First record for Acaena inermis in the North York Moors national park and for the botanical vice county of NE Yorkshire (62)

This blog post reports on the discovery of a small population of Acaena inermis near Danby Beacon in the North York Moors National Park. Unlike other piri piri bur species such as A. novae-zelandiae (e.g. Invasive Species Compendium, CABI, 2021,, A. inermis is not known as an undesirable alien, however population dynamic is relatively unknown in Britain.

The population described here is nonetheless of biological interest based on the distance to known records and the site being located within a designated area for nature conservation. It is also an opportunity to highlight the species and some of its characteristics to other field botanists and conservationists, hopefully to improve recording coverage.

Distribution in Britain and Ireland and description of the Danby Beacon location

A. inermis is a relatively rare alien plant in Britain and Ireland, with scattered records from lowland location (from Southern England to Edinburg) and a few well known clusters of records from upland natural habitats: Isle of Skye, the Grampians, the Southern Uplands of Scotland, and in England in the Cheviot Hills (Coquet dale). These small clusters of upland populations appear well established, some since the 1970s and the Skye population may be increasing with new sites having been reported in recent years (e.g. Bungard, 2019,; BSBI 2021 map).

The new location reported here is isolated by about 100 km from three other English presences hitherto reported (South Yorkshire, Skipton area, Coquet Valley). Although there may be unknown sites in between that could have acted as stepping stones, the population presented here is more likely to be an independent introduction from cultivation into the wild.

At Danby Beacon, the population is located on a lay-by popular with visitor (NZ726085, at or adjacent to NZ726308656), with a lovely view to the SW, popular with visitors for picnics and for quiet time in a camping chair by the car. Due to this relative popularity, it can be speculated that propagules of the plant reached the site on car tyres. The propagules could have been directly brought from a garden or a drive way to to this lay-by by visitors of the national park. The habitat is a species rich acidic grasssland, with species such as Antennaria dioica, Euphrasia sp., Veronica officinalis, Galium saxatile, Nardus stricta, Festuca rubra, Cynosurus cristatus, Calluna vulgaris, Trifolium repens, Polygala serpyllifolia, Carex pilulifera, Pilosella officinals, Leontodon saxatile, and other species.

Invasives and conservation

Reporting the first introduction of alien plant in an area can be important to identify the pace and vectors of colonisation, especially in genera with well known undesirable species. The North York Moors national park authority, has already taken action against A. novae-zelandiae in one location and may want to keep on eye on this new comer in the area, until we know more about the population dynamic of A. inermis in the area. Acidic grassland where the population is located is a highly threatened habitats in Britain (see e.g. Carly Stevens 2011 paper).

Improving our understanding of A. inermis distribution

Acaena inermis is a species from New Zealand, first recorded in the wild in the Britain or Ireland in the 1970s. Identification of the Danby Beacon population was based on the CRIB account for Acaena (Yeo, 1988, There is also abundant photography on the internet as the species is a popular rockery plant. The species, as well as one cultivated variety (Acaena inermis cv ‘Purpurea’) is widely available from nurseries for outdoor gardens. It is not clear to me whether the population described here belongs to this the ‘Purpurea’ cv or not, and even not clear from internet searches whether all specimens of this species can be found under the name ‘Purpurea’ due to the type colouration of the foliage. I would be keen to hear from experienced nursery-people on this point.

At the Danby Beacon site the plant is extremely difficult to spot due to its size, prostrate stem and colour, which mimics topsoil litter. In addition, the bright red spines that can develop on the fruits were not observed by the end of July 2021. 


British Bryological Society’s new website

In my function of trustee and co-website editor, I was able to take part and co-lead the development of a major website for the British Bryological Society (BBS). The new website significantly improves the design, navigation, accessibility, functionality, SEO, and content, in comparison to our previous website – altogether strongly contributing to delivering the mission of the Society: promote a wider interest in all aspects of bryology.

But what is bryology???

Bryology is the study of bryophytes, also known in English as mosses, liverworts and hornworts and the best way to find out more is to head straight away to the relevant page of our new website!

I expect most people will fall in love with the featured photography and these tiny plants, but you will also found a wealth of scientific resources about bryophytes on the new website. There is more than one page per day in the year, each contains expert knowledge about bryophytes, about the Society itself… and even the lives of bygone bryologists.

The new website was developed in close collaboration with  Castlegate IT, a York-based web developer specialised in fully bespoke WordPress sites. They provide more details about the BBS-Castlegate IT collaboration on a page you’ll access following this link.


Celebrating faculty research success

I am incredibly proud and excited to introduce the research blog of the School of Health and Life Science, Teesside University, UK. The SHLS-Research blog was designed as a key instrument, part of a wider effort to celebrate research success in the School.

The editorial will give you some background about the aims and justification for developing this blog website. I look forward to leading the editorial board initially and work alongside early carer researchers to transform the School’s research culture – let’s get writing!

New Paper: Dung fungal spores for the study of past megaherbivores

Van Asperen, E.N., Perrotti, A., Baker, A. (2020) Coprophilous fungal spores: NPPs for the study of past megaherbivores.

Published online on Dec. 2020 /Jan. 2021

This publication, lead by my colleague Eline van Asperen, will be an invaluable resources to scholars researching past populations of megharbivores or other aspects of palaeoeology using non-pollen palynomorphs, whether be it for the MSc dissertation, PhD, postdoc or at any point of their career. It is supplemented by an open-access key to the identification of dung fungal spores, which supersedes that previously provided on this blog (but some may find useful to still have access to both!):


Spores from coprophilous fungi are some of the most widely used non-pollen palynomorphs. Over the last decades, these spores have become increasingly important as a proxy to study the Pleistocene and Holocene megafauna. Although the number of types used in palaeoecology is relatively small, there is a wide range of coprophilous fungal taxa whose utility in palaeoenvironmental reconstruction remains under-researched. However, environmental and taphonomic factors influencing preservation and recovery of these spores are still poorly understood. Furthermore, our understanding of whether and how spores are transported across the landscape is limited.

Dung fungal spore presence appears to correlate well with megaherbivore presence. However, depending on the site, some limitations can remain to quantitative reconstructions of megaherbivore abundance from dung fungal spore records. The presence of dung fungal spores is often more significant than their absence and variation in in abundance with time should be interpreted with caution. Correlation with other proxies may provide a promising way forward.

The majority of studies using dung fungal spores as an indicator for large herbivore abundance are of records of Late Pleistocene and Holocene age, with a focus on Late Quaternary megafaunal extinction. However, more research could potentially extend records further back in time.

Talk at BES’s Festival of Ecology, Dec 2020

I simply can’t wait for the Festival of Ecology in Dec 2020, an all online event that replaces the British Ecological Society’s traditional in-person annual meeting this year. BES events are always a huge source of inspiration with talks from researchers around the World, discussions, and an opportunity to meet with long-time-no-see colleagues.

In addition, this year I am going to present some of my work on megafauna with a 15-mins talk:

Reviving the function of extinct megafauna: inspiration from the past

This talk will be strongly inspired by work recently published and introduced on this blog post and on this one.

It will also be an opportunity to wave high the Teesside flag and highlight the fantastic, positive energy coming from our Earth, Ecology and Environment Research Collective

getting ready for the festival of Ecology 2020

And here is the talk as delivered:

Earth, Ecology and Environment website at Teesside University

I am so incredibly proud and excited to introduce the new Earth, Ecology and Environment website, presenting our research collective at Teesside University.

This website will contribute to raising the profile of our research and academic activities. The hope is that, as we are all individually growing our academic portfolios and that the group grows with new researchers joining, the site will grow into a go-to resource of information about our successes, for colleagues around the world, partners, at the university as well as for existing and prospective students.

New Paper: Late-Quaternary megaherbivore extinctions in interior Alaska

Conroy, K.J., Baker, A.G., Jones, V.J., van Hardenbroek, M., Hopla, E.J., Collier, R., Lister, A.M., Edwards, M.E. (2020) Tracking late-Quaternary extinctions in interior Alaska using megaherbivore bone remains and dung fungal spores. Quaternary Research. DOI:

Article first published online:  28 April 2020

Read article by following this link, taking you to the Cambridge University Press Core collection.

This research is considerably questioning some of the accepted wisdoms surrounding late-Quaternary extinctions of megaherbivore.  While research so far has associated the extinctions with dramatic ecosystem changes and crashes in abundance in all megaherbivores species – including those species that survived – here, we show that it is not systematically the case, by providing the counterexample of interior Alaska.

There is an increasing interest in of the late-Quaternary extinction, to understand their consequences for ecosystems function. Understanding these consequences help us guide rewilding initiatives and harness the potential of large vertebrate as ecosystem engineers in a more creative way, as explained in this article I have written for The Conversation.

Quaternary Research article abstract:

“One major challenge in the study of late-Quaternary extinctions (LQEs) is providing better estimates of past megafauna abundance. To show how megaherbivore population size varied before and after the last extinctions in interior Alaska, we use both a database of radiocarbon-dated bone remains (spanning 25-0 ka) and spores of the obligate dung fungus, Sporormiella, recovered from radiocarbon-dated lake-sediment cores (spanning 17-0 ka).

Bone fossils show that the last stage of LQEs in the region occurred at about 13 ka ago, but the number of megaherbivore bones remains high into the Holocene. Sporormiella abundance also remains high into the Holocene and does not decrease with major vegetation changes recorded by arboreal pollen percentages. At two sites, the interpretation of Sporormiella was enhanced by additional dung fungal spore types (e.g. Sordaria).

In contrast to many sites where the last stage of LQEs is marked by a sharp decline in Sporormiella abundance, in interior Alaska our results indicate the continuance of megaherbivore abundance, albeit with a major taxonomic turnover (including Mammuthus and Equus extinction) from predominantly grazing to browsing dietary guilds.

This new and robust evidence implies that regional LQEs were not systematically associated with crashes of overall megaherbivore abundance.”

The Conversation article: Late-Quaternary megafauna extinctions in interior Alaska

In an effort to make my research more accessible to a wider audience, I have just published an article in The Conversation. The aim of this piece is to explain the relevance of my latest scientific article to nature conservation and as a support for rewilding initiatives around the globe such as Rewilding Britain and Rewilding Europe.

Link for The Conversation article.

Link to original research published in the journal Quaternary Research.


First records of Mentha cervina (hart’s pennyroyal) in Britain

Baker, A. 2020. Mentha cervina (Lamiaceae), an emergent aquatic alien species naturalising at South Gare, North-East Yorkshire. Vol. 2 No. 1 British & Irish Botany.

Mentha cervina in bloom

Published and open access since Feb 26 2020.

Abstract: There is an increasing interest in recording early colonisation of organisms when studying changes in distribution ranges induced by climate change. Here, I describe one population of Mentha cervina L. (Hart’s pennyroyal), naturalising in the wild at South Gare, v.c.62 North-east Yorkshire. Two other populations have been reported in Britain and none are known from Ireland. Of the three populations ever reported from the wild in Britain, two are still extant. It is unclear what vectors disperse M. cervina in Britain and whether the species is becoming increasingly naturalised or not. Diagnostic characters: digitate bracteoles and four calyx teeth, are provided to facilitate the recording of this mint species by field botanists.

Mentha cervina, growing in situ in South Gare