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Effects of hedgerow management and restoration on biodiversity - BD2114

Throughout lowland Britain hedgerows are important landscape and historic features, and they play a key role in wildlife conservation, stock management, shelter and erosion control. The hedgerow network may also play an important future role in adaptation for climate change by facilitating the movement of species through intensively managed landscapes. Hedges require frequent management in order to maintain their character, condition and ecological function, and to prevent them overgrowing and shading crops. These activities can be classified into: a) maintenance, typically trimming every 1 to 3 years, to control competitive species (e.g. Elder), sustain bushy growth and maintain condition, shape and size, and b) restoration, such as laying or coppicing, which is carried out every 20+ years to rejuvenate or restore structural integrity, and prevent hedges from becoming gappy or oversized. Current agri-environment scheme (AES) policy seeks to influence hedgerow management by encouraging more relaxed cutting regimes under the Entry Level Stewardship scheme (ELS) and the conservation of species-rich hedgerows by appropriate management under Higher Level Scheme (HLS). Indeed, cutting hedges every two calendar years (EB1/2) has proved to be one of the most popular ELS options to date. However, the long-term effects of this relaxed cutting regime on hedgerow habitat quality, condition and food resources remain largely untested.

There is some anecdotal evidence that the typical ELS practice of cutting hedges immediately post-harvest on a two year cycle removes the second year berry crop before it can be fully utilised by wildlife and is therefore not resulting in significant increases in cumulative berry production compared with annual cutting (Hillesden Project, unpublished data). The ELS pilot study has also raised the concern that less frequent cutting is resulting in a more open structure and potentially less cover for nesting birds from predators. Finally, there is an urgent need to develop low-cost and effective means of restoring and rejuvenating the increasing stock of hedgerows managed less intensively under the AES. This reflects a number of factors, including a growing number of hedges being left entirely unmanaged, increasing costs of labour, a growing shortage of skilled practitioners, and insufficient funds under HLS for traditional management practices, such as laying.

It is recognised that the impacts of management regimes are likely to take many years to have significant effects on factors such as hedgerow structure. Data analysis at the end of the project will inform any recommendations for a low-cost extension these experiments.
This project has two linked aims focused on management to maintain and restore the hedgerow resource under the agri-environment schemes:

1) to examine the effects of simple cutting management regimes promoted by ELS and HLS on the quality and quantity of wildlife habitat, and food resources in hedgerows; and
2) to identify, develop and test low-cost, practical options for hedgerow restoration and rejuvenation applicable at the large-scale under both ELS and HLS.

These aims will be achieved by establishing a series of integrated replicated experiments on hedgerow types characteristic of different parts of the country. Specific objectives include:
i) Analyse data from the Monks Wood long-term hedge management experiment (1) to rapidly provide policy advice on the effects of timing and frequency of cutting on flower and berry production. This experiment will run for for three years to determine the long-term effects of management on hedge quality, condition and structure;
ii) Establish a new experiment (2) on the three major hedgerow types in eastern-central and western England to examine the effects of a) timing (early autumn vs. late winter), b) intensity (standard cut-back vs. progressively raising the cutter bar), and c) frequency of cutting (1, 2 and 3 year cycles) on hedgerow flower production, berry yield, invertebrate abundance, structure and condition; This experiment will run for six years in roder to generate a robust dataset.
iii) Undertake consultation with practitioners and policy makers in order to identify a number of practical, low-cost approaches to large-scale hedgerow restoration and rejuvenation applicable to both ELS and HLS;
iv) Test the effectiveness and refine a number of these approaches by undertaking a multi-site experiment (3) on hedgerows in eastern-central and western England;
v) Use the experimental sites to undertake training and technology transfer;
vi) Synthesize the results of experiments 1-3 to inform management prescriptions, policy development and further research.
vii) An assessment of the impacts of different cutting regimes on woody re-growth, the findings of which are likely to have significant practical implications for farmers as well as influence future agri-environment option development.
Time-Scale and Cost
From: 2008

To: 2017

Cost: £666,362
Contractor / Funded Organisations
Centre for Ecology and Hydrology
Environmental Protection              
Environmental Stewardship              
Habitat conservation              
Nature conservation