A year in a geodiversity hotspot

Currently there is raised awareness that in addition to biodiversity, there is a thing called geodiversity. Biodiversity means the diversity of biological organisms and geodiversity consequently means the diversity of geological and geomorphological formations and materials.

One of the best places in the world to experience geodiversity of glacial origin is the Rokua area, located in Northern Finland. It also is a part of the UNESCO Global Geopark network! Actually it’s the world’s northernmost Geopark. A part of the Rokua Geopark area is also a Finnish national park: Rokua National Park. The Rokua area has different land forms, their formation dating back to the melting of the massive ice sheet after the ending of the previous ice age. Land forms include eskers, dunes, potholes, ancient shorelines, and many more. In addition to the beautiful, varying landscapes, the diversity of formations offers various habitats for plants, animals and fungi.

Inside the national park. On the left there is a large kettle hole. You can still see some snow in the bottom of it. May 2019.

I have been extremely lucky to spend time in the Rokua area for almost eleven years now. Obviously, I’ve taken loads of photos during the years. To this post, I selected some photos that I’ve taken during the past year: from spring 2019 to winter 2020.

This type of vegetation is common in Rokua: pines here and there, and lichen on top of the barren, sandy ground. The lichen layer is really thin and it gets easily broken when it’s dry, so it’s recommendable that people use the trails to prevent erosion. August 2019.
Here’s some typical species that thrive in Rokua: Cladonia stellaris, Vaccinium oxycoccos, Empetrum nigrum ssp. hermaphroditum, Calluna vulgaris. September, October, August, July, respectively, 2019.

The habitat and microhabitat types in Rokua are rather different to what you can see in the surrounding regions (Do I dare to simplify them as more “normal” boreal forests in a comparatively flat layout?). Anyways, in a regional context, Rokua has exceptional geodiversity, which results in exceptional biodiversity, too. The role of Rokua is huge for regional beta diversity (Can I refer to both bio- and geodiversity with “beta diversity” here? … I dunno :), but I will do it anyways).

Thymus serpyllum (kangasajuruoho in Finnish, Breckland Thyme in English) is a rare species, but grows somewhat abundantly in some places in Rokua. This species enjoys the dry and warm sandy esker ridges facing the sun. It is also an important species as a resource: some threatened butterfly species lay their eggs and feed only on this particular plant species. July 2019.

But you know what? I happen to know a fellow Rokua-enthusiast, Dr. Helena Tukiainen, who is an expert in geo- and biodiversity of this region. I asked her about their latest findings and here’s what she said: “We found a positive relationship between local-scale geodiversity and vascular plant diversity at our study area in Rokua Global Geopark. According to the study, landforms that are moist and that have high hydrological and microtopographical variation (e.g. ravines, river shores and mires) support high biodiversity.” That seems to be really important information for, for instance, conservation planning! You can find Helena’s PhD thesis here and her research profile here.

The last time I was in Rokua was a week ago, in the beginning of January 2020. It seems that this January there was the least amount of snow I have witnessed throughout the years. AND the roads were extremely icy and slippery, which usually happens later in the spring. This winter is not following the normal protocol elsewhere in Finland either (this is true at least for a large part of the country). Earlier this week, according to the Finnish Meteorological Institute, the temperature in Oulu was almost 15 degrees warmer than the average January temperature (based on a time series of measurements starting from 1959; this news was widely distributed by Helsingin Sanomat). Quite an anomaly! We are desperate to get some snow here! Snow is so beautiful and it reflects light really nicely!

Had to walk up the hill to see the sun! That’s about as high as it gets this time of the year. There is some snow, but not a very thick layer: you can see some vegetation underneath the snow cover, meaning that there is actually only a little bit of snow compared to how much there could be. January 2020.

But moving on… Climate change in my mind, I asked Helena’s opinion on the future of geo- and biodiversity in Rokua. This is what she told me: “Geodiversity is usually more stable in the changing climate than biological diversity. Thus, using information on landforms could be useful when considering the sites that best preserve current and future biodiversity of the Geopark area. Furthermore, during the decade that has just started, it would be essential to gain more empirical evidence if a positive connection between geodiversity and biodiversity exists not only in Rokua Global Geopark, but also at different areas and from local to global scales.” Well, there certainly is a need to dig deeper into these themes.

Helena is currently working as a postdoctoral researcher in the iGEOBIO project (Improved geodiversity information in assessing and conserving biodiversity) funded by the Academy of Finland and led by Senior Research Fellow Janne Alahuhta at the University of Oulu, Geography Research Unit. The group is investigating spatial and temporal geodiversity-biodiversity relationships in both terrestrial and aquatic ecosystems. There are several study areas, which also include sites at Rokua Global Geopark. You can follow @GeoBioDiv on Twitter to get the latest news regarding iGEOBIO and their other projects. I wish the best of luck to the group as they are tackling difficult but important questions!

I will end this post with a photo of a dead pine because it’s just so majestic.

This pine is still standing although it has been dead for a while. May 2019.



Luontoon.fi, January 12, 2020. Suomeksi Rokuan luonto. In English Rokua’s nature.

Luontoportti.com, January 12, 2020. Suomeksi kangasajuruoho. In English Breckland Thyme.

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