Maxime Caradec, climbing arborist in South Finistère

The CS TSA, the French national specialist certificate in tree pruning and care, is the French diploma of the arborist's trade. As the profession is not regulated in France, anyone can call themselves a tree surgeon, buy a chainsaw and charge for a job. For a private client, the certificate is therefore one of the few things that can be checked before signing.

A client does not see a diploma. They see a cut, and they see it for the next twenty years. A branch is cut flush with its collar, the ridge of wood that marks where it joins the trunk and that holds the tissue able to close the wound. Cutting into this collar removes that ability. Leaving a stub makes it useless, because the stub dies and the decay works its way down to the trunk. Either way the wound stays open, and a tree does not heal like skin: it compartmentalises, meaning it walls off the damaged area without ever repairing it.

Maxime Caradec's training also covers access to the tree. Rope work and dismantling with a lowering line, where each section is lowered under control rather than dropped, are what make it possible to work above a roof, a conservatory or a fence without breaking what lies below. It is slower than felling in one piece, and it is why two quotes can differ twofold without covering the same job.

Finally, it covers what must not be done. Topping, which means cutting off the top of the tree at an arbitrary height, is still commonly offered. It produces numerous, poorly anchored shoots that grow back faster and break more easily than the branches removed. A topped tree becomes dangerous again within a few years, and the job has to be done again.

The tree heritage of South Finistère is changing, and changing fast. Maxime Caradec sees tree diseases spreading, which he links to global warming and to urban growth. A tree weakened by drier summers, by compacted soil or by a shrinking space at its foot withstands less well what it used to cope with.

At the same time, he sees invasive species advancing. The Asian hornet settles in tree crowns, which raises a safety question before it even raises a health one: a nest found during a climb stops the job. The processionary caterpillar, for its part, is no longer confined to pines and now colonises cedars and gorse, two plants found everywhere on this coast. Its stinging hairs are dangerous to people and to animals, which rules out treating a nest yourself.

These two findings shape the work. They explain why the assessment comes before the job rather than after it, and why biological pest control is preferred to synthetic products in gardens where children and animals live.