A climate and biodiversity crisis was declared in Ireland in 2019. Over 20% of assessed species in Ireland are threatened with extinction. We have 59 protected EU habitats, and 85% of these precious resources are currently listed as being of “unfavourable status”. We have lost 30% of our semi natural grasslands in the past decade and more than half of our native plants are in decline. We need to know about biodiversity to appreciate it and we need to appreciate it to look after it. Biodiversity includes flora, fauna and the habitats in which they exist. Flora includes trees and flowers but also the ‘lower’ species of mosses, lichen and fungi. Fauna includes birds, mammals, amphibians, fish, and a wide range of invertebrates.
Not all flora and fauna are good for biodiversity in Ireland. Native Irish flora and fauna have been in Ireland for 10,000 years since the last ice age and are in tune with each other with regard to their life cycle, where timing is critical, such as bud burst, flowering, fruiting and leaf fall. For example, the Brown hairstreak butterfly caterpillar feeds on delicate new blackthorn leaves after hatching from eggs, which have overwintered on the shrub. Holly blue butterflies breed on holly. Brimstone butterfly caterpillars live on alder and buckthorn.
Invasive alien species are the real baddies – approximately 100 alien species of both flora and fauna are present in Ireland. Their main effect on biodiversity is that they replace and eliminate native Irish species, rather than living in harmony. Ornamental species are bred for their appearance to be attractive to humans but are not as good for supporting native biodiversity. They belong in the garden and not on farmland or in the wider countryside. Our native bluebell has drooping flowers on one side of a gracefully arching stalk suiting bumblebees which land upside down to access the flower. The introduced Spanish bluebell is paler and sturdier with flowers all around the stalk. The native Irish native bluebell hybridises with the Spanish bluebell, resulting in a new cross-bred species. Both the Spanish bluebell and the new hybrid bluebell are very fertile and threaten our native bluebell. This highlights why planting ‘wild’ flowers in the countryside is not good for our plants growing wild and not good for our native Irish biodiversity. Real wildflowers grow wild naturally and are not sown. Introduced species are not as good as native species – examples which surprise people are beech, chestnut and sycamore trees. They have been here for a few hundred years but are not found out in fields – only where people have planted them.
Minding our biodiversity
The quest for neatness should not overrule ecological considerations. Avoid a single species focus – without consideration of the effect on ALL biodiversity. Follow the key principles in the following order of importance:
1. Retain: Existing is always better than new. For example, a new hedge or woodland will take hundreds of years (if ever) to acquire the rich associated biodiversity of old native hedges and woodland. A species rich grassland can never be replaced.
2. Maintain: according to Best Practice. While it is often better to let nature take its course, management is required to maintain semi-natural habitats. One example is species rich grassland which needs to be grazed or cut to prevent scrub taking over with the loss of grassland biodiversity.
3. Enhance: with care not to cause harm. Examples are the rejuvenation of hedges by laying or coppicing.
4. Create: more space for nature but do not replace existing habitats. Natural regeneration is best (Don’t sow, let it grow). If sowing trees or hedges – use native species of Irish provenance, meaning the plants are grown from seed collected from native trees growing in Ireland. Such trees are in tune with Irish biodiversity and reduce the risk of importing disease.
To learn about agri-environment schemes in the CAP Strategic Plan 2023-2027 that are designed to enhance biodiversity on Irish farmland, click here.
Source of image: Catherine Keena, Teagasc.
