Iceland’s landscape often surprises visitors with its vast, treeless expanses, a striking contrast to the forested areas common in many other northern countries. This notable absence of dense woodlands is not merely a quirk of nature but results from a complex interplay of inherent environmental challenges and significant historical human activity. Understanding why trees are so few in Iceland requires looking at both the island’s geological youth and the profound impact of its early settlers.
Natural Environmental Constraints
Iceland’s subarctic location presents formidable environmental challenges that naturally restrict extensive tree growth. The island experiences a short growing season and low average temperatures, which limit the time available for trees to establish and mature. Persistent, strong winds further hinder tree development, causing physical damage, such as abrasion and desiccation, which can stunt growth and prevent tall forest structures from forming.
The island’s geology, primarily volcanic, creates soil conditions largely unsuitable for extensive woodlands. Icelandic soils, often Andosols, derive from basaltic tephra or volcanic ash. These soils typically have low cohesion, making them highly susceptible to wind and water erosion, especially with sparse vegetation. While volcanic ash can be rich in certain minerals, the soil often lacks the depth and fertility, particularly phosphorus, needed to support mature tree root systems. Frequent volcanic eruptions also blanket the landscape with new ash layers, disrupting existing plant life and contributing to soil instability.
Geographical isolation also limits native tree species diversity. Only a few species, such as Downy Birch, Rowan, Tea-leaved Willow, and European Aspen, naturally adapted to these harsh conditions and colonized the island before human arrival. These species face significant hurdles in a climate characterized by strong winds, cold temperatures, and erosion-prone, nutrient-poor soils.
Historical Deforestation
Before human settlement, Iceland was not entirely treeless. Geological evidence indicates that birch woodlands, along with some willow and aspen scrub, covered an estimated 25% to 40% of the island’s land area. These native woodlands, primarily Downy Birch, existed as low-lying forests and scrub.
The arrival of Norse settlers around the 9th century marked a dramatic shift in Iceland’s landscape. These early inhabitants rapidly cleared vast tracts of the existing woodlands. The wood was extensively used for essential purposes, including fuel for heating, smelting bog iron for tools and weapons, and timber for constructing houses and ships. Within approximately three centuries of settlement, an estimated 95% of Iceland’s original forest cover had been destroyed.
The ecological impact of this rapid deforestation was significant. With protective tree cover removed, fragile volcanic soils became highly vulnerable to relentless winds and heavy rainfall, leading to widespread soil erosion and land degradation. Continuous overgrazing by livestock, particularly sheep, further impeded natural forest regeneration. Sheep consume young tree saplings, allowing previously forested areas to transform into barren land or low-lying vegetation.
The Modern Icelandic Forest Landscape
Today, forests in Iceland are scarce, covering only about 0.5% to 2% of the land area. An Icelandic “forest” often consists of small, fragmented patches of stunted birch woodlands, scattered individual trees, or newly planted areas. The native Downy Birch (Betula pubescens) remains the most common tree, often appearing more as a shrub than a tall tree due to challenging conditions. Rowan (Sorbus aucuparia) and Tea-leaved Willow (Salix phylicifolia) are also native species contributing to the limited tree cover.
Despite contemporary efforts, large-scale natural forest recovery remains slow and difficult due to persistent natural and historical factors. The harsh climate, with strong winds and a short growing season, continues to challenge tree establishment. Degraded, erosion-prone soils, a legacy of historical deforestation and overgrazing, also make it difficult for trees to take root and thrive.
Nonetheless, there is a commitment to increasing tree cover in the modern Icelandic landscape. The Icelandic Forest Service, established in 1908, along with various forestry associations, actively engages in reforestation projects. These efforts involve planting native species like birch and rowan, as well as some non-native species such as Siberian larch and Sitka spruce, which have shown adaptability to Iceland’s conditions. While these initiatives aim to restore woodlands and combat soil erosion, they represent a gradual process in a land inherently challenging for widespread tree growth.