Invertebrates

Wales’ invertebrates are incredibly diverse and constitute a high proportion of our biodiversity.  You may hardly notice them, but they are vital to the well-being of our environment.

An estimated 25,000 invertebrate species live in Wales’ land and freshwater habitats.  Our ecosystems simply could not function without them. Their roles include:

• Pollination of wild and cultivated plants
• Providing a source of food for birds and mammals
• Decomposition of decaying vegetation and dung
• Aeration of soil
• Filtration of water

Some of Wales’ invertebrate populations are significant within Europe – for example, the marsh fritillary (Euphydryas aurinia) and the southern damselfly (Coenagrion mercuriale).  Other species have their only British populations in Wales – such as the rainbow leaf beetle (Chrysolina cerealis) and Ashworth’s rustic moth (Xestia ashworthii).

Wales’s climate, geology and topography influence its range of species. Important assemblages of species live in our peatbogs, wet grasslands, oakwoods, sea cliffs and dune systems, shingle river banks and mountains. Most of our species have a northern and western distribution in Britain.

Unfortunately, invertebrates are highly vulnerable to changes in their habitats – alterations to land use, fragmentation of the countryside, deterioration of water quality and climate change.  Reasons for their sensitivity are:

• Most invertebrates have an annual lifecycle and occupy specialised niches related to microclimate, vegetation structure and hydrology.
• Many species have limited dispersal abilities and individuals will not travel far during their lifetime.

There are winners and losers through these evolving changes, but sadly it is usually the more specialised and valued species that suffer most.  Conservation of our invertebrate population is a challenging task that requires us to understand and appreciate the significance of a huge variety of species and their ecological needs.