Hi there!
My research program focuses on the quantification of soil formation and erosion processes to understand landscape evolution in response to land-use and climate change. I combine soil science with geomorphology, isotopic geochemistry, and geochronology to understand soil-landscape relationships across timescales. My projects are field-oriented and include laboratory analyses and modeling approaches to quantify chemical weathering rates, soil formation, soil erosion, and sedimentation rates. I use soil geochemistry, mineralogy, Pu as erosion tracers, and Be and dendrochronology as dating techniques.
239+240
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Hot news!
June 2026
New publication in Catena
In this paper, we used Pu isotopes to quantify soil erosion and deposition rates after whole tree harvesting at the Hubbard Brook Experimental Forest (HBEF). Our findings show that:
- Whole-tree harvesting increased soil erosion and deposition rates on the hillslopes
- Pu isotopes are suitable tracers for acidic sandy soils, and are subjected to vertical and lateral podzolization
These findings highlight the importance of considering soil redistribution processes in forest management to protect soil health, water quality, and long-term soil carbon storage.
Open access paper can be found here: https://www.sciencedirect.com/science/article/pii/S0341816226005151
I would like to thank all my collaborators. Special thanks to Scott Bailey and Diogo Spinola for their continuous support in the field and enlightening discussions, and to Eli Gundersen, who conducted an outstanding senior thesis and contributed to this research. I would also like to thank Dr. Mike Ketterer for the 239+240Pu isotopes measurements. Mike has contributed to many of my research projects over the years, and I greatly appreciate his expertise and collaboration.
Lastly, this study would not have been possible without the Hubbard Brook Experimental Forest. For more than six decades, HBEF has served as a living laboratory, generating transformative discoveries in forest ecology, hydrology, biogeochemistry, and soil science. Long-term ecological research sites such as HBEF are invaluable for understanding long-term processes at the watershed scale. Continued support for these research forests is essential to advance science and inform sustainable land management strategies.
April 2026
Invited talks - EGU Landscapes Live, NAU Forestry Graduate Seminar, UNBC Landscapes Throut Time Conference
What a busy and rewarding week! It was a pleasure and an honour to deliver 3 invited talks on soil formation and erosion processes using Pu isotopes as tracers.
EGU Landscapes Live (April 30)
Many thanks to Jakob Rom, Tamara Aranguiz-Rago and Laurent Roberge, for the invitation and organization. It was great meeting you all and engaging with the audience. Full talk can be found here: https://www.youtube.com/watch?v=ygaYLT7vhc4&t=15s
NAU Forestry Graduate Student Association Seminar (April 29)
It was an honour to share this talk with my long-term collaborator and dear friend, emeritus professor Michael Ketterer (NAU), and to discuss how we have been applying Pu isotopes across a variety of landscapes. Thank you Benjamin Covington for the invitation, and to the seminar coordinators Abi, Alyssa, and Athena.
UNBC Landscapes Through Time Conference (April 27)
Thank you to the organizing committee for a great event and the opportunity to engage with the geology and geomorphology community in Northern BC: Dr. Adam Hawkins, Liz Arich, Dr. Brian Menounos, and Brendan Miller. I learned so many thinks about my landscape surroundings and had a pleasure to meet John Clague from Simon Fraser University.
Thank you all! 😄
August 2025
We are hiring a Master´s student
November 2024
Wildfire and soil redistribution rates in British Columbia
Wrapping up our field season for Andrin Müller’s thesis! We’re investigation soil erosion and carbon dynamics after wildfire in BC, Canada. Thanks to the Cheslatta First Nation, Phil Owens, Mike Ketterer, Markus Egli, Mike Samoil, Adam Hawkins, João Reis for their collaboration!
November 2024
New publication in Catena
Check out our new publication in Catena! We explored how rapid soil formation and soil processes transport carbon into subsurface horizons along a soil chronosequence in SE Alaska. We found that Podzols form in less than 200 years, with most carbon stored in the subsurface after approximately 150 years. Part of the data comes from Alana’s senior thesis. Congratulations to Alana on her first publication!
July 2024
New publication in SSSAJ
I am happy to share our new publication in the Soil Science Society of America Journal on assessing soil redistribution rates using ²³⁹+²⁴⁰Pu across Southeast Alaska. We found that soil redistribution rates are negligible across lithologies, further supporting the idea that Spodosols could indicate slope stability over decadal timescales across the region.
July 2024
New publication in SSSAJ
Check out our new publication on soil formation and soil organic carbon (SOC) in the coastal temperate rainforest of SE Alaska. We found that a greater proportion of SOC is stored in mineral horizons compared to the overlying organic horizons. Nearly 40% of SOC would have been overlooked if sampling had been restricted to the upper 30 cm of the soil. Congratulations on the publication, Jennifer Fedenko!
June and July 2023
Back to Southeast Alaska for fieldwork
It was truly invigorating to return to the beautiful landscapes of Juneau for our fieldwork mission. Our task involved collecting soil samples, a crucial component in our pursuit of understanding the past and current stability of steep slopes across the region. These samples will provide valuable insights into soil erosion rates, helping us understand how lithology controls erosion processes in this mountainous, carbon-rich environment. Stay tune for more to come! You can find pictures of the this expedition on my Twitter account @RaquelPortesGeo.
March 2023
GSA 2023 - Joint SE NE Section Meeting
We recently went to Virginia to attend the SE NE GSA meeting. I was honored to deliver an invited talk at the Radionuclides Symposium, where I focused my discussion on the role of Pu isotopes as cutting-edge erosion tracers. We discussed how they can effectively quantify erosion and sedimentation rates in a faster, cheaper, and more reliable way. This topic is incredibly crucial in environmental science, and I was thrilled to share my research with fellow scholars. Alana and Eli had the opportunity to brilliantly present the results of their theses at the conference. They rocked the stage, and I could not be prouder of them!
October 2022
New publication in Geoderma
Check out our new publication in Geoderma about how lithology controls chemical weathering and mineralogy of Spodosols in SE Alaska. I am so happy this paper is out! Many thanks to Diogo Spinola (UAF) for leading this research and to all collaborators.
July 2022
Fieldwork at Mendenhall and Hebert glaciers in Juneau, Alaska
The #extremepedology team is getting bigger! Alana Margerum and Yakun Zhang joined part of the team for fieldwork at the Mendenhall and Hebert Glacier valleys. We are evaluating the interplay of plant succession and chemical weathering rates along soil chronosequences. The fieldwork included biking to study sites, scouting moraines, describing and sampling soil samples, and coring trees for constraining the age of the moraines and a super delicious soil cake made by Alana!
June 2022
Fieldwork at Hubbard Brook Experimental Forest, New Hampshire
I had a great time with Scott and Eli at the HBEF for another fieldwork season. We are investigating the impact of whole-tree harvest on soil erosion rates and how Pu isotopes behave in depth profiles along slopes that are subject to lateral podzolization. I can not wait to see the results!
May 2022
Off-Campus short-term in Juneau, Alaska!
I had a blast with students and collaborators in Juneau, Alaska! I lived and worked there for two years during the Covid pandemic and could not receive anybody. It was so good to share the place that one day I called home. I created and led this off-campus short-term in Alaska to offer students field-based learning experiences in a variety of Southeast Alaska ecosystems. The Tongass National Forest is home to an extraordinary landscape diversity that offers an excellent natural laboratory on Earth to observe the interactions among geology, climate change, and soil development. Many thanks to Rebecca Minor and Diogo Spinola for supporting this course 24/7, and David D`Amore and Sonya Nagorsky for the amazing guest lectures!
October 2021
The James and Julie Bockheim Distinguished Lecture in Soil Science at UWM! 2
I had a blast during my short visit to the University of Wisconsin Madison for my lecture! I am feeling over the moon to have received such recognition for work. It was an honor to receive an award that carries Prof. Bockheim´s name, who is a reference in pedology and a role model for me. I would like to thank all faculty and students who have received me in Madison, especially Alfred Hartemink, Yakun Zhang, Erika Marin-Spiotta, Nick Balster, Thea Whitman, and Zac Freedman.
October 2021
The James and Julie Bockheim Distinguished Lecture in Soil Science at University Wisconsin M!
I was invited to present my research at the James and Julie Bockheim Distinguished Lecture in Soil Science this year.! I am so honored to have received such an invitation!! Looking forward to meeting the UWM community, present my research, and learn more about Wisconsin soils with Jim Bockheim and Alfred Hartemink in 1-day field trip!
June - July 2021
Summer field work: Sampling a soil chronosequence on moraines of the Mendenhall Glacier, SE Alaska
The soil team took the West Glacier trail and went to the terminus of the Mendenhall Glacier to understand moraines deposition and early stage of soil development. We sampled a 3 years old moraine, which is the youngest soil of our chronosequence. It was like traveling back in time! Certainly, one of the best field work ever!
March 2021
New publication on STOTEN
I`m glad to announce that our new paper review on global soil erosion modelling just came out of the oven! This is a result of collaborative work among 66 soil erosion scientists from 25 different countries. Our goals were to better understand soil erosion modelling worldwide and create and share an open soil database named “Global Applications of Soil Erosion Modelling Tracker (GASEMT)” which includes 3030 records from126 countries.
May 2020
Scouting for a new study area in Douglas Island - Tongass National Forest
June is around the corner and there are still a lot of snowpacks in the high country!
February 2020
Short-term research stay in the Department of Chemistry and Biochemistry - Northern Arizona University
I traveled to Flagstaff (Arizona) for a research stay with Prof. Michael Ketterer at NAU. Mike developed the analytical method to measure Pu isotopes using ICP-MS and I`m so honored and thankful to have received training from him. It`s exciting to come back home with fresh data of our soil samples from SE Alaska!
August 2019
Field trips to Heen Latine Experimental Forest - Tongass National Forest, Alaska
Since June, I have been doing fieldwork together with a great team of soil scientists from the US Forest Service, University Alaska Fairbanks and Oregon State University. This was the last field trip of the season in the HLEF and all soil samples for Pu measurements are done!
July 2019
Field trip to Camp 18 - Juneau Icefield
We had an awesome and successful trip to Camp 18 in the Juneau Icefield. Have a look at the google map below and see the location of this massive ice sheet that covers part of North America.
