Jake Dalzell

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

A factor that I believe has been overlooked in the ecology of hemiparasites is that they could have a significant effect on water availability in grassland communities, by increasing the total evapotransiration in the ecosystem.

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 &#8211; an overlooked factor in grassland hemiparasite ecology?

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

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

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 I started seriously recording plant pathogens, I have been really encouraged by the reception and interest other biological recorders have shown. I think there is a huge potential for recorders on platforms like iNaturalist to generate a lot more data on the distribution of these overlooked taxa. When people have told me my interest is “niche” however, I have had to pause. What does “niche” mean?

Introducing the Field Guide to Plant Pathogens

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

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&#8217;s Tresses: an orchid species new to Ulster

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?

This was a small project we threw together over three days on our Plant Sciences fieldtrip to Portugal. Our project compared the strategies used by two parasitic plants in the Orobanchaceae and a shared host species in the Fabaceae.

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

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

As part of my project recording the plant-pathogenic fungi and oomycetes of Ireland, I received an Irish Naturalists’ Journal grant to buy a new microscope. I finally have it and I am excited to use it in my micromycological research this year! The microscope I got is a Motic Panthera C2 Trinocular.

My new microscope

In September I started a PhD in fungal ecology at Aberystwyth University. This aligning with the end of support for Windows 10 and my old laptop coming up on five years old felt like a good time to invest in a new computer and switch to Linux.

In September I started a PhD in fungal ecology at Aberystwyth University. This aligning with the end of support for Windows 10 and my old laptop coming up on five years old felt like a good time to invest in a new computer and switch to Linux. I care a lot about the right to repair and modify your own hardware, and so after some research the Framework 13 felt like an appropriate choice.

Kit review: Framework 13 Laptop

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

Last year was a big one for me, where my life changed in two major ways. One is that I started seriously studying plant pathogens, which I have found I have a deep passion for and know I want to study for the forseeable future. The other is that I graduated from university. I have made some exciting finds this year.

2024 in Review

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 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

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&#8217;s urban flora

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)

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.

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. You can download a notebook with the code from my GitHub here.

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.

Modelling Yellow Rattle in a simulated grassland

Plant pathogens are ubiquitous in terrestrial ecosystems, but their role in these ecosystems is understudied. One aspect of their ecology that has not been studied is their influence on nutrient cycling.

Irish Plants

The Islands Project

Sligo Stromatolites