United in diversity – the hidden treasure of WILDCARD
by Lucia Seebach
Europe is unique. Within a relatively small geographical area, an extraordinary diversity unfolds: landscapes, climates, forests, and species form a natural treasure of remarkable richness. This biodiversity is one of Europe’s greatest strengths – but also one of its greatest challenges. Protecting and understanding biodiversity is not a one-time task; it is a continuous effort that can only succeed if we work together.
Diversity, by its nature, brings complexity. This is true not only for Europe’s ecosystems but also for the way we observe and measure them. Forests do not stop at national borders, yet the methods used to monitor them often do. While standards for forest inventories exist, each country or institution has developed its own dendrometric survey methods (the measurement of tree and stand characteristics such as tree diameter, height, volume, and growth), shaped by national priorities, management objectives, and historical tradition. As a result, long-term forest information has traditionally been built for regional or national analyses rather than for a harmonised European perspective.
And yet, within this diversity lies a hidden treasure. Across Europe, enormous amounts of valuable data already exist. The key question is: how can we bring this information together? How can we harmonise these datasets to unlock their full potential and create a “golden state” of knowledge that allows us to address pressing issues such as how to store carbon efficiently, reduce biodiversity loss, and understanding and responding to the impacts of climate change? Achieving this requires not only technical solutions, but also time, expertise, and resources to build and maintain a shared database capable of supporting a wide range of scientific and policy-driven questions.
What Is dendrometric data and why do we need it?
Dendrometric data form the backbone of forest monitoring. They include measurements such as tree diameter, species, height, volume, and deadwood – key indicators for forest structure, growth, and carbon stocks. Collecting such data is not new. In many countries, dendrometric measurements have been part of National Forest Inventories (NFIs) for centuries, providing invaluable long-term records.
In strict forest reserves (designated areas of forest set aside e.g. for conservation or research purposes), however, systematic dendrometric monitoring often started much later. One can imagine the current situation as a large puzzle: countless pieces collected over decades, sometimes centuries, using different shapes and scales, all in different countries. Today’s challenge is to fit these pieces together into a coherent European picture that allows us to understand past developments in forest reserves and respond effectively to current and future environmental challenges on a wider scale.
How we tackled this challenge in WILDCARD
Within WILDCARD, we addressed this challenge step by step. Firstly, we established a dedicated data taskforce to work on harmonisation issues and to develop a common data template. This meant dealing with very practical issues, such as different names for the same information, varying definitions, and how to handle tricky variables like deadwood.
The first harmonisation trials were carried out with internal project partners across a limited number of sites. Once the approach proved workable, we extended it to external partners within the European Forest Reserve Initiative (EuFoRIA) network, significantly increasing the number of contributing sites. The result is a unique and growing database that will serve as a valuable resource for future research and collaboration across Europe.
Data heroes behind the scenes
None of this would have been possible without the dedication of the project’s “data heroes.” Harmonising diverse datasets is demanding work, requiring both technical expertise and deep knowledge of forest monitoring practices. Key challenges included dealing with different levels of detail in the data and reconciling fundamentally different monitoring methods – for example, in deadwood assessment, where approaches can vary greatly between countries and institutions. But thanks to the commitment of colleagues of the institution Výzkumný ústav pro krajinu (VUK) in the Czech Republic, these challenges were overcome. VUK, a Public Research Institute dedicated to studying landscapes and their ecosystems, helped to compile dendrometric datasets from more than 800 forest sites all across Europe and harmonized the data within one database. This database ensures that Europe’s diverse forest data can now speak a common language.
In the end, WILDCARD shows that diversity is not a barrier but a strength – if we manage to unite it. By bringing together Europe’s rich and varied forest data of these valuable forest reserves, we are turning a hidden treasure into shared knowledge for the benefit of science, policy, and future generations.
Featured image: forest reserve „Siedigkopf“ in the Black Forest in Germany (photo @Alexandra Kage)
