It has been a busy week here at Lakenheath. Paul our excavator driver has been hard at work improving the site for wildlife with his digger. The ditch between the West Wood and the river bank has now been cleaned out. We had not been able to manage this section of ditch effectively in the past as we did not own the land on the north side of the wood. However after purchasing this 2 years ago we can now get access for the machine on the north bank. Why do we need to clean out ditches? Well over time they silt up and get full of vegetation. Maintaining a mix of newly cleaned, partially vegetated and ditches choked with aquatic plants is very important to keeping the full range of wetland wildlife happy as different animals and plants find a home in different types of water course. In addition this ditch is absolutely key to us being able to move water around the reserve. If we can't move water to where it is needed we can't have a functioning wetland so with the ditch deepened out we can more easily fill up Joist Fen North and beyond and fish can more easily move from one area to another.
After finishing the ditch the digger moved on to New Fen North where Paul removed a couple of crossing points into the reedbed, added a new access and moved a gateway. This now allows us to put grazing animals into the newly cut reedbed for the next two or three summers. We want to do this to rejuvenate the reedbed. Reedbeds are habitats that change over time . Ecologists call this process succession. Reedbeds dry out as the reeds die back and regrow each year and the dead vegetation builds up. If you undertook no management work you would end up with a woodland and no bitterns, cranes, marsh harriers and all the other specialist reedbed species. Again like ditches we want to have a range of different ages of reedbed from young to old as different species have different requirements. New Fen North is the second oldest reedbed on the reserve so it was it's turn this year to get the rejuvenation treatment. It will be exciting to see how things progress over the next few years.
Finally on Wednesday Paul moved the excavator down into Joist Fen North to undertake some key work to improve the fish population there. Fish are a key food source for many of our special animals such as bitterns, otters and kingfishers. As I have said in previous blogs we know that there are good fish populations in some areas but not in others and the sluices which are so essential in controlling water levels can prove to be an obstacle to the free movement of fish. So we are replacing some of our sluices with more fish friendly ones. This work will continue next week, so if you go down to Joist Fen you may see us mixing up concrete and filling sand bags to anchor these new sluices in place and the digger will be installing the structures. We hope to have this work completed by next Friday. There will still be opportunities to see the wildlife from Joist Fen viewpoint though and whilst I was helping Paul out in the reedbed on Wednesday and Friday I heard lots of crane bugling coming from the river bank (which is a favourite place for our two resident pairs to display to each other) and saw cranes flying about the reserve plus I had bitterns and marsh harriers at close quarters.
Excavator working in Joist Fen - image Dave Rogers
Finally we plan to install 3 new bridges which will allow us to connect up some more ditches and improve the opportunities for fish movement. One of these is planned for New Fen Triangle (between the West Wood and Joist Fen) and two up near the Visitor Centre. If time and money permit we may do these in the week beginning 22nd February and we will need to close some paths temporarily whilst the work is undertaken. Please ask in the Visitor Centre for details. All the hides and viewpoints will still be accessible whilst this work is being done.
Our regular Thursday volunteer team were hard at work again this week, with Emma and Katherine taking them out into the reedbeds in the west of the reserve to remove more willow trees in the morning. In the afternoon they worked on cutting back willows near where two of the new bridges will be installed near the visitor centre. Dave M, Phil, Roger and Tony - many thanks for all your hard work bow-sawing down trees.
Lets hope for some good weather next weeks to allow us to complete the work and to provide pleasant conditions for you to come and visit the reserve and see some of our special wildlife.
We hope to see you soon,
Dave Rogers
Site Manager
David Rogers Senior Site Manager - Lakenheath Fen