Peat bogs and Beavers in Latvia
By Melissa Shaw
Peat bogs and cranberry fields.
Approximately 3.9% of Latvia’s land is covered by bogs.. Although there are several other different wetland habitat types, from western taiga to boggy woodlands. During our visit we visited 3 different bogs in several different states. The first bog we visited was a Natura 2000 site and in its current state was as a flooded wetland. The bog had been stripped, complete with railways to remove the peat and a nearby town had been created to house the workers for the peat extraction (Seda). The area was still being stripped and water constantly drained to prevent further flooding of the area. After being stripped of peat, with water partially flooding back in reeds quickly colonised the area with several bird species following. Each year the local ornithologists hold a competition between the viewing tower on the site and another nearby. As a result of this, the greatest total amount of bird species seen in one day was 68. This example shows that despite the bog being almost completely destroyed it can still be a vital place for the conservation of wildlife, albeit for a different set of species. The interpretation boards at the site were set out well and in three different languages, allowing both tourists and locals the ability to read about the key facts about the site and of its history allowing them to better understand the need for the protection of wildlife and nature (Figure 1).
Figure 1: Interpratation Board for Seda Bog Natura 2000 Site
The Seda bog Natura 2000 site was not all too dissimilar to the RSPB site Aber bogs near Loch Lomond) , which has also been stripped and subsequently flooded, leading to a reeds system and fen-like habitat. The next bog that we visited had been damaged, through several ditches, and forested. More recently (less than a year old) an old ditch through both the peat and the forest had been refilled with peat (creating a bund). This new peat bund was not sown with any sphagnum or seeds and yet had a large community of plants. Everything from cotton grass to sphagnum, and moths such as the blood vein moth(Timandra comae), had colonised the bare peat in the months since the dam was blocked, creating a new area of habitat free of tree cover whilst also retaining water within the bog (Figure 2).
Figure 2 Blood Vein Moth
In the forested areas of the bog we came across an adder, several high flying moths and jumping spiders. Comparing it to past experiences with forested bogs in Scotland, such as Collymoon moss, there is a different community composition including plants that are not found in Scotland that seem to replace the (niche) that heather and cross-leaved heath play within the habitat. Spruce and Scots pine saplings were also naturally colonising this raised bog (Figure 3). It appeared that the wood dam was affecting the local water distribution as the vegetation behind the dam was wetter and had a greater number of hydrophilic species than on the other side of the dam which was dry. In addition wood is natural and may at least partially decompose eventually.
Figure 3 Forested raised bog.
To combat the loss of water, carbon and the increase in trees on the bog a dam had been put in on an old ditch using closely packed tree branches to prevent the flow of water. Our host Viesturs informed us that this type of damming is not the most effective and can often blow out at the bottom or the water sneak around the sides during heavy rain. It appeared that the wood dam was affecting the local water distribution as the vegetation behind the dam was wetter and had a greater number of hydrophilic species than on the other side of the dam which was dry. In addition wood is natural and may at least partially decompose eventually.
Figure 4 Wooden Dam to prevent loss of water from a raised bog.
In comparison plastic damming is most frequently used on Scottish peat bogs and they often suffer from similar problems if not put in properly or if water flow rate is too high. To reduce these problems in Scotland several dams are put along the same ditch. Viesturs suggested that peat bunds are the most effective technique to retain water within a bog.
The third bog that we visited was a state stock company owned bog that active peat extraction was occurring (Figure 5).After stripping the food company Very Berry rents the land from the State Stock Company to grow berries such as Canadian blueberry and American cranberry.
Figure 5 Active Peat extraction
After peat extraction is completed an irrigation and watering system is installed along stretches of peat. These are subsequently sown with cuttings from American cranberry plants (Figure 5). These cutting take hold relatively fast and cover the exposed peat. This prevents the peat from drying out, cracking or getting washed away during rainfall or snow melts.
Figure 6 Cranberry fields on stripped peat.
Both the Blueberry and the Cranberry fields contained red data listed species, Short – toed Eagle and green pool frogs, and are not as barren (animal community wise) as many of the re-vegetated stripped raised bogs found in Scotland. In addition there were also several moth species present at the sight, indicating at least a variety of plants in the region as most moths specialise to certain plant species or families as food plants whilst in their larval stage (Figure 7). In addition these two crops, cranberries and blueberries, are grown organically. In some cases in Latvia, stripped bogs are afforested, however trees planted on these areas are often stunted and need addition nutrients provided by fertilizers. In some cases there is an attempt to restore stripped peat bogs, usually occurring in protected areas in Latvia, such as biosphere reserves, national parks, nature reserves and micro reserves (Similar to Sites of Special Scientific Interest in the UK).
Figure 7 Unidentified Caterpillar in Blueberry Fields
Biodiversity and trail signs
During the course of our trip we came across a significant amount of biodiversity in every habitat. Encountering everything from a lesser spotted eagle soaring over fields, to common darters along the river and a vast array of fungi. In some habitats it was hard to walk before stepping on another species of fungi, everything from the Chanterelle mushrooms to the wonderfully purple coloured Amethyst Deceiver. In addition to the obvious wildlife we encountered many signs of animals, mostly mammals, and were subsequently taught the necessary skills to identify both footprints and scats.
Whilst in Latvia we also came across many trail signs of mammals. Our hosts taught us to recognise some of these trails, which were mostly in the form of footprints and faeces. For example, the difference between wolf and dog footprints is that a wolf’s middle toes are further forward in the foot and do not overlap the indentations made by the outer two toes whereas in dogs they do. We also encountered both boar scrapes and footprints. Boar footprints typically have 4 indents 2 large rounded at the front and two almost perpendicular imprints at the back (Figure 8). In addition to these footprints we also encountered moose footprints (and faeces) and badger footprints (Figures 9 &10). In addition to the footprints we also learned to identify both Otter spraints and Pine Marten Scat. An Otter spraint was found need water and are dark in colour, contain many small bones and smell vaguely like jasmine, whereas pine marten scat is found primarily in wooded areas, smells musky and often contains remnants of fruit.
Figure 8 Boar Footprint and scrapes in the dirt (Found in continuous cover forestry.)
Figure 9 Moose Footprint found in continuous cover forestry
Figure 10 Badger footprints in continuous cover forestry
Whilst in Riga we encountered at least two wild beaver families, with eight beavers in total (Figure 11). These beavers did not seem to be affected by sound and light pollution, nor did they seem particularly concerned about either human disturbance or by domestic cats. This was proved when we encountered a kit calmly sitting less than 2 metres away from both us and a busy street occupied by loud revving motorbike engines, loud music, cats and even canoes and rowing boats in the river. In the UK it has yet to be decided whether beavers should be re-introduced and therefore awarded protection, whereas in Latvia, beavers have already been re-introduced. Within the UK there has been some discussion on the viability of re-introducing beavers and in particular their ability to cope with both disturbance and co-existing with humans. Encountering them in the centre of Latvia’s capital, appearing to be disturbed little by loud motorbike gangs, boating along the river at night or cats, shows that beavers are a lot more adaptable than they are often given credit for.
However there has been some conflict in Latvia over their re-introduction. They have caused damage in a few places as the population expanded. One of these problems as been the felling and gnawing of inner-city tree’s causing safety issues within the city. This has been mostly dealt with by protecting the tree through surrounding it with either a cage or protective plastic netting. In addition to this it appears the beavers did not need to create lodges and we suspected they slept in the cities drainage tunnels during the day. Vegetation nearest the stream/river seemed little affected by the beavers and showed little damage.
In fact most passer’s by hardly seemed to notice their guests on the river. However in the countryside there is a slightly different situation. As most of Latvia’s waterways have been altered in some way by man, whether into irrigation ditches, straightened, for both agricultural and forestry uses, there is now a lot more surface area created and therefore a larger area of habitats that the beavers will be able to colonise. This has led to an explosion in the population of beavers since they have been re-introduced to Latvia. To begin with there were a few issues as beaver toppled some trees on the edges of rivers and streams, de-stabilising the river banks. However they have also led to the creation of more wetlands. Due to population pressure the beavers swapped from a specialist diet, concentrating on only certain tree species, to a generalist diet, consisting of many tree species.
Often in rural areas trees (As we observed near parkland next to an ox bow lake from the Gauja River) near riparian habitats can often be found nibbled on. This can cause the tree to become diseased, causing it to rot and die. In some cases the beavers seem to take a small bite, never coming back to the tree to fell, causing problems for farmers and foresters, destabilizing banks and flooding fields. Whilst journeying down the Gauja River we encountered evidence of a large number of beaver using the river, everything from paths leading into the river to half-munched branches strewn across the river beaches.
As there is a large population of beavers in Latvia some hunting of beavers is allowed during the year. However hunting is strictly monitored by Latvia’s state forest service and culling quotas are set to create a sustainable practice. In addition to this hunters have to train to be able to take, and pass, an exam before being allowed to get a licence and buy a gun.
Figure 11 Beaver beside river going through Riga
In comparison to Scotland’s reintroduced beavers, Latvia has had a longer period after re-introduction to assess the impact of beavers on a human altered environment (in both rural and urban habitats).
Although currently in Scotland we are awaiting the Scottish government’s decision on the reintroduction and protection of beavers following the beaver reintroduction trial in Knapdale. Although the only sanctioned re-introduction of beavers was in Knapdale, Perthshire has held a population of beavers for several decades released by animal rights activists from captivity in areas such as fur farms. As Scotland, like Latvia, has many altered waterways and irrigation systems in place on both agricultural and forested land beavers may pose a similar problem. However there are significantly fewer trees within Scotland and quite often most large areas of trees (forest) are planted commercial forests, mostly consisting of Sitka spruce, European larch or Scots Pine. These forests are quite often dense and lack both ground cover and undergrowth and are hence unfavourable habitats for beavers. In Scotland conflicts between beavers and landowners, in the case of flooding due to dams, have been reduced through measures such as inserting pipes into the dams to lower water level, in some cases beaver families have moved after their dam fails to retain water. Whilst in less desirable cases beavers have been shot dead to prevent the building of dams.
In addition the rest of our week was filled with learning about Capercaillie conservation, parkland restoration, large carnivores and hunting as well as the importance continuous cover forestry for diversity and the use of planes and remote sensing in conservation, including the drop of rabies vaccinations for fox throughout Latvia.
With many thanks to the State forest service, Andis Purvis and Baiba Rotberga for showing us their country, wildlife and culture. Also thanks to Janis and Veisturs for sharing their wildlife knowledge and experience as well as all our other guides for parting their knowledge to us. Arch network, Erasmus+, Libby Urquhart for providing funds and organising the trip and learning experience in Latvia.
Read about Melissa’s trip at http://blogs.scottishwildlifetrust.org.uk/osprey/2016/10/01/trip-to-latvia/