Pioneers, pollinators, and standing deadwood
Aalto University’s campus is home to thousands of species. Nature recovers and flourishes through gentle care and room to grow.
Text Minna Hölttä
Photos Jaakko Kahilaniemi
Few places bring together as many layers of landscape history as Otaniemi in Espoo. The campus includes archaeological sites from the Bronze and Iron Ages, as well as a centuries-old alley of linden trees recalling the area’s history as a manor. There are iconic buildings set in a town plan designed by Alvar Aalto and Aino Aalto, and the area has been recognised as a nationally significant built cultural environment.
‘A smart designer works with nature, not against it,’ says Minttu Somervuori, landscape construction specialist at Aalto University Campus and Real Estate (ACRE). Careful nudging in the right direction with plenty of room for natural growth and structured maintenance can achieve remarkable results. Even amid new buildings, there are light rail tracks and streams of people.
Sand and sunlight
In the dry, barren-looking sandy soil, dark green shoots snake across the ground. Wild thyme is doing pioneering work in the sun-exposed meadow established last autumn between the new Marsio building and Otakaari 1, the campus’s former main building.
Meadows are among Finland’s richest habitats but also its most endangered. Their decline hits pollinators especially hard, and nearly all wild plants and most crops depend on pollinators.
In Otaniemi, meadow planting helps combat biodiversity loss while supporting the campus strategy of maintaining open habitats alongside lawns and managed green areas. Flowering seed mixes are also used whenever lawns are reseeded. Beneath large trees, flowering lawn plants brighten the landscape and attract butterflies.
In nutrient-rich soil, wild thyme and other meadow species would quickly lose out to faster-growing competitors. That’s why sand, including organic material from a local data centre construction site in Espoo, was mixed into the growing medium at the Marsio meadow.
The May sun shines high overhead.
At night, the sun-warmed hollows in the sand create their own microclimate where insects like to rest. Seeds for the Marsio meadow were collected from nearby rocky outcrops and coastal areas, bringing in locally adapted meadow and shoreline species.
Using local plants helps species adapt and ensures declining species can survive in urban environments. Wild thyme was the meadow’s most distant arrival, brought from the Porkkala peninsula in Kirkkonummi.
Wild thyme is essential for several butterfly species, whose caterpillars feed exclusively on it. The pink and violet flowers that appear in July and August attract butterflies, bumblebees, and other kinds of bees.
But pollinators and other residents of Otaniemi need more than just food. They also need places to nest – and suitable habitats can often be found within a very short flight.
Life from decay
Behind the red-brick buildings, at the edge of a small forest, stands a spruce trunk cut a few metres above the ground. A fallen neighbouring tree partly tore up its roots in an autumn storm, and the spruce was left in place as a gradually decaying standing deadwood trunk.
The first species to colonise deadwood are usually longhorn beetles and other insects dependent on decaying trees. Solitary bees and predatory wasps later nest in the tunnels they leave behind. Standing deadwood also attracts many bird species, including endangered willow tits.
Around a quarter of Finland’s forest species – some 5,000 species – depend on deadwood. In natural forests, about a quarter of the wood is dead; in commercially managed forests, only a small fraction remains. It’s no surprise that hundreds of Finnish forest species are now endangered.
As decomposition progresses, the fungi and insect species living in deadwood also change. That’s why forests need trunks from different tree species at different stages of decay.
In Otaniemi, this continuity of deadwood is actively maintained: roughly one-third of the deadwood is recently dead, one-third moderately decayed and one-third heavily decomposed. All fallen trees are left in the landscape and integrated into the environment.
The cut spruce snag represents the very beginning of this continuum. A thoughtful forestry worker has carved a bat roost into the top of the trunk, creating a daytime shelter and resting place for the bats living in Otaniemi.
The area is also crossed by Siberian flying squirrels, which nest at the nearby Laajalahti nature reserve. Finland is the westernmost habitat of this endangered species. Within the EU, the Siberian flying squirrel is found only in Finland and Estonia. The shy nocturnal animal is rarely spotted, but the small yellow droppings found at the base of trees reveal its presence.
At the other end of the decay cycle, deadwood becomes humus with the help of fungi and bracket fungi. That’s how nutrients and carbon return to circulation for new generations of life.
From grove to pond
In the shade of the trees, the grass grows lush and tall, and the leaves of herb-paris peek through the stems. They reveal that this is one of Otaniemi’s herb-rich forests.
The key difference between heath forests and lush groves is in the topsoil. In heath forests, soil layers remain clearly separated; in groves, organic matter and mineral soil have mixed into nutrient-rich humus.
This fertile, mildly acidic soil makes groves some of the most biodiverse habitats in Finland, with the greatest numbers of both species and individual organisms among forest types. In many places across Otaniemi, rare hazel shrubs grow, enriching the soil further as their leaves decompose.
Caring for trees was already an important part of Alvar Aalto’s design philosophy. He emphasised harmony and coexistence between nature and the built environment.
Otaniemi’s current tree strategy respects Aalto’s legacy while also responding to major contemporary challenges. The most significant of these are caused by climate change: rising temperatures, drought, winds, and destructive insects.
Pines and spruces suffer the most. Increasing the amount of deadwood can help control pests, because predatory insects that feed on bark beetles – especially the European spruce bark beetle – thrive in decaying wood.
New plantings, however, favour species that can better tolerate changing conditions. One example is the European dwarf birch (Betula nana) growing near Ossinlampi pond, a remnant species from Europe’s last Ice Age.
The 20-centimetre saplings came from Arboretum Mustila, whose mission is to test and study the trees and plants of the future. The birches were planted in small groups around the pond in 2024. Experts selected the site so carefully that the saplings require no separate irrigation. Nutrients come from decaying birch trunks left nearby.
Even at full size, the European dwarf birch remains under three metres tall, making it well suited for areas close to buildings. It represents the current philosophy behind landscape management on Aalto’s campus: adaptation, resource wisdom, and respect for nature’s own processes.
That, above all, is what Minttu Somervuori hopes people will understand.
‘Gardening can maintain a static state, but nature is constantly changing and always in motion.’
Principles of campus nature management
- Strengthening soil vitality
- Renewing forests through natural succession along with planting
- Safeguarding the wellbeing of urban trees, large landscape trees, and future generations of trees
- Favouring local species in lawns and meadow plantings
- Minimising invasive-species risks through the use of local plant material
- Reducing the maintenance backlog and replacing intensive upkeep with gentle guidance
- Encouraging close collaboration and professional pride among specialists
- Challenging old practices through research-based knowledge and bold experimentation
- Building a culture of collective learning, curiosity, and active engagement in nature work
This article has been published in the Aalto University Magazine issue 38, September 2026.