How we get our samples from trees

Generally, there are two methods we use to obtain our samples.  Which one we use depends on several factors:

- If the trees are in a really isolated area away from roads/tracks

- What land management agencies permit

- What sorts of analyses we want to do

- Whether the trees are dead or alive

- If they are dead, whether they are lying on the ground or standing

If its possible and permitted, and the trees are lying on the ground dead, then we prefer to take slabs or dicsc from them because this makes dating them easier and also means that we can use the wood to do multiple analyses because there's more of it. The most commonly measured feature in the wood in the width of the rings, but we can also measure how dense the wood is within each ring, how big the cells are, the angle of fibres and isotope variation (most commonly O18 and C12/C13). To get discs/slabs, we use a chainsaw - see the picture in which I'm using a 'baby saw' to cut a discs from a dead stem on the ground in Mongolia.

 

Sampling in Mongolia

In much of the work we do, however, we need to sample living trees.  of course we can't cut discs from them, so we take what are called increment cores with an increment corer (or borer if you're American/Canadian). See the YouTube video of Jonathan explaining the coring process from one of New Zealand's sub-Antarctic Islands.

Oh, and these places are just two of the really fascinating places we get to go to, just to do our jobs!