ICELAND
Source: https://mossy.earth/projects/reforesting-iceland
In Autumn 2021, we joined forces with the Iceland Forest Service to restore the native birchwoods of Iceland. Iceland is known for is vast open landscapes shaped by massive volcanos and expansive glaciers, but these woodlands are a vital part of the landscape. They are the only woodland type to form in Iceland, and provide food and shelter for biodiversity, help to stabilise soil, provide wind breaks, and sequester carbon. At one point, it is thought that 25-40% of Iceland was covered in birchwoods. Now, it is a mere 1.5%.
Our project aims to restore birchwoods to a degraded upland area on the west coast of Iceland by planting. While natural succession would likely convert this area to woodland eventually, it could take centuries or even millennia. To speed up this process, downy birch is being planted across the landscape, with some scattered rowan, aspen, and tea-leaved willow to add diversity.
The Ecosystem
Tree Species
We plant downy birch (Betula pubescens), rowan (Sorbus aucuparia), aspen (Populus tremula) and tea-leaved willow (Salix phylicifolia).
Priority Species
Redpoll (Acanthis flammea), redwing (Turdus iliacus), snipe (Gallinago gallinago) and ptarmigan (Lagopus muta).
Learn More About the Context Behind this Project
A History of Decline: Reversing centuries of degradation
At the time of human settlement almost 1,150 years ago, Iceland had a forest cover of between 25% to 40%. By the mid 20th century, it is thought to have been reduced to less than 1% of the total land area, perhaps even less than 0.5%.
Huge swathes of forest were cleared by the first settlers of the island, who used the wood for fuel, ships and houses, and then also cleared forest to make room for sheep grazing.
For the last few decades, tree planting projects and afforestation grants have got underway, and today, native woodland cover stands at around 1.5%. The Iceland government aims to increase that number to 5% in the next 50 years.
A Lone Woodland: What makes the ecosystem special?
Iceland birchwoods are unusual in that they are the only type of native woodland to form in Iceland. All other woodland types are comprised of non-native species, such as spruce and larch. Birchwoods are comprised predominantly of a single species – downy birch. Rowan and tea-leaved willow add some diversity to the woodland, as well as aspen, an extremely rare tree in Iceland that exists in only 8 locations. Birchwoods are also not particularly tall, with trees reaching roughly 15m in height in sheltered valleys. Towards the coast and on exposed sites, birchwoods transition to birch and willow scrub, and at high elevations to willow tundra.
Birchwoods provide important habitat for wildlife, particularly birdlife, such as wrens, redwings, and redpolls. They are also important for capturing carbon and as a windbreak. Iceland is well known for its wind, which, combined with its volcanic activity, is a recipe for disastrous sand and ash storms that blow unimpeded across much of the landscape. Birchwoods can help stabilise soils and act as a much-needed barrier against the storms.
The Threats
Deforestation
When settlers arrived in Iceland, they began harvesting birchwoods for fuel, building material and livestock fodder. The most important forest produce at the time was charcoal, needed to smelt iron and make iron tools. Birchwoods were also cut down to create to create fields and grazing land for sheep, which were farmed for wool and later for food.
Overgrazing
Once the trees were cut down, woodland cover continued to decline due to overgrazing by sheep. Sheep roam freely across the landscape and can browse naturally generating birch trees. If you want to keep sheep off your land in Iceland, it is your responsibility to keep them out by building a fence. Today, natural regeneration failure due to livestock grazing is the principle cause of deforestation.
Soil erosion
Iceland has been described as the most eroded land in Europe, possibly the world. As the woodlands and vegetation disappeared, soil was left exposed to the hash Icelandic climate. Over time, this has left poor quality substrate and little in the way of nutrients for trees to grow across many areas in Iceland. Considerable efforts have been put into halting and reversing this trend in the last century, led by the Soil Conservation Service of Iceland.
A changing climate
A cooling climate, volcanic eruptions and other types of disturbance are sometimes cited as causes for the decline in woodland in Iceland, but do not explain the entire picture. Cooling temperatures might have lowered the tree line, as the higher altitude areas became more inhospitable to trees, but do not explain the disappearance of birchwoods in the lowlands. Natural disturbances, such as volcanic eruptions, are sporadic and restricted to particular sites, so not do explain the widespread deforestation across the country.
The Planting Sites
The History
One of the areas we are planting trees in is called, Bakkakotsháls, translated to Bankcroft Hill. Prior to human settlement Bankcroft Hill was almost certainly birch and willow dominated woodland, at least 3-5m in stature. It is likely that woodland clearing to create grazing pastures took place and that sheep grazing since then has prevented regeneration. Bankcroft hill has been a sheep grazing area, during both winter and summer, for most of Iceland’s history. With the cultivation of hay fields, winter grazing was stopped and Bankcroft hill was left abandoned and in 2000, the IFS erected a large fence in the area to exclude grazing. This was the beginning of the restoration efforts.
The Problem with Moss
While the area would likely transition to woodland once again in the absence of grazing, this would be a centuries long process. The site is already in the early stages of succession and there are isolated birch and willow recolonising the area. However, one of the early colonists in particular, a moss called Racomitrium canescens, is dominating the landscape. Racomitrium is problematic because it can slow further succession as other plants are largely unable to become established in the thick, dense moss. Bankcroft Hill is covered in this moss, and before the trees are planted, the IFS will use a rotovator to break up this thick layer and allow the trees to reach to the soil underneath.
SOURCES & FURTHER READING
- “Restoration of birch woodlands in Iceland” – Aradóttir, Á. and Throstur, E. (2005)
- “Soil carbon status after vegetation restoration in South West Iceland” – Nyirenda, H. (2020)
***
