so I think we're going to make a start everyone
so I have the pleasure today of introducing Edith Hammer uh who is is currently a senior Le lecturer
and AP at lund University in microbial ecology she's a pi at the biodiversity in ecosystem
services and a changing climate lab and I'm very excited to introduce this talk because I've
been following Edith for for quite a number of years and seen some of this work beforehand
elsewhere and it's absolutely fascinating and had everybody on the edge
of their seats so
I'm really excited to be able to introduce her today to talk to everybody um Edith has a
special interest in the effects of microscale soil structure on N nutrient cycling and carbon
Dynamics and on the microrisal symbiosis and her group has been using the uh microfluidic chip
systems to simulate the environmental conditions and symbolic and symbiotic interactions found
in soils allowing for video capture of microbial decision-making and behaviors oh I don't know
if the
mic's on see I got a comment from on live um just before we jump into uh Edith's talk
I just wanted to give a little plug to some of the other talks that we have upcoming in the nature
seminar Series so on Tuesday um we have Anna karolina coming to talk about Amazon flux where
uh she'll be talking about her work disentangling biodiversity ecosystem function relationships
through energy flux perspectives and on Friday next week we'll have uh Jerome Lewis who will
be talking about building co
llaborations with indigenous and local communities using extreme
citizen science so please please do come along to those to and uh I would love to Now bring up
Edith to give her a fantastic talk thank you thank Thanks it's a pleasure to to be here it's my
first time in Oxford and I'm really Blown Away by the city it's amazing and I also like
we were just in the park talking about how important it is to have Nature close by and I
I wonder like when was last time you have been digging into th
e soil with your hands maybe
even like when have you kep your hand dirty is that something you that's great because
I mean like then you probably agree with me and uh it's I think it's the most fashion
ecosystem we have on Earth it's um there's you probably have heard that there's more organisms
on a spoon of soil than there there's humans on Earth and it's the species densest habitat
on Earth and there's also more than twice the amount of carbon in the soil compared to all
the living biom
ass and the atmosphere together so there's a lot of superlatives and um what makes
this ecosystem so so um special like how how do we get this huge accumulation of carbon there for
example if we compare a water ecosystem to a soil ecosystem um there is also free Carbon in what
ecosystems um but so much less it's like three orders of magnitudes less carbon compounds in
what ecosystems than there is in soil but like here nanomolar and micromolar but um in addition
to the huge differences in t
he carbon accumulation we also have way more organisms in the soil that
are super hungry they want to eat that carbon they are hungry organisms in the water system
as well but they are much better at taking um what is there and if we but but the soil uh
microbes are seriously hungry if we add some very easily available carbon from the outside to
the system it goes like and it's being respired within a few hours only it takes much longer if
if it's diluted in the water body and to my mind th
e reason for this big difference and for this
huge accumulation of carbon and of species well is this the micro structure that we have in the
soil this is um flight generator through a soil aggregate um uh constructed by John Crawford
um based on a micro c um measurement of a soil Aggregate and there you can imagine what your
life as a microb might be if you have to find your food in this Labyrinth and also try to
not become food yourself at the same time and I have been interested in physi
cal soil carbon
stabilization for a long time so the part of how can um Can things hide in the soil ecosystem
can organic matter be specially hidden from the composers and what what is spatial availability
for microbes to start with so it's a little bit like this pcman game from the 80s but very often
when we study soil Lucas systems that's what we do with them we completely destroy the stru
there has a lot of good reasons I mean like if we want to have a more homogeneous data set
and for
a lot of questions it's maybe not so important but we miss a very important very very
intrinsic characteristic of a soil if we destroy the structure each time we we do experiments
and that's why we have been developing these soil chips those are transpar transparent um micr
labyrinths that we can integrate into the soil we can either put them right down into the soil or
take soil into the lab and then have this like a cyborg uh system where we have a technical easily
U microscop um window t
o the soil um that's the way we construct them we start with designing uh
a spatial design for a certain research question and um then draw this in aat um transfer this to
a photo mask and produce kind of a stamp um that we pour a polymer over that is breathable um it's
good culturing conditions and so on and takes all these micro structures uh down to nanometer
scale can this material take and then we can study things under the write this was us in the
in the um in the clean room when we p
roduce the Masters and then we can study uh ecosystems
um with uh soil ecosystems with these either by having um cultur strains and uh small model
communities or having the whole soil um put as an inoculum we have been working with them a
lot um as static systems really as labyrinths for quite some years but we also getting into
flow those recently and we think that these micro models represent at least some parts of the
soil microhabitat quite well because we have these um very small struc
tures that um represent uh
the word at the microbes experience much better than if we have them on a plate or in a in a
tube um the word at the microscale is quite unint unintensive um to to what we know from
our everyday experience we have um very much higher uh impact of surface tension on capillary
forces um flows that we experience usually is turbulent but Flows at microbes um experience
is laminer and uh for them going through water is like for us maybe going through honey um uh
and a
water bubble oops I wanted to run this video can be completely impossible for bacteria
to to go past even though if it's only a small small water bubble a bacterium will never
be able to pierce through the meniscus of the water surface even though there's
a fungus that very happily just grows through um and we think that these Microsystems
can be quite a handy tool for soil ecology because we can simulate a lot of factors that
otherwise have been difficult to do simulating physical heterog
enity but even chemical um we
can get a lot of different microbes in there to study interactions uh we can also get roots
in there to study um plant microb interactions and there's this uh approach of culturing the
unculturable uh where we have a system um that allows for flow of metabolites but having still
spatial separation so that things don't grow dominant too easily so that you can culture up
to like 50% of the soil microbes suddenly which otherwise is more like 2% or so um but back
to the first question we tried to answer what is spatial availability for microorganisms we
started with um designing uh a labyrinth chip which was kind of five experiments in one where
we wanted to test different special patterns and how fungi react to this um so we had um
angles uh with um pore spaces that opened up and so on and we have been inoculating them
with one two handful of different um fungal species and uh I guess few of you are myologist
um so I'm giving you a little bit of he
lp of um remembering what species we have we had quite
some different um uh Forin strategies in them we have these U coprinellus that is a little bit
like a maritan runner very very very many highi um very fast growing far growing and then we
had this little funny guy SBE that was growing very giggly and didn't really seem to have a
plan often then we had the our zombie fungus uh that was going with a super um dense front
and like plowing down even parts of our chip and destroying them real
ly really strong H and
then we had this one snaky one that uh like to to grow uh and um get stuck in corners and do the
snake um snake structures once in a while and they have quite different um strategies to explore
space here our zombie goes with all fource and and almost grows like the water flows um at the
scale While others are um exploring much sparer also um it's good to know that there's no re W
and there they're just growing in air so they're just really exploring um where they may
be can
find something here and if they are offered with a little bit more space after long time of
constriction we wanted to see do they take that space do they branch in these spaces um and we
found a couple of species that did and a couple of species that don't like pretty consistently
at that scale this is like 150 microns here and then we thought there was some previous work um
saying that um highi want to have an obstacle to induce branching does that happen then if there's
a PO and t
here's a little sand grain to come do then they explore the space if um if they are
forced to take a decision and then Branch it was a bit the same like those species that always
Branch they Branch also happily when they hit the obstacle those that usually don't Branch they
rarely Branch even though there's an obstacle um and we wanted to know what are difficult
structures for fungi like where in the soil pore space could be um could be areas that are
very difficult for them to access and w
e have been looking yeah could be that um funy like to
go radial and straight maybe they don't like to go through uh sharp angles so have been setting
up um channels of different angles and that was true for most species most species don't like
to uh to continue in channels that uh have um acute angles except for the snaky one it loved it
and it grew much much further in uh in the very windy roads than the other even not even didn't
care but it preferred them so it was funny to see and this
is how it looks like in a time lapse
so it's totally okay with these 90° which are in the direction of the growth but but already if
you just turn the 90 degrees that they sometimes uh are 90 degrees towards the growth Direction
and it's very difficult for a lot of species already so it really gets stuck there and kind
of clogs this whole Channel until in the very last part of that weekend when we took that
time lapse it found a way to continue and we have also been putting a micro fungi i
nto these
um chips which was uh quite complicated because of all the plant part that you also need to
have but we managed in the end and um they have a very distinct um way of space exploration
and um I mean they have their carbon Supply from the plants so they are not carbon Limited in
systems um and we thought that they maybe are even more prone to go and Scout around because
they maybe have the opportunity better to go and look into spaces that are less attractive
for separate troughs t
hat always need to find uh energy um resources as well um we found that
also these angly roads were not very preferred by um the ab vascular microle fungi but it was
very funny because in these H you can really see the decision like it tested it for a couple of
micrometers and then saw no there's nothing for me to get here and it's uh getting uncomfortable
then it takes all its movable biomass all the cytoplasm back and translocates it somewhere
else so here we have a intact highi and here
we have a retracted part and it does that very
very frequently here's a bit more complex um part and you can see the cytoplasm streaming
but you can also at the same time now let me see if I get this wrong we have here detour
that is cut off wasn't deemed necessarily here a here is a no I do like this here's a corner U there was nothing to get so
those parts are abandoned again also if you remember uh the other fungi
exploring or not exploring um um open spaces and that were pretty much pro
grammed by um
by their species identity of what they wanted to do that's very different like um there's a
strong responsiveness in this avascular microle fungi that reacts very strongly to obstacles and
was like branching every almost every time when there was an obstacle coming in its way and
the funny thing I don't know if anybody has ever worked here with cultures of of a vascular
microa maybe you because I was super amazed to to see that they're doing this they are producing
spores in
our chips and uh usually they are these beautiful balloon round balls when you siiv the
soil that you can use for speci identification as well but they form them in this Labyrinth space as
well and they take the shapes of of the the space that they have um making me realize like in my
master seases long time ago I have been counting spores uh for estimating inoculums we probably
rarely get them out and um uh and this is also probably the reason for that uh people see that a
vascular microa
really change um soil properties for example the water huling capacity because
they change the horse base distribution quite a lotten um then we wanted to go the next step
further and uh not only look where can microbes get and go but also what is happening with
organic matter in different spaces so so um for the next series of experiments we have
been adding fluorescent organic compounds into the system to see where and how fast and to
what extent organic matter is being used and degraded
um and um we have been doing this in
a in a neat model system using one fluorescent bacterium one fluorescent fungus and then a
florescent substrate as well we started with a chip that um had some more variations
of uh angled roads and our hypothesis was a easy path for organism microorganisms is
something that they like to find their food but if the road gets more windy they uh get
a little bit angry and if it gets even worse they get really angry and think this is uh
too much effort so o
ur hypothesis was the straighter and easier the access to food uh um
the more easily and the stronger it will be used um and uh we hypothesized um that would be this
the case for fungi because we just uh found these things in other experiments uh we were not so sure
how we would find this with the bacteria because we thought they can go everywhere there's a water
connection so they can't really go everywhere but we also strongly found less biomass less less
bacteria and also less um organic
metad degraded in systems where we only had bacteria and we
think it's a little bit because they're like vacuum cleaner robots they uh go back and forth
and if they are in a windy road they probably use more energy and resources to go into the wrong
direction to um to exploit things um probably so we have a decreasing biomass uh with increasing
spatial complexity and also a decreasing uh substrate usage organic matter um degradation at
least when fungi are there as well but then a soil agg
regate is rarely having super long windy roads
only but it's more like a labyrint and the next experiment we did was uh designing a space filling
fractal landscape where we have um more or less connectivity of our paths so we were using the
hbit curve uh in simple versions of the Hilbert curve we have um roads that are connected like New
York City maybe um uh squares going everywhere and then we have something that's maybe more like old
Oxford where a lot of dead end streets uh and and uh s
mall um alleys that uh that are not connected
and again our hypothesis would be that in a connected um system we have a higher availability
um both spatial access and uh and um uh energy um input to to get to these resources um than in a
very highly intricate Labyrinth system and that was straightforward for the fungi um the more
dead end streets we have in the system the more difficult it is for a fungus to go through they do
after a while but it takes them quite a long time so the system
is being explored M at a much slower
space uh pace and here's a little time lapse again of fungi entering and then we found
something that we were not expecting I was quite amazed I'm not a um a person having
worked super much with bacteria and then suddenly we got these swarm uh pack hunting
um systems here in the system and then also especially in the more intricate labyrinths and
that was already hinting at something that we did not expect to start with because if we look
at the bacteri
al biomass it increases in the uh more complicated labyrinths in the more dead end
labin and the organic metal usage increases very strongly there uh there was a surprise to to
me being not the bacterial physiologist but it probably has to do with um the onset of quum
sensing and enzymes not diffusing so easily so that um the organic metad degradation can
be done in a much more efficient way probably so there's more work to to do in this in
this story we have been looking into the higher sp
atial details because we have these
labyrinths um as a whole um we have a higher degradation activity when there's a complicated
Labyrinth but how is it if we look into the very deep parts of this Labyrinth um depending on
how far uh an a space here is from the entry and then we saw um that um biomass fungal biomass
steep steeply declines but um bacteria biomass until the very deep Parts first increases but
then decreases and the same with Organic metad degradation so we have a strong enhan
cement in the
complicated labyrinths but not deep inside them so there um the hypothesis uh of organic matter
maybe being physically occluded uh again can hold um next things we're doing but that's all
very recent is to look at resources which are not spatially homogeneous but patchily located so
we have started to build little nutrient patches that we want to play with and um also instead
of only looking at um fluorescent reporters and so on we also look at more detailed
chemical changes
uh with especially with Ramen spectroscopy which we can do through
the chips inside at the micrometer scale as well um but when have been doing quite some work
now with real soil chips where we use real soil as an inoculum um and we either can take this in
um and and inoculate or incubate them in soil for for weeks or months depending on what we want
to do or we take soil into the lab and then we can also do to um time lapses on the microbial
community that comes into those chips you see uh
a gift of uh a bit more than a month of
EX experiment where there was also it was a Airfield system to start with um after a while
fungi come in and they drag water with them and then the whole other microbal community follows
and you have a very high turnover of the highi as well and working with soil we realize yeah we
have this um Pacman allery but it's probably more like this does anybody of you know that
board game yeah uh for for you that don't it's um every time it's your turn you t
ake um
this one of the cards and you push um a row of this Labyrinth so it changes each time so there
are new um paths emerging emerging and also new Dead ends um starting uh and you can annoy your
uh your play partners by um putting things into their way and that is probably what's happening
all the time in the soil for space as well here is um a shot of a chip that was drying a
little little bit um we had it um out in the air for a while and then water is being
dragged out from the chip
and at this scale it's really like a tsunami and this is only
a few uh nanoliters of water moving but if you are in these small pores this is having
a really big effect and we have been trying to qu ify this a little bit as well by particle
tracking and can speed this up a little bit and I I just uh told you that I also studied a bit
of geography uh a long time ago and I love um space spatial things and isn't this a beautiful
um uh flood EST opening up uh at the micrometer scale there we ha
ve areas that are super high
velocities and if you a microb there you you better hold on um if you are just 50 microns
away from there there probably nothing happens for quite a long time but maybe you also don't
get so much resources to your spot so there's always this trade-off but it's a very strongly het
heterogeneous um landscape that the microbes are facing and um I also have been realizing more and
more that decomposers are not only deconstructing things but they also constru workers
they really
shape their environment um glue things together build things build their word and they um are
very um important for for the structure that we have in the soil that are their word but
they have been uh contributing creating it a lot as well right uh not not only by gluing but
also by pushing uh new past this was our zombie um fungus that has been really destroying our
chips here on each of those Corners where it should turn it didn't want to um and um I
was asked by yep to brie
fly talk a little bit also about um synchrotron work and he's
not here unfortunately but I now talk about this anyway and we have been looking at these
gluing activities of fungi um as well uh at the high scale again so we have been taking different
fungi with different minerals uh and grow in them this time on plates not in chips um on optical
Windows like this even with a vascular microle fungi um to then study them um under the sticks
and beam line uh at some different synchrotrons looki
ng at the um chemistry of the exodites that
emerge when different fungi get in contact with different minerals and how uh the interactions
between the cell and the mineral then is so we can see that um fungal exodites um touch uh
easily a mineral that they come across and they even like float and flip across those exodites
uh and start to cover um cover the surfaces also on the other side of of the fungi um and in
some of the cases some Ecto micro isal fungi even uh induce um reduction of o
f the minerals
so we have a iron 3 to iron 2 reduction which probably is super important for their way of um
accessing organic matter via um radical producing um so that um there is this gluing
effect but there Al can also be more chemical alterations um um induced
quite strongly then by by a single high and uh we also have been recently looking at
um how a bit larger scale Aggregates are built up um by labeling batches of um completely
deaggregated soil with Rare Earth elements um so we c
ould uh for example label a batch
with straw with one Rare Earth element and a batch with maze very different carbon nitrogen
ratios um oops um which are benefiting more the fungal decomposition Channel or more the
bacterial decomposition Channel and see then when we mix them how newly formed Aggregates
are being um being uh constructed and we see for example large areas of the maze Bri
batches still coherent uh while the straw batch has been intermingling more and and
being distributed to
much smaller chunks uh in in a newly formed aggregate so um or
the organic matter but also the microbes are playing a very important role in cre creating
the structure um of the environment they live in um something that I think is important an
important advantage of using those microchips in soil ecology experiment is that we can
combine the very high controllability that we can do in lab studies with relevant ecosystem
comp lexity and uh we have for example been studying ecotoxicology qu
estions by uh looking at
how microbes react um to nanoplastics um with soil inocular um well we can look at whole microbic
communities um and how they're affected by a pollutant in this case um Plastics and we could
see that uh bacteria for example grow much worse when uh when they are swimming in a soup of
of plastics and the same was happening with fungi uh but only for a while um we realized
that some fungal Hy the first coming into an area that is polluted are actually attracting
those
plastic particles and they are getting stuck on on the hyi threads um so the green
here is the plastic the red is the fungus and the first hiy have been cleaning up uh the
whole environment there that was quite amazing to see we have been testing this under very
many different conditions and also with uh other species and with um soil uh in ocula
and that was quite consistent was uh funny the Swedish media took this up as the fungal
vacuum cleaners uh that are um our hope now for solving t
he plastic problem I don't know
if uh if I would go so far but it was very interesting to see that this um was happening
that um the plastic particles are adhering so strongly um we also have a couple of exciting
Master students um working with uh different ecosystems one um with uh biooss from Greenland um
where we have with climate change um more time of the year where there is no snow cover and then
we get much um uh Stronger free star Cycles in these ecosystem so we have been simulating
uh what
happens if uh we mess around with free star Cycles um of these um uh of these biocrusts and the first
thing that I before doing this didn't realize well is that freezing is such a physical disturbance
as well um we are freezing here live under the microscope and you see now there is like a lot
of water movement first and here's the ice front coming and it's pushing the organisms the Hy all
the minerals around sorting it quite neatly and um such a incoming ice front can like kill 50
%
of the organisms very easily and we have been sometimes chasing some protees and some didn't
survive when these very sharp ice fronts are coming in um and then we have been looking in to
how organisms interact again here with space and we found if we do this freezing thawing often uh
then there then we have a much higher colonization of the labyrinth spaces than the Open Spaces
and this is probably because there you have much more refugia left because the ice front is
coming and pushing
also all the all the dissolved salts they accumulate stronger and um lower the
freezing point so you have water pockets in the dead end um parts that you can also then very see
in these areas so there's like at minus8 there is a lot of areas in the so that is not frozen yet
where um the organisms and happily can continue living uh while in the open areas uh there's
a higher risk um of of dying them apparently and another master this is uh was by Eric um
actually out in the field in Kenya an
d that was also amazing that we could get off a uh handhold
mini microscope that was doing well enough work to to do um studies right in the field in Africa
so that was also really nice he was looking at the effects of biochar uh on so microbial communities
at the cellular scale now here again and in order to um to work with real soil inocula we
have been looking into uh deep learning image recognition because we again of course want
to estimate biomass and cell numbers and so on so we star
ted with um um segmenting bacteria and um
this is working quite well um so far so we can count bacteria but not only count but also then
at the same time get their spatial distribution their size and morphology and that is something
which is probably very nice complement to a lot of uh DNA studies where you don't get all of
these informations so doing both at the same time is something that we're planning to do
in our future experiments now uh so we can measure the organisms and the biodive
rsity
and we also want to study the biodiversity much more we have been starting with pilots and
we're going to do um the summer a lot of field work um uh looking at a lot of different land
use types and this was um the pilot where we were taking some samples from Arab field and the
adjacent Cow Meadow and the communities look like this you can you guess what was the cow Meadow
and what was the plow field that was in the winter though but probably you can guess or so
that was quite strikin
g to see that difference there are organisms but they are so wet way less
so high abundance in the meadow compared to the plow field like 100 times or 50 times more
um protest abundance similar and then also the protest richness uh also very very strong
difference um and that then gets us of course also to a lot of thoughts like what can we
do to increase soil microbal diversity soil Health um I've been just discussing with
Jed as well like should we and can we rewi soils is that something
like I'm not at all an
expert in this field at all but that's maybe something very interesting to discuss with
you here today I mean very important things of course preserve the structure like don't
destroy the structure and do as much as you can to to rebuild soil structure because
that's the of this microbial diversity um also vegetate as much as you can and like
sometimes the municipality was asking like what can we do in Lun municipality to increase
our carbon storage and so on there's
a lot of things that they can do but like a very simple
thing is like don't mow the the grass in the park so much that's very easy thing because like
uh the you probably notice the the length of of the leaves is very um strongly correlated to
the root um development as well and of course all the carbon also then going to the rest
of the the soil Community feeding the soil by vegetating but also like by adding organic
matter if it's needed if you take away organic matter in agriculture for
example and um of
course that's uh super important to have the healthy ecosystems uh because they will also be
the base for our own health in the end you know probably the one health concept but in agriculture
it's probably difficult to get a really amazingly healthy soil ecosystem because that's what we want
to have in the end like something like this that is full of highi and full of different organisms
there's a little silia there's like hundreds of bacteria just in this uh image here we
need to
have a strong um good plant biodiversity and um perennials so there are big challenges um for
agriculture to to be sustainable for their soil ecosystems um and I think I've been realizing
more and more the last years that I'm actually maybe in the wrong business because I'm a
natural scientist but I think all these big issues these big Frontiers for sustainability
they and the social sciences uh because it all come comes down to what we decide to do and not to
do and so on and uh
that's why I think it's very important for me personally now also to spread
the word of how amazing and how exciting and how special soils are like all these creatures
that there are that we don't know anything about uh that we have hardly studied and like no
lay person knows what's going on under our field and uh kids love Pokémon yes that's great but
we can maybe make more realistic Pokémons for them as well so that they learn something uh
useable at the same time as well and we just rece
ntly started a little YouTube channel where
we compile uh a lot of the videos that we take and we explain what's happening and uh hopefully
very soon there will be more this what so far is one video up but more to come hopefully and with
this I want to conclude and thank you so much for listening so I just wanted to say thank you so much for
such an incredible talk and every time I see those videos it's just blows me away completely
uh for the work you've been doing and and the the work you
're furthering um I'll take this
opportunity now to ask some questions or if there are any questions in the room um for
Edis and uh we'll also probably take some from online as well sorry well I I said
I told myself I wouldn't butt in because I'm no longer active in the field but I'm just
blown away of course do you think it's possible that you you know we have a gut microbiome
that everybody's begun to be very aware of and we're eating flax seeds and blueberries and
so on um do you think
there's a soil microbiome that has evolved to create the right sort of
spaces and to build its own architecture I'm pretty sure that there's super much feedback
going on all the time yeah I mean they have been involved the microbes have been evolving in
different soil parent materials and um adapting uh and and creating their own word that they
are um home in they have been building their home and they have been involving in this
I'm pretty sure and I also like very much the comparison we'r
e getting more and more aware
of uh all the beneficial and important microbes that inhabit us and I sometimes say like I don't
want to have any strange dietary uh um tips or whatever I think I just need to think I need
to feed my microbes when I eat or so we have to think the same with our soil like we need to
feed also because it's a living tissue kind of as well am I poing you this so that people online can
hear um yeah thank you very much does it does it work oh all right all right all r
ight sorry um
I was wondering what happens if you take one of this um uh tiled field and turn it back into a
CO pasture uh how you know do you have any idea how long how long it takes for the diversity to
to come back and and also would it make sense to have soil transplants as you would do with the
gut microba to to inseminate back and the the Lost diversity yeah absolutely I think that's
a a good way to speed up uh regeneration of of a degraded soil is to to have some soil from
NE we hav
e also been just discussing this U an hour ago um the possibility to buy in ocular
for example for micro isal um species uh to put in into a foreign environment is probably
much less efficient than if you take just an inoculum from near buy of a healthy soil and
get a community in oculum um the exact timing of how long it takes uh for for um Community
to reestablish I don't know uh it depends of course Very Much on how degraded the system
was like how degraded the habitat is as well I that'
s also like a long time ago synchrotron uh
story um my very first time I wanted to look at um organic iron in that um in soils iron is
bridging between minerals and organic matter lot is very important for building up structure
um I was trying out some um some techniques and I didn't get any differences in my experiments
with the technique I was trying to measure and I thought okay now I going to uh measure something
that was really extreme where I last year added 20% volume organic matter
into meshback that had
been in the soil there was a Tunisian soil also very degraded half desert soil so that must be
like really strongly affected because it got so much organic matter I still couldn't see this
on the molecular level because um it takes so much more time for a soil to build up that stru
structure to have um the degradation of organic matter turned into U dissolved organic matter
and into exodites and stuff that can create those structure and those um also organic
Min orga
nic metal mineral interactions so that wasn't at all enough with 20% organic
meta for a year in a Tunisian soil to make any difference there so building up uh from
a very degraded habitat can take quite a long time um thank you that was absolutely
mind-blowing uh was just fascinated by seeing that uh completely blown away um I guess
a two-part question the first one is more sort of social is like when you're looking at those uh
videos like as as scientists you get in trouble for like anthro
pomorphizing uh fungi and things
like that but I find it very hard not to sort of look and see oh like traits foraging traits is
sort of personality and stuff so that sort of first question is is uh what are your thoughts on
that how do you deal with it but but the second one more actually looking at those traits so you
have that sort of very direct zombie uh forager and and and the the snake like one um have you
had any conjectures of sort of the types of soil environments where one might
flourish versus
the other and whether you know there's there's any way of relating that to the to the sort of
field environments yeah the the zombie fungus for example um they are all lit decomposers
that we have been comparing there um in that first study to your very first question we we
don't anthropomorph anthropomorphize them in the scientific papers we only for a talk um
and the the zombie one goes for much larger chunks of litter so more like Woody Parts
uh of of small root pieces a
nd so on so it needs to uh be much more like protective of the
resources that it finds uh has to invest a lot of enzymes so it's important for it to have a much
denser melium then some of the others there's a a dang uh decomposer for example that uh is
really opportunist that uh has to deal with longer distances to to their next uh research
patch and so on and is therefore more prone for for uh foraging far instead of dense even if
there's no nutrient reward to any of them in those experien
ce yeah thank you for a truly beautiful
talk um so I work on antibiotic resistance and so I'm fascinated by the ability of some fungi and
soil bacteria to make product antibiotics and I was really intrigued by all the different sort
of space filling strategies that the fungi have that you show but the bacteria you studied
mainly look like they're sort of planktonic and just swarming around but there are some
filamentous bacteria in soil like streptomyces so is there any Prospect of investig
ating how
they behave I guess the structures have to be much smaller because they're just smaller
but yeah I'd like to know about that yeah I also definitely would like to to work uh with
filamentous bacteria we haven't done it yet um uh it would be possible to construct smaller
um smaller spaces that even would challenge them uh and I mean like that's always the thing
like we want to challenge them um but it's also for microscopy if you have spaces that are much
larger than the organisms
and things overlay a lot um which makes it more difficult to to image
them so that would but it would be technically definitely possible um I've been thinking in
like now we are especially constraining size exclusion in our assistance by the um the ceiling
it's only 10 microns high so you get quite large organisms but then they still need to squeeze
in the Z Direction um and it's possible to make like a stair wise um lowering of the ceiling
as well at some point so that would be very nice a
ll thank you thank you for the talk uh so
I'm curious I work a lot with tropical forest uh like across the four tropical continents and
and I was wondering in one of your slides you put kind of like the higher number of of perhaps of
tax that you have for bacteria and fungi at the same time kind of increases if I understood
properly the the composition of organic mat matter uh well I don't biomas was there was
only one species Okay so my question would be would you what kind of relationship
would you
expect like between funga and bacteria for the composition of biomass or or M organic material
material across the tropics um uh in these kind of pristine ecosystems in which for example only
climate changes there is no anthropogenic direct effect and the second is to what extent would
you be able to if we have a lot of soils from many different tropical forests would you be
interested actually using some of it for your analysis as well that you have been showing
absolutely um t
he interactions between funi and bacteria are very different depending on the
the specie identity um they often are competitive in our experiments also usually like as soon as
we put both in both grow on a bit lower level because they share the same resources um when we
have been looking at a soily ular where we have a large variety we see often also so um mutualistic
interactions or at least um bacteria that are very happy to follow um fungi um both because they
probably um get a little bi
t of free meal there but also because of the hydraulic conductivity
um that the the fungi drag water films with them so they can only move across air pockets um via
them but then we have been showing in a study that um the um uh amount of of fungal highy in
a poor space is very strongly predicted for the amount of bacteria we find in there because of
this they only can move and um disperse uh over air pockets when when there is fungi making water
Bridges but not in all cases there was quite
some varation because I think there are quite some
antibiotic producers like in some areas there's High Fe but it's completely bacteria free as
well so there's a lot of different combinations possible I think we're going to take some
questions from online so I'm going to pass to see them just one online question from
Sarah um she's from a climate Action Group that's got a film called six inches of soil but
her question I think you mentioned just relates about the YouTube um uh video that y
ou're doing
and and how can you make this kind of research and presentation more accessible to schools
and children um and is this where some of the changes that we we need to see are going to be
about kind of inspiring the Next Generation to think more about soil and so I I don't if you
could maybe mention uh what the YouTube channel is and and sort of what reactions you've had
from from this kind of work with with younger uh school children and so yeah this is still
very new so not super
much reactions yet um I think like we have like 13 um Preen numerations
yet so not very very early but I totally agree with Sara um that it's super important to um to
get children closer to uh to soil biology um and we just have been ordering more of these uh field
microscopes as well because the one that was with the master student in Kenya we left in Kenya for
them um so that we have something to live be able to look at uh at soil uh communities also then
in the classroom and that's some
thing I want to do uh a little bit on the site in the future as
well brilliant so if we have no more questions I just want to say thank you so so much again for
such a wonderful presentation and uh yeah and there will be a drinks reception in this room
afterwards so please stick around Mill around and have lovely chats and yeah thank you very
much again and we'll see everyone on the next one
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