2018 Ph.D. Natural Resources and Ecohydrology. University of Arizona, USA.
2011 MS. Forest Sciences and Forest Ecology. Georg-August-Universität Göttingen, Germany.
2007 Forest engineering. Universidad Austral de Chile, Chile.
2020 - present Research associate, Instituto de Geología, Universidad Autónoma de México
2018 - 2020 Postdoctoral research associate. University of Arizona USA
2022 Sistema Nacional de Investigadores de Maexico SNI Nivel 1
2022 Fellow of the International Mobility Research Fellowship Program for Latin American and Caribbean early-career scientists on past global changes.
2019 Invited trainee, Expert Witness Training Academy for climate scientists, Mitchell Hamline School of Law, St. Paul, MN
2017 Outstanding Research Award (Graduate Studies), College of Science, University of Arizona.
2017 College of Science Galileo Circle Scholar, University of Arizona.
2016 Andrew Ellicott Douglass Memorial Scholarship. The Douglass Scholarship indicates outstanding academic achievement and high expectations of future contributions to dendrochronology.
2016 Invited DAAD Lecture, European Conference of Tropical Ecology and the International DAAD Alumni Seminar, Germany.
2016 Ameridendro Travel Grant, 3rd American Dendrochronology Conference, Argentina
2014 Research-in-Residence Award, Inter-University Training for Continental-Scale Ecology (ITCE), Research opportunity in Salt Lake City, UT
2009 DAAD Scholarship (2 years), Georg-August-Universität Göttingen, Germany.
2008 Best Student Award (2007 Forestry Cohort), Universidad Austral de Chile.
Publications (Google Citations)
27 Guobao Xu, Xiaohong Liu, Jia Hu, Isabel Dorado-Liñán, Mary Gagen, Paul Szejner, Tuo Chen, Valerie Trouet, Intra-annual tree-ring δ18O and δ13C reveal a trade-off between isotopic source and humidity in moist environments, Tree Physiology, 2022, tpac076, https://doi.org/10.1093/treephys/tpac076
26. Cabon, A., Kannenberg, S. A., Arain, A., Babst, F., Baldocchi, D., Belmecheri, S., Delpierre, N., Guerrieri, R., Maxwell, J. T., McKenzie, S., Meinzer, F. C., Moore, D. J. P., Pappas, C., Rocha, A. v., Szejner, P., Ueyama, M., Ulrich, D., Vincke, C., Voelker, S. L., … Anderegg, W. R. L. (2022). Cross-biome synthesis of source versus sink limits to tree growth. Science, 376(6594), 758–761. https://doi.org/10.1126/science.abm4875
25. Leavitt, S. W., & Szejner, P. (2022). Intra-annual tree-ring isotope variations : do they occur when environment remains constant ? Trees, 0123456789, 1–4. https://doi.org/10.1007/s00468-022-02304-1
24. Yocom, L., Ogle, K., Peltier, D. et al. Tree growth sensitivity to climate varies across a seasonal precipitation gradient. Oecologia (2022). https://doi.org/10.1007/s00442-022-05156-1
23. Cerano-Paredes, J., Szejner, P., Gutiérrez-García, G., Cervantes-Martínez, R., Cambrón-Sandoval, V. H., Villanueva-Díaz, J., Estrada-Arellano, J. R., Franco-Ramos, O., Vázquez-Selem, L., Castruita-Esparza, L. U. How to Extract Climate Variability from Tree-Rings. <em>J. Vis. Exp.</em> (181), e63414, doi:10.3791/63414 (2022).
22. Belmecheri, S., Wright, W.E., Szejner, P. (2022). Sample Collection and Preparation for Annual and Intra-annual Tree-Ring Isotope Chronologies. In: Siegwolf, R.T.W., Brooks, J.R., Roden, J., Saurer, M. (eds) Stable Isotopes in Tree Rings. Tree Physiology, vol 8. Springer, Cham. https://doi.org/10.1007/978-3-030-92698-4_4
21. Kannenberg SA, Driscoll AW, Szejner P, et al (2021) Rapid increases in shrubland and forest intrinsic water-use efficiency during an ongoing megadrought. Proc Natl Acad Sci 118:e2118052118. https://doi.org/10.1073/pnas.2118052118
20. Szejner P, Belmecheri S, Babst F, Wright WE, Frank DC, Hu J. Monson RK. 2021. Stable isotopes of tree rings reveal seasonal-to-decadal patterns during the emergence of a megadrought in the southwestern US, Oecologia, https://doi.org/10.1007/s00442-021-04916-9
19. Xu G, Liu X, Sun W, Szejner P, Zeng X, Yoshimura K, Trouet V. 2020. Seasonal divergence between soil water availability and atmospheric moisture recorded in intra-annual tree-ring δ18O extremes. Environmental Research Letters 15: 094036.
18. Szejner P, Clute T, Anderson E, Evans MN, Hu J. 2020. Reduction in lumen area is associated with the δ18O exchange between sugars and source water during cellulose synthesis. New Phytologist 226: 1583–1593.
17. Szejner P, Belmecheri S, Ehleringer JR, Monson RK. 2020. Recent increases in drought frequency cause observed multi-year drought legacies in the tree rings of semi-arid forests. Oecologia 192: 241–259.
16. Monson RK, Szejner P, Belmecheri S, Morino KA, Wright WE. 2018. Finding the seasons in tree ring stable isotope ratios. American Journal of Botany 105: 1–3.
15. Belmecheri S, Wright WE, Szejner P, Morino KA, Monson RK. 2018. Carbon and oxygen isotope fractionations in tree rings reveal interactions between cambial phenology and seasonal climate. Plant Cell and Environment 41: 2758–2772.
14. Szejner P, Wright WE, Belmecheri S, Meko D, Leavitt SW, Ehleringer JR, Monson RK. 2018. Disentangling seasonal and interannual legacies from inferred patterns of forest water and carbon cycling using tree-ring stable isotopes. Global Change Biology 24: 5332–5347.
13. González-Reyes Á, McPhee J, Christie DA, Le Quesne C, Szejner P, Masiokas MH, Villalba R, Muñoz AA, Crespo S, et al. 2017. Spatiotemporal variations in hydroclimate across the Mediterranean Andes (30°-37°S) since the early twentieth century. Journal of Hydrometeorology 18: 1929–1942.
12. Szejner P, Wright WE, Babst F, Belmecheri S, Trouet V, Leavitt SW, Ehleringer JR, Monson RK. 2016. Latitudinal gradients in tree ring stable carbon and oxygen isotopes reveal differential climate influences of the North American Monsoon System. Journal of Geophysical Research: Biogeosciences 121: 1978–1991.
11. Wright WE, Baisan C, Streck M, Wright WW, Szejner P. 2016. Dendrochronology and middle Miocene petrified oak: Modern counterparts and interpretation. Palaeogeography, Palaeoclimatology, Palaeoecology 445: 38–49.
10. Babst F, Wright WE, Szejner P, Wells L, Belmecheri S, Monson RK. 2016. Blue intensity parameters derived from Ponderosa pine tree rings characterize intra-annual density fluctuations and reveal seasonally divergent water limitations. Trees - Structure and Function 30: 1403–1415.
9. Munoz A, Gonzalez-Reyes A, Lara A, Sauchyn D, Christie DA, Villalba R, Isabella A-B, Urrutia-Jalabert R, Mundo I a., Szejner P, et al. 2016. Streamflow variability in the Chilean Temperate-Mediterranean climate transition (35°S-42°S) during the last four hundred years inferred from tree-ring records. Climate Dynamics.47: 12, 4051-4066.
8. Stahle DW, Cook ER, Burnette DJ, Villanueva J, Cerano J, Burns JN, Griffin D, Cook BI, Acuña R, Torbenson MCA, Szejner P. et al. 2016. The Mexican Drought Atlas: Tree-ring reconstructions of the soil moisture balance during the late pre-Hispanic, colonial, and modern eras. Quaternary Science Reviews 149: 34–60.
7. González ME, Szejner P, Donoso PJ, Salas C. 2015. Fire, logging and establishment patterns of second-growth forests in south-central Chile: implications for their management and restoration. Ciencia e investigación agraria 42: 11–11.
6. González ME, Donoso PJ, Szejner P. 2015. Tree-fall gaps and patterns of tree recruitment and growth in Andean old-growth forests in south-central Chile. Bosque (Valdivia) 36: 383–394.
5. Babst F, Alexander MR, Szejner P, Bouriaud O, Klesse S, Roden J, Ciais P, Poulter B, Frank D, Moore DJP, et al. 2014. A tree-ring perspective on the terrestrial carbon cycle. Oecologia 176: 307–322.
4. Szejner P, Cuc E. Bahamondez A, Reyes AG. 2013. Precipitation and river-flow reconstruction in the Choapa watershed Precipitation and river-flow reconstruction in the Choapa watershed. Proceedings Environmine conference 2013
3. Szejner P, Le-Quesne C, Gonzalez ME, Christie DA. 2011. Recuperación de bosques de Pilgerodendron uviferum (D. Don) Florin luego de perturbaciones antrópicas en la Cordillera de la Costa de Valdivia, Chile. Gayana. Botánica 68: 196–206.
2. Moorman MC, Eggleston DB, Anderson CB, Mansilla A, Szejner P. 2009. Implications of Beaver Castor canadensis and Trout Introductions on Native Fish in the Cape Horn Biosphere Reserve, Chile. Transactions of the American Fisheries Society 138: 306–313.
1. Arismendi I, Szejner P, Lara A, González ME. 2008. Impacto del castor en la estructura de bosques ribereños de Nothofagus pumilio en Tierra del Fuego, Chile. Bosque (Valdivia) 29: 146–154.
2022 Szejner P, (Responsable). “Strengthening collaboration networks and enhancing scientific capabilities for climate change studies in Latin America through innovative research between tree-ring research groups from Mexico and Chile” Fuente de financiamiento: International Mobility Research Fellowship Program for Latin American and Caribbean early-career scientists on past global changes.
2021-2022 Szejner P, (PI). “Ecophysiological variations along the tree growing season recorded in the dendrochronological archives of Mexico”. UNAM Internal Support Program for Research and Technological Innovation Projects (PAPIIT), US $20,000 (This is a grant to develop mass spectrometer facilities for the purpose of dendrochronological research.)
2021-2023 Szejner P, (CO-PI). "Temporal variations of the isotopic composition of atmospheric CO2 as indicators of emission sources in Mexico City." UNAM Internal Support Program for Research and Technological Innovation Projects (PAPIIT), US $30,000 (This is a grant to study atmospheric CO2 dynamics in the vicinity of Mexico City.)
2012-2013 Szejner P, (PI). "Reconstruction of the Precipitation and streamflow of the Choapa basin, using Kagenekia Angustifolia tree-ring chronologies.” Antofagasta Minerals, US $80,000 (This is funding from the private sector as a consultancy/research project)
2022 Lecturer National Autonomous University of Mexico UNAM. Biogeoquimica de isótopos estables. (Graduate level)
2021 Lecturer National Autonomous University of Mexico UNAM. Introduction to Dendrochronology. (Graduate level)
2020 Lecturer National Autonomous University of Mexico UNAM. Introduction to Dendrochronology. (Graduate level)
2012 Lecturer, Workshop on Applied Dendrochronology in Tropical Species, Universidad Autónoma Gabriel Rene Moreno in Santa Cruz Bolivia. "Steps and tools to develop tree-ring chronologies in the Tropics".
2011 Lecturer, Workshop on Applied dendrochronology in Tropical species, the Universidad Autónoma Gabriel Rene Moreno in Santa Cruz Bolivia. “Methodological considerations in the analysis of forest dynamics and disturbances”
23. Szejner P. (2020), “Some perspectives from the forests during the transitions to the Anthropocene”. Instituto de Geología, UNAM, Mexico (Invited).
22. Bailey K, Szejner P, Strange B, Monson R.K, Hu J. (2020), “Differential use of North American monsoon precipitation by Pinus ponderosa in the American southwest”. Ecological Society of America ESA.
21. Hu J, Szejner P, Clute T, Anderson E, Evans M. (2020), “Reduction in lumen area increases the amount of δ18O exchange with source water during cellulose synthesis”. European Geophysical Union, EGU GU2020-11215
20. Belmecheri S, Szejner P, Frank D, Voelker S, Lavergne A. (2020), “Global trends of tree-ring carbon isotope discrimination under rising atmospheric CO2 and changing climate”. European Geophysical Union, EGU, GU2020-12240
19. Szejner P, Belmecheri S, Ehleringer J.R, Monson R.K. (2019), “Recent increases in drought frequency cause observed multi-year drought legacies in the tree rings of semi-arid forests”. American Geophysical Union AGU B31I-2503
18. Belmecheri S, Szejner P, Frank D. (2019), “Global trends of Forest´s water use efficiency responses to ricing CO2”. American Geophysical Union fall meeting. AGU B24D-06.
17. Szejner P, Belmecheri S, Ehleringer J.R, Monson R.K. (2018), “Increased drought frequency over the past twenty years has caused multi-year legacies in semi-arid forests”. Conference Mountain Climate, MntClim2018, Gunnison, CO
16. Szejner P., Clute, T., Anderson E. and Hu J. (2018), “The relative humidity induces isotopic differences in tree-ring cellulose but does not necessarily induces changes in anatomical characteristics”. American Geophysical Union, AGU B21G-18.
15. Belmecheri S, Morino K, Knowles J.F, Szejner P, Wright W.E, Monson R.K, Barron‐Gafford G, Frank D. (2018), “The pulse of a semi-arid forest: intra-seasonal progression of water and carbon exchange”. American Geophysical Union Fall meeting. AGU B21G-13
14. Belmecheri S, Wright W.E, Szejner P, Morino K, Monson R.K. (2018), “Carbon and oxygen isotope fractionations in tree rings reveal interactions between cambial phenology and seasonal climate”. Ecological Society of America ESA.
13. Szejner P. (2018), “Increasing drought frequency causes multi-year legacies in semi-arid forests” .The Brimensdorfer Tree-Ring Lectures at the WSL, Switzerland. (Invited)
12. Monson R.K, Szejner P, Belmecheri S, Morino K, Wright W.E, Babst F, Hughes M, Leavitt S.W, Trouet V, Ehleringer J.R. (2017), "Reconstructing drought legacies in the North American monsoon climate system using tree-ring stable isotopes". Ecological Society of America ESA.
11. Yocom-Kent L, Ogle K, Liu Y, Szejner P, Monson R.K, Peltier D.M.P. (2017) “Tree growth response to climate varies across a monsoon precipitation gradient”. Ecological Society of America ESA.
10. Szejner P. (2017) “Latitudinal Gradients in Tree-Ring Stable Carbon and Oxygen Isotopes Reveal Inter-seasonal dependencies distinct anatomical domains of tree rings from the North American Monsoon region” Laboratory of Climate and Environmental Research, France. (Invited)
9. Szejner P. (2016) “Latitudinal Gradients in Tree-Ring Stable Carbon and Oxygen Isotopes Reveal Differential Climate Influences of the North American Monsoon System”. The GFZ in Potsdam, Germany. (Invited)
8. Szejner P, Wright W.E, Babst F, Belmecheri S, Trouet V, Leavitt S.W, Ehleringer J.R, Monson R.K. (2016)"Latitudinal Gradients in Tree-Ring Stable Carbon and Oxygen Isotopes Reveal Differential Climate Influences of the North American Monsoon System". third American Dendrochronological conference ¨Ameridendro 2016¨, Mendoza Argentina.
7. Szejner P, Wright W.E, Babst F, Belmecheri S, Trouet V, Leavitt S.W, Ehleringer J.R, Monson R.K. (2016) "Latitudinal Gradients in Tree-Ring Stable Carbon and Oxygen Isotopes Reveal Differential Climate Influences of the North American Monsoon System". American Geophysical Union Fall meeting AGU
6. Szejner P, Wright W.E, Leavitt S.W, Belmecheri S, Monson R.K. (2016), “The potential use of Stable isotopes in tree-rings to understand tree–climate response in tropical regions”. European Conference of Tropical Ecology. Tropical diversity, ecology, and land use GTö. Göttingen Germany.
5. Szejner P. (2016), “Potential use of Stable isotopes in tree-rings to understand tree–climate response in tropical regions”. International DAAD Alumni Seminar at Göttingen University, Germany. (Invited)
4. Szejner P. (2015), “The importance of the monsoon rainfall for Ponderosa pine growth throughout the US Southwest”. The Earth week plenary oral session at the University of Arizona. (Invited)
3. Szejner P, Villanueva J, Cerano J, Worbes M. (2013), “False rings of Pinus oocarpa and their relations with climate events in Eastern Guatemala”. American Dendrochronological conference AmeriDendro, Tucson USA.
2. Gonzalez M, Munoz A, Szejner M, Szejner P, Silva J. (2009), “Post-fire passive restoration in Andean Araucaria-Nothofagus forests: fire severity and species recovery”. 19th Conference of the Society for Ecological Restoration International. Perth, Western Australia, Australia.
1. Szejner P, Le Quesne C, González, M.E, Christie D.A, Bustos-Schindler C. (2007), “Conservation state of Pilgerodendron uviferum forests in Valdivia National Reserve Valdivia“. III Encuentro binacional de Ecología Aplicada. La Serena, Chile.
Reviewer of Scientific Journals: Global Change Biology, Proceedings of the National Academy of Sciences, Journal of Geophysical Research-Atmospheres, Nature Geoscience, Agricultural and Forest Meteorology, Oecologia, Journal of South American Earth Sciences, Nature Communications, Trees Structure and Function, Ecological Indicators, Current Forestry Reports, International Association of Wood Anatomists (IAWA), Climate of The Past, iForest, Water Resources Research, Dendrochronologia, Journal of Geophysical Research-Biogeosciences, Geosciences, Forests, Climatic Change , International Journal of Biometeorology, Earth and Planetary Science Letters, Environmental and Ecological Statistics, Journal of Tropical Forest Science, Tree-ring research.
Reviewer of Research Proposals: The National Science Foundation (NSF, USA).
Guest Editor of Scientific Journals: Frontiers in Forest and Global Change, Jove
Co-organizer and Convener at scientific meetings:
Chair and convener “New Avenues of Multiproxy Dendroecology: Synthesis, Challenges, and Opportunities of High-Resolution Tree Ring Research ” eLightning session at American Geophysical Union Conference 2019, San Francisco, USA.
Co-Chair and convener “High Resolution Dendrochronology: Extracting the Mechanism Behind Plant–Atmosphere Interactions” eLightning session at American Geophysical Union Conference 2018, San Francisco, USA.
Coding in R: Quantitative data analysis, and Spatial and temporal analysis.
Languages: Spanish (native) and English (Fluent).