Threats

Many mosses and liverworts have become increasingly scarce in Wales in recent decades, due to a number of factors. These include:

Habitat Loss

This has been the major cause of the decline in abundance of many mosses and liverworts in the last 20-30 years, and is still continuing at an alarming rate. For instance:

• Many native broad-leaf woodlands have been replanted with conifers. Most of these are evergreen and cast dense shade throughout the year, inhibiting the growth of bryophytes.
• Many peat bogs have been drained, ploughed and re-planted for forestry or agriculture, destroying the natural vegetation communities originally present, including the Sphagnum mosses and other bryophytes. Others have been heavily damaged by commercial peat extraction.

Air and Water Pollution

Compared with for example the flowering plants, lower plants such as mosses and liverworts are particularly susceptible to air pollution. This is clear if you compare trees in urban situations with those in the countryside. In the countryside of Wales trees generally have a number of mosses and liverworts (and usually some lichens) growing on their trunks and branches. In towns, especially near main roads or factories, but even often in parks, you will see very few mosses or liverworts on trees. (Often you will see a green "slime" which is a pollution-resistant alga).

Legal Protection

Priority Species