TWIC Excursion September 2010: Melville Castle
For our final excursion of the year we visited Melville Castle in Midlothian. The site is mainly composed of mature mixed plantations either side of the River North Esk.
So far, we have received records of 282 different species of plant and animal that were made on the day, although there are still a few more records to come in so this is set to increase! So far, we have records of 179 species of vascular plant, 48 species of moss, 8 species of liverwort, 69 species of lichen and 3 species of lichenicolous fungi, 7 crustaceans, 7 millipedes, 3 centipedes, 1 earwig, 2 booklouse, 10 beetles and 17 true flies.
From this high diversity of organisms there were a few that stood out in particular;
A large number of large reddish slugs, many with dark grey soles, were discovered at the site. These slugs, shown above, are an unusual find and are yet to be identified to species level, but are thought to be Arion ater agg. To the right is a picture of a pair of the slugs mating.
A new species of woodlice was found at the site that is thought to be new to either Scotland or to Britain. This species keyed out as Oritoniscus flavus, but the common central European species Hyloniscus riparius also shares the same morphological characteristics. Since O. flavus is an Atlantic species known from the Pyrenees to southern Ireland (i.e. in warm damp regions) it is more likely that H. riparius would be found in the cold eastern regions of Scotland. Both of these species have been spread by human activity. However, since the specimen collected was a female, it has not so far been possible to distinguish which of the species it is. Further specimens will be collected to resolve this issue.
Of the 69 lichens that were found, one species, Chaenotheca hispidula, is of very local occurrence in the Lothians.
Weissia brachycarpa and Mnium stellar are indictors of base-rich substrates and Fissidens crassipes is at its Northern-most limit on the east coast of Britain.