Maunula nature trail

Old forests may look like they are standing still, but all the time a steady and continuous natural cycle is taking place.

This cycle can be seen in the food chain: A worm eats a leaf, a shrew eats the worm, a tawny owl eats the shrew, micro-organisms and worms decompose the owl, and around it goes.

The food chain is actually more of a food web, as food chains intersect and run many courses.

Much of the natural cycle occurs unseen on the elemental level, such as in the carbon cycle: A living tree stores carbon from the atmosphere in its trunk and roots, as well as in the soil. The tree continues to bind the carbon in the soil even after it has reached its full height.

When the tree eventually decomposes, approximately as much carbon is released as is stored by the growth of a new tree. Old pine forests and the soil on which they grow are a vital carbon sink, helping to prevent climate change.

Atop the hill appears the bald crown of Old Man Bedrock. The sides of his rocky head are covered by undemanding lichen, shrubs and pines. Soil has accumulated in the wrinkles of his face, attracting mosses and grasses with its moisture. On his shoulders the Old Man carries boulders that the ancient sea failed to wash away. Some of the boulders are reminders of the Ice Age, transported here from far away by glacial melt waters.

The Ice Age also gave the Old Man his jacket of moraine containing rocks, gravel, sand and clay. It provides an excellent base on which his woody overcoat can grow. The Old Man still remembers the quake that created the adjacent fault line. The base of the resulting gorge was covered in clay transported by the rivers that fed the ancient sea. The moisture and nutrients in the clay nourished the lush vegetation. Today the gorge and its streams are teeming with life that keeps the wise Old Man amused.

The seven stars of the Big Dipper make it easy to locate the North Star, around which the other stars appear to rotate through the night. The hourglass shape of the constellation Orion represented the hunter in ancient legends. It can be identified by the line of three stars forming Orion’s Belt. Viewed from Earth, Sirius is the brightest star after our own star, the Sun.

Christmas stars: This star chart shows the main constellations as they would appear when viewed from Helsinki at 10pm on 24 December. The brightest star in the constellation Lyra (Latin for lyre, which it resembles) is called Vega. The cross-shaped constellation Cygnus resembles a swan flying across the Milky Way. The brightest star in the constellation is called Deneb and represents the tail of the swan.

If you look up on a clear night you can see constellations, other planets orbiting our own star, the Sun, and interstellar “fog”. You may even see the centre of our own galaxy, the Milky Way, as a light ribbon across the night sky. All elements heavier than hydrogen and helium were created by fusion within stars, which continue to form new matter as revealed by the visible light that is generated by the same reactions. Over billions of years the matter that was fused together by the stars became the building blocks of our own planet. All life on Earth is formed from the same matter, including us. So we really are all made of stars!

Rainwater in nature either evaporates or is absorbed into the ground, where it seeps slowly and quite steadily into watercourses. Rain that falls in the city onto roofs, streets and paved courtyards flows rapidly along drains and ditches into creeks. This stormwater carries away all kinds of dirt. During downpours, runoff water gushes into creeks and onwards into the sea, but at other times the creeks can dry up altogether. Plants and animals prefer creeks with clean water that flows steadily. People too can enjoy the diverse nature along the city’s creeks. Runoff water can be cleaned by using plants and basins to retard the flow of creeks.

Let’s keep our natural water resources clean! The Maunulanpuro creek, the eastern branch of the Haaganpuro creek, flows beneath this hill. All the rainwater that falls in the Haaganpuro catchment area flows down these creeks into the Pikku Huopalahti bay and onwards into the Baltic Sea. The catchment area covers almost 11 square kilometres – as much as 2,000 football fields. A third of this area is impermeable to water, so enormous quantities of rainwater wash off into ditches, drains and creeks.

Groves are real cradles of life. In spring the bushes are filled with the singing of warblers, thrushes and many other birds, while the ground is covered in a kaleidoscope of spring flowers: blue and white anemones, spring peas, lilies of the valley…

In summer the dense foliage of the trees shades the ground and conceals nests and chicks readying themselves for flight. This particular grove also boasts rare hazel bushes, small-leaved linden trees (Maunula’s signature tree) and sturdy aspen trees dyed red from algae. This valuable area is a protected habitat, so tread carefully where you go. Hazel bushes grow on Helsinki’s slopes and bedrock, where they took root after the last Ice Age. The yellow catkin of the hazels flower in spring before the leaves appear. The nuts that ripen in autumn are a treat for squirrels and birds.

Tree of knowledge

According to the druids, the wise men of the ancient Celts, the hazel bush was a tree of knowledge that had the ability to send messages to other trees. This belief is in fact backed up by modern science: Many plants actually communicate with each other, through both the soil and the air. They could be saying, for example, “Watch out, there’s a plant eater about – start producing some foul-tasting protective substances fast!”

If you watch quietly you might see trout – either a small young fish or fully grown adult that has returned from the sea to spawn. It’s wonderful that the extremely endangered trout has returned to the urbanised Maunulanpuro creek. The City of Helsinki together with the “Stream Maintenance Association” (Virtavesien hoitoyhdistys) and volunteers proved that the creek could be restored as a breeding ground for this fine fish. Gravel and rocks were added to the bed of the creek, and small rapids were created to attract the fish. To help the trout thrive, fishing in the creek is prohibited. The water that flows into the creek is kept as clean as possible, and the natural curves of the creek have been retained.

Different types of trout

Trout spawn in rivers and streams. Some of the young fish migrate to the sea or lake to grow, while others stay behind at home and do not grow as big as the migrating fish. These different types of trout are referred to as sea trout, lake trout and stream trout, i.e. brown trout. They are nevertheless all members of the same species: trout.

The natural trail that starts from the Maunula recreational hut (Maunulan maja) passes through the Maunula Urn Cemetery. Just follow the signs along the nature trail and you’ll get to the right gate to exit the urn grove. The gates to the cemetery close at 10pm, but you can still get out after this through the main entrance on Pirkkolantie.

This is the biggest urn cemetery in Finland and a place for quiet meditation for the relatives of the 22,000 people laid to rest here. At the same time it offers a beautiful setting for admiring the nature.

A wide range of perennials, shrubs and trees grow in the well-maintained cemetery. Special trees include cherries, hemlocks, hawthorns, walnuts, weeping katsuras and red oaks.

The diverse plant life also attracts many insects and birds. Flycatchers, thrushes and waxwings feed among the shrubs. You may also see a tawny owl or goshawk on the lookout for prey. Carp, tadpoles and frogs live in the pond, which is also used to collect local stormwater.

The water in the Haaganpuro creek is clearer than before thanks to restoration work. The nature in and along the creek is rich and diverse in organisms.

Endangered sea trout rise up the creek here and onwards up the Maunulanpuro creek to spawn. The playful dipper dives in the water in wintertime to feed on the larvae of caddisflies and stoneflies.

The signs of a healthy and naturally diverse creek include a meandering stream bed, babbling clear water, shady trees along the banks, trees and branches in the water, a bed of gravel and sand, water mosses, benthic invertebrates, fish larvae, flying insects and the birds that feed on them. Which of these characteristics can you identify in this creek?

Impatiens glandulifera is an invasive plant species that grows along the creek in places. It spreads rapidly and claims territory from indigenous plants. The help of volunteers is needed remove any of these invasive plants they come across.

Natural streams and creeks help purify the water. Rapids and waterfalls aerate the water, which is very important for the fish in particular. Countless microorganisms also play a vital role in cleaning the water. They convert the leaves and other organic materials that fall into the water into food suitable for fish and larger animals.

Helsinki has a tradition of allotment gardens stretching back over a 100 years. Today there are 41 allotment gardens in the city that are rented out by local district and allotment garden associations. The allotment gardens here are rented out by Maunulanpuiston Palstaviljelijät ry. The size of each allotment usually ranges between 50 and 100 square metres. Visitors are free to walk along the paths between the allotments and admire the gardens. The allotments themselves, however, are private property, so visitors should not pick anything or walk across them.

The allotments are used to ecologically cultivate a wide range of vegetables, herbs, flowers and berries. Such home-grown food is packed with vitamins. The gardening enthusiasts who rent these allotments can witness the miracle or growth and enjoy knowing exactly what they are eating. Composting recycles the nutrients in gardening waste back into the allotments, and green fertilisers fortify the soil. In this way, the ecological footprint of food production is reduced.

Urban farming is very popular, but there are not enough allotments for everyone. The backyards of the homes in Maunula are quite large, so local residents could also grow food in plant boxes. All they need is the permission of the housing association and a couple of enthusiastic neighbours.

Polypores are fungi whose mycelia are hidden inside trees or the soil. Most polypores are wood-rotting fungi. Slowly over the course of decades they decompose dead trees into soil nutrients that are used by other plants. In this way the nutrient cycle continues, and the forest remains alive and diverse.

Different types of polypores require trees of different ages, and some require specific tree species. Many polypores also work together with living trees, exchanging water and nutrients for photosynthesis products.

The trees decomposed by the polypores make ideal nesting and feeding places for many insects, birds and small mammals. Rotten trees are purposely left in the park to protect natural diversity.

Old forests are extremely vital living environments for many endangered plants and animals. Forest ecologists therefore pay a lot of attention to polypores, which can tell a lot about the inhabitants and conservation value of the forest.

Over 70 different species of polypores have been identified in Maunula – representing more than a quarter of all the polypore species identified in Finland.

Excess soil from urban construction has been transported here, creating a layer many metres thick. This area has since been used as a sports field, as a dog park and as a dumping ground for snow in winter. Today it is dominated by lush meadow plants.

This apparent wasteland of weeds is actually very rich in nature. The soil that has been transported from elsewhere contains the seeds of many plants, and additional seeds are brought here by animals and the wind. Meadow plants support butterflies, hymenoptera such as bees and wasps, and many other insects that are needed to transport pollen. Insects in turn attract insectivores. Throughout the summer the meadow is abuzz with activity. In wintertime, flocks of birds come to the meadow in search of the seeds that have dropped from the plants.

If wasteland is left untouched for a long time, it will gradually become overgrown with shrubs and trees. The groundcover plants will diminish, and the forest will take over. This process is known as natural succession.

Pollinating insects carry pollen from one flower to another like a package that is delivered door to door. Plants that are pollinated by insects require very little pollen as a result. In contrast, plants that are pollinated by the wind produce enormous quantities of pollen in the hope that some of this mass distribution will find the right address.

You are nearing the end of Maunula Nature Trail. From here you can either head west back to the Maunula recreational hut (Maunulan maja) or continue southwards for another 300 metres to the pet cemetery on the other side of the Metsäläntie underpass.

Maunula Nature Trail has highlighted natural diversity and the cycle of life. Death and grieving are an unavoidable part of this cycle, as is the new life – with its own joys and sorrows – that sprouts after death.

The pet cemetery has around 3000 small graves. The individual gravestones and mementos reflect the longing of people after the death of their beloved pets. The pet cemetery is maintained by the Helsinki Humane Society HESY (the Helsinki Society for Animal Protection).

Life continues its cycle in the dense spruce forest that surrounds the cemetery. Tits and crests chirp on the branches while voles and mice scurry around below. The life cycle of anyone of these could end suddenly in the claws of a fox, owl or hawk, who in will turn have food to feed their young.

The cycle continues.