New publication: to core, or not to core, that is the question.

How does drilling holes into the world’s most valuable trees impact on their health?

“Ask the trees how they want to be educated, they will teach you about them more than books” – Wilhelm Leopold Pfeil (1866)

To core, or not to core

Iconic baobabs (top) and ancient Bristlecone pines (bottom) have all been sampled with an increment bore corer (centre), despite little understanding of how this technique impacts on tree health. (Image credits: Larre, Tommaso Sitzia, Rick Goldwaser)

Trees are natural sources of invaluable environmental information that is preserved in the growth and structure of their stems, branches and roots.  This insight is tapped by taking a narrow core of wood from the tree trunk with a coring device.  The resulting data provides powerful insights for diverse fields including ecology, climatology and archaeology archaeology, biogeography, ethnobotany, and even carbon accounting programs, and the approach is rapidly increasing in popularity.

In most studies it is assumed that this coring has no impact on tree health, including changes in reproduction, stress, trunk strength and even growth rates. There is, however, a small body of research reporting significant, and in some cases fatal outcomes, from this sampling technique. Of great concern is that many of the world’s most iconic and valuable living trees, including the ancient Bristlecone pines of the Methuselah stand in California and heritage Baobab trees in South Africa and Madagascar, have been cored.  In a recent example, the coring of a critically endangered Mauritian endemic tree was a strong contributor to the death of the first known tree of that species, leaving just two remaining adult individuals in existence.

In a new manuscript out today in Biological Reviews, led by Edward Tsen, we show that because of the very limited knowledge on how trees respond to coring, and how variable known responses are both within and between different species, that considerable caution must be applied to all future studies involving this technique.  We outline a new framework for guiding best-practice application of tree coring to minimise negative impacts on tree health, while working towards maximising scientific insight from this incredibly useful method.

Read more by downloading the paper here.

Tsen, E.W.J., Sitzia, T. & Webber, B.L. (2015) To core, or not to core: the impact of coring on tree health and a best-practice framework for collecting dendrochronological information from living trees. Biological Reviews (Online early; DOI: 10.1111/brv.12200).