The Spruces of the Krukawe Woods The Spruces of the Krukawe Woods
Nature

The Spruces of the Krukawe Woods

New Life in the Białowieża Forest
Michał Książek
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In the Białowieża Forest, a small spruce grows on an oak tree. Tree on tree. Roughly 20 metres above the ground.

In the Krukawe Woods near Teremiski, some trees grow on tiny hillocks. Those that grow lower have high, stilt-like roots. I wondered why this was the case, until in autumn 2017, when several days of rain filled all the hollows with water. It became clear that Krukawe was once wet woodland, and marshland in places. The islets, now covered with black alder, Norway spruce and the increasingly rare European ash, were the only places where the seeds did not rot and were able to germinate. The stilt-like roots are yet more proof that the forest was once marshland: young trees grew and came into leaf on fallen trunks, which formed a kind of island in the water (so-called ‘nurse logs’). In order to eventually reach the soil, the young spruces had to engulf the nurse log with their roots. When the nurse log rotted and decayed, the spruce roots remained in a stilt-like, straddle position.

The Białowieża Forest has been dry for several years, so the new generation of woodland has no need for the islets or nurse logs. Over the last half-century, the period of snow cover in the Białowieża Forest has fallen from 80 to 40 days. Rainfall tends to be sudden and heavy, and the ubiquitous draining ditches quickly remove the rainwater from the land. The forest is drying out.

Seeds

It’s spring and I’m watching falling spruce seeds. Triangular blades with a dot in the corner, they’re lighter than flies. They fall in different ways, some straight down, others at a greater angle, and others circling round and round in spirals. Only very few try to climb. Their flight is so unpredictable that the birds can’t catch them in the air. No species feeds that way. I picked up about a hundred, expecting them to be identical, but no, each one was different! Not a single repetition. At first, the shape of the blades seems to be the same. But in fact, they are all folded to a greater or lesser extent; sometimes they have small spurs, sometimes recessions. They resemble the wings of chrysopids.

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Their different blade shapes probably influence their types of flight. The spruce appears to try various ways to send its seeds as far as possible, even to the meadows along the Łutownia river. If they all landed in one place, this would result in fierce competition in their early days and the imminent death of many of them (which in any case is unavoidable). It is in the interests of the tree – or rather, the species – to send its ‘children’ as far as possible. The literature tells us that spruce seeds can fall as far as several hundred metres away. That is the size of its biological footstep. It seems like a lot for a plant, but the tree can only mark this distance once a year.

Where the seeds fell 100 years ago, trees now grow. Spruces appeared in the places where the restless specks landed. Nobody planted them there. Krukawe is a collection of deciduous and coniferous coincidences. It wouldn’t have taken much for everything to be different here. A few wetter years would have sufficed for the hillocks to be under water too. Instead, they fulfilled the role of a matrix, a form that gave the coordinates and vectors for the organic matter jostling into the space: spruces, oaks, maples and hornbeams. The places without trees are those where it was too dark, too wet, too dry.

At the eastern edge of the Krukawe Woods, by the Royal Oaks trail, a seed came to rest a few years ago at a height of 20 metres, on the mighty bough of an ancient oak. It’s still there to this day, and you don’t need to climb the tree to see it.

Young spruce

That morning, I’d been tracking the female of the white-backed woodpecker – a species no longer found in most forests – for a good hour. She was migrating along the Łutownia, flying from alder to alder, up to the crowns of the royal oaks at Stara Białowieża. By April, white-backed woodpeckers are already sitting on their eggs, so I was hoping that she would show me her nest hole (they drill them so beautifully!). She had been foraging for some time on an oak named Alexander Jagiellon, when instead of a nest hole, just above the bird, I saw a young spruce. What was a spruce doing that high up? On King Alexander? I rubbed my eyes, brushed away a tick, but the view remained the same. No, the spruce wasn’t growing beside the oak, it wasn’t protruding from behind it. At a height of about 20 metres, in a fork of the oak’s boughs, a tree was growing on a tree. A little spruce. I counted about six whorls of branches, so it was already about 10 years old (each whorl is a year of life, plus 3-4 years to grow upwards). The female white-back had disappeared from my sight. That was the spring when I started looking at trees even more closely.

The spruce wasn’t sprinting upwards but growing in width. It had developed broad, heavily-needled branches, thus taking the form of a ball. On earth, trees like this are found in the open, outside the forest, where there is no competition for light. The oak provided similar conditions: the spruce had no need to compete with anything there. It was also hard to shake the impression that the spruce had some sort of ‘self-preservation instinct’ that was protecting it from overly hasty growth: had it rushed upwards, like its fellow trees in Krukawe, it would soon have fallen over. After all, its root system, which it had crammed into a crevice or hollow in the oak, was not particularly extensive or stable. It had to save itself using some internal growth correlation mechanism that influences the desired proportions of the tree, in conditions that are more appropriate for woodpeckers than spruces.

Might a population of ‘oak spruces’ have been functioning in the Białowieża Forest before thousands of the magnificent oaks were removed by foresters? Did they produce cones and seeds? Did their seeds fly better than those of other spruces, since they were the descendants of good aviators? Before the war, the existence of another oak spruce was reported by the late Professor Józef Paczoski: “[…] in unit 398, on the branches of a giant oak […] at a height of about eight metres grows a five-year-old spruce, and on the other side a rowan.” Furthermore, Professor Bogdan Jaroszewicz from the Białowieża Geobotanical Station at the University of Warsaw recently saw a spruce growing on a broken pine, six metres above the ground. The tree was already about four-metres tall, thus the pine/spruce Frankenstein reached to 10 metres.

However, it is difficult for trees to grow on trees. Their roots are unable to draw water from the body of another living tree (like mistletoe does). They usually grow in cracks, forks and hollows, as long as there is enough water there, and their roots find enough organic matter to anchor the fragile organism. This is unlikely to last more than 15 years or so.

Krukawe

I like the Krukawe Woods, the section of the Białowieża Forest between the village of Teremiski, Stara Białowieża and the Łutownia river. It’s a place where you can always find respite. And whatever you look at, it seems like a patchwork of the same substance, revealing its organic identity through whatever is growing and rotting beside it. Spruces, maples, oaks. Bastard balm, herb-paris and yellow archangel. They’re actually the same. The soft humus soil consists of what grows out of it: trees, leaves and herbs. It’s no surprise to find the leg of a doe eaten by wolves. The legs and abdomens of insects: ground beetles, flower chafers, marbled rose-chafers. Or ‘ghost trees’, the dead logs overgrown with mosses and liverworts, whose shapes are increasingly difficult to distinguish in the topography of litter and undergrowth. The organic nature of this forest harmonizes with human physiology. Carbon dioxide, ammonia, hydrogen sulphide. In-breath. Out-breath. Whoa!

Bigfoot and Chuck

All spruces have a flat root system, but the one above the creek really looked as if it was stood on a big chicken’s foot (I named it Chuck). Or actually, on the claws themselves. The claws form a tent that you can crawl under and check out what the robin’s getting up to (although it’s better not to venture under fallen or leaning trees, they can ‘close’ like traps!). When Chuck was growing up, there was an abundance of water, but when it ran out, the huge organism had no chance of survival. It received no help from the creek on whose banks it stood, which has been largely dry for years. Ephemeral, like desert streams. During the downpours in May, water appeared for a few days, but it quickly flowed into the Łutownia through the draining ditches dug by the Forestry Commission.

A spruce without water cannot defend itself against those who eat it. Resin is its weapon. In order to produce resin, it must drink. When dehydrated and weakened, it falls victim to insects and fungi. It is one of the most drought-sensitive trees. It’s not because of the bark beetle that the spruce is dying out in the Białowieża Forest. It’s due to the spruces dying out that so many bark beetles are present.

In the north-eastern part of Krukawe, where there are quite a few green spruces, grows Bigfoot (thus baptized by Adam Wajrak, with whom I regularly visit the woods along the Łutownia). The tree is about one metre in diameter, almost 30-metres high and well over 100 years old. Bigfoot copes well with bark beetles. It coats the males that first eat their way under the bark in sticky resin. In the spring, in the lower part of the trunk, I counted six holes through which bark beetles had tried to penetrate the body of the tree: all were sticky with resin, and one contained a trapped beetle. Why did Bigfoot survive, and Chuck didn’t? Perhaps the former has more water. Maybe it has developed a deeper root system? Although during the storms in May, Bigfoot was stirring as if it wanted to leave. Even healthy spruces are embedded shallowly in the soil and tip over very easily.

Light

A root system of this kind that is uprooted from the ground creates a new element in the forest architecture: a fallen tree. These fallen trees, tangled roots covered in soil and turf, are willingly inhabited by wrens and robins. Even a blackbird or a song thrush might build its nest there. Closer to the Łutownia, they can be used by kingfishers. The ornithologist Eugeniusz Pugacewicz wrote of the fact that in the Białowieża Forest, kingfishers dig their burrows amid fallen trees rather than on high riverbanks, which are non-existent there. Pugacewicz was a legendary explorer of the Białowieża Forest who once found a kingfisher’s nest in the roots of an overturned tree. In addition to birds, they are also home to wood mice and bank voles, which find shelter on the tiers of fallen trees during heavy rains or wet years. And, of course, tree seedlings.

The massive gap that emerges after a spruce falls is like an open window in the woods. Before it is closed by hornbeam branches, the seeds that have been waiting years for light absorb the sun’s heat and germinate. Oaks don’t need much light to start growing. They take advantage of the huge reserves accumulated in the acorn. In contrast, spruces seem to need more sun in the first days of life. I find them mainly in exposed places. The Krukawe Woods demonstrate that the Białowieża Forest can survive without cutting, ploughing and planting. It has its own, ancient, proven methods of rebirth and renewal. Foresters are not a prerequisite for photosynthesis and cell division.

I gently dig up one of the seedlings to see if it has as flat a root system as Bigfoot or Chuck. As it turns out, the rootlet is straight and reaches deep into the ground. Foresters call this a ‘tap root’. This is what pines have, while the spruce’s roots are plate-like. I check another seedling, and another: all three have straight rootlets, with a single offshoot. The rootlet is approximately one third of the length of the entire seedling. So why do spruces change the shape of their roots later on? Why do they give up the safety of an anchor in favour of a flat foot, which causes them to tip over so often? And are they susceptible to water shortages and bark beetle attacks? Maybe because they chose a strategy for taking advantage of shallow soils, and the water derived from melting snow and rain? Or maybe because it pays for them to topple over sometimes, giving space and light to the young generation? Although that sounds like suicide… I don’t know. But sometimes it’s good not to know.

 

Translated by Kate Webster

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Nature

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A Forest Full of Birdsong
Michał Książek

After a few seconds had passed, Pinocchio said tsree and flew off, its wings leaving a breeze on my forehead.

Zee zee said the goldcrest, which can be translated as ‘here here’. Tsrree!, the treecreeper zealously agreed, dropping down like a leaf. Tsrree tsrree, the tits joined in a similar dialect, nodding their heads. Somewhere to the side, a nuthatch started to mock them. The single kik of the great spotted woodpecker mixed with the eager chit chit of the willow tit and marsh tit. Within a minute, floating right above me in the crowns of the pines and spruces, and even all around in the hornbeams and hazels, was a cloud of sounds and movement. Movement, because it was difficult to spot anything straight away. Waving. Jumping. Short bursts of flight. Something you could notice even in the remains of the nettles or reeds and on the ground. I was standing in the middle of a mob of birds, though I can’t fly.

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