The Country 17/06/25: Dr Beata Bukosa talks to Jamie Mackay

A Niwa-led study has found New Zealand’s native forests are absorbing more carbon dioxide (CO2) than previously thought. We catch up with the Niwa atmospheric scientist, who led the study, to learn more.

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Episode Transcript

Speaker 1 (00:00):
So here's a good news story for you on a Tuesday.
A new one lead study has found New Zealand's native
forests are absorbing more carbon dioxide than previously thought. The
study leader joins us now on the show. Her name
is doctor Biatabukosa, and she says this could have real
implications for New Zealand's greenhouse gas reporting, carbon credit costs,

(00:25):
and climate and land use policies. So how come you
figured this one out, doctor Biata, Because I would have
thought and native forests would have sucked up plenty of
CO two.

Speaker 2 (00:37):
Yeah, that's a very good point. So native forests are
actually assumed to be carbon assumed to be carbon neutral,
so they absorb and emit the same amount of carbon dioxide.
So we use a method called a top down method
where we use atmospheric measurements to calculate how much carbon
dioxide is being taken up and released by New Zealand

(00:57):
on a national scale, including forest and what we found
is that there are some quite big differences down in
the South Island, around Fjordland and the southwest coast of
the South Island, where it seems to be much more
sew to being taken up by these forests than I can.

Speaker 1 (01:14):
I to stop you there? Sorry, can I to stop
you to avoid confusion and ask you this question. You
said previously you thought these native forests were carbon neutral.
I thought all along I would have to be carbon positive,
absorbing more than they're emitting.

Speaker 2 (01:31):
Yeah, so this is really a balance between mature forests
and other forests just because they start growing it. Basically,
the traditional thinking is their carbon neutral because all the
carbon that they could absorb is already in the tree,
so there's no additional carbon that they can take up.
In contrast to for example, exotic forests, there are a
fast growing forests, then year to year, as they're growing,

(01:53):
they're taking up more and more carbon. And the type
of forests that we have down in South Island, there
are indigenous forests. So that's why this thinking, this first
thinking was happening. However, as I said, it seems like
that that might there might be some other processes that
are leading to additional carbon updates.

Speaker 1 (02:17):
Obviously there's regeneration and these night of forests that must
be sucking up a favorite carbon.

Speaker 2 (02:23):
Absolutely, and that's a brilliant point because that is one
of the one of the explanations of this carbon uptake.
We need to remember that these are environments that we
have quite a little bit of landslides, slips, erosion, and
quite a bit of precipitation as well, so some of
the carbon might be transported down into rivers and out

(02:44):
the ocean. But also we have other forms of disturbance
and pest control for example, that can then lead to
additional carbon updates.

Speaker 1 (02:52):
Okay, So so while the South Island and particularly the
Fiordland Night of Forests doing better than I don't know,
Central north Land Night of Forest.

Speaker 2 (03:02):
I mean, it's really the different We think it's really
due to different environments that have the different impacts that
we have there. As I said, these slips and landslides,
So the North Island is also taking up quite a
bit of carbon. However, when we do this calculation from
atmospheric measurements, our measurement network coverage is stronger in the

(03:25):
South Island at the moment, so we can estimate these
numbers better in the South Island, while in the North
Island there are a few places where we are missing
atmospheric measurement, which means that there might be additional carbon
happening there as an updake happening there as well, or
carbon source. We can't really know at this moment, depending

(03:46):
on where we put additional measure additional measurement site.

Speaker 1 (03:49):
So so the final question for you, what are you
guys at may we're going to do with the some promotion.

Speaker 2 (03:55):
Yes, So at the moment, with the study, we identify
that there is a discrepancy on how much carbon is
being taken up by this forest. However, we have it
identified the exact processes that are responsible for that carbon
utic and also where the carbon goes. So our next
step is to develop a very detailed method and research

(04:18):
idea to exactly identify the processes responsible for this carbon sink.

Speaker 1 (04:23):
Doctor Bieta Bucosa, I love that name. What's the heritage
of that name? For the origin?

Speaker 2 (04:30):
Yeah, so it is originally Hungarian, but I was born
in Serbia, so my accent is kind of a combination
of Serbian Hungarian.

Speaker 1 (04:40):
Did you play tennis as a kid. All the good
women's pliers come out of Serbia.

Speaker 2 (04:44):
Yeah, I was more more interested in basketball.

Speaker 1 (04:48):
Okay, good on, Thanks very much for some of your
tom Thanks for being a good sport. Interesting information here
on the country.

Speaker 2 (04:54):
We'll see you later, thank you