The predominant trees in Rathcoole Woodlands are Willow (Salix spp.), Downy Birch (Betula pubscens) and hazel (Corylus avellana)1. Other trees noted in the Woodland are Mountain Ash or Rowan (Sorbus aucuparia), Whitethorn (Crataegus monogyna), Blackthorn (Prunus spinosa), Silver Birch (Betula pendula), Silver Willow, Holly (Ilex aquifolium), Oak (Quercus petraea) and the naturalised Elder tree, (Sambucus nigra). There are currently 9 of the 22 native Irish tree species2 known to be present in the Woodlands (Photographs 1-9). There may be other trees in the Woodland that have not been recorded. An extensive and representative survey of the area would need to be undertaken to establish a complete list of the trees in the Woodland. There are several native willow including oat, grey, bay, eared, purple, and sally along with osier, crack willow, and white willow from Britain. And more than one willow species is present in the Woodlands. All Willow trees thrive on wet and /or waterlogged soils. Willow often topples over, so that horizontal trunks dot the woodland. The stem will regenerate new shoots, which will grow into new trunks if the original stem is connected to the ground.
Willow will support a staggering number of invertebrates (450 species). A great variety of birds are therefore attracted to wet woodland because of the invertebrate bounty on offer. A great variety of mosses and ferns also thrive in the humid atmosphere of the woodland. All willows are rich in insects and so provide a good food source for insect eating birds in summer, notably for the willow warbler3.
There are two common native species of Birch, Silver Birch, Betula pendula, and Downy Birch, Betula pubescens. Both species favour acid soils, with Silver Birch tending to occur on sandy, gravely soils, while Downy Birch prefers wetter soils and a cooler climate. The two species can often be found together in the same areas. Both species are present in Rathcoole Woodlands. Birches are not long-lived trees, rarely exceeding 80 years old. As a pioneer species they also require fairly high light levels. Both species are commonly found along the banks of streams and rivers and wherever poor drainage results in wet soils.
- Ronan Mac Diarmada & Associates (2020, unpublished) Rathcoole Woodland – Review of Existing Woodland. 11pp