Trees and humans in Ireland have shared a turbulent history. The 20th century started with the green landscapes of Ireland containing a mere 1% of forests. Over the centuries, the forests that once spread across more than 80% of the country were cut down for timber and farming, starting from the Stone Age, until only isolated patches of ancient woodland were left.
There has been an impressive growth in forest coverage over the last century, from the prior 1% to more than 11%. This enlargement is predominantly owing to the plantation of foreign conifer species. A lone species, the Sitka Spruce from the west coast of North America, constitutes nearly half the forested region of Ireland.
Today’s forests present a single-hued picture like a landscape mosaic. Although Sitka Spruce is a highly effective timber tree that also amasses and stores carbon, its large-scale plantation can negatively affect native biodiversity if not properly managed. Inadequately located and poorly managed woodlands may negatively impact biodiversity.
Forests provide a vast range of benefits vital to our economy, health, and wellbeing. These include timber production, water purification, flood control, habitats for flora and fauna, climate regulation, and mental health benefits.
The ‘mosaic’ and ‘multifunctional’ approaches can yield different advantages. For instance, forests situated near urban areas offer recreational benefits due to more human interaction, whereas those located in uplands have the potential to sustain water retention, enhancing water quality and preventing floods downstream.
Carbon sequestration and storage are other benefits of appropriately managed forests in suitable soil types, aiding in the reduction of harmful CO2 in the atmosphere. Once trees have been chopped down and the wood is used in long-lasting products such as building materials or furniture, the carbon footprint can be stored for several decades or even centuries. Concurrently, more trees can be replanted or naturally regenerated in the same land, capturing more carbon.
However, given the rapid rate of forestation in Ireland, the country is at risk of hitting a ‘carbon cliff’. By 2025 to 2030, the forests are predicted to shift from being a carbon sink to a source of greenhouse gas (GHG) emissions.
Multiple factors have led to a concerning trend of forest decline. Firstly, more forests are reaching maturity and being harvested than are being replenished, causing an imbalance. Additionally, forests planted on peat soils in the 1980s report high emissions of greenhouse gases when drained. Another adverse factor is the slower growth rate of older trees compared to their youthful counterparts.
Nonetheless, there are various solutions at our disposal to tackle forestry issues. Supported by Ireland’s Forest Strategy, the move towards multi-functional forests and more varied forest designs is gaining momentum. In this endeavour, the planting of more broadleaf trees and the maintenance of open, non-forest ecosystems within the forest locale is encouraged.
Continuous canopy forestry or near-natural forest management are noteworthy practices. They involve the regular crop of a small number of trees while preserving the forest canopy and thereby, avoiding complete forest felling. This approach safeguards the soil and helps maintain carbon within the ecosystem, and also allows the best timber to be extracted and replaced either naturally or through plantation. Over time, this leads to a beautifully diverse forest structure brimming with trees of various sizes and species, which ultimately benefits nature.
In order to ensure that 18 per cent of our land is forest-covered by 2050, we must plant at least 8,000 hectares of forest annually. As these new forests will exist for many years, it is vital they serve multiple functions – aiding climate, flora and fauna, timber industry, human interaction, and both economic and rural growth. This will depend on investment into both public and private forestry divisions to hasten diverse and multifunctional mosaic forest plantations.
In view of the long-term investment nature of the forestry sector, it is crucial to boost confidence and government support, acknowledging the multitude of ecosystem services offered by forests beyond just timber. Within the Fores research project, we are innovating tools to map, measure and analyse the various ecosystem services from different types of forests, regardless of their management practices, to appreciate their invisible yet crucial values as they continue expanding.
Yvonne Buckley, a professor of Zoology at Trinity College Dublin and co-director of Climate + Biodiversity + Water Co-Centre, contributes to this view.