11 Sharon Robinson: Antarctic moss

[00:00:09] [SPEAKER_02]: I'm Catherine Polcz and this is Plant Kingdom. I'm recording in Sydney on the land of the

[00:00:15] [SPEAKER_02]: Gadigal people of the Eora Nation, and I pay respect to their elders past, present, and

[00:00:20] [SPEAKER_02]: future. Plant Kingdom is a conversation series about plants, nature, and environment featuring

[00:00:26] [SPEAKER_02]: scientists, artists, researchers, and writers. We release two conversations each month and

[00:00:32] [SPEAKER_02]: hear from people who have an intimacy with plants and nature. We discuss their work, stories,

[00:00:37] [SPEAKER_02]: and reflections from the field. Today's conversation is with University of Wollongong Professor and

[00:00:44] [SPEAKER_02]: Dean of Researcher Development Dr. Sharon Robinson. In our conversation we travel thousands

[00:00:51] [SPEAKER_02]: of kilometers by virtual sea to Casey Station Antarctica where Sharon has been researching

[00:00:57] [SPEAKER_02]: ancient moss beds since 1996. Here's our conversation.

[00:01:07] [SPEAKER_02]: Well, thank you so much for chatting with me today again. I've been really looking forward to

[00:01:13] [SPEAKER_02]: speaking again about all of your incredible work. I guess to start us off, it's always interesting

[00:01:21] [SPEAKER_02]: to hear people's journey into their research and also when kind of plants became alive for them

[00:01:28] [SPEAKER_02]: in part of their work. And did your research start in the lab and then fieldwork came after

[00:01:35] [SPEAKER_02]: for you or what's kind of your relationship with lab and fieldwork? I guess when I was doing

[00:01:40] [SPEAKER_00]: my degree in my third year, I did an undergraduate research project. I was working on zinnias cells

[00:01:47] [SPEAKER_00]: and trying to make cells in culture produce plant pigments, which is kind of interesting because

[00:01:53] [SPEAKER_00]: then I came back into that as a postdoc many years later. But that thing of the fact that you

[00:01:59] [SPEAKER_00]: can take a plant and then take cells from it and regrow a plant or make the cells produce

[00:02:07] [SPEAKER_00]: things, that sort of ability of plants to reproduce in that way was really fascinating

[00:02:13] [SPEAKER_00]: to me. And so that was when I sort of really got into the research side of things, but very

[00:02:19] [SPEAKER_00]: much in the lab. I did carrot cell cultures for my PhD. So I stayed in that cell culture space

[00:02:24] [SPEAKER_00]: using a whole load of different techniques to study how plants work. And that's always been

[00:02:29] [SPEAKER_00]: something that I've been really fascinated by. You know, what makes them tick? There's so much

[00:02:34] [SPEAKER_02]: alchemy in everyday, everyday plants and what they accomplish and of course your research

[00:02:40] [SPEAKER_02]: plants that are dealing with a lot of challenges and where they live, which I guess will dive into

[00:02:48] [SPEAKER_02]: next. So a lot of your research is on Antarctic mosses and you've been studying these mosses

[00:02:55] [SPEAKER_02]: I believe for decades. And I'd love to just go back to how this started for you. So

[00:03:01] [SPEAKER_02]: you heard about the mosses before you saw them. What kind of interested you

[00:03:06] [SPEAKER_00]: originally in the mosses? So I was actually working on the plants that grow in Australian

[00:03:13] [SPEAKER_00]: rainforests and I was really interested in the way in which they are, you get a whole bunch of

[00:03:19] [SPEAKER_00]: rainforest plants that produce, instead of producing green new leaves with chlorophyll in,

[00:03:26] [SPEAKER_00]: they produce leaves with different pigments and particularly red pigments. So you can go

[00:03:30] [SPEAKER_00]: into a rainforest and see all these pink leaves. Sometimes they're white because they have no

[00:03:36] [SPEAKER_00]: pigments in but often they're pink or bronzy coloured. And I was really interested in what it was that

[00:03:41] [SPEAKER_00]: the plants were doing, you know why weren't they making chlorophyll? Why were they putting these

[00:03:45] [SPEAKER_00]: other pigments in? What sort of protection did that give them or you know what was the reason

[00:03:50] [SPEAKER_00]: behind it? I was giving a talk at a conference and somebody came up and said oh if you're

[00:03:54] [SPEAKER_00]: interested in red pigments in plants you should go to Antarctica because the moss turns red every

[00:04:00] [SPEAKER_00]: summer. And I thought oh that's really fascinating and I'd never thought about working in Antarctica or

[00:04:06] [SPEAKER_00]: doing work with mosses particularly. But I thought well maybe that's to do with, maybe one of the

[00:04:12] [SPEAKER_00]: reasons why the plants might produce red pigments is to protect themselves from excess radiation

[00:04:18] [SPEAKER_00]: and particularly ultraviolet radiation. And so with the ozone hole being a big thing at the time

[00:04:24] [SPEAKER_00]: and wondering whether the reason the plants were going red was because of extra UV because of ozone,

[00:04:31] [SPEAKER_00]: it seemed like a reasonable thing to investigate. And so I wrote a grant and I was successful

[00:04:37] [SPEAKER_00]: and that's where my Antarctic career took off from. So it was really an accident, it was

[00:04:43] [SPEAKER_00]: a fortuitous, you know one of those serendipitous moments. Yeah changed the whole course of your

[00:04:50] [SPEAKER_02]: research and quite a shift in preparing for field work when it's in the Australian rainforest

[00:04:55] [SPEAKER_02]: versus Antarctica. And I guess for that first trip what was it like when you landed in an

[00:05:07] [SPEAKER_02]: arctic? Was it what you had expected? Did you have expectations? Was there anything that

[00:05:13] [SPEAKER_02]: anything that really surprised you or was unexpected upon that first landing?

[00:05:18] [SPEAKER_00]: Well I guess the whole thing was pretty unexpected because I mean I didn't know,

[00:05:24] [SPEAKER_00]: you know I'd not really been on a long sea voyage before it was 10 days by ship from Hobart.

[00:05:31] [SPEAKER_00]: So it was my first experience on a ship, my first experience traveling across the Southern Ocean

[00:05:36] [SPEAKER_00]: which is you know a pretty big sea and so quite exciting. And luckily I wasn't sea sick so that was

[00:05:44] [SPEAKER_00]: a big bonus but just that sense of distance, you know the fact that it takes 10 days of you just

[00:05:52] [SPEAKER_00]: plodding across the sea and this ship bouncing up and down really gives you an idea of how far

[00:05:57] [SPEAKER_00]: away from Australia and other countries how far away Antarctica really is. And then we went in

[00:06:06] [SPEAKER_00]: really early in the year so back then the first ship into Casey would go in around October

[00:06:12] [SPEAKER_00]: and so we went in early in the season and that meant that the sea ice was still really thick

[00:06:17] [SPEAKER_00]: around the station so about 100 kilometers offshore we were put on a helicopter and we flew

[00:06:25] [SPEAKER_00]: into the station and so again it was my first helicopter ride lots of firsts and we were flying

[00:06:32] [SPEAKER_00]: over sea ice and you see all the different sorts of sea ice so you start off you know you have

[00:06:37] [SPEAKER_00]: a very very thin layer on the on the on the sea when when the ice starts to form and then it

[00:06:43] [SPEAKER_00]: becomes you get pancakes forming which are small blobs of sea ice that bash up against each other

[00:06:49] [SPEAKER_00]: and the edges get sort of mixed crunched up and then it slowly becomes thicker sea ice as those

[00:06:56] [SPEAKER_00]: patches those pancakes fuse together and so you go through all those different forms of ice

[00:07:03] [SPEAKER_00]: and eventually it's just like a white the the sea disappears and you've just got white rafts of

[00:07:09] [SPEAKER_00]: big rafts of sea ice and big sheets of sea ice and then we flew into the station and the

[00:07:18] [SPEAKER_00]: stations the Australian stations are built on ice free areas so they do actually melt out and they're

[00:07:24] [SPEAKER_00]: on ground that you can see in the summer but in October it was still all picture perfect white

[00:07:32] [SPEAKER_00]: snow background and so that was all amazing and then then the other thing I think that really

[00:07:38] [SPEAKER_00]: I really noticed about Antarctica was you expect it to be white but you don't expect all the

[00:07:43] [SPEAKER_00]: other colors so the blue of the sea and the the amazing light that you get because the solar

[00:07:49] [SPEAKER_00]: angle the sun is really low and so you get you get that sort of dawn and dusk colors for hours

[00:07:56] [SPEAKER_00]: in the summer it's 24 hours of light but you have a very long time where you've got

[00:08:00] [SPEAKER_00]: really beautiful pinks and purples and yellows in the sky and the other thing that really

[00:08:05] [SPEAKER_00]: amazed me was you get to see the sun and the moon at the same time because it's 24 hours

[00:08:11] [SPEAKER_00]: of light so when it's a full moon you've got the moon going across the sky as well.

[00:08:16] [SPEAKER_02]: Wow yeah and we never have thought about the sky there and what that looks like

[00:08:22] [SPEAKER_02]: and can you just describe where Casey's station is?

[00:08:26] [SPEAKER_00]: So Casey's station is in East Antarctica and it's pretty much due south of Perth in Western

[00:08:32] [SPEAKER_00]: Australia and so we traveled you know about three and a half thousand kilometers across

[00:08:38] [SPEAKER_00]: the ocean from Hobart to get there so it is a very long way away and then within Antarctica

[00:08:45] [SPEAKER_00]: there's there's a French station off to the east about a thousand kilometers one way and then

[00:08:52] [SPEAKER_00]: a few thousand kilometers the other way we have there's other stations like Davis

[00:08:58] [SPEAKER_00]: station which is another of the Australian stations and some other country's stations so

[00:09:03] [SPEAKER_02]: very very isolated. Long way from the comforts of home and when you're speaking about the different

[00:09:10] [SPEAKER_02]: colors there when you arrived I guess there's not much green right and when you arrived the

[00:09:17] [SPEAKER_02]: mosses were still under snow I guess can you just introduce us to what these moss beds that

[00:09:25] [SPEAKER_02]: you were hunting for are like and what's the story of these moss beds?

[00:09:32] [SPEAKER_00]: So we didn't know where the moss beds were going to be because I was down there with a new

[00:09:37] [SPEAKER_00]: with a student of mine Jane Rosley who now works at the Australian Antarctic Division.

[00:09:42] [SPEAKER_00]: Both of us were new to the place and when we got there there was more than a meter of snow

[00:09:47] [SPEAKER_00]: over everything and so we knew where the moss should be but we couldn't see anything

[00:09:54] [SPEAKER_00]: and then as the spring progressed the snow melted out and eventually the moss beds came came into view

[00:10:01] [SPEAKER_00]: and then you see this amazing verdant green and I was not expecting that absolutely sort of almost

[00:10:10] [SPEAKER_00]: psychedelic green it was like because compared to the snow and you know it's just such a vibrant

[00:10:17] [SPEAKER_00]: gam contrast and so that was really beautiful. Casey has some of the best moss beds on the whole of

[00:10:24] [SPEAKER_00]: East Antarctica and they rival some of the moss beds that you get on the peninsula and I had heard

[00:10:31] [SPEAKER_00]: that anecdotally that when I went in so I knew Casey did have these good moss beds and they are

[00:10:36] [SPEAKER_00]: amazing but the more places that I've been to since the more I realize and appreciate those

[00:10:42] [SPEAKER_00]: moss beds that Casey's just the extent of them so they do go red when they're stressed the mosses

[00:10:48] [SPEAKER_00]: go red if they're really stressed they go brown and gray but when they're in peak health and they're

[00:10:56] [SPEAKER_00]: being fed by plenty of meltwater they're just luscious green and it's just really it really

[00:11:02] [SPEAKER_00]: is amazing and there are long streams and around lakes that are present in the region

[00:11:09] [SPEAKER_00]: and so we are really lucky that we have those those moss beds that Casey and they are pretty unique

[00:11:18] [SPEAKER_00]: I mean there are some some other amazing mosses that grown pillars in freshwater lakes near one

[00:11:25] [SPEAKER_00]: of the Japanese stations but I've never actually been there but you can dive amongst the moss

[00:11:31] [SPEAKER_00]: pillars which would be pretty amazing pretty cold but yeah for it's for the brave there isn't it

[00:11:41] [SPEAKER_02]: are the mosses kind of the dominant flora of Antarctica I think it's pretty would surprise

[00:11:47] [SPEAKER_02]: a lot of people to think about plants growing in freezer conditions there can you can you just

[00:11:53] [SPEAKER_02]: talk a bit about them in context of the other plant species there what can you what can you

[00:11:59] [SPEAKER_00]: yeah so all the plants are really tiny or all the vegetation is really tiny mosses for most of

[00:12:05] [SPEAKER_00]: Antarctica mosses are the main the largest species of plant and basically everything has to be able

[00:12:14] [SPEAKER_00]: to survive in those windswept freezing conditions and so you get mosses you get amazing lichens

[00:12:21] [SPEAKER_00]: so the lichen vegetation is even probably more spectacular than the mosses and there's many

[00:12:26] [SPEAKER_00]: more lichen species and the lichens cover a much bigger area the other things that you get are

[00:12:34] [SPEAKER_00]: cyanobacterial mats and you get terrestrial algae so you get things like Ulva they look like Ulva

[00:12:42] [SPEAKER_00]: they're called called praise Yola but it looks like the Ulva that you get on the beach so green

[00:12:46] [SPEAKER_00]: green algae that grow on the ground and they're particularly prevalent around penguin colonies

[00:12:53] [SPEAKER_00]: so where there's lots of nutrients off the penguin colonies you get these bursts of very very bright

[00:13:00] [SPEAKER_00]: green sheets of algae basically and then in the middle of the summer when the snow starts to melt

[00:13:07] [SPEAKER_00]: the water starts to melt within the snowpack you get snow algae and that they're little

[00:13:13] [SPEAKER_00]: single celled organisms which swim through this through the water that's surrounding the

[00:13:19] [SPEAKER_00]: snow particles and they are red green yellow all different colors and so you get these blooms

[00:13:25] [SPEAKER_00]: these snow algal blooms where the whole other side of a snowpack like a great big area hundreds of

[00:13:31] [SPEAKER_00]: meters across might go pink and so that's the vegetation it's all really small

[00:13:39] [SPEAKER_02]: wow does this snow I've never have to go look up snow algae after this does it occur

[00:13:45] [SPEAKER_02]: anywhere else or is that only in in the Arctic I mean in the in other polar regions so in the

[00:13:50] [SPEAKER_00]: Arctic in on the tops of mountains so basically where there's snow and again you have to have water

[00:13:57] [SPEAKER_00]: surrounding the ice so there has to be there has to be something that those algae can swim through

[00:14:03] [SPEAKER_02]: for them to be able to bloom incredible and just to go back to moss can you just remind us

[00:14:12] [SPEAKER_02]: what types of organisms mosses are what makes the moss a moss what's what's unique about moss

[00:14:19] [SPEAKER_00]: so mosses are one of the earliest forms of plants so that's not to say that the ones that we're

[00:14:25] [SPEAKER_00]: working on are ancient particularly but mosses are one of the early forms of plants and their

[00:14:31] [SPEAKER_00]: unique characteristics are that they really don't they don't have plumbing or they

[00:14:39] [SPEAKER_00]: can survive in Antarctica is because they don't have plumbing so there's no plumbing to get frozen

[00:14:44] [SPEAKER_00]: by the freezing conditions and so that's their superpower if you like in Antarctica and other

[00:14:51] [SPEAKER_00]: polar regions and so it means that basically everything that washes over them in the water

[00:14:57] [SPEAKER_00]: is is there instead of having roots that can take minerals up from the soil

[00:15:02] [SPEAKER_00]: what they do is they take minerals out of the water as it's running over them

[00:15:06] [SPEAKER_00]: and so they're much more sensitive to environmental pollutants that might be coming down in rain

[00:15:13] [SPEAKER_00]: but equally they can mop up those compounds they're really good at grabbing onto any compound

[00:15:19] [SPEAKER_00]: that's dissolved in rain but because of that they don't have the waterproof strengthening

[00:15:25] [SPEAKER_00]: tissue that higher plants have and that means they don't have very much in the way of support

[00:15:31] [SPEAKER_00]: that means they can't grow very big so hence they're very small stature they don't and they don't have

[00:15:37] [SPEAKER_00]: they don't have roots as a way of holding themselves into the soil as well so they

[00:15:44] [SPEAKER_00]: they're all of those things are reasons why they can't grow very big you know they don't

[00:15:49] [SPEAKER_00]: have roots that can go down deep into the soil and tap for water so they're reliant on the

[00:15:54] [SPEAKER_00]: water that flows over them they can only be growing when the water's flowing over them

[00:16:00] [SPEAKER_00]: if the water disappears they just dry out and then they can survive frozen

[00:16:07] [SPEAKER_00]: freeze dried or they can survive dried and really hot so the crazy thing about moss is that we can

[00:16:14] [SPEAKER_00]: find the same species in the hot deserts in south Australia and at 50 degrees plus 50

[00:16:22] [SPEAKER_00]: and the same thing will survive same species will be surviving in Antarctica

[00:16:28] [SPEAKER_00]: at minus 40 in the winter and they're unique in the plant kingdom because they the adult body of the

[00:16:37] [SPEAKER_00]: of the moss plant is haploid so they only have one set of genetic information and it's only when

[00:16:43] [SPEAKER_00]: they sexually reproduce and you get the capsules formed that you get caps capsules with

[00:16:49] [SPEAKER_00]: haploid the spores you have a very short period where the capsule which is producing

[00:16:54] [SPEAKER_00]: the spores is a diploid organism so with all the other plants that we look at you know a tree that

[00:17:01] [SPEAKER_00]: we look at outside that's like us it's got two sets of chromosomes mosses have only got one

[00:17:07] [SPEAKER_00]: they can also reproduce just by cloning so if a small fragment of moss breaks off from a larger

[00:17:14] [SPEAKER_00]: patch and ends up somewhere with good conditions they will it will just resprout so they they have

[00:17:21] [SPEAKER_00]: that which is another thing that really helps them in Antarctica because where we are at Casey

[00:17:26] [SPEAKER_00]: there aren't any capsules there's never any sexual reproduction all of the all of the

[00:17:33] [SPEAKER_00]: spreading that they do happens because little fragments get washed down streams or little

[00:17:38] [SPEAKER_00]: clumps get washed away or blown away and end up somewhere where there's water and nutrients

[00:17:42] [SPEAKER_02]: and they grow so does that mean they're all clones like it's one genotype or yeah there's

[00:17:51] [SPEAKER_00]: there's a few but there's there is actually quite limited genetic diversity on the peninsula where

[00:17:58] [SPEAKER_00]: it's warmer there's an the growing season is long enough and there's enough water for the sperm to

[00:18:04] [SPEAKER_00]: swim to the eggs and you actually do get sexual reproduction but it's only on the peninsula

[00:18:08] [SPEAKER_02]: how many species of moss are there and do we know how they how they got there have they clung on since

[00:18:15] [SPEAKER_02]: Antarctica looked very different and was warmer or have they have they migrated there do we know

[00:18:23] [SPEAKER_00]: so so we used to think that everything in Antarctica had actually come in that you know

[00:18:28] [SPEAKER_00]: that the whole lot had been covered by ice sheets and so everything that was there when

[00:18:32] [SPEAKER_00]: Antarctica was warmer had disappeared but now we know that the tops of the mountains

[00:18:39] [SPEAKER_00]: that stick up through the snow and ice so these might be a mountain that's three to four kilometers

[00:18:45] [SPEAKER_00]: tall but the very top of it is sticking out through the ice sheets and at the top of those

[00:18:51] [SPEAKER_00]: mountains you get these unique communities of invertebrates and mosses and plant and other

[00:18:57] [SPEAKER_00]: things that are that have basically been been isolated there in refuge those refugia for a very

[00:19:04] [SPEAKER_00]: very long time so some of the things that are there have probably been there for an extremely

[00:19:09] [SPEAKER_00]: long time and possibly since you know Antarctica was warmer millions and millions of years yeah

[00:19:16] [SPEAKER_00]: wow but then there are other ones that have probably come in more recently via the wind

[00:19:23] [SPEAKER_00]: and because the wind patterns around Antarctica is so strong we think that a lot of the vegetation

[00:19:30] [SPEAKER_00]: like at spores would will obviously be coming in and some of those again might might take

[00:19:35] [SPEAKER_02]: take root they could be blowing in on the wind and how beautiful to think about those communities

[00:19:42] [SPEAKER_02]: just hanging on in isolation on those mountain tops over millions of years of change yeah so we

[00:19:48] [SPEAKER_00]: like to think about them as it's like their islands in the ice so then you get these island

[00:19:52] [SPEAKER_00]: communities that are all different from one another because they've been separated by ice for all those

[00:19:57] [SPEAKER_02]: thousands of years I guess there's extremes in the conditions they're surviving in the summer

[00:20:02] [SPEAKER_02]: and in the winter what are the harsh conditions that these moss beds are surviving so basically

[00:20:09] [SPEAKER_00]: everything has to grow be able to grow through the very short summer season which might be only

[00:20:16] [SPEAKER_00]: a few weeks or a couple of months long so that's usually December and January the rest of the year

[00:20:23] [SPEAKER_00]: it's frozen and so the thing that mosses are able to do and lichens and all the animals that live in

[00:20:29] [SPEAKER_00]: the moss beds they can all survive frozen in the snow under snow for eight to ten months a year

[00:20:37] [SPEAKER_00]: and emerge for a very very quick growing season of a few weeks and make enough carbon make

[00:20:45] [SPEAKER_00]: enough new growth in that time to maintain their growth rates so desiccation tolerance

[00:20:53] [SPEAKER_00]: so the conditions and in the summer air temperatures will be one or two degrees

[00:20:59] [SPEAKER_00]: and get down to minus 10 overnight in the winter we're looking at temperatures on the coast where

[00:21:05] [SPEAKER_00]: the nighttime temperatures will be minus 40 and the daytime temperatures will also be below zero

[00:21:11] [SPEAKER_00]: so that's the time when the mosses are basically just frozen dried dormant in the snow and

[00:21:19] [SPEAKER_00]: it's also really windy and obviously in the winter there's no water so there's no light in

[00:21:25] [SPEAKER_00]: the middle of winter there's no water and then in the summer you've got water from the snow melt

[00:21:31] [SPEAKER_00]: you've got 24 hours of sunlight and you've got the sun also helping to warm the moss beds up

[00:21:38] [SPEAKER_00]: so we know that in the summer the moss beds can be 20 degrees above the air temperature because they're

[00:21:44] [SPEAKER_00]: basking in the sun and warming themselves up and that because of that they're able to actually

[00:21:50] [SPEAKER_00]: focus on the size and in their in their little micro habit hats tucked away behind rocks

[00:21:56] [SPEAKER_02]: sheltered from the wind yes they're kind of creating their own micro climate for themselves

[00:22:03] [SPEAKER_02]: and then benefits a lot of other creatures right you you refer to them as as nurseries for

[00:22:10] [SPEAKER_02]: other plants and also old growth forests at the same time what's kind of the ecology of the moss

[00:22:16] [SPEAKER_02]: beds in terms of what what else is kind of hitching a ride so so the moss is a home to

[00:22:24] [SPEAKER_00]: a number of the invertebrates that live in Antarctica so there's tardy grades which

[00:22:28] [SPEAKER_00]: we like to call moss piglets so if you imagine that you're sort of a few millimeters high and

[00:22:34] [SPEAKER_00]: you're walking through a forest of moss and you've got these animals that are similarly the moss piglets

[00:22:39] [SPEAKER_00]: would probably be about piglet size then but you've you've basically your animals living inside

[00:22:44] [SPEAKER_00]: those moss terfs the moss terfs will only be a few centimeters high they're not very tall

[00:22:51] [SPEAKER_00]: because the growing conditions are so harsh that their growth rates are sort of in the

[00:22:55] [SPEAKER_00]: range of like one millimeter a year so tiny growth rates growing really slowly which makes them really

[00:23:02] [SPEAKER_00]: old if there are even if they're only 10 centimeters tall that's you know a lot of that's can be a

[00:23:09] [SPEAKER_00]: hundred years or more so they can be they're really old they're home to invertebrates and they're

[00:23:14] [SPEAKER_00]: home to fungi and algae and cyanobacteria and bacterial communities I like to think of them

[00:23:21] [SPEAKER_00]: as a forest full of these very very tiny animals and other plants it's beautiful yeah the complexities

[00:23:29] [SPEAKER_02]: of the relationships between species is as complex as another forest system and it was that

[00:23:36] [SPEAKER_02]: so individuals can be 100 years old and the beds themselves are thousands of years old is that

[00:23:43] [SPEAKER_00]: accurate yeah so in in east Antarctica near Casey where we're working we know individual

[00:23:50] [SPEAKER_00]: plants can be more than 100 years old when we go to the peninsula we find layers and layers of moss

[00:23:57] [SPEAKER_00]: building up into peat banks and those can be thousands of years old but they will be multiple

[00:24:02] [SPEAKER_00]: multiple individuals that have grown on top of each other and so it's a different that's not

[00:24:09] [SPEAKER_00]: one individual that's been growing in that same place for more than 100 years which is what

[00:24:13] [SPEAKER_00]: we find at Casey and we've done and we think the reason why the moss beds are so special at Casey

[00:24:20] [SPEAKER_00]: is because they've been growing they're growing in these areas that used to be covered in penguin

[00:24:26] [SPEAKER_00]: colonies and as this as the ice has retreated the land has has risen up we call it isostatic

[00:24:33] [SPEAKER_00]: uplift and the penguins are now down at the coast but they left behind thousands of years ago

[00:24:41] [SPEAKER_00]: they left behind all this penguin poo or this guano and so they're really richly fertilized

[00:24:47] [SPEAKER_00]: wow and the great thing about Antarctica in its frozenness is that everything just gets

[00:24:52] [SPEAKER_00]: freeze dried and stays there and so these beds where the mosses are underlying them is all of

[00:25:00] [SPEAKER_00]: this rich guano which is what makes those moss beds so um so unique and so so big and so

[00:25:07] [SPEAKER_00]: and special for Antarctica we think that that's probably true around the continent as well that

[00:25:12] [SPEAKER_00]: most of the best moss is growing in places where previously there's been penguin colonies and so

[00:25:18] [SPEAKER_00]: there's there's a whole load of nutrients stored away and those penguin colonies we know were there

[00:25:24] [SPEAKER_00]: five to eight thousand years ago it's old it's old fertilizer and still good and what a

[00:25:34] [SPEAKER_02]: interesting way to be able to read the history of change and animal movement and migration through

[00:25:41] [SPEAKER_02]: the moss beds too another thing i wanted to to ask you is that the moss themselves are recording

[00:25:49] [SPEAKER_02]: environmental change over time and also some other interesting anthropogenic signatures in them

[00:25:57] [SPEAKER_02]: what can what's the environmental information that is being recorded in the mosses bodies

[00:26:05] [SPEAKER_00]: so so as the plants grow they um they take up carbon dioxide in photosynthesis and that carbon

[00:26:14] [SPEAKER_00]: has a signature of what's happening in the environment at the time they were growing

[00:26:18] [SPEAKER_00]: and because they have no plumbing that signal doesn't get mixed up that signal remains

[00:26:23] [SPEAKER_00]: in the same layer where where it was deposited in the first place and so using that that enables us

[00:26:31] [SPEAKER_00]: both to date them because we can trace down a moss chute and go can we see the peak in radio

[00:26:37] [SPEAKER_00]: activity that occurred when the maximum amount of nuclear testing was happening when we had

[00:26:43] [SPEAKER_00]: when we still had atomic testing aerial atomic testing nuclear testing of bombs there was a

[00:26:51] [SPEAKER_00]: an increase in the amount of radiocarbon across the globe and plants growing at that time all took up

[00:26:59] [SPEAKER_00]: that radioactivity into their bodies so we can see this in tree rings and and we know that there's

[00:27:06] [SPEAKER_00]: a peak in the 19 middle of the 1960s where that atomic testing was at its height and then

[00:27:12] [SPEAKER_00]: that nuclear test ban treaties came in and so we reduced the amount of radioactivity in the

[00:27:18] [SPEAKER_00]: atmosphere what we did was with colleagues at anstew we've gone down our moss chutes and gone

[00:27:23] [SPEAKER_00]: where's that where's that peak in radioactivity so they're picking up that radiocarbon and we know

[00:27:29] [SPEAKER_00]: what bit was growing in 1965 and we can also use other isotopes of carbon to tell us how wet or

[00:27:37] [SPEAKER_00]: dry the environment that the moss was growing in was at the time they were growing and using

[00:27:43] [SPEAKER_00]: that data we've been able to show that the moss beds at Casey even though they look amazing

[00:27:48] [SPEAKER_00]: they're actually drying compared to what they the environment they would have been in in the 1960s

[00:27:55] [SPEAKER_00]: and so most of the moss that we see is actually growing in drier conditions than it was in the

[00:28:02] [SPEAKER_00]: 1960s and that's to do with ozone depletion and climate change making it windier basically so

[00:28:09] [SPEAKER_00]: even though there's water melting more of it is evaporating away we think so they they store those

[00:28:16] [SPEAKER_00]: environmental records and what we're doing at the moment is trying to see whether one of the other

[00:28:21] [SPEAKER_00]: isotopes in the in the sugars and the and the more compounds that they make which is oxygen

[00:28:26] [SPEAKER_00]: whether we can tell from the oxygen what the temperature was and what the where the sources

[00:28:33] [SPEAKER_00]: of the water were so they're the things that we're working on at the moment with them but

[00:28:37] [SPEAKER_00]: in those peat banks you can see on the peninsula you can see things like when people were gold mining

[00:28:45] [SPEAKER_00]: first in in South America so when pollution gets into Antarctica again the mosses take

[00:28:54] [SPEAKER_00]: have a layer representing that so so they're really good proxies for coastal climates around

[00:29:02] [SPEAKER_02]: Antarctica and that even in there such extreme isolation that they're absorbing these pollutants

[00:29:11] [SPEAKER_00]: and it's a really I think it's a really good warning to us you know we we sort of tend to

[00:29:16] [SPEAKER_00]: think that Antarctica is this pristine place that's locked away at the bottom of the earth and it's

[00:29:21] [SPEAKER_00]: it's safe from us yeah but obviously whatever we do here in terms of whether it's atomic testing

[00:29:28] [SPEAKER_00]: or climate change it's it's impacting Antarctica and you've just mentioned a bit climate change is a

[00:29:36] [SPEAKER_02]: big part of your current research on on the moss any insights into what the future looks like for

[00:29:44] [SPEAKER_00]: those mosses I mean I was really shocked when we started we were the first to start monitoring

[00:29:50] [SPEAKER_00]: the moss beds to see if we could see change and and partly that was because everyone on station

[00:29:56] [SPEAKER_00]: would be get would go oh so are they doing better or worse than they used to and nobody knew and that

[00:30:03] [SPEAKER_00]: was what God is on the path of trying to date them so we actually knew how old they were and also

[00:30:08] [SPEAKER_00]: working out whether their environment whether they preserved a signature of their environment as

[00:30:13] [SPEAKER_00]: they grew so it's led to really interesting research but I at the time thought well we

[00:30:20] [SPEAKER_00]: should do this because if we don't start monitoring we'll never know how they're doing

[00:30:25] [SPEAKER_00]: but I really didn't expect there to be change actually I thought I'd be retired before we

[00:30:30] [SPEAKER_00]: saw any change and the biggest shock I've had is just how fast their environment is changing

[00:30:37] [SPEAKER_00]: because of those things like the ozone hole but also because of climate change and so

[00:30:42] [SPEAKER_00]: the fact that we're having that impact on these things that have been growing there for all those

[00:30:47] [SPEAKER_00]: hundreds of years and you know it's a very long way away and we can see that signature even though

[00:30:55] [SPEAKER_00]: it's quite hard to see a consistent signature in the climate records which it's beginning to emerge

[00:31:02] [SPEAKER_00]: now but for a long time we weren't even sure that there was you know we were able to see a

[00:31:08] [SPEAKER_00]: signature of climate change in Antarctica and so the mosses were picking that up for us even

[00:31:13] [SPEAKER_02]: before we knew it was there I suppose. What what is the state of the ozone hole? Has it

[00:31:21] [SPEAKER_00]: gotten better or is that not? So the Montreal Protocol was is the most successful environmental

[00:31:28] [SPEAKER_00]: treaty and so in terms of controlling the substances that break down the ozone layer

[00:31:34] [SPEAKER_00]: Montreal Protocol has been really successful all countries in the world have signed up to it

[00:31:39] [SPEAKER_00]: so it's a real success story in terms of what humanity by working together can do the problem

[00:31:46] [SPEAKER_00]: is that when you perturb the climate it takes a very long time for that to repair back to where

[00:31:52] [SPEAKER_00]: it was and so even with all of that work in the Montreal Protocol and most of those compounds

[00:31:57] [SPEAKER_00]: being banned and then the ones that we still use are really highly controlled it's still going

[00:32:03] [SPEAKER_00]: to take until probably 2060 or 2070 for the ozone layer to recover okay and that's if we that's

[00:32:11] [SPEAKER_00]: assuming that we don't do anything in the meantime to increase the numbers of those compounds that

[00:32:17] [SPEAKER_00]: are released into the atmosphere so there is concern the last few years have actually seen

[00:32:23] [SPEAKER_00]: really large ozone holes and that's been because of bushfires from the Australian bushfires so when

[00:32:31] [SPEAKER_00]: you have really intense bushfires the particles from that can get into the stratosphere and

[00:32:37] [SPEAKER_00]: start to break down ozone and also volcanoes and we can't do anything about volcanoes but

[00:32:43] [SPEAKER_00]: you know climate change is the main thing that's driving those really intense really frequent bushfires

[00:32:50] [SPEAKER_00]: and they have the potential to make the ozone you know create problems for the ozone layer as

[00:32:56] [SPEAKER_00]: well so that's another example where actually acting on climate change and making sure that we

[00:33:02] [SPEAKER_00]: don't have more and fierce bushfires is really important for multiple reasons.

[00:33:10] [SPEAKER_02]: Yeah and similar with climate change if we were to stop all emissions we would still be

[00:33:17] [SPEAKER_02]: locked into 20 years of warming or something right like similarly can't just turn it off.

[00:33:22] [SPEAKER_00]: You know we should have done we should have been doing the best time to do it was 20 years ago

[00:33:28] [SPEAKER_00]: but the next best time to do it is today. Yes yes agree agree.

[00:33:34] [SPEAKER_02]: So I guess in since your first time in 1996 going there you've seen a lot of firsthand change.

[00:33:43] [SPEAKER_00]: Yeah so most of the I guess the change in East Antarctica is still luckily is still

[00:33:49] [SPEAKER_00]: relatively slow there's change because of station building and there's change there is some change

[00:33:57] [SPEAKER_00]: but the biggest change we see is on the peninsula it's one of the most rapidly warming places on

[00:34:02] [SPEAKER_00]: the planet and there you see whole areas of land that have been opened up because glaciers

[00:34:08] [SPEAKER_00]: have retreated and in the Australian context Herd Island which is one of our world heritage

[00:34:15] [SPEAKER_00]: islands halfway between Australia and Africa it's the glaciers there have been retreating

[00:34:21] [SPEAKER_00]: kilometres over you know the last few decades and so where you've got taking us back to that

[00:34:28] [SPEAKER_00]: my early interest in geology and the fact that you can have a valley that's full up with ice

[00:34:35] [SPEAKER_00]: and then within human lifetime that hole all that ice just melts away and new land is

[00:34:42] [SPEAKER_00]: you know there's new land there's vegetation moving in there's all sorts of changes there's

[00:34:48] [SPEAKER_00]: new lakes just that whole sort of landscape being reformed as a result of that rapid

[00:34:54] [SPEAKER_00]: loss of glaciers and that's the most dramatic thing that you see that's happening in Antarctica.

[00:34:59] [SPEAKER_02]: Yeah it took thousands of years to accumulate and then how fast it's gone I spoke to

[00:35:04] [SPEAKER_02]: a few years ago a researcher who was studying Antarctic corals but she was speaking about

[00:35:10] [SPEAKER_02]: just the experience of hearing the glaciers calving off and breaking off and just how loud that was and

[00:35:20] [SPEAKER_00]: how arresting that experience was. It's because it can be you can be near to those glaciers and

[00:35:28] [SPEAKER_00]: it can be pretty much silent and then there'll be this incredible sound of the cracking of the

[00:35:34] [SPEAKER_00]: ice and then masses of ice just falling into the water it's it is truly truly awe or inspiring.

[00:35:43] [SPEAKER_02]: And another aspect of your your work I wanted to to speak to you about I already just in this

[00:35:50] [SPEAKER_02]: conversation we've spoken about the ozone hole nuclear signatures of the atomic bombs recorded

[00:35:57] [SPEAKER_02]: in the mosque the climate catastrophe and a lot of your work is to understand the impact of these

[00:36:06] [SPEAKER_02]: changes on the mosques and these vulnerable life forms and but you also do a lot of communication

[00:36:12] [SPEAKER_02]: and sharing of your knowledge and I think a part of that is also mentoring scientists as well.

[00:36:18] [SPEAKER_02]: Why is it important for you to communicate this this work and share what you're what

[00:36:25] [SPEAKER_00]: you're seeing and learning? I just feel that I've been really fortunate to just been a real

[00:36:31] [SPEAKER_00]: privilege to be able to work in Antarctica and to be able to satisfy my own curiosity I suppose

[00:36:38] [SPEAKER_00]: around. I find those plants fascinating and understanding what they can tell us about the

[00:36:43] [SPEAKER_00]: climate is something that I've been really passionate about but given that the work

[00:36:47] [SPEAKER_00]: that I do is funded you know by the Australian government I think there's a real responsibility

[00:36:52] [SPEAKER_00]: on us to communicate our findings and to communicate what we're doing to the public to

[00:37:00] [SPEAKER_00]: kids in schools so that they hopefully will be inspired to do science as well and so

[00:37:05] [SPEAKER_00]: and I and I think really with working in Antarctica you know you get such amazing

[00:37:09] [SPEAKER_00]: photographs there's real opportunities for art and there's really opportunities

[00:37:15] [SPEAKER_00]: in that storytelling to excite people about science. I really enjoy that communication I really

[00:37:22] [SPEAKER_00]: enjoy the storytelling but I think it's something that we really need to do because but also because

[00:37:28] [SPEAKER_00]: it's so important that we do something about climate change we don't want to be in a situation

[00:37:33] [SPEAKER_00]: where those Antarctic ice sheets are melting and the water is coming to beaches near us as sea

[00:37:41] [SPEAKER_00]: level rise and as tidal surges and storm surges and so it's both it's both partly paying back for

[00:37:48] [SPEAKER_00]: the that privilege that I spoke about but I think it's also the responsibility to say hey we're

[00:37:53] [SPEAKER_00]: we're really doing damage to those pristine areas of the world and it's not just going to stay

[00:38:00] [SPEAKER_00]: there and be a sort of an interesting scientific discovery it's something that's going to affect

[00:38:06] [SPEAKER_00]: everybody because sea level rise which is going to predominantly come from ice sheet melting Antarctica

[00:38:12] [SPEAKER_00]: and the Arctic is is a real threat to humanity and to all the all the other organisms on the planet.

[00:38:20] [SPEAKER_02]: Yeah and you get to know so intimately these places a lot of people won't get to see in

[00:38:26] [SPEAKER_02]: these organisms a lot of people have not thought of so thank you so much for for sharing that.

[00:38:46] [SPEAKER_02]: That was my conversation with Dr. Sharon Robinson. Thank you for listening and thank you to Sharon

[00:38:51] [SPEAKER_02]: for sharing her work. Plant Kingdom is hosted and produced by me Catherine Pultz and our music

[00:38:57] [SPEAKER_02]: is by Carl Dider. Listen to us wherever you get your podcast and check out our website at plantkingdom.earth.