Winter work at RSPB Lakenheath Fen by the staff of the Morgan Sindall Group

During the winter months at RSPB Lakenheath Fen, whilst we are outside of the nesting season for our breeding birds, we try to focus as much as we can on reedbed management. Towards the end of February, we had a couple of Volunteer Days for the staff of Morgan Sindall Group at the reserve, whereby they donate their time (and energy!) into helping us to manage the reserve. Here’s a video filmed by our Site Manager Dave Rogers on the day, showing the team hard at work:



Many of those who read our blogs on a regular basis will remember that in January 2023 the Morgan Sindall Group kindly agreed to donate the funds needed for us to purchase 54 hectares of intensively farmed arable land off Cowles Drove, north of the river Little Ouse. This land was adjacent to our own and its acquisition is intended to allow us to modify the land (both new and old) by raising the water levels to trigger a transition from arable land to wet grassland, grazed and un-grazed marshland. The map below shows the extent of the purchase. Our ‘old’ fields are A1, B1-3, C1, D1 and E1. The ‘new’ land purchase covers plots A2, C3 (a conifer plantation) and field F (the large field).



The raised water levels will hopefully encourage breeding Lapwing, Snipe and Redshank in the coming years, thanks to a network of new ditches and dams that will also help to retain rainwater and hold it on the new land. The carbon storage ability of the new land will be much improved too, as the wetter it is, the more carbon can be locked away underground. Plants contribute to carbon storage when they photosynthesise- by absorbing carbon dioxide from the air, and using it to form cells as they grow, they 'lock' it away inside themselves and in the soil in their root systems. Sometimes, the tide can even turn from carbon loss (from dry, bare arable land) to a carbon sink (where the grassland actually absorbs more than it emits) if it is wet and vegetated enough.

The staff at MSG have been keen to also donate their time to us through Volunteer Days, but at the moment there isn’t a great deal for work parties to do at this stage on the new land. So, the staff have been helping us to clear willow scrub from the reedbeds on the ‘old’ reserve south of the river. This scrub clearance is essential if we are to maintain the reedbeds for the wildlife here- reedbed is what is termed a ‘successional’ habitat in that it isn’t a final product, but a stage in a natural process of an area of land slowly moving towards woodland. The Common reed, Phragmites australis, is a ‘pioneer’ species which thrives in open areas of water where it copes with being submerged. Pioneer species are the first species to colonise a newly-created habitat, and are often species which are better able to cope with extreme conditions such as very wet, dry, hot, cold or windy situations. Over the years, the old stems, leaves and flowers of the reeds decay and build up under the water surface. This material build-up allows wet-loving tree species such as willows to get a foothold in the reedbed. Without their removal, these willows slowly dry out the reedbed and allow other trees to thrive too, such as Aspen, Alder and Silver birch. Eventually, the reedbed becomes a woodland. So without intervention, specialist reedbed birds like Bittern, Bearded tit and Reed warbler would face a future with less and less suitable habitat available for them to live and breed within.

What happened before humans came along, you may ask? Thousands of years ago, species such as Bison, Auroch and Przewalski’s horse were abundant and natural grazing pressure was much higher than it is now, and these large herbivores maintained the open areas of water on their own.

Fast forward to the modern world, and during the Volunteer Day, MSG’s videographer Tom from ATom Production joined us and took these lovely images of MSG and RSPB staff in action:

















The cleared willows will also help to open up sightlines along channels and across reedbeds to aid our volunteer and staff surveyors on our weekly Spring nesting surveys. We use a network of high seats which enable good views with a few feet of elevation, and clearing sightlines really helps surveyors to keep track of where the Bitterns and Marsh harriers are coming from and going to! The more we know about the birds, the better we can estimate where nests might be, to gain an accurate count and inform future reserve management.
In total, 10 members of MSG staff joined us on the Tuesday work party, and in the afternoon Dave took them on small group tours of the new land in one of our reserve trucks. On Thursday, we had an additional 9 staff so there was a very good turn out! We are very grateful to all those who came along to help, and for MSG’s ongoing support with our management of the new land.

We hope this blog has provided an interesting change from the usual ‘wildlife sightings’ blogs and given our readers a bit of an insight into what actually happens on our winter work parties! Some of the cut willow provides shelter for wildlife, and sometimes we even sink bundles of them to act as refugia (shelter) for fish in some of the pools around the reserve.

by Heidi Jones (Visitor Experience Officer, RSPB Lakenheath Fen).