI: http://doi.org/10.1371/journal.pone.0158346
• Dorado-Liñán, I., Sanchez-Lorenzo, A., Gutiérrez Merino, E., Planells, O., Heinrich, I., Helle, G., Zorita, E. (2016): Changes in surface solar radiation in Northeastern Spain over the past six centuries recorded by tree-ring δ13C. - Climate Dynamics, 47, 3, pp. 937-950. DOI: http://doi.org/10.1007/s00382-015-2881-x
• Hogg, A., Southon, J., Turney, C., Palmer, J., Bronk Ramsey, C., Fenwick, P., Boswijk, G., Büntgen, U., Friedrich, M., Helle, G., Hughen, K., Jones, R., Kromer, B., Noronha, A., Reinig, F., Reynard, L., Staff, R., Wacker, L. (2016): Decadally Resolved Lateglacial Radiocarbon Evidence from New Zealand Kauri. - Radiocarbon, 58, 4, pp. 709-733. DOI: http://doi.org/10.1017/RDC.2016.86
• Hogg, A., Southon, J., Turney, C., Palmer, J., Bronk Ramsey, C., Fenwick, P., Boswijk, G., Friedrich, M., Helle, G., Hughen, K., Jones, R., Kromer, B., Noronha, A., Reynard, L., Staff, R., Wacker, L. (2016): Punctuated Shutdown of Atlantic Meridional Overturning Circulation during Greenland Stadial 1. - Scientific Reports, 6, 25902. DOI: http://doi.org/10.1038/srep25902
• Hogg, A., Southon, J., Turney, C., Palmer, J., Ramsey, C. B., Fenwick, P., Boswijk, G., Buntgen, U., Friedrich, M., Helle, G., Hughen, K., Jones, R., Kromer, B., Noronha, A., Reinig, F., Reynard, L., Staff, R., Wacker, L. (2016): Decadally Resolved Lateglacial Radiocarbon Evidence from New Zealand Kauri – CORRIGENDUM. - Radiocarbon, 58, p. 947. DOI: http://doi.org/10.1017/RDC.2016.108
• Palmer, J. G., Turney, C. S., Cook, E. R., Fenwick, P., Thomas, Z., Helle, G., Jones, R., Clement, A., Hogg, A., Southon, J., Bronk Ramsey, C., Staff, R., Muscheler, R., Corrège, T., Hua, Q. (2016): Changes in El Niño – Southern Oscillation (ENSO) conditions during the Greenland Stadial 1 (GS-1) chronozone revealed by New Zealand tree-rings. - Quaternary Science Reviews, 153, pp. 139-155. DOI: http://doi.org/10.1016/j.quascirev.2016.10.003
• Pritzkow, C., Wazny, T., Heußner, K. U., Slowinski, M., Bieber, A., Liñán, I. D., Helle, G., Heinrich, I. (2016): Minimum winter temperature reconstruction from average earlywood vessel area of European oak (Quercus robur) in N-Poland. - Palaeogeography Palaeoclimatology Palaeoecology, 449, pp. 520-530. DOI: http://doi.org/10.1016/j.palaeo.2016.02.046
• Seim, A., Omurova, G., Azisov, E., Musuraliev, K., Aliev, K., Tulyaganov, T., Nikolyai, L., Botman, E., Helle, G., Dorado Liñan, I., Jivcov, S., Linderholm, H. W., Liang, E. (2016): Climate Change Increases Drought Stress of Juniper Trees in the Mountains of Central Asia. - Plos One, 11, 4. DOI: http://doi.org/10.1371/journal.pone.0153888
• Siegmund, J. F., Sanders, T. G. M., Heinrich, I., van der Maaten, E., Simard, S., Helle, G., Donner, R. V. (2016): Meteorological Drivers of Extremes in Daily Stem Radius Variations of Beech, Oak, and Pine in Northeastern Germany: An Event Coincidence Analysis. - Frontiers in Plant Science, 7, 733. DOI: http://doi.org/10.3389/fpls.2016.00733

Report

• Hevia, A., Sánchez-Salguero, R., Linares, J. C., Olano, J. M., Camarero, J. J., Gutiérrez, E., Helle, G., Gärtner, H.(2016): Proceedings of the DENDROSYMPOSIUM 2015 : May 20th - 23rd, 2015 in Sevilla, Spain, (Scientific Technical Report ; 16) , 14th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) (Sevilla, Spain 2015), GFZ German Research Centre for Geosciences : Potsdam, 152 p. DOI: http://doi.org/10.2312/GFZ.b103-16042

Conference Paper

• Heinrich, I., Balanzategui, D., Heußner, K., Pritzkow, C., Giese, L., Graaf, J., Lindemann, J., Schirmer, T., Dorado Liñán, I., Wazny, T., Scharnweber, T., van der Maaten, E., Helle, G., Blume, T., Pohlmann, S. (2016): A 911 year chronology from earlywood vessels of European oak in NE-Germany and its use for climate reconstructions, (Geophysical Research Abstracts, Vol. 18, EGU2016-15347) , General Assembly European Geosciences Union (Vienna, Austria 2016).
• Helle, G., Baschek, H., Heinrich, I., Navabzadeh, N., Riedel, F., Wilmking, M., Heußner, K. (2016): A 430 year record of hydroclimate variability for NE-Germany based on stable carbon and oxygen isotopes from pine and oak tree rings, (Geophysical Research Abstracts, Vol. 18, EGU2016-8008-2) , General Assembly European Geosciences Union (Vienna, Austria 2016).
• Siegmund, J., Sanders, T., Heinrich, I., Helle, G., Donner, R. (2016): Climatic Triggers of Extremes in Daily Beech, Oak and Pine Stem Diameter Growth and Shrinkage in Northeastern Germany: An Event Coincidence Analysis, (Geophysical Research Abstracts, Vol. 18, EGU2016-11768) , General Assembly European Geosciences Union (Vienna, Austria 2016).

2015

Paper (SCI/Scopus journals)

• Baker, J. C., Hunt, S. F., Clerici, S. J., Newton, R. J., Bottrell, S. H., Leng, M. J., Heaton, T. H., Helle, G., Argollo, J., Gloor, M., Brienen, R. J. (2015): Oxygen isotopes in tree rings show good coherence between species and sites in Bolivia. - Global and Planetary Change, 133, pp. 298-308. DOI: http://doi.org/10.1016/j.gloplacha.2015.09.008
• Frank, D. C., Poulter, B., Saurer, M., Esper, J., Huntingford, C., Helle, G., Treydte, K., Zimmermann, N. E., Schleser, G., Ahlström, A., Ciais, P., Friedlingstein, P., Levis, S., Lomas, M., Sitch, S., Viovy, N., Andreu-Hayles, L., Bednarz, Z., Berninger, F., Boettger, T., D‘Alessandro, C. M., Daux, V., Filot, M., Grabner, M., Gutierrez, E., Haupt, M., Hilasvuori, E., Jungner, H., Kalela-Brundin, M., Krapiec, M., Leuenberger, M., Loader, N. J., Marah, H., Masson-Delmotte, V., Pazdur, A., Pawelczyk, S., Pierre, M., Planells, O., Pukiene, R., Reynolds-Henne, C. E., Rinne, K. T., Saracino, A., Sonninen, E., Stievenard, M., Switsur, V. R., Szczepanek, M., Szychowska-Krapiec, E., Todaro, L., Waterhouse, J., Weigl, M. (2015): Water-use efficiency and transpiration across European forests during the Anthropocene. - Nature Climate Change, 5, 6, pp. 579-583. DOI: http://doi.org/10.1038/nclimate2614
• Krottenthaler, S., Pitsch, P., Helle, G., Locosselli, G. M., Ceccantini, G., Altman, J., Svoboda, M., Dolezal, J., Schleser, G., Anhuf, D. (2015): A power-driven increment borer for sampling high-density tropical wood. - Dendrochronologia, 36, pp. 40-44. DOI: http://doi.org/10.1016/j.dendro.2015.08.005
• Schleser, G., Anhuf, D., Helle, G., Vos, H. (2015): A remarkable relationship of the stable carbon isotopic compositions of wood and cellulose in tree-rings of the tropical species Cariniana micrantha (Ducke) from Brazil. - Chemical Geology, 401, pp. 59-66. DOI: http://doi.org/10.1016/j.chemgeo.2015.02.014
• Schollaen, K., Karamperidou, C., Krusic, P., Cook, E., Helle, G. (2015): ENSO flavors in a tree-ring δ18O record of Tectona grandis from Indonesia . - Climate of the Past, 11, 10, pp. 1325-1333. DOI: http://doi.org/10.5194/cp-11-1325-2015

Paper (Other journals)

• Schollaen, K., Baschek, H., Heinrich, I., Helle, G. (2015): Technical Note: An improved guideline for rapid and precise sample preparation of tree-ring stable isotope analysis . - Biogeosciences Discussions, 12 DOI: http://doi.org/10.5194/bgd-12-11587-2015

Report

• Wilson, R., Helle, G., Gärtner, H.(Eds.) (2015): Proceedings of the DENDROSYMPOSIUM 2014 : May 6th - 10th, Aviemore, Scotland, UK, (Scientific Technical Report ; 15) , 13th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) (Aviemore, Scotland 2014), Deutsches GeoForschungsZentrum GFZ : Potsdam, 122 p. DOI: http://doi.org/10.2312/GFZ.b103-15069

Conference Paper

• Buras, A., van der Maaten, E., Scharnweber, T., Simard, S., Heinrich, I., Helle, G., van der Maaten-Theunissen, M., Eusemann, P., Schnittler, M., Wilmking, M. (2015): Tuning the voices of a choir: Introducing a new tool to enhance the signals that are stored in tree-ring archives, (Geophysical Research Abstracts, Vol. 17, EGU2015-3303-1) , General Assembly European Geosciences Union (Vienna, Austria 2015).
• Dorado Liñán, I., Sanchez-Lorenzo, A., Gutiérrez Merino, E., Planells, O., Heinrich, I., Helle, G., Zorita, E. (2015): Changes in surface solar radiation in Northeastern Spain over the past six centuries recorded by tree-ring δ13C, (Geophysical Research Abstracts, Vol. 17, EGU2015-11723-1) , General Assembly European Geosciences Union (Vienna, Austria 2015).
• Heinrich, I., Knorr, A., Heußner, K., Wazny, T., Slowinski, M., Helle, G., Simard, S., Scharnweber, T., Buras, A., Beck, W., Wilmking, M., Brauer, A. (2015): Climate reconstructions from tree-ring widths for the last 850 years in Northern Poland, (Geophysical Research Abstracts, Vol. 17, EGU2015-1806) , General Assembly European Geosciences Union (Vienna, Austria 2015).
• Simard, S., Blume, T., Heidbüchel, I., Heinrich, I., Dreibrodt, J., Güntner, A., Helle, G. (2015): Interactions and feedbacks of a temperate lake ecosystem in NE Germany, (Geophysical Research Abstracts, Vol. 17, EGU2015-10912) , General Assembly European Geosciences Union (Vienna, Austria 2015).

2014

Paper (SCI/Scopus journals)

• Büntgen, U., Tegel, W., Kaplan, J. O., Schaub, M., Hagedorn, F., Bürgi, M., Brázdil, R., Helle, G., Carrer, M., Heussner, K., Hofmann, J., Kontic, R., Kyncl, T., Kyncl, J., Camarero, J. J., Tinner, W., Esper, J., Liebhold, A. (2014): Placing unprecedented recent fir growth in a European-wide and Holocene-long context. - Frontiers in Ecoloy and the Environment, 12, 2, pp. 100-106. DOI: http://doi.org/10.1890/130089
• Konter, O., Holzkämper, S., Helle, G., Büntgen, U., Saurer, M., Esper, J. (2014): Climate Sensitivity and Parameter Coherency in Annually Resolved δ13C and δ18O from Pinus uncinata Tree-Ring Data in the Spanish Pyrenees. - Chemical Geology, 377, pp. 12-19. DOI: http://doi.org/10.1016/j.chemgeo.2014.03.021
• Pieper, H., Heinrich, I., Heußner, K. U., Helle, G. (2014): The influence of volcanic eruptions on growth of central European lowland trees in NE-Germany during the last millennium. - Palaeogeography Palaeoclimatology Palaeoecology, 411, pp. 155-166. DOI: http://doi.org/10.1016/j.palaeo.2014.06.012
• Pritzkow, C., Heinrich, I., Grudd, H., Helle, G. (2014): Relationship between wood anatomy, tree-ring widths and wood density of Pinus sylvestris L. and climate at high latitudes in northern Sweden. - Dendrochronologia, 32, 4, pp. 295-302. DOI: http://doi.org/10.1016/j.dendro.2014.07.003
• Saurer, M., Spahni, R., Frank, D. C., Joos, F., Leuenberger, M., Loader, N. J., McCarroll, D., Gagen, M., Poulter, B., Siegwolf, R. T., Andreu-Hayles, L., Boettger, T., Dorado Liñán, I., Fairchild, I. J., Friedrich, M., Gutierrez, E., Haupt, M., Hilasvuori, E., Heinrich, I., Helle, G., Grudd, H., Jalkanen, R., Levanič, T., Linderholm, H. W., Robertson, I., Sonninen, E., Treydte, K., Waterhouse, J. S., Woodley, E. J., Wynn, P. M., Young, G. H. (2014): Spatial variability and temporal trends in water-use efficiency of European forests. - Global Change Biology, 20, 12, pp. 3700-3712. DOI: http://doi.org/10.1111/gcb.12717
• Schollaen, K., Heinrich, I., Helle, G. (2014): UV-laser-based microscopic dissection of tree rings - a novel sampling tool for δ13C and δ18O studies . - New Phytologist, 201, 3, pp. 1045-1055. DOI: http://doi.org/10.1111/nph.12587
• van der Sleen, P., Soliz-Gamboa, C. C., Helle, G., Pons, T. L., Anten, N. P. R., Zuidema, P. A. (2014): Understanding causes of tree growth response to gap formation: ∆13C-values in tree rings reveal a predominant effect of light. - Trees - Structure and Function, 28, 2, pp. 439-448. DOI: http://doi.org/10.1007/s00468-013-0961-2

Report

• Di Filippo, A., Piovesan, G., Romagnoli, M., Helle, G., Gärtner, H.(Eds.) (2014): Proceedings of the DENDROSYMPOSIUM 2013 : May 8th - 11th, 2013 in Viterbo, Italy, (Scientific Technical Report ; 14) , 12th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) (Viterbo, Italy 2013), Deutsches GeoForschungsZentrum GFZ : Potsdam, 138 p. DOI: http://doi.org/10.2312/GFZ.b103-14055

 
Conference Paper

• Kaplick, J., Fenwick, P., Helle, G. (2014): δ18O and δ13C floating chronologies from Late-Glacial New Zealand kauri (Agathis australis), (Conference Program Book) , 9th International Conference on Dendrochronology (Melbourne 2014) (Melbourne, Australia 2014), p. 63.
• Liang, W., Heinrich, I., Helle, G. (2014): Confocal laser scanning microscopy for deriving climate signals from cell anatomy of Scots pine, (Conference Program Book) , 9th International Conference on Dendrochronology (Melbourne 2014) (Melbourne, Australia 2014), p. 74.
• Pieper, H., Brauer, A., Kaiser, K., Miramont, C., Nievergelt, D., Büntgen, U., Helle, G. (2014): Is Lateglacial/Early Holocene climate variability reflected in annually resolved tree-ring stable isotope chronologies from Central Europe?, (Conference Program Book) , 9th International Conference on Dendrochronology (Melbourne 2014) (Melbourne, Australia 2014), pp. 96-97.
• Pieper, H., Brauer, A., Miramont, C., Nievergelt, D., Büntgen, U., Helle, G. (2014): Annually resolved stable isotope chronologies from Lateglacial Central European tree rings, (Geophysical Research Abstracts, Vol. 16, EGU2014-883-8, 2014) , General Assembly European Geosciences Union (Vienna, Austria 2014).
• Schollaen, K., Karamperidou, K., Helle, G. (2014): ENSO flavors in a tree-ring δ18O record from Indonesia, (Geophysical Research Abstracts, Vol. 16, EGU2014-4550, 2014) , General Assembly European Geosciences Union (Vienna, Austria 2014).
• Schollaen, K., Karamperidou, C., Helle, G. (2014): ENSO flavors in a tree-ring δ18O record of Tectona grandis from Indonesia, (Conference Program Book) , 9th International Conference on Dendrochronology (Melbourne 2014) (Melbourne, Australia 2014), p. 101.
• Simard, S., Heinrich, I., Helle, G., Blume, T., Güntner, A. (2014): Dynamic tree growth response to changing climatic and hydrological conditions in temperate forest , (Conference Program Book) , 9th International Conference on Dendroclimatology (Melbourne 2014) (Melbourne, Australia 2014), p. 106.
• Simard, S., Heinrich, I., Pohlmann, S., Buras, A., Scharnweber, T., van der Maaten, E., Wilmking, M., Helle, G. (2014): Similarities and discrepancies of sessile oak performance along a topographic gradient, (Geophysical Research Abstracts, Vol. 16, EGU2014-14180, 2014) , General Assembly European Geosciences Union (Vienna, Austria 2014).
• Slotta, F., Riedel, F., Heubner, K., Helle, G. (2014): The African Baobab - a high-resolution archive for climate variability of semi-arid Africa?, (Conference Program Book) , 9th International Conference on Dendroclimatology (Melbourne 2014) (Melbourne, Australia 2014), p. 107.

2013

Paper (SCI/Scopus journals)

• Dorado Liñán, I., Gutiérrez, E., Andreu-Hayles, L., Heinrich, I., Helle, G. (2013): Potential to explain climate from tree rings in the south of the Iberian Peninsula. - Climate Research, 55, 2, pp. 121-136. DOI: http://doi.org/10.3354/cr01126
• Heinrich, I., Touchan, R., Dorado Liñán, I., Vos, H., Helle, G. (2013): Winter-to-spring temperature dynamics in Turkey derived from tree rings since AD 1125. - Climate Dynamics, 41, 7, pp. 1685-1701. DOI: http://doi.org/10.1007/s00382-013-1702-3
• Liang, W., Heinrich, I., Helle, G., Dorado Liñán, I., Heinken, T. (2013): Applying CLSM to increment core surfaces for histometric analyses: A novel advance in quantitative wood anatomy. - Dendrochronologia, 31, 2, pp. 140-145. DOI: http://doi.org/10.1016/j.dendro.2012.09.002
• Liang, W., Heinrich, I., Simard, S., Helle, G., Dorado Liñán, I., Heinken, T. (2013): Climate signals derived from cell anatomy of Scots pine in NE Germany. - Tree Physiology, 33, 8, pp. 833-844. DOI: http://doi.org/10.1093/treephys/tpt059
• Schollaen, K., Heinrich, I., Neuwirth, B., Krusic, P. J., D’Arrigo, R. D., Karyanto, O., Helle, G. (2013): Multiple tree-ring chronologies (ring width, δ13C and δ18O) reveal dry and rainy season signals of rainfall in Indonesia. - Quaternary Science Reviews, 73, pp. 170-181. DOI: http://doi.org/10.1016/j.quascirev.2013.05.018
• Sidorova, O. V., Siegwolf, R. T. W., Myglan, V. S., Ovchinnikov, D. V., Shishov, V. V., Helle, G., Loader, N. J., Saurer, M. (2013): The application of tree-rings and stable isotopes for reconstructions of climate conditions in the Russian Altai. - Climatic Change, 120, 1, pp. 153-167. DOI: http://doi.org/10.1007/s10584-013-0805-5

 

Paper (Other journals)

• Mingram, J., Lauterbach, S., Prasad, S., Helle, G., Plessen, B., Schettler, G. (2013 online first): Paläoklima, Umwelt und Klimawandel in Zentralasien . - System Erde, 3, 2 DOI: http://doi.org/10.2312/GFZ.syserde.03.02.9

 
Report

• Helle, G., Gärtner, H., Beck, W., Heinrich, I., Heußner, K., Müller, A., Sanders, T.(Eds.) (2013 online first): Proceedings of the DENDROSYMPOSIUM 2012 : May 8th - 12th, 2012 in Potsdam and Eberswalde, Germany, (Scientific Technical Report ; 13) , 11th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) (Potsdam and Eberswalde 2012), Deutsches GeoForschungsZentrum GFZ : Potsdam, 178 p. DOI: http://doi.org/10.2312/GFZ.b103-13058

Conference Paper

• Baschek, H., Schollän, K., Helle, G. (2013): A guideline for high throughput cellulose extraction on whole wood thin sections, (TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013)) , TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013).
• Ben, T., Hart, P., Helle, G. (2013): Evidence for annual growth rings in Akoko (Euphorbia olowaluana) an endemic Hawaiian tree with C4-photosynthetic pathway, (TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013)) , TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013).
• Freund, M., Cubasch, U., Helle, G. (2013): On similarities and Distinctions In Climate response of european tree ring widths and Stable Isotopes. Do Oxygen isotopes provide a higher potential for spatial reconstruction approaches?, (TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013)) , TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013).
• Kaplick, J., Pieper, H., Palmer, J., Hogg, A. G., Helle, G. (2013): Preliminary results of stable carbon and oxygen variability of 12,000yr-old Kauri (Agathis australis) from New Zealand. Towards a dendroclimatological reconstruction of the Late Glacial-Early Holocene transition in the Southern Hemisphere, (TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013)) , TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013).
• Pieper, H., Heinrich, I., Heußner, K., Helle, G. (2013): The influence of volcanic eruptions on growth of central European lowland trees in NE-Germany during the last Millennium, (Geophysical Research Abstracts, Vol. 15, EGU2013-1013, 2013) , General Assembly European Geosciences Union (Vienna, Austria 2013).
• Pieper, H., Heinrich, I., Heußner, K., Brauer, A., Helle, G. (2013): The influence of volcanic eruptions on growth of central European lowland trees in NE-Germany during the last Millennium, (TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013)) , TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013).
• Pritzkow, C., Heinrich, I., Grudd, H., Helle, G. (2013): Relationship between cell features, tree ring widths and density of Pinus sylvestris L. and temperature at high latitudes in northern Sweden, (TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013)) , TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013).
• Schollaen, K., Helle, G. (2013): Testing the influence of graphite and gypsum markings on stable isotope values (δ13 C, δ18 O) of tropical tree rings, (Proceedings) , DENDROSYMPOSIUM (Potsdam/Eberswalde, Germany 2012).
• Schollaen, K., Helle, G. (2013): UV-laser microdissection system - A novel approach for the preparation of high-resolution stable isotope records ( delta13 C/ delta18 O) from tree rings, (Geophysical Research Abstracts, Vol. 15, EGU2013-1016-2, 2013) , General Assembly European Geosciences Union (Vienna, Austria 2013).
• Schollaen, K., Heinrich, I., Helle, G. (2013): A novel approach for the preparation of high-resolution stable isotope records from tropical tree-rings, (Proceedings) , DENDROSYMPOSIUM (Potsdam/Eberswalde, Germany 2012).
• Schollän, K., Heinrich, I., Neuwirth, B., Krusic, P., D‘Arrigo, R., Karyanto, O., Helle, G. (2013): Multiple tree-ring chronologies (ring width, delta13 C and delta18 O) reveal dry and rainy season signals in Indonesia, (Geophysical Research Abstracts, Vol. 15, EGU2013-13529, 2013) , General Assembly European Geosciences Union (Vienna, Austria 2013).
• Simard, S., Heinrich, I., Helle, G., Blume, T., Güntner, A. (2013): Pine, beech and oak sensitivity to changing water availability in NE-Germany, (Program and Abstracts of the Dendrosymposium 2013) , TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013), p. 41.
• Slotta, F., Helle, G., Heinrich, I., Heußner, U., Shemang, E., Riedel, F., Tarasov, P. (2013): On the potential of the African baobab, Adansonia digitata, for palaeoclimatic studies, (TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013)) , TRACE 2013 - Tree Rings in Archaeology, Climatology and Ecology (Viterbo, Italy 2013).

2012

Paper (SCI/Scopus journals)

• Brienen, R. J. W., Helle, G., Pons, T. L., Guyot, J., Gloor, M. (2012): Oxygen isotopes in tree rings are a good proxy for Amazon precipitation and El Niño-Southern Oscillation variability. - Proceedings of the National Academy of Sciences of the United States of America (PNAS), 109, 42, pp. 16957-16962. DOI: http://doi.org/10.1073/pnas.1205977109
• Dorado Liñán, I., Gutiérrez, E., Heinrich, I., Andreu-Hayles, L., Muntán, E., Campelo, F., Helle, G. (2012): Age effects and climate response in trees: a multi-proxy tree-ring test in old-growth life stages. - European Journal of Forest Research, 131, 4, pp. 933-944. DOI: http://doi.org/10.1007/s10342-011-0566-5
• Dorado Liñán, I., Büntgen, U., González-Rouco, F., Zorita, E., Montávez, J. P., Gómez-Navarro, J. J., Brunet, M., Heinrich, I., Helle, G., Gutiérrez, E. (2012): Estimating 750 years of temperature variations and uncertainties in the Pyrenees by tree-ring reconstructions and climate simulations. - Climate of the Past, 8, 3, pp. 919-933. DOI: http://doi.org/10.5194/cp-8-919-2012

 
Paper (Other journals)

• Bens, O., Schwank, M., Blume, T., Brauer, A., Güntner, A., Heinrich, I., Helle, G., Itzerott, S., Kaiser, K., Sachs, T., Hüttl, R. F. (2012 online first): TERENO : eine Monitoring- und Forschungsplattform zur Erfassung langfristiger Auswirkungen des Globalen Wandels auf regionaler Ebene. - System Erde, 2, 1 DOI: http://doi.org/10.2312/GFZ.syserde.02.01.13
•  Helle, G., Heinrich, I. (2012 online first): Baumjahresringe als chemisch-physikalischer Datenträger für Umwelt- und Klimainformationen der Vergangenheit. - System Erde, 2, 1 DOI: http://doi.org/10.2312/GFZ.syserde.02.01.11

Report

• Gärtner, H., Rozenberg, P., Montès, P., Bertel, O., Heinrich, I., Helle, G.(Eds.) (2012): Proceedings of the DENDROSYMPOSIUM 2011 : May 11th - 14th, 2011 in Orléans, France, (Scientific Technical Report ; 12) , 10th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) (Orléans, France 2011), Deutsches GeoForschungsZentrum GFZ : Potsdam, 126 p. DOI: http://doi.org/10.2312/GFZ.b103-12036

Conference Paper

• Dorado Liñán, I., Zorita, E., González-Rouco, F., Andreu-Hayles, L., Campelo, F., Helle, G., Gutiérrez, E. (2012): Estimating past temperature variations in the South of Spain, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Fregien, K., Heinrich, I., Helle, G., Neuwirth, B. (2012): Growth response of sessile oak to regional climatic variability in West and Northeast Germany, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Haase, C., Pohlmann, S., Heinrich, I., Heußner, K., Helle, G. (2012): Dynamic growth responses of oak and beech to changing climatic and hydrological conditions in NE Germany, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Knorr, A., Heinrich, I., Slowinski, M., Beck, W., Wazny, T., Heußner, K., Helle, G., Brauer, A. (2012): Climate dynamics in N-Poland: Multi-proxies from trees and lake sediments, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Konter, O., Holzkämper, S., Helle, G., Büntgen, U., Esper, J. (2012): Climate signals in annually resolved δ13C and δ18O tree-ring data from Pinus uncinata in the Spanish Pyrenees, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Liang, W., Heinrich, I., Helle, G. (2012): Confocal laser scanning microscopy for studying cell structures of Pinus sylvestris as a novel research method in dendrochronology, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Pieper, H., Heinrich, I., Heußner, K., Tegel, W., Büntgen, U., Helle, G. (2012): The influence of volcanic eruptions on growth of trees in Central European lowlands and Southeastern Europe since AD 1000, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Schollaen [Hennig], K., Heinrich, I., Neuwirth, B., Brauer, A., D’Arrigo, R., Helle, G. (2012): Climate signals in multiple tree-ring proxies (TRW, δ13C, δ18O) from tropical trees in SE-Asia, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Slotta, F., Heinrich, I., Helle, G., Heußner, K., Shemang, E., Tarasov, P., Riedel, F. (2012): Baobabs - A new auspicious climate archive for the semi-arid tropics, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Tegel, W., Büntgen, U., Kaplan, J. O., Collins, P. M., Schaub, M., Hagedorn, F., Bürgi, M., Brazdil, R., Helle, G., Carrer, M., Heußner, K., Hofmann, J., Kontic, R., Kyncl, T., Tinner, W., Liebhold, A. (2012): Placing modern European fir growth in a Holocene-long context, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).
• Wabersky, N., Pieper, H., Miramont, C., Helle, G., Kaiser, K. (2012): Stable isotopes in tree-rings at the Allerød/YD-transition - a kick-off study, (TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012)) , TRACE 2012 - Tree Rings in Archaeology, Climatology and Ecology (Potsdam and Eberswalde, Germany 2012).

 

2011

Paper (SCI/Scopus journals)

• Andreu-Hayles, L., Planells, O., Gutierrez, E., Muntan, E., Helle, G., Anchukaitis, K. J., Schleser, G. H. (2011): Long tree-ring chronologies reveal 20th century increases in water-use efficiency but no enhancement of tree growth at five Iberian pine forests. - Global Change Biology, 17, 6, pp. 2095-2112. DOI: http://doi.org/10.1111/j.1365-2486.2010.02373.x
• Dorado Liñán, I., Gutiérrez, E., Helle, G., Heinrich, I., Andreu-Hayles, L., Planells, O., Leuenberger, M., Bürger, C., Schleser, G. H. (2011): Pooled versus separate measurements of tree-ring stable isotopes. - Science of the Total Environment, 409, 11, pp. 2244-2251. DOI: http://doi.org/10.1016/j.scitotenv.2011.02.010
• Grießinger, J., Bräuning, A., Helle, G., Thomas, A., Schleser, G. H. (2011): Late Holocene Asian summer monsoon variability reflected by δ18O in tree‐rings from Tibetan junipers. - Geophysical Research Letters, 38. DOI: http://doi.org/10.1029/2010GL045988
• Pons, T. L., Helle, G. (2011): Identification of anatomically non-distinct annual rings in tropical trees using stable isotopes. - Trees - Structure and Function, 25, 1, pp. 83-93. DOI: http://doi.org/10.1007/s00468-010-0527-5
• Wieloch, T., Helle, G., Heinrich, I., Voigt, M., Schyma, P. (2011): A novel device for batch-wise isolation of α-cellulose from small-amount wholewood samples. - Dendrochronologia, 29, 2, pp. 115-117. DOI: http://doi.org/10.1016/j.dendro.2010.08.008
• Zacharias, S., Bogena, H., Samaniego, L., Mauder, M., Fuß, R., Pütz, T., Frenzel, M., Schwank, M., Baessler, C., Butterbach-Bahl, K., Bens, O., Borg, E., Brauer, A., Dietrich, P., Hajnsek, I., Helle, G., Kiese, R., Kunstmann, H., Klotz, S., Munch, J. C., Papen, H., Priesack, E., Schmid, H. P., Steinbrecher, R., Rosenbaum, U., Teutsch, G., Vereecken, H. (2011): A network of terrestrial environmental observatories in Germany. - Vadose Zone Journal, 10, 3, pp. 955-973. DOI: http://doi.org/10.2136/vzj2010.0139

Report

• van der Maaten-Theunissen, M., Spiecker, H., Gärtner, H., Heinrich, I., Helle, G.(Eds.) (2011): Proceedings of the DENDROSYMPOSIUM 2010 : April 22nd - 25th, 2010 in Freiburg, Germany, (Scientific Technical Report ; 11) , 9th TRACE (Tree Rings in Archaeology, Climatology and Ecology) conference (Freiburg 2010), Deutsches GeoForschungsZentrum GFZ : Potsdam. DOI: http://doi.org/10.2312/GFZ.b103-11074

Conference Paper

• Dorado Liñán, I., Gutiérrez, E., Heinrich, I., Andreu-Hayles, L., Muntán, E., Campelo, F., Helle, G., van der Maaten-Theunissen, M., Spiecker, H., Gärtner, H., Heinrich, I., Helle, G. (2011): Climate signals in width, density, δ13C and δ18O tree-ring series at two Iberian sites, (TRACE - Tree Rings in Archaeology, Climatology and Ecology ; 9, Scientific Technical Report ; 11/07) , Dendrosymposium (Freiburg 2010) (Potsdam).
• Heinrich, I., Touchan, R., Helle, G., van der Maaten-Theunissen, M., Spiecker, H., Gärtner, H., Heinrich, I., Helle, G. (2011): Long-term drought and streamflow variations in Turkey, (TRACE - Tree Rings in Archaeology, Climatology and Ecology ; 9, Scientific Technical Report ; 11/07) , Dendrosymposium (Freiburg 2010) (Potsdam).
• Pieper, H., Heinrich, I., Heußner, K. U., Helle, G., van der Maaten-Theunissen, M., Spiecker, H., Gärtner, H., Heinrich, I., Helle, G. (2011): Influence of volcanic eruptions on tree growth in NE-Germany during the last Millennium, (TRACE - Tree Rings in Archaeology, Climatology and Ecology ; 9, Scientific Technical Report ; 11/07) , Dendrosymposium (Freiburg 2010) (Potsdam).
• Schollaen [Hennig], K., Helle, G., Heinrich, I., Neuwirth, B., Karyanto, O., Winiger, M., van der Maaten-Theunissen, M., Spiecker, H., Gärtner, H., Heinrich, I., Helle, G. (2011): Toward multi-parameter records (ring width, δ13C, δ18O) from tropical tree-rings - A case study on Tectona grandis from Java, Indonesia, (TRACE - Tree Rings in Archaeology, Climatology and Ecology ; 9, Scientific Technical Report ; 11/07) , Dendrosymposium (Freiburg 2010) (Potsdam).

2010

Paper (SCI/Scopus journals)

• Fichtler, E., Helle, G., Worbes, M. (2010): Stable carbon isotope time series from tropical tree rings indicate a precipitation signal. - Tree-Ring Research, 66, 1, pp. 35-49. DOI: http://doi.org/10.3959/2008-20.1
• Loader, N. J., Helle, G., Los, S. O., Lehmkuhl, F., Schleser, G. H. (2010): Twentieth-century summer temperature variability in the southern Altai Mountains: A carbon and oxygen isotope study of tree-rings. - Holocene, 20, 7, pp. 1149-1156. DOI: http://doi.org/10.1177/0959683610369507
• Martín-Benito, D., Del Río, M., Heinrich, I., Helle, G., Cañellas, I. (2010): Response of climate-growth relationships and water use efficiency to thinning in a Pinus nigra afforestation. - Forest Ecology and Management, 259, 5, pp. 967-975. DOI: http://doi.org/10.1016/j.foreco.2009.12.001
• Weidner, K., Heinrich, I., Helle, G., Löffler, J., Neuwirth, B., Schleser, G. H., Vos, H. (2010): Consequences of larch budmoth outbreaks on the climatic significance of ring width and stable isotopes of larch. - Trees - Structure and Function, 24, 3, pp. 399-409. DOI: http://doi.org/10.1007/s00468-010-0421-1

Report

• Kaczka, R. J., Malik, I., Owczarek, P., Gärtner, H., Heinrich, I., Helle, G., Schleser, G.(Eds.) (2010): Proceedings of the DENDROSYMPOSIUM 2008, April 27th - 30th, 2008 in Zakopane, Poland, (Scientific Technical Report ; 9) , 7. TRACE (Tree Rings in Archaeology, Climatology and Ecology) Conference (Zakopane, Poland 2008), Deutsches GeoForschungsZentrum GFZ : Potsdam, 226 p. DOI: http://doi.org/10.2312/GFZ.b103-09038
• Levanič, T., Gričar, J., Hafner, P., Krajnc, R., Jagodic, , Gärtner, H., Heinrich, I., Helle, G.(Eds.) (2010): Proceedings of the DENDROSYMPOSIUM 2009, April 16th - 19th, 2009 in Otočec, Slovenia, (Scientific Technical Report ; 10) , 8. TRACE (Tree Rings in Archaeology, Climatology and Ecology) Conference (Otočec, Slovenia 2009), Deutsches GeoForschungsZentrum GFZ : Potsdam, 169 p. DOI: http://doi.org/10.2312/GFZ.b103-10058

2009

Paper (SCI/Scopus journals)

• Gessler, A., Brandes, E., Buchmann, N., Helle, G., Rennenberg, H., Barnard, R. L. (2009): Tracing carbon and oxygen isotope signals from newly assimilated sugars in the leaves to the tree-ring archive. - Plant Cell and Environment, 32, 7, pp. 780-795. DOI: http://doi.org/10.1111/j.1365-3040.2009.01957.x
• Heinrich, I., Weidner, K., Helle, G., Vos, H., Lindesay, J., Banks, J. (2009): Interdecadal modulation of the relationship between ENSO, IPO and precipitation: insights from tree rings in Australia. - Climate Dynamics, 33, 1, pp. 63-73. DOI: http://doi.org/10.1007/s00382-009-0544-5
• Laumer, W., Andreu, L., Helle, G., Schleser, G. H., Wieloch, T., Wissel, H. (2009): A novel approach for the homogenization of cellulose to use micro-amounts for stable isotope analyses. - Rapid Communications in Mass Spectrometry, 23, 13, pp. 1934-1940. DOI: http://doi.org/10.1002/rcm.4105
• Planells, O., Gutiérrez, E., Helle, G., Schleser, G. H. (2009): A forced response to twentieth century climate conditions of two Spanish forests inferred from widths and stable isotopes of tree rings. - Climatic Change, 97, 1, pp. 229-252. DOI: http://doi.org/10.1007/s10584-009-9602-6
• Treydte, K. S., Frank, D. C., Saurer, M., Helle, G., Schleser, G. H., Esper, J. (2009): Impact of climate and CO2 on a millennium-long tree-ring carbon isotope record. - Geochimica et Cosmochimica Acta, 73, 16, pp. 4635-4647. DOI: http://doi.org/10.1016/j.gca.2009.05.057

2008

Paper (SCI/Scopus journals)

• Andreu, L., Planells, O., Gutierrez, E., Helle, G., Schleser, G. H. (2008): Climatic significance of tree-ring width and delta C-13 in a Spanish pine forest network. - Tellus - B, 60, 5, pp. 771-781. DOI: http://doi.org/10.1111/j.1600-0889.2008.00370.x
• Heinrich, I., Weidner, K., Helle, G., Vos, H., Banks, J. (2008): Hydroclimatic variation in Far North Queensland since 1860 inferred from tree rings. - Palaeogeography Palaeoclimatology Palaeoecology, 270, 1, pp. 116-127. DOI: http://doi.org/10.1016/j.palaeo.2008.09.002
• Kirdyanov, A. V., Treydte, K. S., Nikolaev, A., Helle, G., Schleser, G. H. (2008): Climate signals in tree-ring width, density and δ13C from larches in Eastern Siberia (Russia). - Chemical Geology, 252, 1, pp. 31-41. DOI: http://doi.org/10.1016/j.chemgeo.2008.01.023
• Voronin, V. I., Tartakovsky, V. A., Volkov, Y. V., Schleser, G. H., Helle, G., Nesvetailo, V. D. (2008): Tree-ring isotope chronologies of the Baikal region and their connection with ice isotope chronology of Greenland. - Atmospheric and Oceanic Optics, 21, 1, pp. 50-54.
• Weigl, M., Grabner, M., Helle, G., Schleser, G. H., Wimmer, R. (2008): Characteristics of radial growth and stable isotopes in a single oak tree to be used in climate studies. - Science of the Total Environment, 393, 1, pp. 154-161. DOI: http://doi.org/10.1016/j.scitotenv.2007.12.016

Report

Elferts, D., Brumelis, G., Gärtner, H., Helle, G., Schleser, G.(Eds.) (2008): Proceedings of the DENDROSYMPOSIUM 2007 : May 3rd - 6th 2007, Riga, Latvia, (Scientific Technical Report STR ; 8) , 6. TRACE (Tree Rings in Archaeology, Climatology and Ecology) conference (Riga, Latvia 2007), Deutsches GeoForschungsZentrum GFZ : Potsdam, 197 p. DOI: http://doi.org/10.2312/GFZ.b103-08056

2007

Paper (SCI/Scopus journals)

• Treydte, K., Frank, D., Esper, J., Andreu, L., Bednarz, Z., Berninger, F., Boettger, T., D'Alessandro, C. M., Etien, N., Filot, M., Grabner, M., Guillemin, M., Gutierrez, E., Haupt, M., Helle, G., Hilasvuori, E., Jungner, H., Kalela-Brundin, M., Krapiec, M., Leuenberger, M., Loader, N. J., Masson-Delmotte, V., Pazdur, A., Pawelczyk, S., Pierre, M., Planells, O., Pukiene, R., Reynolds-Henne, C. E., Rinne, K. T., Saracino, A., Saurer, M., Sonninen, E., Stievenard, M., Switsur, V. R., Szczepanek, M., Szychowska-Krapiec, E., Todaro, L., Waterhouse, J. S., Weigl, M., Schleser, G. H. (2007): Signal strength and climate calibration of a European tree-ring isotope network. - Geophysical Research Letters, 34, 24. DOI: http://doi.org/10.1029/2007GL031106

Paper (Other journals)

• Boettger, T., Haupt, M., Knöller, K., Weise, S. M., Waterhouse, J. S., Rinne, K. T., Loader, N. J., Sonninen, E., Jungner, H., Masson-Delmotte, V., Stievenard, M., Guillemin, M., Pierre, M., Pazdur, A., Leuenberger, M., Filot, M., Saurer, M., Reynolds, C. E., Helle, G., Schleser, G. H. (2007): Wood cellulose preparation methods and mass spectrometric analyses of delta C-13, delta O-18, and nonexchangeable delta H-2 values in cellulose, sugar, and starch: An interlaboratory comparison. - Analytical Chemistry, 79, 1 DOI: http://doi.org/10.1021/ac0700023

2006

Paper (SCI/Scopus journals)

• Treydte, K. S., Schleser, G. H., Helle, G., Frank, D. C., Winiger, M., Haug, G. H., Esper, J. (2006): The twentieth century was the wettest period in northern Pakistan over the past millennium. - Nature, 440, pp. 1179-1182. DOI: http://doi.org/doi:10.1038/nature04743

Chapter in Book

• Berthold, J., Helle, G., Kitagawa, C., Peters, J., Strauch, F. (2006): Nordsee oder Mittelmeer? Römische Austern und andere Speiseabfälle einer gehobenen Küche aus den Thermengrabungen in der Colonia Ulpia Traiana. - In: Müller, M.(Ed.), Xantener Berichte: Grabung - Forschung - Präsentation, Bd. 14, Verlag Philipp von Zabern, pp. 265-302.

2005

Paper (SCI/Scopus journals)

• Sass-Klaassen, U., Poole, I., Wils, T., Helle, G., Schleser, G. H., van Bergen, P. F. (2005): Carbon and oxygen isotope dendrochronology in sub-fossil bog oak tree rings - A preliminary study. - IAWA Journal, 26, 1, pp. 121-136.

2004

Paper (SCI/Scopus journals)

• Helle, G., Schleser, G. H. (2004): Beyond CO2-fixation by Rubisco – an interpretation of 13C/12C variations in tree rings from novel intra-seasonal studies on broad-leaf trees. - Plant Cell and Environment, 27, 3, pp. 367-380. DOI: http://doi.org/10.1111/j.0016-8025.2003.01159.x
• Verheyden, A., Helle, G., Schleser, G. H., Dehairs, F., Beeckman, H., Koedam, N. (2004): Annual cyclicity in high-resolution stable carbon and oxygen isotope ratios in the wood of the mangrove tree Rhizophora mucronata. - Plant Cell and Environment, 27, 12, pp. 1525-1536. DOI: http://doi.org/10.1111/j.1365-3040.2004.01258.x

Chapter in Book

• Helle, G., Schleser, G. H. (2004): Interpreting climate proxies from tree-rings. - In: Fischer, H., Kumke, T., Lohmann, G., Flöser, G., Miller, H., von Storch, H., Negendank, J. F.(Eds.), The Climate in Historical Times : Towards a Synthesis of Holocene Proxy Data and Climate Models, (GKSS School of Environmental Research), Springer, pp. 129-148. DOI: http://doi.org/10.1007/978-3-662-10313-5_8
• Kumke, T., Hense, A., Schölzel, C., Andreev, A. A., Brüchmann, C., Gebhardt, C., Helle, G., Kienel, U., Kühl, N., Litt, T., Neumann, F., Schleser, G. H. (2004): Transfer functions for palaeoclimate reconstructions - Applications. - In: Fischer, H., Kumke, T., Lohmann, G., Flöser, G., Miller, H., von Storch, H., Negendank, J. F.(Eds.), The Climate in Historical Times : Towards a Synthesis of Holocene Proxy Data and Climate Models, (GKSS School of Environmental Research), Springer, pp. 245-262.

Conference Paper

• Helle, G., Treydte, K., Verheyden, A. (2004): Tropical Swietenia macrophylla wood reveals a systematic recurring carbon isotope pattern, ( TRACE - Tree Rings in Archaeology, Climatology and Ecology, volume 2 : proceedings of the Dendrosymposium 2003, May 1st - 3rd 2003, Utrecht, the Netherlands) , Dendrosymposium (Utrecht 2003) (Utrecht).

2003

Paper (SCI/Scopus journals)

• Poszwa, A., Wickman, T., Dambrine, E., Ferry, B., Dupouey, J., Helle, G., Schleser, G. H., Breda, N. (2003): A Retrospective Isotopic Study of Spruce Decline in the Vosges Mountains (France). - Water, Air and Soil Pollution : Focus, 3, 1, pp. 201-222. DOI: http://doi.org/10.1023/A:1022176025379

Paper (Other journals)

• Attendorn, H., Helle, G., Strauch, F., Thüry, G. E. (2003): Provenienzuntersuchungen an römischen Fundaustern aus der Zone nordwärts der Alpen. - Römisches Österreich, 23

2002

Conference Paper

• Helle, G., Schleser, G. H., Bräuning, A. (2002): Climate history of the Tibetan Plateau for the last 1500 years as inferred from stable carbon isotopes in tree-rings, (Proceedings ) , International Conference on the Study of Environmental Change Using Isotope Techniques (Vienna, Austria 2001) (Vienna 2001), pp. 301-311.

1999

Paper (SCI/Scopus journals)

• Lücke, A., Helle, G., Schleser, G. H., Figueiral, I., Mosbrugger, V., Jones, T. P., Rowe, N. P. (1999): Environmental history of the German Lower Rhine Embayment during the Middle Miocene as reflected by carbon isotopes in brown coal. - Palaeogeography Palaeoclimatology Palaeoecology, 154, 4, pp. 339-352. DOI: http://doi.org/10.1016/S0031-0182(99)00122-4
• Schleser, G. H., Helle, G., Lücke, A., Vos, H. (1999): Isotope signals as climate proxies: the role of transfer functions in the study of terrestrial archives. - Quaternary Science Reviews, 18, 7, pp. 927-943. DOI: http://doi.org/10.1016/S0277-3791(99)00006-2

1998

Chapter in Book

• Helle, G., Schleser, G. H. (1998): Die Eichenbohlen des neolithischen Brunnens von Erkelenz-Kückhoven als Klimaarchive. - In: Koschik, H.(Ed.), Brunnen der Jungsteinzeit. Internationales Symposium in Erkelenz 27.-29.10.1997, (Materialien zur Bodendenkmalpflege im Rheinland, Bd. 11), Rheinland-Verlag, pp. 271-277.