How much can a stalagmite tell us about the Earth’s past, and what can stalagmites reveal about climate change?

In the second season of “Keeping up with the Boost Fellows”, GSO’s Birte Seffert travels across Germany to visit the 15 fellows who started their Klaus Tschira Boost Fund projects in 2025. The series offers a closer look at their research, their working environments, and the realities of building a research career in Germany today.

This time, the visit leads to the University of Trier and to Björn Klaes, Akademischer Rat and head of the soil science laboratory, whose work connects soil science, geology, climate research, and long-term scientific curiosity.

What stalagmites can tell us about climate

Björn’s research centers on speleothems, mineral formations that grow in caves over long periods of time. One of the most well-known types are stalagmites, which grow upward from the cave floor.

At first glance, they might look like simple rock formations. But they are, in fact, detailed archives of environmental history. Similar to tree rings, stalagmites grow in layers. Each layer captures information about the conditions at the time it formed, including rainfall, temperature, vegetation, and even events like volcanic eruptions. Such stalagmites can record several thousands of years at high resolution down to (sub)annual time scales.

Björn’s Boost-funded project uses such stalagmites from South Patagonia to reconstruct past climate variability across different latitudes in the Southern Hemisphere. The goal: to better understand how climate systems evolved during the Holocene with implications for the understanding of the current climate situation.

A project shaped by continuity

The material Björn works with comes from a unique collection of speleothems from the Patagonian fjord region, originally gathered by Prof. Rolf Kilian. Björn had planned to pursue his PhD under Kilian. Kilian entrusted him with responsibility for this collection, but tragically died during a field expedition in Patagonia. Therefore, Björn sees his work as a continuation of what Kilian started.

The remote study areas within the Patagonian fjords are difficult to access and characterized by extreme climate conditions. Fieldwork there is logistically complex and currently nearly impossible. This makes the existing collection even more valuable, and shifts the focus from collecting new material to analyzing what is already there.

What the Boost Fund makes possible

Working with speleothems is not only intellectually demanding, it is also technically and analytically complex. Understanding how a stalagmite forms, and how to interpret its chemical and isotopic signals, takes years of experience. The analysis itself requires time, specialized methods, and sustained focus. “I have the material and strong research partners,” Björn explains.

“What I need, and what the Boost Fund provides, are the resources for the long and complex analysis.”

The Boost Fund enables him to systematically analyze this unique collection and extract high-resolution climate data that would otherwise remain unavailable.

From vocational training to research

Björn’s path into academia did not start with a straight line.

Before his studies, he completed vocational training and worked in an engineering office during his bachelor’s and master’s studies. This experience still shapes how he approaches research and teaching today. It influences how he structures work, how he thinks about practical feasibility, and how he interacts with technical staff and students. It also brings a different perspective on timelines, communication, and problem-solving — one that is grounded in applied work environments.

Leading a lab: more than just research

In addition to his research, Björn now also leads the soil science laboratory.

Being a laboratory head means more than overseeing experiments. It involves responsibility for equipment, safety, workflows, and people, from students to technical staff. It also means balancing long-term research goals with day-to-day operational demands.

Akademischer Rat: a specific role in the system

Björn also holds the position of Akademischer Rat, a permanent academic role within the German university system.

This role typically combines teaching, research, and administrative responsibilities, often with a strong institutional anchoring. Compared to a professorship, it usually comes with less formal independence in terms of chair structures, funding authority, or long-term strategic direction.

At the same time, it is important to be clear about what this role is and what it is not:

• It is not a standard or widely available career path
• Positions are relatively scarce
• They depend strongly on institutional structures and long-term staffing decisions

For many, it can offer stability and continuity. But it is not a guaranteed or scalable pathway within the academic system.

About the KT Boost Fund

The Boost Fund supports postdoctoral researchers and early group leaders in Germany with flexible funding for independent, often higher-risk and interdisciplinary projects, combined with career development opportunities and access to a strong peer network.

The program addresses a critical phase after the PhD, where researchers are expected to develop independence, but often lack the resources and flexibility to do so. It creates space to explore new directions, build collaborations, and take responsibility early on.