The Mawndir Mon Project

Seeing as the LIFE project has come to an end, I was fearful that the Anglesey fens may start to deteriorate once more! However, a £73,000 grant from Natural Resources Wales will fund scrub removal from three sites Cors Erddreiniog, Cors Goch and Cors Bodeilio, each of which I visited during the LIFE conference. Its good to see that these habitats will be maintained as not only are they rich in biodiversity, they also help improve drinking water quality of the Cefni reservoir as well as reducing flood risk! Let's hope more funding will come for these amazing habitats.

Some more information including PDFs with detailed work to be carried out can be found here

BATTLE: In the fen corner Cors Erddreiniog and in the bog corner Migneint

So, along with a group of Bangor University undergraduates we visited two different sites with aims to see the difference between them both.

The first site we visited was Cors Erddreiniog which we previously visited during the LIFE conference a blog on which can be found here.

This time however we had to get our hands dirty! We started the day with some talks, then split into groups to measure diversity using quadrats, plunge sticks to measure peat depth and measuring pH and conductivity of the soil with special appliances.

The Migneint is the second site we visited, it is the largest area of  blanket bog in the UK and is situated in central Snowdonia. It is a Special Area of Conservation (SAC) and work has been carried out to help restore it since large areas have been damaged by ongoing afforestaion, drainage, grazing and also burning, in hopes to make it better for agriculture. Being an important breeding ground for Hen Harriers it is in the interest of many to bring the area back to its full potential including the RSPCA who have been undertaking many projects which can be found here. An interesting article and video can be found on the BBC website giving an insight into the conservation efforts of the site.

Peat erosion complex at the Migneint

At the Migneint there were strange peat erosion complexes, these are where the peat has been degraded possibly due to the previous drainage issues at the site meaning the peat gets an influx of oxygen which increases degradation. These complexes show how deep the peat could have been if the site was left in its natural state. 

Differences

The main visual difference when comparing the two sites is definitely the height of the vegetation.Walking along the boardwalks at Cors Erddreiniog you are surrounded by vegetation almost at eye level, whereas at the Migneint the vegetation is almost all low lying comprising mainly of mosses and Juncus. The main reasoning for this could be that the water supply for blanket bogs is nutrient poor as it all comes from precipitation in comparison to the Cors Erddreiniog fen which is fed by a mixture of rain water and groundwater increasing nutrient levels and improving primary production. Conductivity was much higher at the fen and pH was recorded to be close to neutral, due to the calcium ions increasing the pH compared to the lower pH of the Migneint and also the lower conductivity.

Image showing some peat cuttings in the background

Life Conference: Cors Erddreiniog

Cors Erddreiniog is the largest of the Anglesey fens covering 289ha thus making access to the site quite difficult unless you can speak the secret language of 'farmer'. Luckily, the project had a few translators on hand.

The large site is lime rich and made up of a mixture of habitats, similar to Cors Goch it was formed by the terrestrialisation of Llyn yr Wyth - a glacial lake. The centre of the site is comprised of calcareous fen with areas of alkaline fen and both wet and dry heathland around the edges. Being such a rare type of wetland the site is protected by RAMSAR and is recognised as a SSSI and also a SAC.

Redirected spring water

For many years the site was used for agriculture and many ditches had been dug to drain the land, this along with the use of fertilizers had drastically reduced biodiversity at the site. Management of the site has improved the quality of the fen, by filling in drainage ditches and the with use of a piston bully, the site is now know as "Jewel in the crown of Anglesey fens".

The piston bully was used to remove vast amounts of "improved soils". These are soils which have been heavily fertilized and are not suitable for peat producing species to colonise. The LIFE project removed the soil and exposed the white marl that lay beneath the top layers, by diverting the spring waters hydrological pathways to what they would have naturally been, a new lease of life was given to the site. Seeing natural colonisation of many wetland loving species.

Constructed wetland in the foreground
natural wetland in background

The water to the fen is fed by limestone 3 springs and before it reaches its destination some of the spring water passes through a specifically constructed wetland. The constructed wetland is used as a treatment area to denitrify the spring water utilising denitrifying bacteria. The water that enters the wetland has been contaminated with N from the fertilizers of the farms surrounding the site. The constructed wetland was colonised naturally with species such as Stonewort. Some spring water is also passed through a mixing chamber which also removes excess N. The denitrifyed water can then spread over travel down to the site, specific fen species such as M15 and M19 have a higher chance of establishing in the areas where N has been removed from the water. The communities of these species developed over 5 years which is surprisingly fast compared to other less well managed sites.

To keep the fen in prime condition grazing is carried out by some dairy cattle of  the local farmers. However the dairy cattle cannot be kept here for a long period of time because of the poor nutrient content of the grazing. The LIFE project introduced Konic and Welsh Mountain Ponies onto the site during the times when cattle grazing is not suitable. Grazing is a key part in the management of the site, it prevents build-up of a thick thatch of vegetation which prevents light penetrating through to establishing plant species. In more sensitive parts of the site local contractors are hired to strim cut the vegetation.

Wildlife
There is a rich variety of wildlife found at Cors Erddreiniog. I will list some below..

• Great fen sedge
• Blunt-flowered rush
• Black bog rush
• Columbine
• Grass-of-Parnassus
• Sphagnum moss
• Cross leaved heath
• Marsh gentian

Bog stars also known as Grass of Parnassus

The site is special to contain many species of orchid that cannot be found anywhere else in Britain other than a few sites on Anglesey and the Llyn Peninsula. These include

• Northern marsh orchid
• Fen orchid
• Marsh helleborine
• Fly orchid

Insect life is rife at the reserve, the marsh fritillary, one of Britains most threatened butterflies can be found here along with species of dragonfly and damselfly, including the rare southern damselfly. With insects usually comes birds, the fen attracts a variety of bird life with winter bringing hunting hen harriers and lapwings to the site and with the arrival of summer sees birds such as the willow tit and grass-hopper warblers arriving at the reserve. There are also many other animals at the site, so eyes should be kept peeled for toads, adders, otters, brown hare and water voles.

Becoming a Wetlander

If you asked me a month ago what a wetland was the only word that would've popped into my head would've been swamp. But NO wetlands come in many varieties.... who'd have known?

Identifying a wetland is not as simple as it might seem. When a botanist wants to identify a plant there are various keys that can be used to differentiate between plants, but a key for identifying wetland types? Don't be ridiculous. Even the definitions are pretty vague.

The Ramsar Convention defines a wetland as...
"Areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters"

That makes things a lot clearer doesn't it? Yep, didn't think so.

The best way for me to get my head round the many different types of wetlands is to experience them first hand.

My first experience of a wetland was at the Life Conference at Plas Menai. Over the 3 day conference we visited CORS GOCH, CORS ERDDREINIOG, CORS BODEILIO and CORS GEIRCH (Handy tip: WEAR WELLIES).