Combermere Abbey Wetland Regeneration

Combermere Abbey Wetland Regeneration

Combermere Abbey in Cheshire, once a Cistercian monastery and now a private estate, comprises 1000 acres of ancient parkland and woodland encircling a spectacular mere formed during the last ice age. These diverse habitat features make it a very important place environmentally, as it sustains huge numbers of migrating and native wetland birds, other significant native wildlife such as badgers, hares and dormice and essential flora like veteran oak and yew trees as well as various wildflowers. We were therefore thrilled when we were invited to implement a large wetland regeneration scheme on this historical estate by Natural England in the winter of 2014.

The Stews at Combermere are two acres of young scrub and woodland situated in a natural depression, mostly surrounded by open pasture and with a stream running along one side. The site had historically been a naturally wet and boggy area; the water course had run through it and low growing wetland flora covered the ground which allowed for a sightline across the estate from a nearby hilltop monument. Over time however, moisture loving tree species such as Alder and Willow had self-seeded and colonised the area, drying up the ground considerably and encroaching on the parkland vista due to their height. The stream was also diverted around 20 years ago to skirt around the site which further reduced ground saturation.

Our brief from Natural England was to reinstate the wet conditions, encouraging habitat diversification within the area and opening up the view across the estate again. To achieve this, the dense swathes of Willow, Alder, Elder and Dogwood scrub would need to be cleared and killed off permanently with herbicide and the original water course that bisected the site reinstalled with the use of dams. There were also 15 Alder trees and one large Willow on the boundary to be felled and removed from site, along with any other brash. 



Our methods for achieving these results were carefully considered and based around a low impact approach. We decided to use as little heavy machinery as possible; logistically to minimise the chance of getting stuck and environmentally to reduce the destruction of any wetland flora already present in pockets of the site that still became saturated after rainfall. This meant that burning the brash rather than chipping it was the best option, using tin sheets raised on large diameter logs to avoid the ground being scorched and allowing us to collect the ash for removal so as to prevent over-enrichment of the soil or eutrophication of the water course.




We opted for regular chainsaws to remove the trees and scrub, with the reasoning that a part of our team could be safely clearing and felling whilst the others burnt the brash in their wake.




A two person team was used to kill each tree or sapling stump individually. The first staff member reduced the stump to ground level with a chainsaw and the second applied a glyphosate based herbicide using a paint brush. Being this meticulous ensured that we prevented scrub re-growth without any unnecessary damage to surrounding flora.

Our first week on site really made us appreciate the scale of the project we had undertaken and the ability of dense vegetation to totally dominate an area when left unchecked. We spent two days clearing scrub and three days burning what we had cut down, clearing around a quarter of the scrub in this time without including the large boundary trees. Over the following weeks the scrub did not let go of its stranglehold on the area easily, with an amazing labyrinth of Dogwood being the most frustrating to remove and burn due to its bizarre shapes.




Heavy rainfall also proved a challenge to our keeping our fires burning as the site began to flood naturally. However, the emerging species of ground flora encouragingly showed that some of the area was already prone to water-logging, with Opposite-leaved Golden Saxifrage and stands of Marsh Marigold in abundance. 

Removing the large Willow tree on the boundary necessitated some aerial cutting of limbs before felling. We were also aided by nature in this respect as we returned to site one morning to find a huge limb had been torn from the tree by the high-speed winds the night before.




With the site cleared, the brash burned and the ash removed, we flooded it permanently by installing a series of dams along the existing stream and directing the water down the old stream depression running through the site. The insertion of these six dams necessitated the use of a digger for two days at the end of the project. The digger allowed us to push the sturdy plastic pilings one to two metres down into the stream bed quickly and accurately, massively reducing the amount of time that it would have taken manually. It also provided us with the power to rapidly move large amounts of logs and earth to barricade either side of the dams, fixing them in position and making them water tight. 





The dams fulfilled their purpose amazingly quickly and the stream was back to flowing within its original course in just one day, with the majority of the site wet or flooded too. 




As this regeneration involved such a striking transformation of a large piece of land, we decided to document the process using not only our cameras on the ground, but aerially too. Our friends at Orbital Pictures used their high-flying technology to capture some brilliant footage of our team at work during the project, as well as illustrating the beauty of the surrounding countryside. We are hoping that they can return to film the site in the future now that it has been re-wetted and once the original boggy habitat has established and been restored.

 


Update - October 2014   
 
Having checked the progress of the site from March 2014 to October 2014 we have witnessed our work bringing huge benefits to the site. These include the rapid growth of wetland plant species such as rushes and sedges, in turn attracting and supporting more wetland wildlife species such as Common Snipe (Gallinago gallinago).