Is it birch or is it birch? 

They may look similar at first glance, but Britain is home to three native birch species. The most common one is silver birch (Betula pendula), followed by the dominant species of the Scottish Highlands, downy birch (Betula pubescens), and, lastly, the rare dwarf birch (Betula nana). 

Birches are very common and beloved trees, known for their white, peeling bark. They are also widely planted. As a matter of fact, the total number of birch seedlings being planted in the UK each year is increasing faster than any other tree species. The tree supply report for last year shows that downy birch is by far the most produced broadleaf, with more than 8.8 million trees in the 2024-2025 season, followed by the silver birch with 5.4 million trees. Combined, this puts birch in second place among all trees, just below Sitka spruce.  

Figure 1: Samples need to stay chilled throughout the analysis to prevent cell degradation.

Although silver birch and downy birch can look very similar, they have important biological differences. In many woodland surveys the two species are recorded together because they can be difficult to tell apart by eye, but choosing the right species for the right site can make a real difference to long-term tree health and performance. Hence, Future Trees Trust is selecting and maintaining a collection of “plus trees” with favourable characteristics for timber production to create a separate seed orchard for each species. These seed orchards are hugely beneficial for a steady supply of well-defined seed of known origin and species, avoiding poor establishment and growth in the decades after planting.  

All the laboratory work has been conducted at the UK Centre for Ecology & Hydrology (UKCEH) near Edinburgh, where our Senior Researcher, Domen Finzgar, has been trained to analyse the collected leaves. With more samples still to collect and analyse, the work is ongoing, but early results are already providing valuable insights. 

This type of research further strengthens collaboration between UKCEH and Future Trees Trust and provides an invaluable insight into the biology of one of the most common British species. Most importantly, the final results will detect the “odd one out” in our birch collections and provide the right seed for the right place when needed. 

Domen In Lab