Jake Dalzell

In July I spent a few days in Sligo as a field assistant with an international, interdisciplinary team who are studying peritidal stromatolites. Stromatolites are layered rock formations created by microbes, and peritidal stromatolites form in the area of the shore that is affected by seawater from the tide or from sea spray. This makes them unique as they can experience large changes in salinity.

Sligo Stromatolites

Today I went to the BSBI’s November conference in the Natural History Museum in London! I presented my poster on my summer project surveying islands on Strangford Lough, and got to do a 60 second flash talk. It was really great to meet other people who are passionate about plants and learn from them. Read the html version of my poster here. Watch my (very brief!) flash talk here.

British and Irish Botanical Conference, November 22

This summer I am cataloguing the flora and plant communities of twelve islands [EDIT 20/11/22: it ended up being eleven islands!] in Strangford Lough, with the help of a BSBI Plant Study Grant. The goal is to have a complete species list of each island and a map showing all of the plant communities and where they occur. I have been kayaking to these islands and doing a thorough survey, and also quadrats in each distinct plant community.

The Islands Project

Slievenacloy Nature Reserve is an Ulster Wildlife reserve in Antrim. It is very well managed for upland grassland, with a wealth of Devil’s-Bit dominated grassland.

Plasmopara euphrasiae: a downy mildew species new to Ireland

On the thirteenth of August, I was at Killard National Nature Reserve, Co. Down, with my mum. We were looking for Frog Orchids and other species rare in the county like Quaking Grass and Field Scabious. She found a plant she didn’t recognise and asked me what it was, and it was Autumn Lady’s Tresses. I knew I hadn’t seen it before and wasn’t sure it had been recorded anywhere near before.

Autumn Lady’s Tresses: an orchid species new to Ulster

The model in this post is based on the one in Cameron et al. (2009), improving how seed dispersal is modelled and the dynamics are visualised.

I have become a bit obsessed with hemiparasitic plants recently. When I found Cameron et al.’s paper on how Yellow Rattle can create interesting spatial dynamics in grasslands¹, I got quite excited. I have been learning python this year so I thought I may as well try to replicate their model.

Modelling Yellow Rattle in a simulated grassland

The Regulation of the Water Potential Gradient in the Host and Parasite Relationship betweenSorghum bicolorandStriga hermonthica

Ecophysiology of the holoparasitic angiosperm Cistanche phelypaea (Orobancaceae) in a coastal salt marsh

by Jake Dalzell, Hazel Garrett, Catriona Forrest, Wayne Liang, Rosalind Mackey, Denis Pavlov, and Josh Simpson  This was a small project we threw together over three days on our Plant Sciences fieldtrip to Portugal. Everyone on the fieldtrip used six different techniques to explore plant physiology and ecology, and each group came up with a research question that could be answered using some of these techniques.

Comparing parasite and host strategies in a Portuguese grassland

My favourite butterfly, which I first saw during lockdown. They are the most delicate of the white species (Pieridae) found in Ireland and flutter through grasslands in May and June. Taxonomy For a long time, scientists wondered why Wood Whites (

 Leptidea sinapis

) were fairly widespread and common in Ireland, when they were so rare in England.

The Cryptic Wood White butterfly

This is an adapted version of my poster, which is also available as a pdf or png. As with all my work on this site it is CC BY 4.0 (free for use/adaptation as long as I am credited).

The Meadow Maker Yellow Rattle (

 Rhinanthus minor

) has become well known in restoration ecology and wildlife gardening as a “meadow maker”, which can transform a species-poor patch of grasses into a biodiverse and flower-rich one.

Yellow Rattle

Introducing ecosystem engineers for grassland biodiversity conservation: A review of the effects of hemiparasitic Rhinanthus species on plant and animal communities at multiple trophic levels

Hemiparasite-density effects on grassland plant diversity, composition and biomass

Water flows in the parasitic association Rhinanthus minor/Hordeum vulgare

Integrating ecology and physiology of root‐hemiparasitic interaction: interactive effects of abiotic resources shape the interplay between parasitism and autotrophy

Root hemiparasites and plant diversity in experimental grassland communities

Facilitating grassland diversification using the hemiparasitic plant Rhinanthus minor

7/10/2023 UPDATE: I have discovered other authors came up with this idea before me, as noted by Press and Phoenix¹¹. At least two authors have mentioned it: in the context of mistletoes¹²; and a North American root hemiparasite,

 Triphysaria

¹³. However, as far as I can tell the hypothesis has never been tested.

Total ecosystem evapotranspiration – an overlooked factor in grassland hemiparasite ecology?

As someone who has been deeply interested by plants as long as I can remember, I have grown to appreciate all the different habitats I come across in Ireland. Each has its own unique set of species, but one that has always particularly caught my attention is our grasslands.

Why care about grasslands?

03/11/2023 EDIT:

actually a rediscovery, this species was recorded in Belfast pre-1930 Earlier this year, I found a species of grass I didn’t recognise, growing as a pavement plant in East Belfast. With a guide I identified it as

 Polypogon monspeliensis

(Annual Beard-grass), a new species for County Down. This species is known from Dublin and Cork, and there is a previous Ulster record from Keady in Armagh.

Annual Beard-grass: a new species for County Down (H38)

Disease is something few people love. There are exceptions though, particularly among those who appreciate the diversity and ecological role of plant disease. The early conservationist, Aldo Leopold, described the role of tree diseases in creating food and shelter for the animals on his farm in Wisconsin:  I met Chris Preston, a Cambridgeshire botanist, when I was in the first year of my degree.

In Defence of Disease

Since 2022 I have been recording the flora of some islands in Strangford Lough. I received a Plant Study Grant from the BSBI to work on this in the Summer of 2022 but as it turned out I had committed to a much bigger project than I first thought! I recently submitted my records and can now finally say I have finished my first large recording project.

Strangford Lough flora: an update

In the nineties, the Belfast Naturalists’ Field Club extensively surveyed the urban flora of Belfast, resulting in a book,

 Urban Flora of Belfast

. Many plants new to Down and Antrim were found, and most of these were new to Ireland as well. This was a three-year effort involving some thirty-one recorders.

Belfast’s urban flora

Hemiparasitic plants are those which steal water and nutrients from other plants, but still photosynthesise (so are green). They are an interesting part of the Irish flora, and some can play an important role in grasslands by weakening other plants – particularly Yellow Rattle.

Hemiparasitic plants in Irish grasslands

Today I had the opportunity to work as a field assistant with a PhD student, Thomas Marquand. He is researching CO₂ and methane dynamics in soil in restored and reclaimed fens in East Anglia (with the Centre for Landscape Regeneration). We took samples from the fen exhibit in the Cambridge Botanic Gardens and used a spectrometer to measure CO₂ and methane concentration, and also δ¹³C-CO₂.

Fen soil carbon flux

Irish Plants

My favourite butterfly, which I first saw during lockdown. They are the
most delicate of the white species (Pieridae) found in Ireland and
flutter through grasslands in May and June.

<figure class="wp-block-image size-large">
<img
src="https://irishplants.org/images/other_grasslands/lagan_meadows/courting_flight.jpg"
decoding="async" width="650" height="464" />
<figcaption>June 2021 A male Wood White courting a
female.</figcaption>
</figure>

#### Taxonomy {#taxonomy .wp-block-heading}

For a long time, scientists wondered why Wood Whites (*Leptidea
sinapis*) were fairly widespread and common in Ireland, when they were
so rare in England. Then, first in the 80s and then in 2011, it was
realised that there were two more "cryptic species" hidden within the
Wood White¹. Réal's Wood White (*Leptidea reali*) was the first to be
discovered and said to be found throughout Ireland (except for the
Burren, where *L. sinapis* is found). However, when it was further split
in two in 2011, our species was named the Cryptic Wood White (*Leptidea
juvernica*)². It's a great demonstration that insect taxonomy is
challenging and that there is a lot of hidden biodiversity yet to be
discovered.

<figure class="wp-block-image size-full">
<img
src="https://irishplants.org/blog/wp-content/uploads/2022/12/20210524_121244.jpg"
class="wp-image-295" loading="lazy" decoding="async"
srcset="https://irishplants.org/blog/wp-content/uploads/2022/12/20210524_121244.jpg 1900w, https://irishplants.org/blog/wp-content/uploads/2022/12/20210524_121244-300x236.jpg 300w, https://irishplants.org/blog/wp-content/uploads/2022/12/20210524_121244-768x605.jpg 768w, https://irishplants.org/blog/wp-content/uploads/2022/12/20210524_121244-1536x1210.jpg 1536w"
sizes="(max-width: 1900px) 100vw, 1900px" width="1900" height="1497" />
<figcaption>A Cryptic Wood White butterfly at Lagan Meadows,
Belfast.</figcaption>
</figure>

#### Ecology {#ecology .wp-block-heading}

Cryptic Wood Whites can be difficult to see during the flight period in
May and June, but at the right site they can be common. The best site I
have found for them was [Lagan
Meadows](https://irishplants.org/other_grasslands/lagan_meadows.html){rel="noreferrer noopener"
data-type="URL"
data-id="https://irishplants.org/other_grasslands/lagan_meadows.html"
target="_blank"}, in a patchy mosaic of damp species-rich grassland and
bramble scrub. Here the foodplants (vetches) are common in young,
developing scrub and in long grass. I have also seen them at Murlough
NNR on mature dune grassland. The species can exist on very small and
fragmented sites: the site at Lagan Meadows is small (around 5 ha)³; I
believe [our
field](https://irishplants.org/field.html){rel="noreferrer noopener"
target="_blank"} was colonised from a hedgerow/road verge population
with little-to-no species-rich grassland nearby.

<figure class="wp-block-image size-large">
<img
src="https://irishplants.org/images/other_grasslands/lagan_meadows/wood_white_on_cardamine.jpg"
decoding="async" width="700" height="340" />
<figcaption>May 2021 A Wood White nectars on
Cuckooflower (Cardamine pratensis) in a damper part of Lagan
Meadows.</figcaption>
</figure>

##### Foodplants {#foodplants .wp-block-heading}

Warnock⁴ studied the species' preferences in Armagh and found they
mostly prefer to lay their eggs on Meadow Vetchling (*Lathyrus
pratensis*), also using Lesser Bird's-foot Trefoil (*Lotus
corniculatus*), Greater Bird's-foot Trefoil (*Lotus pedunculatus*), and
rarely Bush Vetch (*Vicia sepium*). At Murlough they mostly use Lesser
Bird's-foot Trefoil⁴. in Edenderry, O'Neill and Montgomery³ only saw
egg-laying on Meadow Vetchling.

In the same study⁴ nectar plants included Bush Vetch, Meadow Vetchling,
Lesser Bird's-foot Trefoil, Tufted Vetch (*Vicia cracca*), Ragged Robin
(*Lychnis flos-cuculi*), and Red Clover (*Trifolium pratense*). At
Murlough they have been observed using Tormentil (*Potentilla erecta*).

##### Courtship {#courtship .wp-block-heading}

Courtship generally occurs on the nectar plant. I have observed two
courtship displays on Bush Vetch, and one on grass. The male hovers
behind and above the female, then lands facing her and begins to wave
his proboscis on either side of her, while she occasionally flaps her
wings. If she approves of the male, mating follows, but I have never
seen this and it seems to be rare⁴ -- most males are rejected.

<figure class="wp-block-image size-large">

<figcaption>May 2020 A video of two pairs at Lagan
Meadows courting. In both, the female rejected the male.</figcaption>
</figure>

This fairly complex ritual has evolved as a response to the similarity
of the different *Leptidea* species -- the female has to spend a long
time working out if the male is actually the same species as her⁵. Why
do they stay separate species at all then? Well, the different species
occupy different niches in the areas where their ranges overlap. It is
advantageous for them to make sure they mate with those of the same
species, as the offspring will then share the specialisation to that
niche⁶. Hybrid offspring would be less well-adapted to either of the
niches of its parents; this is a form of *[outbreeding
depression](https://en.wikipedia.org/wiki/Outbreeding_depression){rel="noreferrer noopener"
data-type="URL"
data-id="https://en.wikipedia.org/wiki/Outbreeding_depression"
target="_blank"}*.

#### Conservation {#conservation .wp-block-heading}

Heal⁷ reported that the Cryptic Wood White spread rapidly northwards
into north-east Ulster along the railways in the mid-20th century. It is
now in retreat⁴^,^⁸; the main concern is habitat loss⁹. At Lagan Meadows
the habitat is quickly becoming inappropriate as grazing has stopped --
this will stop the disturbance needed to create new areas of young
scrub, and lead to the loss of the species-rich grassland.

<figure class="wp-block-image size-large">
<img
src="https://irishplants.org/images/other_grasslands/lagan_meadows/leptidea_print.jpeg"
loading="lazy" decoding="async" width="650" height="457" />
<figcaption>December 2021 A linocut print I made
inspired by the Wood Whites I saw over lockdown.</figcaption>
</figure>

## References {#references .wp-block-heading}

*N.B.* I have changed the format to superscript numbers Vancouver style
as I think it is less intrusive!

1. Dincǎ, V., Lukhtanov, V. A., Talavera, G., & Vila, R. (2011).
 Unexpected layers of cryptic diversity in wood white *Leptidea*
 butterflies. *Nature Communications*, *2*(1).
 https://doi.org/10.1038/ncomms1329
2. Cryptic Wood White. \[online\] *UK Butterflies*.
 https://www.ukbutterflies.co.uk/species.php?species=juvernica
 \[accessed 31 Dec 2022\]
3. O'Neill, J., & Montgomery, I. (2018). Demographics and spatial
 ecology in a population of cryptic wood white butterfly Leptidea
 juvernica in Northern Ireland. *Journal of Insect Conservation*,
 *22*(3--4), 499--510. https://doi.org/10.1007/S10841-018-0077-5
4. Warnock, N. (2008). The ecology and conservation of *Leptidea reali*
 (Real's Wood White) in Northern Ireland. MSc Thesis, Queen's
 University Belfast.
 http://ns340113.ip-5-196-79.eu:7080/images/3_programmes/papillons/biblio/43.pdf
5. Friberg, M., Vongvanich, N., Borg-Karlson, A. K., Kemp, D. J.,
 Merilaita, S., & Wiklund, C. (2008). Female mate choice determines
 reproductive isolation between sympatric butterflies. *Behavioral
 Ecology and Sociobiology*, *62*(6), 873--886.
 https://doi.org/10.1007/S00265-007-0511-2
6. Friberg, M., Leimar, O., & Wiklund, C. (2013). Heterospecific
 courtship, minority effects and niche separation between cryptic
 butterfly species. *Journal of Evolutionary Biology*, *26*(5),
 971--979. https://doi.org/10.1111/JEB.12106
7. Heal, H. (1965). The Wood White, *Leptidea sinapis* L., and the
 Railways. *The Irish Naturalists' Journal*, *15*(1), 8--13.
 https://www.jstor.org/stable/25536916
8. Staats, W. T., & Regan, E. C. (2014). Initial population trends from
 a 5-year butterfly monitoring scheme. *Journal of Insect
 Conservation*, *18*(3), 365--371.
 https://doi.org/10.1007/S10841-014-9644-6
9. *Leptidea juvernica* -- cryptic wood white. \[online\] *Northern
 Ireland Priority Species*.
 http://www.habitas.org.uk/priority/species.asp?item=430857
 \[accessed 31 Dec 2022\]