In 2014 and 2024 Sidmouth Arboretum undertook surveys of the local trees.
The 2014 survey revealed that, apart from nearly half a million trees, there are over 500Km (300 miles) of hedges currently enclosing farmers’ fields in the two local valleys. Apart from framing the local landscape visually, they are rich ecosystems that act as linear nature reserves for a wide range of plants, fungi, invertebrates, reptiles, birds and mammals.
In 2020, we carried out a survey of a sample of the hedges. In summary:
- 83 hedges were surveyed with a total length of 12.69km, 2.5% of the valley’s estimated 500km of agricultural hedge.
- Hedges ranged from 30-450m in length.
The shrub layer of hedges ranged in height from absent to 5m tall with a mean average of 1.8m and a modal average of 2m. - The shrub layer ranged in depth from absent to some untended hedges spreading to 15m, the mean average is just over 2m and the modal average is 2m.
- 45 (54%) of the 83 hedges were recently maintained and tidy, the total length of tidy hedges is 7.4Km which is 58% of the sample.
- 41 of the tidy hedges were maintained by tractor mounted flail, 4 were maintained by recent laying.
- 21 (25%) of the hedges had been neglected for so long they had lapsed and consisted almost exclusively of trees with varying lengths of space between them and little or no shrub storey, these are termed relict hedges.
- 31% of the hedges were roadside, 17% were beside a track or unmade road, 52% were solely field boundaries.
69% of the hedges were planted on a bank. - The number of woody species in a single hedge ranged from 2-13 with an average (mean, median and modal) of 8 species, 41 different woody species were recorded.
- A total of 780 standard trees was recorded, this extrapolates to just over 31,000 hedgerow standards across the valley.
- The most common species of standard were Ash (158), Oak (142), Beech (145) and Sycamore (69), together comprising 66% of all standards. 87 (60%) of the Beech standards were concentrated in just three relict hedges, and 36 (56%) of the Sycamore were in a single, relict hedge.
- 33 (41%) of the hedges were considered to have a rich diversity of herbaceous species in their ground storey, while 20 (24%) were considered to have poor herbaceous diversity. More than 140 herbaceous species were recorded.
