Over the next month or so one of the main jobs that our wardens and work party will be doing is the management of our hedgerows and areas of scrub. This is the ideal time to do hedgerow & scrub work so it can be completed before our breeding birds begin to nest later in March.
Creating a management cycle
The team have been working hard to create a management plan for these habitats to ensure that we have a schedule and cycle for habitat management – this will make sure that there are always suitable areas that provide nesting opportunities, plentiful food and shelter.
As an example, after a hedge is layed or scrub cleared back it may take 5 years or more for it become suitable for nightingales. It might then be perfect for 5 years before the trees start to shade out the vegetation underneath. That’s when we need to go back to year 1 and start again. By working on rotation we should be ensuring that there is always somewhere suitable for nightingales – they might just need to move around the site a bit!
The planning will also ensure that the hedgerows and scrub can act as wildlife corridors – if we are working on the hedgerow on one side of the path then the other side will not to be managed for a few years to ensure that there is continuity of cover.
Hedgerows and scrub are important for a wide range of wildlife here at Pulborough Brooks, including these:
Brown hairstreak butterflies like fresh new blackthorn growth
Nightingales like a combination of song perches and dense cover for nesting.
Adders like to bask in the sheltered sunny spots in front of hedgerow and scrub - they will also use the hedgerows as corridors so they can move more safely across the reserve.
What makes a good hedgerow?
An ideal hedge should be thick and bushy, with plenty of new growth and then occasional larger trees allowed to mature as standards - it then provides nesting, feeding, sheltering and commuting opportunities for a host of wildlife.
To keep hedgerows in good condition they need to be managed regularly. This can be done through rotational trimming which helps to regenerate hedgerow trees and shrubs and can boost the berry crop. Hedgerow management can also include hedge laying or coppicing – this helps to prevent gaps developing in the hedge or it turning into a line of trees with little understory.
For the first few years after laying or coppicing the hedgerow has less value for breeding birds but the new growth that is stimulated at the base of the hedgerow subsequently provides excellent nesting opportunities.
This is why it is so important to plan hedgerow management and undertake work on a long term rotational basis to ensure that this always suitable nesting habitat and good diversity.
What makes good scrub?
Diverse scrub is the most valuable to wildlife - scrub of varied age, species and structure supports the widest range of wildlife. The scrub edge is often rich in flowering plants which provide nectar for insects and seeds for birds and mammals. Structure is particularly important for nesting birds Yellowhammers, linnets and whitethroats favour young, scattered scrub and nightingales require very dense stands of, for example, blackthorn or brambles.
Scrub requires periodic maintenance to retain its character and its wildlife value. Scalloped edges provide sunny and sheltered spots and increase valuable ‘edge’ habitat. Cutting encourages re-growth which is favoured by some species and helps to diversify structure. In most areas our scrub management is about regeneration but in some we are trying to reduce the encroachment of bramble. Bramble can be a bit of a bully and can overtake some of the more delicate wildflowers – reducing the bramble in some areas helps keep the reserve and trail side vegetation floristically diverse.
This year the main areas we'll be working on will be along the zig zags and in the vicinity of Winpenny hide & along adder alley.
Management work planned for the next few months
The Zig Zags
We’ll be doing hedge-laying in a couple of zones along the zig zags. We’ll be thinning out some of the birches (approximately 1 in 3) and hedgelaying the rather scrappy old blackthorn in a couple of sections. You’ll see that some of the hedge is currently very gappy so we’ll be hoping to stimulate new growth. We’ll be doing relatively short sections this year, monitoring the regrowth and then reviewing which sections will be tackled in the subsequent years.
We may also create some scallops within the top section of blackthorn between the main path & the zig zag path as we found very little new growth and very few brown hairstreak eggs this year. Allowing a little more light into this patch and stimulating new growth will help our special butterfly.
Along the right hand side of the zig zags, along our boundary line we may thin out some of the dead trees and clear out the ditch. We will also be planting some new disease resistant elms to replace those that are on their way out. We found a small colony of white letter hairstreaks using these elms in 2019, despite the elms starting to look rather poorly so getting some new ones established is very important.
Much of the winter work here has already been completed with the clearance around the twin ponds and rides cut into the scrub around the courtyard.
As part of our plans to make best use of the water on site we’ll be creating a few more wet features within the scrub – employing our youth group to create some ‘leaky dams’ which will help create temporary pools within the scrub.
We’ll be hedgelaying a section at the Redstart Corner end of the deer proof fence, regenerating the rather gappy hedgeline and also thinning out some of the birches.
Between Redstart Corner and Winpenny we’ll be coppicing some of the willows and removing some of the dead elms. This is in part to make the most of the wonderful views south across the wetlands and towards the downs.
Much of this work has already been done with the hedgelaying that was completed in autumn and some of the bramble reduced. We may do a little more cutting back of the bramble, reducing the height in some areas to allow the sunshine to reach the other side of the trail where we’ll be creating some more scallops. This should improve the area for our reptiles and for invertebrates.
There is a possibility that some additional memorial planting of blackthorn within the deer proof zone.
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