News and updates

News and updates from the project, writings about kelo trees

19.1.2023 – From a seedling to a kelo and from a kelo to decayed woody debris – Lifecycle of a kelo tree takes breathtakingly long

Drawings of a Scots pine turning
Scots pine turning slowly into a kelo tree

Would you like a short and sweet introduction into what we know about kelo trees so far? In this post, I would like to present you an online booklet that I made, called “Lifecycle of a kelo tree”. With illustrations and texts you get to follow the lifecycle of one Scots pine tree, from seedling to a fallen kelo log. You can access booklet by clicking here.

I was prompted to make this booklet after reading all kinds of texts about kelos. Texts online and in books often state things about kelos, that are not based on research, but seem to be passed on from text to text without any idea of the original source and its accuracy. So in this booklet I made, I wanted to use only published scientific articles, to tell you what we know about Scots pine and its kelo form based on research so far. I can tell you right now, that there are only a handful of articles on kelo trees! The aim is to update this booklet as we get our own study results which hopefully will fill the knowledge gaps of kelo trees and their formation.

Best regards, Tilla

11.1.2023 – When a journalist accompanied us in the field last autumn

Tuomas coring a kelo in Cajander forest
Tuomas coring a kelo from one of our study plots in North Carelia in October

Last October, journalist Sampsa Oinaala joined us – Tuomas, Pem and Tilla – as we went to two of our study plots in the Cajander old-growth forest in Northern Carelia. We wanted to take some samples for preliminary analysis before the actual sample collection next summer, and Tilla and Pem also took the opportunity to practise their tree coring skills.

Sampsa followed our work and interviewed us as we travelled two hours from Joensuu. Based on that day and its discussions, Sampsa wrote a fine article about our research and kelo trees. It is now published in the Kone Foundation website, and you may read it by clicking here.

22.11.2022 – Aleksi Nirhamo: Kelos are important for lichen biodiversity

Calicium tigillare on an old fencepost. This species does not have pin-like fruiting bodies, but it forms a spore mass the same way as other calicioids. A similar-looking species called Calicium pinicola is known from Sweden and Norway, but unfortunately it does not occur in Finland. Photo: A. Nirhamo

Lichens are omnipresent in Finnish nature but taking notice of the full range of their diversity requires careful and detailed observation. Kelo trees, especially long-lasting ones, are also often full of diverse lichens.

In the summer of 2022, I surveyed a group of kelo trees in Patvinsuo national park in eastern Finland. I collected similar data from snags (standing dead trees) on logging sites formed from retained pines. The lichen communities on the kelo trees were highly species-rich: on average, 23 lichen species were found on the kelo trees, and one bore as many as 39 lichen species. Species richness was also rather high on snags on logging sites (avg. 18 species), but the species composition was distinctively different. Nearly all lichen species that specialize in growing on deadwood are small crustose lichens (also known as microlichens). In addition, larger generalist species and crustose lichens that also occur on bark may be found deadwood. The species assemblage on snags on logging sites consisted in a much larger extent of generalists, whereas the assemblages on kelo trees consisted of more specialized species. This is reflected for example in the occurrence of red-listed species: snags had, on average, 0,6 red-listed species, while kelo trees had on average 3,7 red-listed species, with 8 red-listed species on one kelo at the highest. Red-listed species often observed on kelo trees included Micarea elachista, Ramboldia elabens and Calicium denigratum. These numbers demonstrate the high importance of kelo trees to lichen diversity.

Calicium viride on the bark of Picea abies. The “pins” are the apothecia i.e. the fruiting bodies of the mycobiont, and they have developed an exceptionally long stalk. Another exceptional feature of these lichens is that the apothecia do not “shoot” the spores to be carried by the wind, instead the spores remain on top of the apothecium as a spherical spore mass. This way, the spores may be attached to woodpeckers or other birds and thus be dispersed to other trees with the birds. Photo: A. Nirhamo

However, at least in Patvinsuo the situation is worrisome, since it is evident that the kelo continuity of the areas, where I collected the data, is being disrupted. Because of logging operations completed before the founding of the national park, there are almost no large, old pines from which long-lasting kelo trees could form in the next decades. Scarce kelo trees may still be found in the area, and surveying these trees made me feel like an archaeologist studying ancient relics. These kelo trees may have originated from trees that were left as seed trees in previous loggings, or perhaps they were already dead at the time of the loggings. When the current kelo trees are eventually decomposed, it appears that there will be no new kelo trees for the lichens to colonize, which would mean local extinctions of the species dependent on kelo trees. There is likely a similar situation in many other Finnish protection areas. Loggings that cause disruptions of kelo continuities are also completed today especially in northern Finland. The continuing decline of kelo trees leads to the decline of lichens and other species dependent on kelo trees.

“Scarce kelo trees may still be found in the area, and surveying these trees made me feel like an archaeologist studying ancient relics.”

The research on the lichens on kelo trees will continue next summer. With the data we will collect then, we may look into the development of the lichen communities on kelo trees over time after their death. Previous studies have strongly suggested that the value of kelo trees for lichens increases with the time after their death, but the studies so far have been insufficient. In addition, we may look into how the lichen communities are affected by the chemical features of the wood. For example, lichen communities on bark and rock substrates are known to be strongly affected by the chemical variation of the substrate. This could also be the case for deadwood substrates, but it has not been studied.

Micarea hedlundii requires moister conditions, and thus it is not found on kelo trees in (sub)xeric pine forests. It may, however, be found at the base of kelo trees or fallen kelo trees in spruce-dominated forests, where the moisture of the substrate and the immediate surroundings is higher. Photo: A. Nirhamo

What kind of lichens do we find on kelos?

  • About 1 700 species of lichens are known from Finland
    • About one-third of them are epiphytic i.e. growing on trees
    • About 10 % of epiphytes are found only on (dead)wood
  • In addition several species grow primarily on wood, and facultatively on bark
  • Out of the red-listed epiphytic lichen species, one-fourth (78 species) occur primarily on wood
  • The lichens that grow on wood may coarsely be divided into species found on decaying and moist wood and species found on decay-resistant, dry wood
    • For the latter, kelo trees are the most important substrate
  • “Kelo species” may also be found on fences, the walls of sheds or barns, piers and other wooden structures

Out of the lichens found on deadwood, perhaps the most startling are the calicioids, which include for example the species from the genera Chaenotheca and Calicium. Calicioids are a taxonomically disparate group, but they share similar morphological and often also ecological features. There are also non-lichenized fungi that are also referred to as calicioids, which share a similar morphology with calicioid lichens. Many calicioids (both lichenized and non-lichenized) are specialized to deadwood, and they are also characteristic for kelo trees. For example, Chaenotheca ferruginea, Calicium viride, the rare Calicium tigillare, or the non-lichenized Chaenothecopsis fennica may be found on kelo trees.

This article was written and photos were taken by Aleksi Nirhamo, our lichen specialist (you can read more about him in the People-tab)

19.10.2022 – Kelo-project in the Cold Forests-conference

Pem presenting in the conference
Pem presenting in the conference

Tilla, Pem and Aleksi from the Kelo-project held presentations of their PhD-projects in the “International Research Network on Cold Forests”-conference, which was held in Joensuu this year, in the beginning of October. From down below you can watch the five minute presentations uploaded in Youtube.

Tilla’s presentation
Pem’s presentation
Aleksi’s presentation

12.9.2022 – Project kicked-off properly, and the first post

Salamanperä forest and an old charred stump
Salamanperä forest and an old charred stump

Hello, this is Pem and Tilla, working on our doctoral disserations in the Kelo-project and managing this website. We started just at the beginning of the summer. Tilla will be diving into the chemical composition of kelo trees and Pem will be focusing on the dynamics of kelo trees – how often and where they form and how long do they remain standing.  Together, we aim to answer how and why some pines become kelo trees, and what are the factors responsible for creating this one-of-a-kind forest structure.  

In this September evening, we have just finished our first summer of field work. Yay! We started it in the cloudberry-rich Kuusamo in northeastern Finland, continued in the steep hills and eskers of Northern Karelia, and have now wrapped up the establishment of our sample plot network in the rocky forests of Salamanperä just as autumn colours are starting to bloom in the birches and mires.  

With help from Romain Bergeret (visiting us from AgroParisTech in Nancy, France), and the kelo-project’s lichen specialist Aleksi Nirhamo, we mapped  kelo trees, their characteristics and peculiarities in circular sample plots inside some of the best remnants of old-growth forests still remaining in Finland. This network of field plots forms the backbone of next summer’s fieldwork, where we will sample the trees for their growth history, chemical composition, and the species that dwell on them. You can get to know all the people involved in this project through this link

We saw some very old and remarkable kelos, in addition to multiple cut stumps and trees that had died young. It is surprising how far human influence reaches even in the most distant forests of Finland! Fires had been present in the history of most stands, and we were able to observe trees with multiple fire scars and charred surfaces. The fire history of the trees is of interest for both of our studies.  

Now we will continue to develop our research methods through the winter and do some preliminary analysis from the collected data. What might we find?