OAK/HAZEL WOODLANDS ON THE ISLE OF MAN

Part One: The Natural History of Manx Oak/Hazel Woodlands

Wildflowers of Mann Project 2011

Oak/Hazel Woodlands of

the Isle of Man

Part One: The Natural History of Manx Oak/Hazel

Woodlands

Andree Dubbeldam

Wildflowers of Mann Project Manager Manx Wildlife Trust 7-8 Market Place

Peel Isle of Man

IM51AB

andree@manxwt.org.uk

Wildflowers of Mann

A Government partnership project funded by Department of Environment, Food and Agriculture (DEFA), Department of

Infrastructure (DOI), and Department of Economic Development (DED).

Manx Wildlife Trust 2011

The Isle of Man has little remaining woodland. David Allen writing on ‘The Vanished Forests’ in 1956

is particularly tough on our forefathers who harvested timber for house-building, agriculture, fuel,

boats, furniture and implements but ‘never thought to replant a tree’. By the 16th century essentially

all forests had gone from the Manx landscape.

We therefore need to conserve what we have left of our woodland heritage. To that end the first

step is a description of the natural history and an inventory of what we have with detailed

descriptions of site history, maps and surveys of the wildlife contained: for example birds, plants

fungi, and invertebrates.

This is what Andree Dubbeldam of the Wildflowers of Mann Project, supported by the Manx Wildlife

Trust, has done for oak/hazel woodland in this excellent and beautifully illustrated monograph.

Some of these sites are fragments, the largest in Glen Roy covers more than 20ha.

Once we know what remains and the condition and special features of the individual sites, then

conservation efforts can be soundly based - with regular repeat surveys following appropriate

conservation action and education and publicity to underlie and explain the importance of this

heritage to our citizens.

This publication is the first step in rescuing the remaining oak/hazel woodland on the Isle of Man -

a conservation project that will take considerable time and commitment in order that future

generations will enjoy it as we do: as William Morris declared in 1880: ‘We are only custodians for

those that come after us’.

Dr Stephen Jeffcoate, Chairman, Manx Wildlife Trust. 2011

FOREWORD

Page

FOREWORD iii

CONTENTS iv

SUMMARY 1

1 INTRODUCTION 2

2 THE NATURAL HISTORY OF OAK/HAZEL WOODLAND 3

2.1 Why Oak/Hazel woodlands? 3

2.2 Areas Omitted 4

2.2.1 Woodlands without oak and hazel 4

2.2.1.1 The River Neb at St Johns/Tynwald Mills 4

2.2.1.2 Upper Sulby River 4

2.2.2 Alder carr woodland 4

2.2.2.1 Parts of the Central Valley Curragh 4

2.2.2.2 Fragments of alder carr at Cornaa and Port Soderick 4 2.2.3 Planted native woodlands 4 2.3 Which Oak? 4 2.4 Associate/Indicator Species 5 2.4.1 Oak 5 2.4.2 Hazel 5 2.4.3 Hay-scented Buckler-fern 6 2.4.4 Hard Shield-fern 6 2.4.5 Beech Fern 6 2.4.6 Wood Horsetail 6 2.4.7 Wood Vetch 6 2.4.8 Bitter Vetchling 6 2.4.9 Wild Strawberry 6 2.4.10 Spindle 6 2.4.11 Aspen 6 2.4.12 Goat Willow 7 2.4.13 Woodruff 7 2.4.14 Wood Speedwell 7 2.4.15 Common Cow-wheat 7 2.4.16 Marsh Hawksbeard 7 2.4.17 Hawkweeds 7 2.4.18 Sanicle 7 2.4.19 Hairy Woodrush 8 2.4.20 Remote Sedge 8 2.4.21 Wood Sedge 8 2.4.22 Smooth Stalked Sedge 8 2.4.23 Pale Sedge 8 2.4.24 Wood Melick 8 2.4.25 Wood Fescue 8 2.4.26 Wood Meadow-grass 8 2.4.27 Extinct Species 8 2.5 Flavour Species 8 2.6 Invasive Non-natives 9 2.6.1 Beech 9 2.6.2 Japanese Knotweed 9 2.6.3 Cherry Laurel 9 2.6.4 Rhododendron 9 2.6.5 Fuchsia 10 2.6.6 Salmonberry 10 2.6.7 Himalayan Balsam 10 2.6.8 Pyrenean Valarian 10 2.6.9 Hybrid Bluebell 10 2.8 Veteran Trees 10 2.9 Wych Elm 11 2.10 Natural Processes 11 2.11 Geography 12 3 THE SURVEY 13

CONTENTS

3 THE SURVEY 13 3.1 The Preliminary Survey 13

3.2 The New Flora of The Isle of Man 13 3.3 The Vascular Plant Survey 13 3.4 The Mollusc Survey 14 3.5 Historic Maps 14 3.5.1 Elfin Glen in a 1869 Historic Context 16 3.4.2 Glen Maye in a 1869 Historic Context 17 4 DISCUSSION 18 4.1 The Survey 18 4.2 The Sites 18 4.2.1 Tier 1 Sites 18 4.2.2 Tier 2 Sites 19 4.2.3 Tier 3 Sites 19 4.3 Further Research 20 4.4 The Future of Oak/Hazel Woodlands 20 5 CONCLUSIONS 21 6 ACKNOWLEDGEMENTS 22 7 REFERENCES 23

Appendix I National Vegetation Class Woodland Types in Oak/Hazel Woodlands 24

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Oak/hazel woodlands are the Island’s ancient woodland resource. They are the irreplaceable natural capital

that contains the most important woodland biodiversity on the Isle of Man.

In this study thirty sites have been identified as probably native oak and or hazel woodland from tiny

fragments of less than 0.1ha at Ohio plantation to Glen Roy which covers over 20ha. The total resource is over

127ha. Sites are found around much of the Island, but are concentrated on the north and eastern edge of the

Northern Hills, where they generally form narrow ravine woodlands between 50 and 150m in altitude.

The sites are in various

conditions from the pristine

semi-natural woodland in

Narradale through to heavily

replanted sites such as

Groudle and Glen Maye, which

while somewhat diminished,

still contain significant

conservation value. Many rare

and protected species, such

as beech fern and wood

fescue, are found wholly or

mostly within these sites. The

study looked primarily at the

flora of the woodlands to

make assessments of their

relative importance, but Dr

Keith Alexander, an

entomological consultant was

contracted to look at

woodland slug and snail fauna

to corroborate findings from

the floral surveys.

This is the first part of a two

part study. The second part is

an inventory of the sites studied.

SUMMARY

Downy birch at Glen Killey

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Relic oak stands have long been known to occur on the Island

with ecologists such as Larch Garrad (1972) and David E Allen

(1984) associating these relic woodlands with species such as

sanicle. In a British context the association of relic ‘ancient

semi-natural woodland’ with rich biodiversity has been

academically established since the 1970’s by noted ecologists

such as Oliver Rackham (1976) and George Peterken (1981)

and since then the study of ancient woodlands has taken off

with gusto. Now ‘ancient’ is the popular benchmark for an

ecologically interesting woodland, with the term recognised in

British planning law and in many aspects of countryside policy.

On the Isle of Man, ancient woodlands have until now avoided

an in depth study, probably due to the perception that the

resource is not extensive enough to warrant closer inspection,

though interest in native woodlands, particularly planting new

ones has been strong for some time, championed by

individuals such as Andrew Millichap and the ‘Native Oak

Group’.

Interest from the Wildflowers of Mann Project began in

earnest in 2008 with surveys for the Project’s ‘Rare Species

Action Plans’, which aimed to identify the most rare species

under threat from Island extinction and put in place action

plans to ensure their survival. As many of these species

occurred in woodlands a thorough survey was required to

establish their status on the Island.

It soon became apparent that the current level of woodland

natural history knowledge did not reflect the biodiversity on

the ground, with even the 2006 ‘The Evolution of the Natural

Landscape’, designed to be the standard text on the Island’s

geology and natural history, giving ancient woodland hardly a

mention. While some woodlands such as Narradale, Dhoon,

Glen Maye and Santon Gorge have been repeatedly

highlighted as of interest, other sites of equal interest such as

Groudle, Glen Roy, Brookdale and the Ramsey Glens had not

been identified as of importance. A limited study as part of a

PhD project by Rob Bohan, published in 1998, led to

interesting conclusions based upon historic maps, but was only

supplemented by limited field work. Never the less, the

conclusions reached about the antiquity of sites such as Glen

Roy and Santon Gorge are largely confirmed by this study.

The state of woodlands on the Isle of Man today is extremely

interesting, as semi-natural woodland are continuing a

century-long trend towards rapid natural expansion up

riversides, into marshes and along steep upland fringe areas.

The area of semi-natural woodland is greater now than for

probably a millennium, and yet the flora of ancient woodland

relics is showing a reversal of fortune and would appear to be

in decline, with species such as field rose, hairy brome and

three-nerved sandwort probably now extinct on the Island, the

last two disappearing in the last decade.

This study aims to quantify the resource, by surveying,

mapping and producing an inventory to look at its significance,

through vascular plant and invertebrate surveys to compare

sites against each other and put them in a British context. The

survey will aim to bring to attention the importance of our relic

woodlands as part of the Island’s natural capital. With

recognition should come action to manage these sites with the

protection of biodiversity the priority.

It is hoped that this report will be of interest to professional

ecologists, foresters, decision makers and to lay readers

improving their local knowledge of the Island’s natural history.

With this wide audience in mind the use of Latin names and

technical jargon has been avoided wherever possible. The

classification of woodland types into National Vegetation

classification codes such as W7 or W17 (a standard shorthand

to describe different plant communities) is unavoidable in the

document for reasons of space, but a full explanation of the

codes is given in Appendix I. Readers not familiar with

National Vegetation Classification are advised to read this

appendix prior to reading the remainder of this document.

NB where latin names are used they are in italics and the

names used are taken from Stace 3rd edition

1 INTRODUCTION

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2.1 Why Oak/Hazel woodlands?

This study started as a study of ancient woodlands on the

Island using the presence of oak and hazel as the prime

indicators for their presence. This was a good premise for

such a study as preliminary surveys soon revealed; where

good stands of oak and hazel grow together a suite of other

‘indicators’ are sure to be present such as sanicle and hairy

woodrush. It was soon apparent however that an ‘ancient’ tag

was not academically defensible due to the lack of historical

map evidence. Early 19th Century maps recorded oak and

plantations rather well, but large stands of hazel were often

conspicuously absent. This was either because hazel coppice

was not treated as woodland or that these trees were planted,

which was rather unlikely given the number of woodland

species present in these woodlands now.

The nature of the woodlands is also quite different to much of

lowland Great Britain with dynamic boundaries that contract

and expand over time, thus parts may be ancient and others

rather more recent. In most ravine sites where soils have

never been modified, old semi-natural secondary woodland is

indistinguishable from an ancient one, especially if indicator

species such as sanicle and remote sedge have colonised.

Oak/hazel woodlands should therefore encompass the sites

that would be classed as ‘ancient woodlands’ as well as the

bio-diverse areas adjacent to these sites. As the primary

purpose of an ancient woodland classification is to indicate

areas of native biodiversity, a local ‘oak/hazel’ classification

serves the same purpose.

Oak/hazel woodlands are not necessarily those that are

dominated by these two species, but those woodlands where

they are present, (sometimes just oak or hazel on their own).

In some cases such as Brookdale, oak and hazel are present in

90% of the site, whereas in Glen Helen, the proportion is

probably little more that 10%. The survey attempted to

differentiate those woodlands where oak and hazel are clearly

planted and those where these species are semi-natural. This

is not always easy, especially with oak which was planted

commonly in the 19th Century. As many of these plantings

were then cut down in the First World War, they subsequently

re-sprouted from the cut stumps and now look like overgrown

ancient coppice woodlands, unfortunately they are impossible

to tell apart from true ancient coppice. Sites such as Glen

Tramman and Glen Killey may well be predominantly of

planted origin. Ballaglass Glen contains a rare example of an

early 19th Century oak stand that was not felled in the 20th

Century. In this case it is adjacent to hazel and oak that would

appear to be of ancient origin thus much of the site is now

treated as oak/hazel woodland.

20th Century plantings of oak and hazel such as those in the

western part of Glen Auldyn (SC422929) still grow with a

conifer nurse and so are definitively of plantation origin and

not included.

2 THE NATURAL HISTORY OF OAK/HAZEL WOODLANDS

Mature hazel at Brookdale

Planted Beech at Glen Helen

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2.2 Areas Omitted

Sites were identified during the initial recce survey by a

mixture of local knowledge and speculative pedestrian

investigations of ravine sites. Thirty sites were identified

across the Island with some of the less likely sites only found

due to gratefully received tip-offs. There are bound to be

some small sites in private ownership that have not been

identified.

2.2.1 Woodlands Without Oak and Hazel. With the scope

of the survey being restricted to oak/hazel woodlands there

may also be relic sites of ash and elm that are not picked up

and unless they come with accompanying indicator species will

probably never be identified. Two likely sites are;

2.2.1.1 The River Neb at St Johns/Tynwald Mills,

where a cluster of interesting species such as sanicle, bitter

vetchling, goat willow, wild strawberry and smooth-stalked

sedge grow with a rich woodland flora. Remote sedge

becomes common towards Peel in the same vicinity. Probably

the largest alder tree on the Island also grows here. A few

sessile oak trees present on the river banks are probably of

planted origin.

2.2.1.2 The Upper Sulby River. While a tiny

fragment of oak/hazel woodland occurs here at Bloc Eary, sites

such as Tholt-y-Will Glen have a surprisingly rich flora for

150m above sea level, with smooth-stalked sedge and wood

anemone. Beech fern was recorded up to Llergyhenny, now

possibly under the Sulby Reservoir and down to Bloc Eary,

where it was found up to 1990’s. Three nerved-sandwort, a

common ancient woodland indicator in Britain, was formally

found lower down the Glen from Ballakerka down to the Sulby

Claddaghs.

2.2.2 Alder Carr woodland. There are also clusters of

species rich alder carr. While much alder carr is a more recent

coloniser of marsh, there are places where it would seem to be

older such as:

2.2.2.1 Parts of the Central Valley Curragh,

particularly around Greeba Castle. Here the woodland is

particularly rich, with some widely scattered hazel and hairy

woodrush as well as marsh hawksbeard.

2.2.2.2 Fragments of Alder Carr at Cornaa and Port

Soderick Glen.

2.2.3 Planted Native Woodlands. The Native Oak Group

have raised tens of thousands of native trees over more than a

decade. Many of these have been planted by Government in

forestry plantations, particularly in ravines such as along the

Colden river. While these plantings will become a wildlife-rich

valuable woodland habitat, they will not be the equal of their

semi-natural cousins.

2.3 Which Oak?

The identification of the species of oak on the Isle of Man is a

difficult problem to solve. There are some trees that are clear

pedunculate oak or sessile oak, but the vast majority are fertile

hybrids. Telling apart hybrids from sessile oak is somewhat

difficult and a number of leaves (from the canopy) are needed

to be looked at to determine the species. Most hybrids are

close to the pure sessile species. Pedunculate oak is

somewhat simpler as its short petioles (leaf stalks) are very

diagnostic. Pedunculate oak is also more likely to be planted,

such as those in Glen Mona, that are clearly planted as a

roadside avenue. The only pure pedunculate oaks that could

be native were found in Elfin Glen and around Ramsey. Pure

sessile types are rather associated with stunted coastal trees

where the soil is skeletal and very dry, and where the plants

are surely native.

The hybrid oak is the common native type found in Scotland

and probably on the Island and is a good indicator that the

plant is native rather than planted, as a planted tree is likely to

be ‘pure’. It may also be a sign of planted trees from locally

collected native trees. While fertile hybrids are often thought

Sulby Glen

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of as a corrupted species, in oak it is perfectly normal and

patterns of hybridisation are a part of the local biodiversity.

The Native Oak Group commissioned a genetic study of the

oak from various sites such as Narradale and Glen Tramman,

which showed the genotype belonging to a regional

north-western England type, and therefore likely to be native

to site.

2.4 Associate/Indicator Species

Note: The term ‘indicator’ in this context is rather misapplied as the species mentioned do not

so much indicate biodiversity as are the biodiversity. The term associate species is more

applicable in this situation.

These are the species that set the oak/hazel woodlands apart

from other woodlands, not only plants but also many

invertebrates, lichens and mosses. Most of these species

occasionally occur outside of oak/hazel woodlands but are

more likely to be found in or associated with them. These are

the woodland species that have poor dispersal mechanisms

and are rarely able to survive for long outside of the humidity

and shade of a woodland.

The number of ancient woodland indicator species on the

Island is rather small. In Keith Kirby’s (2004) compilation of

British ancient woodland vascular plants he lists 189 indicator

species. Of these 87 are native to the Island but more

significantly only about 29 have any value as indicators of

ancient woodland on the Island.

The main reason for this is that the Island‘s humid Atlantic

climate allows many woodland plants like wild garlic, primrose

and bluebell to thrive outside of woodlands, with these species

common on sea cliffs, hedge banks and rapidly colonising

secondary woodlands and plantations. Where soils have not

been enriched with chemical fertilisers such as phosphate,

secondary woodlands rapidly develop a rich woodland flora,

deficient in all but the few indicator species of the oak/hazel

woodlands.

Another problem with the use of indicator species is that most

occur in the most species rich W7 and W8/9 communities

which tend to be uncommon on the typical acid Manx slates.

On many of these sites oak and hairy woodrush are the only

plant indicators present, which without more corroborating

indicators makes differentiating planted and native trees

problematical.

The following species are those plants that are to some degree

strongly associated with relic oak/hazel woodlands. They are

all considered ancient woodland indicators in some parts of the

British Isles.

2.4.1 Oak (Quercus sp.). Very obviously a good indicator of

oak/hazel woodland. Native oak also grows as individual trees

in some areas such as the Corrany Valley and Glen Rushen, or

as stunted coastal bushes on sea cliffs. It is however

conspicuous by its absence in the wider countryside on the

Island, occurring neither in secondary woodlands or

hedgerows away from the immediate environment of a relic

oak woodland. The down side to the species as an indicator is

it was occasionally planted in the 19th and to a lesser extent

20th Centuries and it is difficult to tell apart native from

non-native plants as previously discussed.

2.4.2 Hazel (Corylus avallana). As with oak a definer of

oak/hazel woodland and probably less likely to have been

widely planted, though examples may well exist. Garrad

(1972) reports that cobs (a selected type of hazel) were

imported from Holland. Glen Mooar (of Laxey Wheel fame) has

a considerable number of hazel plants with the characteristic

large cob nut and it could be that the hazel woodland here is of

planted origin, indeed in Glen Roy the size of the site and the

density of the planting would have entailed infill planting of

hazel to create the industrial coppice seen here. While this sort

of infill would traditionally have been achieved through

layering native trees on site and collecting local seed, the

nature of landowners wanting to improve the countryside in

this period may have led to the import of young bushes for

planting.

Apparently pure sessile oak on cliffs at Dhoon Glen

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Thus planted hazel is a possibility, but as the period of tree

planting gained momentum in the 19th century, the period of

coppice management was being replaced by the era of high

forest management that prevails today, thus the decline of

hazel as a useful species. It remains more likely that most

hazel is of native origin (though quite possibly locally

transplanted within a site). It is also true that hazel is much

more confined to ravines than oak, which is often found on the

flatter flanks of a ravine, where it is more likely to be planted.

2.4.3 Hay-scented Buckler-fern (Dryopteris aemula).

Recently discovered to be rather widespread on sea cliffs in

the south-west of the Island. In the remainder of the Island it

is strongly associated with oak/hazel woodlands, common in

Dhoon and Glen Mona and found in Brookdale and Ballure. A

Schedule 7 Wildlife Act 1990 species.

2.4.4 Hard Shield-fern (Polystichum aculeatum). Rare,

though probably rather under-recorded. Closely linked to

oak/hazel woodlands especially at Glen Roy. It has historically

been found in a few sites outside woodlands in the Douglas

area.

2.4.5 Beech Fern (Phegopteris connectilis). Traditionally

restricted to three districts; Glen Mona and Cornaa, Upper

Sulby Glen and Glen Roy (with a very old record for Glen

Killey). Most sites are by oak/hazel woodlands, though at Sulby

Glen the species appears to have ranged widely in a number of

different sites. Its latest site was at Glen Roy, recorded during

this survey. Attempts to re-find it in Sulby Glen and Glen Mona

have not yielded results. A Schedule 7 Wildlife Act 1990

species.

2.4.6 Wood Horsetail (Equisetium sylvaticum). A species

found in or near several oak/hazel woodlands, though also

found in many ravine sites outside of woodlands and is

particularly common in the Central Valley Curragh.

2.4.7 Wood Vetch (Vicia sylvatica). Only found in Glen Maye

and on a coastal cliff a mile to the north. Once found much

deeper into Glen Maye it is now confined to a few plants above

the river along the cliff section of the site below old hazel

bushes and one plant at the top of the cliff section. A Schedule

7 Wildlife Act 1990 species.

2.4.8 Bitter Vetchling (Lathryus linifolius). Found in several

shaded coastal cliff sites, the species is also found in a few

glens such as Crogga Glen, where it grows down as far as

Soderick Glen, and in Santon Gorge and Narradale. In St

Johns it is found along shaded hedge-banks by the River Neb.

2.4.9 Wild Strawberry (Fragaria vesca). Not really found

within oak/hazel woodlands but often around the outside of

them such as at Narradale, Ballure and Groudle. In Glen Duff

the species is rampant, having spread through much of the old

quarry, and around Silverdale it is equally common in local

hedge-banks. The species is found elsewhere, but is

surprisingly scarce on the Island.

2.4.10 Spindle (Euonymus europaeus). A single plant found

in Santon Gorge. A Schedule 7 Wildlife Act 1990 species.

2.4.11 Aspen (Populus tremula). Perhaps as strongly linked

with riparian areas as ancient woodlands on the Island. Where

it is found within oak/hazel woodland such as at Groudle Glen

and at Glen Roy it would appear to be an integral part of the

relic flora, but in other sites such as Santon Gorge and

Brookdale it is found on the edge of the site and probably only

incidentally related to the oak/hazel flora.

Hay-scented Buckler-fern at Dhoon Glen

Wood Horsetail at Port Soderick Glen

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2.4.12 Goat Willow (Salix caprea). The association with

oak/hazel woodlands is rather loose with this species and

mature specimens are rather uncommon on the Island, with

notable ones in Glen Auldyn, Lower Ballig Farm, and

particularly in Glen Roy. While found in other sites, particularly

younger plants, the presence of mature goat willow in

oak/hazel woodlands add an authentic flavour as oak is its

common associate in Britain.

2.4.13 Woodruff (Galium odoratum). Thought of as

non-native in Allen’s 1984 flora, woodruff has now been found

in many oak/hazel woodlands including Ballaglass, Glen Helen,

Brookdale, Glen Roy, Silverdale and Groudle and formally in

Dhoon. Its location in Glen Roy, Silverdale, Brookdale and

Ballaglass are rather close to (but not within) old gardens, so

the species cannot quite shake off its ‘non-native’ stigma, but

the number of woodruff populations in oak/hazel sites is fairly

conclusive. A small clump at the base of a mature oak below

Elfin Glen in someone’s front garden, is perhaps a little more

difficult to pin down, but could be quite a likely relic of a former

more extensive woodland. The species is found in many old

gardens on the Island, but escapes from these are fairly easy

to detect.

2.4.14 Wood Speedwell (Veronica montana). A fairly

reliable woodland Indicator in Britain the species had long

been known from the Lower Narradale area where the species

occurred from below the oak/hazel woodland down to the

Sulby River, where it grows with wood sedge, sanicle and

formally with three-nerved sandwort. The preliminary survey

revealed the species to also occur in Groudle Glen and then the

vascular plant survey found the species to be on the fringes of

Elfin Glen, growing down into an oak parkland suburban site

with remote sedge. A Schedule 7 Wildlife Act 1990 species.

2.4.15 Common Cow-wheat (Melampyrum pratense).

Long found in Narradale the last woodland site for this species

that was formally also found in Dhoon and Groudle Glens. The

species is also still found near the summits of North and South

Barrule. A Schedule 7 Wildlife Act 1990 species.

2.4.16 Marsh Hawksbeard (Crepis paludosa). Long found

in a small area of the Central Curraghs that may well be

ancient alder carr woodland, it is also found in open ground

above the Glen Roy oak/hazel woodland by the Glen Roy

reservoir. Its presence here, by a Victorian reservoir, indicates

it must have colonised from somewhere nearby since the site

was created. This population may well still be found. The only

clear ancient woodland site is at Brookdale where the species

grows in the deep shade of a ravine bottom below an oak

canopy in several locations along the woodland. A Schedule 7

Wildlife Act 1990 species.

2.4.17 Hawkweeds (Hieracium sp). A number of hawkweed

species occur on the Island but two would appear to have

strong relic woodland connections. H. scabricetium occurs only

in Santon Gorge and H. cravoniense only in Tholt-y-will. Other

species listed as under the umbrella classification of H.

vulgatum for the Island may well be separated in future.

2.4.18 Sanicle (Sanicula europaea). The wildflower species

most associated with oak/hazel woodlands, normally growing

where both hazel and oak occur together. Outside of oak/hazel

woodlands the species is found in two locations. One is by the

River Neb in St Johns where just one or two plants grow

together. The area is rich in other indicator species such as

smooth stalked sedge, remote sedge and bitter vetchling, thus

the woodland here may well be ancient in character. The other

site is the Sulby Claddagh, where the species grows with wood

vetch, wood speedwell and (formally) three nerved sandwort.

In many sites the species is rather restricted in distribution

such as at Glen Roy or Glen Maye, but in other sites,

particularly Elfin and Ballure Glens the species is common and

spreading out into secondary woodland. This would often

reflect the public access on these sites, with the species

particularly frequent near paths, where it can be dispersed via

its sticky seeds.

Common cow-wheat at Narradale

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2.4.19 Hairy Woodrush (Luzula pilosa). A species with a

curious Island distribution. In the mild, humid southern hills it

abundantly grows in heathland, bracken and even mown

lawns. Despite a reoccurrence on the top of Snaefell, the

species is fairly confined to oak/hazel woodlands in the

remainder of the Island. It is also one of the only indicators to

grow in W17 acid woodland. This makes it a particularly useful

species.

2.4.20 Remote Sedge (Carex remota). Like hairy woodrush

this is a species with two characters. In southern rivers such as

the Silverburn, Colby and Neb Rivers and their tributaries, the

species seems to occur in many secondary woodlands and wet

places. In the north-east however, it is rather restricted to

oak/hazel woodlands like Groudle, Dhoon and Elfin Glens,

though especially in the latter is showing a capacity to migrate

out of its core sites where damp shaded conditions occur

nearby.

2.4.21 Wood Sedge (Carex sylvatica). The dual character of

this species is between native populations in oak/hazel

woodlands and probably-introduced populations around

Douglas, such as Summerhill Glen and the Nunnery. Most

native sites are between Groudle Glen and Narradale. It

reappears in Glen Maye, though only as a few plants.

2.4.22 Smooth Stalked Sedge (Carex laevigata). This

could well be called the ‘glen sedge’ for its close relationship

with glens. While it normally occurs in damp areas of oak/hazel

woodlands it can also be found in mire and alder carr

woodland in glens. It has also been recorded in one flushed

seaside location on the south-west coast which is the only

non-glen site for the species.

2.4.23 Pale Sedge (Carex pallescens). A rare species on the

Island normally found in a few damp lowland meadows in the

Northern Plain of the Island. It is also found on a road verge

emanating alongside Narradale. This may or may-not be a

co-incidence. The species was found in wood-pasture with

smooth stalked and wood sedge at 130m in Glen Roy during

this survey. This is clearly an ancient woodland relic site. A

Schedule 7 Wildlife Act 1990 species.

2.4.24 Wood Melick (Melica uniflora). A species that has

declined remarkably on the Isle of Man, indeed it was

considered extinct on the Island for many years until

discovered in Narradale on the preliminary survey. Of the

many Manx records for the species most are in oak/hazel

woodlands, particularly those that have been replanted with

beech and conifer such as Groudle and Glen Maye. A Schedule

7 Wildlife Act 1990 species.

2.4.25 Wood Fescue (Festuca altissima). Long found at

Dhoon, this woodland species has never been found

elsewhere. A Schedule 7 Wildlife Act 1990 species.

2.4.26 Wood Meadow-grass (Poa nemoralis). Listed in

Allen’s flora (1984) as non native, its presence in hedge-banks

around Glen Roy’s oak/hazel woodland would indicate a native

status for the species.

2.4.27 Extinct Species. Several other woodland species

now thought extinct on the Island may be refound including

hairy brome (Bromopsis ramosa), previously found in Glen

Maye, Silverburn, and Santon Gorge, Three Nerved Sandwort

(Moehringia trinerva) previously found in Sulby Glen and Field

Rose (Rosa arvensis) from Groudle Glen.

2.5 Flavour species. Many other species become more

significant when found within oak/hazel woodlands for what

they say about the vegetation, so pill sedge, goldenrod,

slender St Johns wort and wavy hair grass are distinctive floral

components in dry acid woodlands (W17) while the more

fertile W8/9 is picked out by enchanter’s nightshade, wych

elm and ground ivy. See Appendix 1 for more details.

Pale sedge on the Narradale Conservation Verge

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2.6 Invasive Non-natives

All sites contain non-native species with some capacity for

self-regeneration, but most of these species like sycamore or

pink purslane cause little ecological harm. Many other species

however can be to some extent damaging ecologically in that

they tend to shade out or otherwise out-compete native

species. Control measures for many species are well

researched with plenty of literature available, though for

others such as fuchsia, control will be a site-specific solution.

The list starts with the most damaging.

2.6.1 Beech (Fagus sylvatica). Native to Europe including

southern Britain, this tree species has been widely planted in

most glens and forms large rather magnificent mature trees

which considerably add to the amenity value of many sites.

They have a strong capacity to regenerate under quite shaded

conditions, which they do very well particularly in more acid

and humid conditions. Their strong competitive edge in these

conditions means that the next generation of trees in many

glens or parts thereof will be beech. The down side to this is

that beech casts a very heavy shade and has an acidifying

leaf-litter. The combination of these factors is that the ground

flora is much reduced creating significant and sometimes

widespread biodiversity damage.

As one of the few broadleaves that does not coppice well when

cut down, control of beech is probably easier than for most

invasive exotic species and should be achievable using entirely

mechanical means by cutting saplings down before they

become large ‘valued’ trees. With persistence, beech can be

gradually phased out from oak/hazel woodlands without too

much public concern so long as the mature trees are allowed

to age and die out naturally.

Ballaglass Glen is probably where the species is most prolific

with early 19th and early 20th Century planted cohorts and a

more recent self sown cohort. The mid 20th Century cohort is

most damaging as it was planted beneath the finest oak stand

on the Island, not only do the beech shade out the ground

flora but they will also overtop and eventually crowd out the

nearly 200 year old oak trees as their vigour begins to diminish

with age. Here and in Groudle Glen it may be necessary to

remove some mature trees where they threaten valued native

specimens.

It should be noted that in secondary woodland beech can

make a valuable contribution to the ecology of the site.

2.6.2 Japanese knotweed (Fallopia japonica). A notorious

invasive exotic from the far east and already the subject of

control measures on the Island. The species grows in the same

riparian habitat as most of the rare and notable native

woodland species and can grow vigorous enough to smother

some species. Japanese knotweed generally spreads using

watercourses or humans as a vector for dispersal.

Control in oak/hazel woodlands could be more damaging than

the having the plant however as an indiscriminate overhead

spraying programme could yield significant collateral damage

to the surrounding flora. Fortunately the more targeted direct

injection method is gaining acceptance as a preferred control

method and should be considered best practice in oak/hazel

woodlands. Douglas Corporation and the Water Authority are

trialing this control method on their properties. Biological

control is also being considered for trial.

Glen Maye is the site where this species is most problematic as

it directly competes for habitat with wood vetch along the

watercourse. Hairy brome has already apparently disappeared

from the site where it grew in areas now occupied by

knotweed.

2.6.3 Cherry Laurel (Prunus laurelcerasus) Native to

southern Europe this continues to be widely planted for

amenity reasons. This evergreen shrub spreads vegetatively

by layering its stems along the woodland floor and via its bird

dispersed fruit. By casting a dense shade and being shade

tolerant cherry laurel smothers all ground vegetation and

prevents the natural regeneration of trees. Control is by

cutting down stems and winching out stumps or spraying

re-growth.

Control in parts of Glen Helen has been very successful, indeed

cleared areas have revealed smooth stalked sedge,

reappearing from buried seed.

2.6.4 Rhododendron (Rhododendron ponticum). Similar to

cherry laurel in appearance and in the damage it does to the

ecology of a site, it is not yet a significant problem in oak/hazel

woodlands, though it is present in many, such as Glen Roy and

Dhoon Glen where it is gradually increasing.

Evidence from the rest of the British Isles where the species is

often a significant problem would indicate that early control

would save an expensive problem in future.

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2.6.5 Fuchsia (Fuchsia magellenica). A South American

species, that is well adapted to the cool temperate humid

conditions prevailing on the Island. It is able to tolerate most

soil conditions from waterlogged to skeletal types and is

surprisingly shade tolerant. It is widely planted and rarely

causes any ecological harm. In some conditions it can become

an ecological pest, smothering the ground flora beneath its

layering branches. These conditions are found in Brookdale

where a mixture of windblown trees falling on bushes and a

gravel based stream allow for the rapid layering of the species,

affecting populations of the rare marsh hawksbeard. Fuchsia

is found in many glens and in some it is gradually spreading

along watercourses. In many of these sites it has the potential

for a rapid increase, as has happened at Brookdale.

2.6.6 Salmonberry (Rubus spectabilis) This shrub is

currently only a problem species in Crogga Glen, although it is

also spreading into Glen Roy. This species spreads by seed

with the potential to spread greater distances via birds. Like

most other problem species it is both shade tolerant and

castes a dense shade. Control is either through cutting and

spraying or by pulling out smaller plants.

2.6.7 Himalayan Balsam (Impatiens glandulifera). An

annual Asian species frequently found spreading along

watercourses and wet areas. While very invasive, the

ecological harm done to riparian woodlands is rather minor

and control (hand pulling or spraying) is unlikely to be

successful in the long term. A policy of tolerance is advised.

2.6.8 Pyrenean Valarian (Valeriana pyrenaica). A species

that is locally rampant in Glen Roy sometimes covering many

square metres. This is a wind dispersed herbaceous plant that

can be sprayed or dug out, however complete control would

be very difficult. It would appear to have reached a steady

state in Glen Roy and should it remain at its current abundance

it is probably little cause for concern, but will need to be

monitored.

2.6.9 Hybrid Bluebell (Hyacinthoides x massartiana). This

hybrid between native and Spanish bluebell (Hyacinthoides

hispanica) is common in the wider countryside, but so far

rather limited to the edges of oak/hazel sites where it does

occur. It is likely that over time it will become more frequent as

it hybridizes with the native species further. Little can be done

to stop this process.

2.7 Veteran Trees

Perhaps one of the most significant ecological developments

across Manx woodlands today is the gradual maturing of the

tree population, probably the first time in a millennium that

significant numbers of large mature trees have existed on the

Island. While natural death, wind-blow and human

intervention put a considerable rate of attrition upon trees, a

reasonable proportion of the large tree species (oak, ash, elm,

sycamore, beech and sweet chestnut) are becoming mature

Salmonberries

Rampant fuchsia in Brookdale

Hybrid Bluebell

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and veteran trees. Loosely defined, a veteran tree for an oak

or beech is about a 200 year old tree (they mature at about

120 years), (English Nature 1999). A 300 year old oak or

beech could reasonably be called an ancient tree. Other

species become veterans rather faster, so a 100 year old birch

would be a significant veteran.

A veteran tree will generally support vastly more biodiversity

than a mature tree, which in turn supports more diversity than

a sapling. This happens partly due to the accrual of dependent

species such as lichens and invertebrates over time, but also

as the number of niche habitats such as deadwood, holes and

epiphytic plant species increase.

Many of the sites contain significant populations of veteran

trees. Probably the most important are the stands of maiden

oak trees in Glen Roy and Narradale that are now 200 or more

years old; in Brookdale they are probably well over 150 years

old. The most impressive stand is in Ballaglass with many well

grown trees nearly 200 years old, but probably planted in

origin (though wildlife does not care if a tree is planted or

native!). Mature stands of stunted coppice stools in Lower

Ballabeg (in Baldrine) and Santon Gorge are probably over 200

years old. Glen Maye and Ballaglass likewise have individual

old coppice (200+/-year old) stools. A few stunted coastal oak

trees at sites such as Glen Maye, and particularly at Dhoon are

veterans and possibly ancient (300+years) trees.

Non-oak veteran trees are also common with ash and

sycamore on the fringes of Brookdale particularly notable.

The generation of mid to late Victorian plantings are now

approaching veteran status, particularly plantings of beech in

sites such as Glen Helen, however the shallow-rooted beech

tends to fail before reaching 200 years on most ravine sites.

A veteran tree register does not yet exist for the Isle of Man,

though it is likely that a good proportion of entries would be

within oak/hazel woodlands.

2.8 Wych Elm

Most oak/hazel sites contain some mature wych elm trees,

probably native to site. Given the much diminished nature of

the species in the British Isles due to Dutch elm disease, the

Island’s population is significant, with major concentrations in

native oak/hazel woodland.

2.9 Natural Processes

As important as the biodiversity are the natural processes

within a woodland, indeed the two are closely linked.

Many of the sites looked at showed extremely natural

conditions, which was unexpected for such a small resource.

Natural regeneration of most native species was observed,

including for oak and hazel. Some regeneration was in canopy

gaps but more commonly occurring as advance regeneration

under shade. Most commonly observed was regeneration into

open ground initiating seral succession to woodland. Habitats

becoming colonised include bracken, gorse, bog, marsh and

pasture. In areas such as Glen Roy, Narradale and Santon

Gorge the fringing area of recent semi-natural woodland is

many times the size of the core oak/hazel site.

Fallen trees have allowed large quantities of deadwood to

accumulate in many sites, often in streams where significant

deadwood dams have formed. Indeed in Glen Roy these dams

Veteran oaks in Ballaglass

Deadwood dam in Glen Roy

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have been colonised by sapling trees and appear to be very

long-term features, capturing silt and raising the riverbed by

up to a metre or more.

The deadwood beetle fauna of the Island is thought to be very

poor and it is likely that most other deadwood taxonomical

groups are also impoverished. This probably reflects a history

of woodland management, that persisted probably even in

remote sites, depriving the Island of a continuity of deadwood

habitats. The generous amounts of deadwood currently seen

in many sites may well be the first time this habitat has existed

on the Island in quantity for many centuries.

Many areas of stream continue to gouge the ravines deeper,

with sites such as Brookdale showing evidence from exposed

tree roots of the deepening of the river-bed by over 30cm in

the past century. This in turn has made them vulnerable to

land slips during periods of heavy rain. Brookdale and Glen Roy

contain some of the most interesting recent slips that form

natural glades in dense woodland, with young trees and

wildflowers gradually establishing on the bare ground.

In sites replanted as pleasure grounds in Victorian times, the

process of reversion back to a more semi-natural state is well

underway as that generation of planted trees begins to fail and

a species rich ground flora colonises. Glen Helen has seen

major wind-blow events fell stands of beech to be replaced by

more mixed semi-natural vegetation. The non-native plantings

have however left a legacy of non-native species as described

earlier.

2.10 Geography

As can be seen from the Distribution Map (right), oak/hazel

woodlands are generally found on the upland fringes around

the Island. The main concentration is between Sulby and

Douglas and no sites are found in the south-west (Rushen

Parish) or the northern plain of the Island.

Some sites go down to sea level, but 150m is a fairly consistent

upper limit for oak and hazel with only Glen Killey reaching

160m. The reason for this is unclear as in sheltered sites

broadleaves are able to make reasonable growth up to 200m,

beyond which native broadleaves are rarely little more than

scrub. The most likely explanation is that the most steep, deep

ravines seem to occur at 50-150m, coinciding with the vast

majority of the resource. Above and below this altitude the

ground tends to level out.

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3.1 The Preliminary Survey

This survey was conducted by the author, occasionally with

the help of other interested individuals. Likely sites were

identified from aerial photographs, biological records and

finally speculative hunting in ravines around the Island. Much

of the work was as part of ‘Rare Species Action Plans’, with

later work continuing to early 2011 for the specific benefit of

this report.

The National Glens were looked at first and it was here it soon

became apparent that sites with the presence of oak and or

hazel were of significantly greater botanical interest than those

without. Hairy woodrush was one of the most useful species,

almost always occurring in the footprint of native hazel or oak,

and as an evergreen, allowed for a long season of recce

surveys.

Preliminary surveys noted the presence of oak and or hazel in

sites and looked for a few other key indicators and rarities to

give an impression of the ecological interest of sites.

Crawford’s (2009) list of Scottish Ancient Woodland Indicators

as well as Kirby’s (2004) list formed the basis of drawing up a

Manx List.

Interesting records obtained in this survey were wood

speedwell in Groudle Glen, wood melick in Narradale and the

rediscovery of wood fescue in Dhoon after several decades

without it being recorded. It is fair to say these finds wetted

the appetite for a more in depth study.

3.2 The New Flora of the Isle of Man

While the recce surveys where taking place another survey

initiated by the Wildflowers of Mann Project was starting. This

survey led by the Wildflowers of Mann Project, the Manx

Wildlife Trust, the Botanical Society of the British Isles, Manx

National Heritage and the Isle of Man Government’s Wildlife

and Conservation Division (now integrated within the

Department of the Environment, Food and Agriculture). This

involved the complete survey of the Island’s flora by a team of

volunteers, a survey still underway.

This wider survey has already given a much clearer picture of

the Island’s flora, including its woodland plants. Pertinent finds

include hitherto unknown colonies of hay-scented buckler fern

on cliffs along the south-west coast, a very wide distribution of

hairy woodrush in the Southern Hills and many more locations

for smooth stalked sedge. The survey has still a few years to

run and will no doubt help our understanding of the Island’s

woodland flora further.

3.3 The Vascular Plant Survey

Conducted in the spring and summer of 2011, this involved a

walkover survey of each site recording all vascular plant

species present. The survey covered the footprint of the

oak/hazel woodlands and their associate species where

clusters of these occurred beyond the oak and hazel trees. As

well as the footprint of the sites, the edge habitat was also

surveyed, as were small glades and rides with in the sites.

Of the 30 identified oak/hazel sites 15 were fully surveyed,

covering all the more interesting sites as well as a selection of

the smaller sites. Surveys took an average of one day per site

depending upon the size and difficulty of terrain.

As anticipated, the survey uncovered several new populations

of Schedule 7 species. Wood speedwell was found next to Elfin

Glen, hay scented buckler fern was found in Brookdale, as was

marsh hawksbeard, the first ancient woodland site for this

species on the Island. Also a first ancient woodland location

was found for pale sedge in Glen Roy. Beech fern was re-found

in Glen Roy and Glen Mona after nearly two decades of the

species not being recorded on the Island. Southern Polypody

(the second Island site after Glen Maye) was found in Santon

Gorge, on the same woodland edge location as the only Island

site for the hawkweed Hieracium scabrisetium and spindle. All

these finds have contributed to giving a clearer picture of the

importance of many of these sites for the Island’s biodiversity.

Not surprisingly the vascular plant survey revealed that the

largest site (Glen Roy) had the greatest species number (195

species). Other much smaller sites such Santon Gorge

recorded impressive totals for sites below 1ha in size. Of

greater interest is the number of associate species found per

site with good sites getting between 8 and 14 species (out of

30). This ‘key species’ list also includes those historically

recorded at the site, but not found in the survey.

In the case of Glen Maye and Santon Gorge the key list

includes the non-woodland but notable species- maidenhair

fern and Southern polypody.

3 THE SURVEY

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3.4 The Mollusc Survey

To increase, depth, reliability and academic validity of the

research it was decided that a corroborating taxa investigation

was desirable.

While lichens and bryophytes are often used in ancient

woodland research (Coppins and Coppins 2002), a history of

coppicing and the mild Atlantic climate could render these taxa

less useful on the Isle of Man. It was decided therefore to

concentrate on an invertebrate group, molluscs, which are

known to have a suite of ancient woodland indicator species.

Dr Keith Alexander, an invertebrate ecologist, was contracted

to survey woodland sites for a week in August 2011. The

survey and background research in museum collections and

biological records, revealed that ancient woodland molluscs

did indeed inhabit most oak/hazel woodland sites. He used a

mixture of sweep-netting, ground searches and the inspection

of leaf-litter under a microscope.

Of the nine species known to be good indicators of British

ancient woodlands, six occur on the Isle of Man and four of

these where found during the survey, and one other (the

plated snail (Spermodea lamellata) was found to have been

previously (1968) recorded in Glen Roy.

The Ash Black Slug (Limax cinereoniger) associated with

old-growth forest was the most important species found. This

was found in Brookdale, one of the sites where it was last

recorded in 1909 (Fern Glen), thus a significant rediscovery.

The species is widespread but uncommon throughout Europe.

Brown snail (Zenobiella subrufescens) was perhaps the

easiest snail to detect as it can be sweep-netted from lush

vegetation such as greater woodrush. It was found in three of

the 8 sites looked at. (Ballure, Narradale and Glen Roy).

The English chrysalis snail (Leiostyla anglica) was found in

Ballure, Elfin Glen and Narradale. This species mostly occurs in

leaf litter and under deadwood and debris.

Point Snail (Acicula fusca) was only recorded from Ballure

Glen, (a single specimen), a site that was notable not only for

the greatest number of species, but also the only site where

large numbers of woodland molluscs were found.

While in any survey it is commonly noted that the absence of

evidence is not evidence of absence, this rings particularly true

for this aspect of the oak/hazel woodland survey. Most records

related to just one or two specimens found, with a mixture of

careful searching and good fortune responsible for many finds.

It was noted by Dr Alexander that the survey should be seen

as ‘very much an initial exploration’. The mollusc survey

conclusively shows that ancient woodland molluscs are found

in most good oak/hazel sites on the Island.

3.5 Historic Maps

Looking at historic maps (See Elfin Glen and Glen Maye maps

overleaf) is the most direct way of assessing the historical land

use. The first really reliable map on the Island is the 1869 map,

which has been digitised which allows for easy analysis. In

many places it is very revealing, showing that sites such as

Dhoon Glen, Groudle Glen and Glen Maye had a very mixed

picture of woodland coverage with a third of the current

species rich oak/hazel woodland open ground prior to 1869.

Dr Alexander inspecting a sweep-net for brown snail

Ash-black slug in Brookdale

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Most sites did show that they were predominately woodland

however, with even small sites such as Ohio showing tree

cover. The wider picture shows that the Island was already

well wooded by this time with estate plantations common and

already obscuring the distribution of relic oak/hazel

woodlands. This makes any historical analysis of sites such as

Glen Tramman, Glen Duff, Glen Helen and Glen Killey

impossible with these maps. This is particularly frustrating as

these are the most difficult sites to ecologically interpret on the

ground. In some areas, such as Glen Roy, the reproduction

quality of the map was too poor to assess the woodland cover.

Two very small sites (Colby Glen and Santon Gorge) did not

show woodland cover, indeed Santon Gorge is not shown as

woodland on the 1929 or the 2009 Ordinance Survey maps.

Further study of historic maps is recommended particularly

older early 19th Century maps.

Table 1 Oak/hazel Sites Ranked by Key Species

Site name Key Plant

Species

Protected

Species*

Recorded

Species

Size

(Ha)

Mollusc

Species

Ancient

Woodland

Molluscs **

Woodland

Presence on

1869 Map

Glen Roy 14 2 195 20.0 16 1(2) Not Clear

Groudle Glen 14 3 168 6.0 9 (1) 70%

Dhoon Glen 13 3 146 4.3 ns (1-3) 60%

Ballure Glen 10 2 144 5.2 23 3 (4) 90%

Narradale 10 3 139 5.6 15 2 80%

Glen Maye 9 4 159 4.2 ns (1-3) 50%

Silverburn 9 1 ns 0.9 14 (2) Not Clear

Brookdale 8 2 139 3.6 18 1 90%

Santon Gorge 8 3 157 0.7 4 (1) 0%

Glen Helen 7 0 149 15.0 ns 100%

Elfin Glen 7 1 131 6.0 15 1 100%

Garwick Glen 6 0 ns 1.2 ns 30%

Glen Mona 5 2 ns 9.8 ns 40%

Crogga Glen 5 0 ns 5.0 ns (1) 70%

Ballaglass 5 0 145 5.5 ns (2) 100%

Glen Duff 5 0 ns 2.6 ns 70%

Nut Glen 5 0 79 2.6 ns 80%

Glen Tramman 4 0 ns 10.3 ns 100%

Lower Ballabeg 3 0 ns 1.1 ns 50%

Barnell 3 0 ns 0.2 ns 50%

Block Eary 3 1 ns 0.1 ns 100%

Glen Killey 3 1 74 5.4 ns 100%

Glen Auldyn 3 0 96 2.5 ns 80%

Glen Dhoo 3 0 ns 0.7 ns 70%

Glen Kylley 2 0 ns 0.3 ns 100%

Bishop’s Court 2 0 74 1.3 ns 100%

Glen Mooar (Laxey) 2 0 ns 1.4 ns (1-3) 100%

Skyhill 2 0 69 0.5 ns 50%

Ohio 2 0 ns 0.1 ns 100%

Colby 1 0 ns 0.4 ns 0%

ns=not surveyed *Wildlife Act 1990 Schedule 7 plant species, (not including heath spotted orchid) **Figures in brackets refer to totals including

previously recorded mollusc species. Where a range of numbers is given this indicates unlocalised records most likely in this location.

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3.5.1 Elfin Glen in an 1869 Historic Context

The Elfin Glen 1869 map on

the left clearly shows the oak

hazel area as woodland

present at this time. It also

shows that the species rich

areas where remote sedge,

sanicle and wood speedwell

occur outside of the oak/hazel

woodland were woodland or

tree lined paths 140 years

ago.

At this time much of

Claughbane and Llergy Frissel

plantations had already been

planted, which is apparent

from some of the large

Douglas fir and other large

tree specimens found in the

plantation now.

Not yet present on the map

are the Mountain Road

(Hairpin), Manx Electric

Railway or Ramsey suburbs

which were built during the

following 80 years.

This map shows that the

process of Victorian woodland

creation was well underway

by this time.

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3.5.2 Glen Maye in an 1869 Historic Context

The Glen Maye 1869 map

clearly shows that woodland

only covered about half the

site.

Much of the remainder of the

site is marked open ground

with trees, presumably

woodland pasture, or open

ground around mine

workings. This latter area is

still mostly open ground,

though the woodland pasture

area is now dense

sycamore-dominated

woodland, differentiated from

the older woodland by the lack

of hazel in the understorey

that is very characteristic of

the north half of the site.

The sanicle and hairy

woodrush that is found along

the paths in the southern half

is either a relic of the

woodland pasture or has

spread into this area from the

northern part. The wood

sedge is only found in the

northern part.

The wood vetch, Southern

polypody and (formally) hairy

brome are in an area that was

clearly more open in 1869

than it is now.

Older maps would show if the mine works were woodland prior to mining activities, joining the eastern dense woodland with the

cliff-side hazel on the western side.

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4.1 The Survey

This is the first attempt at a comprehensive survey of the

Island’s ancient woodland resource. Linking ancient

woodlands to the oak/hazel populations has proved to be

valid, with a consistent suite of associate species of plant. The

mollusc survey has corroborated the vascular plant survey

very well and confirms that this is a useful taxonomical group

for the study of Manx ancient woodlands.

While the study has given a good insight into Manx ancient

woodlands its limitations should also be noted. Oak and hazel

have probably been widely planted on the Island over the past

200 years or more. In the case of hazel, planting is most likely

to have been on sites where hazel was already present to

thicken up the density of stools for exploitation of the coppice

products. Oak is more difficult. In some cases such as at

Ballaglass the magnificent oak stand is likely to be of planted

origin, while Narradale and Brookdale are most likely to be

native. In other sites such as Glen Helen and Glen Tramman it

is much more difficult to determine, indeed we will probably

never know and the answer is likely to be that these sites

contain both planted and native trees. There are also many

species rich wet woodlands on the Island that would never

support oak or hazel or many associated species and would

not easily be determined as ancient or recent.

4.2 The Sites

The 30 sites can be ranked into three groups, Tier 1 sites of

significant Island value where most woodland biodiversity is

concentrated, Tier 2 sites containing interesting woodland

species and communities and Tier 3 sites are of historical note,

but little wider biodiversity importance beyond that of a

mature secondary woodland.

4.2.1 Tier 1 Sites. These eight sites are the elite woodland

biodiversity sites. None can be considered above the other as

all have unique attributes not found elsewhere. It is

recommended that the management of these sites would best

be to prioritise the biodiversity above other management

goals.

Prioritising biodiversity essentially means that public access,

recreation, field sports, landscape and timber production are

all secondary in importance to biodiversity and natural

processes, but would normally continue as traditionally

practiced where this does not harm biodiversity. It should be

assumed that these sites are managed towards a semi-natural

vegetation, thus replacing planted exotics such as beech and

conifers with natives as and when they fail. It would also mean

that the natural regeneration of these exotics should be

removed before they can contribute to the canopy. The

non-native sycamore is not practical to replace due to its

capacity for natural regeneration, but does little ecological

harm, so it can be treated as an exception. Replacement is

most desirable by natural regeneration, which can be copious

in ungrazed stands. If this does not occur then planted trees of

native stock should be used.

The control of invasive non-native species such as cherry

laurel should be prioritised in these sites.

Returning some of these sites to traditional hazel coppice with

standards is appropriate where they are not part of the

National Glen network. The sites are a mixture of private and

publicly owned properties and government leadership would

be required to move forward a coherent strategy for the

management of these sites.

The enlargement of these woodland sites would be of great

benefit and in most sites this is happening through natural

regeneration into abandoned farmland. In sites such as Ballure

and Brookdale that are hemmed in by conifer plantation, there

exists the opportunity for significant expansion after clearfell.

While natural regeneration should be the preferred method of

woodland expansion the planting of native oak at very wide

spacing would ensure this species becomes part of the canopy

of the first generation of trees. Natural regeneration will

probably require some cleaning operations to eliminate

concentrations of Sitka spruce, lodgepole pine and beech,

though these species are quite acceptable at low

concentrations.

The production of management plans for these sites should be

a long-term goal that will bring together landowners,

woodland users and ecologists to produce a positive

consensus.

Part ii of this report contains the full site descriptions and

locations.

4 DISCUSSION

W i l d f l o w e r s o f M a n n P r o j e c t

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The Sites:

Glen Roy. The largest site with beech fern and pale sedge

populations. What sets this site apart is that its size and

naturalness give natural processes an opportunity to develop.

Groudle Glen. Heavily replanted and much diminished,

Groudle still has an impressive diversity of flora and niche

habitat types and could be gradually restored to a more

semi-natural state.

Dhoon Glen. The most studied and well known of the

oak/hazel woodlands This ASSI is the only recorded site for

wood fescue on the Island. While heavily replanted in places,

its semi-natural core is intact and remains a biodiversity

hotspot.

Glen Maye. Also an ASSI, little semi-natural woodland

remains in this heavily replanted and somewhat diminished

site, however at its seaward edge it remains extremely species

rich with a large suite of rare flora and fauna.

Santon Gorge. Containing so much in its very small area

including the only Island site for spindle and the British

endemic Hieracium scabricetium, this is a completely unspoilt

fragment of oak/hazel woodland.

Ballure and Elfin Glen complex. Two sites with their

adjoining plantations that are gradually becoming one

ecological unit to form a large significant woodland area with

relic spots penetrating into the suburbs of Ramsey town. While

the sites are heavily replanted in places, the majority of the

glen areas remain ancient semi-natural woodland. They are

identified in this study as the most important woodland

mollusc sites on the Island.

Brookdale. At its core this is an un-spoilt ancient semi-natural

oak/hazel woodland and the site of the rare ash black slug and

marsh hawksbeard. Around its fringes the woodland has many

relic fragments as well as expanding boundaries.

Narradale. Largely un-spoilt semi-natural oak/hazel

woodland with the only Island site for wood melick. Narradale

has long been known as one of the Island’s best relic woodland

sites and has the largest stock of native veteran oak trees on

the Island.

4.2.2 Tier 2 Sites.

These are the sites that contain significant ancient woodland

characteristics and can be considered ancient woodland at

least in part. Some sites such as Glen Helen and Glen

Tramman are large, but the oak and/or hazel interest is widely

dispersed throughout, with the majority of the site secondary

or plantation in nature. In these sites the high botanical quality

of the secondary woodland is probably a reflection of the

intimate mixing with ancient woodland areas that has allowed

local colonisation of species such as hairy woodrush and

smooth stalked sedge to occur in to the secondary woodland

areas.

The sites are markedly more interesting than secondary

woodlands and some such as Lower Ballabeg in Baldrine,

Crogga Glen and Glen Mona are worthy of further study as

they are likely to contain many unrecorded species of interest

and potentially be Tier 1 sites.

While often species rich, these sites tend not to contain the

unique features, habitats and species that are found in Tier 1

sites.

Management in these sites should as a minimum be to retain

their current level of native canopy; though a policy of

returning to 100% native canopy would naturally be of further

benefit. Otherwise the sites should be managed with

biodiversity as a key objective. The expansion of these sites is

likely to be of significantly greater biodiversity benefit than the

expansion of secondary woodlands.

The sites are: The Silverburn series, Glen Helen, Garwick Glen,

Glen Mona, Crogga Glen, Ballaglass Glen, Glen Duff, Nut Glen,

Glen Tramman, Lower Ballabeg and Glen Killey.

4.2.3 Tier 3 Sites.

Generally small and without significant known features that set

the sites apart from secondary woodland (beyond the

presence of oak and/or hazel). These relic sites are of

historical interest and may well contain unrecorded species of

interest.

These sites should be managed to retain their relic features

and would make suitable nuclei of semi-natural woodland

creation schemes.

The sites are: Barnell, Block Eary, Glen Auldyn, Glen Dhoo,

Glen Kylley, Bishop’s Court Glen, Glen Mooar (in Laxey),

Skyhill, Ohio and Colby Glen.

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4.3 Further Research

A key objective of identifying the top 8 woodland sites is that

this will help direct future research and survey effort. While

molluscs have proved a rewarding subject for study, other taxa

from bryophytes (mosses and liverworts) and lichens to

diptera (flies) and coleoptera (beetles) would further enlighten

our knowledge of the natural history of Manx ancient

woodland.

While this study has uncovered a great deal about the flora

and mollusc fauna of the sites, it is by no means complete, and

there doubtless remains much more that can be discovered,

both in the more studied sites and in those where time did not

permit in depth surveys. The exceptional size and diversity of

Glen Roy in particular should mean this site could still contain

many undiscovered natural treasures.

The cultural history of Manx oak/hazel woodlands is poorly

known, with the narrative really only picking up from the 19th

Century early tree planting, tourist and industrial eras. Most of

the sites have a strong heritage of mining and milling leaving

behind mill races, wheel pump casings and engine houses.

Mine adits still remain in some sites, often carved into

stream-sides (Ohio and Glen Roy) or as in the case of

Brookdale, behind a waterfall. The tourist infrastructure is a

more recent human deposit and of active interest to many.

Bohan’s 1989 studies showed that studies of old Manx maps

are revealing and closer study of maps pre-1869 will be a

necessary first stop in the further investigation of the history of

these sites.

Ancient tree research including good age estimation is now

possible with modern wood-coring techniques. This could well

shed more light on the history and age of stunted relic coastal

specimens as well as veteran trees in sites such as Narradale

and Brookdale. With an ageing tree population it may well

now be time for the creation of an ancient tree register.

Dr Alexander’s mollusc survey has also highlighted the

ash-black slug as a particularly notable species whose Island

population should be investigated further.

Manx ancient woodlands contain a rich seam of potential

undergraduate and post graduate studies.

4.4 The Future of Oak/Hazel Woodlands

The great expansion of semi-natural woodland on the Island,

often with oak/hazel woodland at its core, is a process that

would appear to have some way yet to go, as large areas of

the upland fringe are able to develop into woodland faster than

a low intensity of grazing can keep it clear in gorse and

bracken dominated areas.

Along the north scarp of the Northern Hills this allows the

possibility that many oak/hazel woodlands are gradually going

to coalesce into larger blocks of woodland. With a little

imagination and perhaps some Government policy guidance a

forest from Sulby to Ramsey can be allowed and encouraged

to develop. The benefits to biodiversity are evident, but public

recreation, water quality, flood control, carbon storage and the

landscape are all benefits that would accrue.

While woodland is spreading comparatively fast across the

landscape, the specialised biodiversity of the oak/hazel

woodlands will be rather slower to follow and the importance

of these core sites will remain for centuries to come. Within

these sites some positive management will be required to

negate the impact of invasive exotic species. In some sites the

reintroduction of hazel and oak coppice management will be

needed for the vulnerable woodland edge species, though

minimal intervention to maximise the naturalness, veteran

trees and deadwood resource in most sites would be the most

sensible way forward.

Leadership from Government will be the key to the future of

the resource. It is the largest landowner and bringing all its

own sites into a favourable condition will take over 100 years.

While the costs are very low, the time commitment is great. It

has a leadership role to play for the wider resource as well,

bringing together landowners, ecologists and stakeholders to

produce management plans for important sites with multiple

landowners. Fortunately time is on our side, as the most

positive management action is often to do nothing. This should

not mean however that action is not required now, as

developing partnerships and taking collective action could take

years to negotiate.

Some threats are more imminent, such as in Brookdale where

fuchsia is threatening the rare marsh hawksbeard. On the

same site providing the rare ash black slug with a regular and

large supply of deadwood, to promote the spread of the

species, could be a long-term positive intervention.

The first step for oak/hazel woodland conservation should be

their recognition, and inclusion and provision in the up coming

Biodiversity Strategy for the Island.

W i l d f l o w e r s o f M a n n P r o j e c t

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Manx oak/hazel woodlands are by no means the equal of their

cousins in Great Britain, the resource is small and the Island’s

floral diversity is modest which is reflected in the woodland

diversity. The extremely temperate Atlantic conditions

prevailing on the Island also mean that the sharp floristic

divide between ancient woodland and other habitats is much

less pronounced here than in an area such as lowland England,

therefore the relative importance placed upon ancient

woodlands is also somewhat reduced.

While recognising that the Island’s ancient woodland resource

has little significance in the British context, its local significance

has now at last been recognised, surveyed, inventoried and

conclusions made. These are summarised below;

The long held link between relic oak and ancient

woodland has been firmly established and widened to

include hazel.

Most oak/hazel woodland sites are predominantly, or

at least partially ancient, though have somewhat

dynamic boundaries, expanding and contracting due to

human influence over time.

At least 30 of these woodland sites occur on the

Island covering an area of about 125ha. More may well

lie unfound in the many tiny ravines that thread their

way through the Island’s hills.

The 1869 map is not particularly useful at defining

the ‘ancientness’ of oak/hazel sites as it occurs

sometime after significant woodland planting took

place.

A group of about 30 plant species and up to six

mollusc species have been identified as ‘associate’

species in that they are to some degree only found, or

most commonly found, within oak/hazel woodlands.

Many of these species are associate species in eastern

glens but occur in the wider countryside in the southern

hills and coast.

The resource is gradually expanding as oak, hazel

and associate species move into surrounding

plantation, scrub and secondary woodland.

The oak/hazel woodland resource is important for

many rare species on the Island, particularly Schedule

7 Wildlife Act (1990) species.

The resource has become a hostile environment for

some associate species due to levels of shade from

planted species and lack of traditional management.

Some of these species have become very rare or

extinct as a result.

There are many invasive exotic species in oak/hazel

woodlands that require management intervention to

prevent them from causing ecological harm.

The identified sites are an irreplaceable part of the

Island’s natural capital.

Gradually steering the modified and replanted sites

back to a semi-natural state through the natural

regeneration of native species should be a conservation

priority in the Tier 1 sites and good practice in the other

sites. Any planting should be of native species of Manx

origin.

A return to traditional coppice management in

selected sites will be required to maintain long-term

biodiversity in the resource.

Further study of the resource is recommended.

5 CONCLUSIONS

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6 Acknowledgements

This report has been many years in the making, accruing a weighty list of people who have helped along

the way. Doubtless the following list of thanks could be much expanded.

In the Project’s gestation Andrew Millichap (Mill) of the Native Oak Group was a tireless supporter.

Without Mill it is hard to imagine that this report would have ever existed. Further along Dr Philippa

Tomlinson and Dr Peter Davey’s academic scrutiny sharpened and refined initial ideas.

The continued support of the Wildflowers of Mann Steering Committee Chaired by Bill Henderson MHK

has provided the ‘green light’ to progress beyond initial stages. Thanks also go to the staff and volunteers

of the Manx Wildlife Trust for most notably engaging in many one-sided woodland ecology discussions as

well as providing the essential support and infrastructure.

Elizabeth Charter, the Isle of Man Government’s Principal Biodiversity Officer was instrumental in the

successful funding application to the Joint Nature Conservation Council, whose funding enabled the

completion of this report. It should also be mentioned the continued funding from the Isle of Man

Government to the Wildflowers of Mann Project, particularly the Department of Infrastructure,

Department of Economic Development and Department of Environment Food and Agriculture.

Dr Keith Alexander proved to be a true expert conchologist whose contribution was way above and

beyond that contracted. His tenacious background research as well as site surveys created a picture of

woodland mollusc distribution that has proved to be a pillar of support for the research.

Isle of Man Government foresters, past and present for their help and guidance.

Dr Peter McEvoy and Dr Richard Selman of the Isle of Man Government and the British Pteridological

Society who helped round off the surveys with a master class in fern identification in many oak/hazel

sites. The re-finding of Wilson’s filmy fern in the Colden Stream near a single hazel bush and some

scattered oaks may well make this site the 31st Island oak/hazel site though too late and perhaps rather

too tenuous to be included in this report.

Thanks to Dr Stephen Jeffcoate, a woodland enthusiast as well as lepidopterist and chair of the Manx

Wildlife Trust for kindly writing this report’s foreword.

Also thanks to Aline Thomas for support and proof reading, and to the many others including Amber

Cordwell, David Bellamy and Brian Cousins for important snippets of information that added depth and

scope to the report.

W i l d f l o w e r s o f M a n n P r o j e c t

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Alexander K.N.A (2011) A Survey of Ancient Woodland Indicator Molluscs in selected sites on the Isle of Man. (Draft report)

Allen D.E. (1956) The Vanished Forests. Peregrine, 2, 2-9.

Allen D.E. (1984) Flora of the Isle of Man. Manx Museum and National Trust, Douglas.

Bohan R. (1998) Manx Woodland History and Vegetation. In Kirby K.J. & Watkins C. (eds) The Ecological History of European Forests.

Cab International.

Chiverrell R. & Thomas G. (Eds) (2006) A New History of the Isle of Man. Volume 1: The Evolution of the Natural Landscape. Liverpool

University Press. Liverpool.

Coppins A.M. & Coppins B.J. (2002) Indices of Ecological Continuity for Woodland Epiphytic Habitats in the British Isles. British Lichen

Society.

Crawford C.L. (2009) Ancient Woodland Indicator Plants in Scotland in Scottish Forestry. Vol 61, 1.

Dubbeldam A. (2007) Supporting Rare Wildflowers: A Wildflowers of Mann Programme. Manx Wildlife Trust

Dubbeldam A. (2011) New Flora of the Isle of Man: Survey Database. Manx Wildlife Trust (unpublished)

Garrad L.S. (1972) The Naturalist in the Isle of Man. David and Charles, Newton Abbot.

Kirby, K. English Nature (2004). Table of Ancient Woodland Indicator Plants. in Rose F. (2006). The Wildflower Key. Updated by O’Reilly C. Warne. London

Peterken G.F. (1981) Woodland Conservation and Management. Chapman and Hall. London

Rackham O. (1976) Trees and Woodlands in the British Landscape. Dent. London.

Rodwell J.S.(ed) (1991) British Plant Communities. Volume 1: Woodlands and Scrub. Cambridge University Press. Cambridge.

Stace C. A. (2010) New Flora of the British Isles (3rd edition). Cambridge University Press. Cambridge

Watkins C. (1990) Britain’s Ancient Woodland ; Woodland Management and Conservation. David and Charles. Newton Abbot

7 References

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W1 Grey Willow-Marsh Bedstraw woodland

This is a broad community of varied willow woodland types

and makes up one of the Ballaugh Curragh vegetation types.

In this survey this community refers to pioneer woodland on

mineral soils on former open marsh and wet riverside habitats.

Initially very open with rush dominated vegetation like that of

the marsh. As the canopy closes in with grey and eared willow,

the rush is shaded out leaving just the shade tolerant species

such as tufted hair grass, yellow pimpernel, devils bit, bugle,

heath spotted orchid and marsh bedstraw. The community

here is temporary as ash, sycamore, alder and downy birch

colonise and overtop the canopy and species such as

enchanter’s nightshade and opposite-leaved golden saxifrage

enter the ground flora marking a transition to the W7

Alder-Ash-Yellow Pimpernel community.

Many glen woodlands such as Elfin Glen and Nut Glen contain

this community at their upper edge, often a mobile colonising

front along stream-sides. Above 200m it may well be a climax

community type as it is beyond the natural limit for W7, but the

increase in acid peaty soils means the community tends to be

replaced by the W4 Downy Birch-Purple Moor-grass

community.

W4 Downy Birch-Purple Moor-grass woodland

Similar to W1 this woodland type generally occurs on the Isle

of Man where downy birch, eared willow and grey willow

invade an acid peaty bog habitat. It typically has sphagnum

moss and purple moor-grass ground vegetation. Unlike W1

woodland however, this is less likely to be a transitory

succession phase, but instead remain as climax scrubby

woodland, though with increasing birch dominance. If

however the trees dry out the underlying peat it is likely further

successional changes will take place, most likely to W17

Sessile Oak-Downy Birch-Greater Fork-moss

community.

This community is somewhat uncommon within oak/hazel

woodlands (though good examples can be found well within

Glen Helen and Glen Roy), but form a colonising scrub where

woodlands are adjacent to wet upland vegetation such as at

Brookdale. Incidences of the community increase greatly

above 150m. W4 is by far the dominant vegetation type of the

Ballaugh Curragh.

W7 Alder-Ash-Yellow Pimpernel woodland

This is the standard community of wet areas within oak/hazel

woodland. Occurring in patches from less than a metre across

and rarely covering more than 500m2. Sometimes it forms thin

ribbons along stream-sides, occasionally as marsh in flat river

terrace areas, but most frequently as wet flushes on a ravine

side. While nominally an alder woodland community, some

localised parts of the Island like Ramsey and Glen Auldyn lack

this species completely so ash, birch, grey willow and

sycamore make up the canopy.

Almost always the most species rich community in a woodland

and in sites dominated by the rather species poor W11

Oak-Downy Birch-Wood Sorrel community the contrast in

species richness can be dramatic. Better examples of the

community can contain wood horsetail, sanicle,

smooth-stalked sedge, heath spotted orchid and in one case

marsh hawksbeard. Almost all will have enchanter’s

nightshade, bugle, opposite-leaved yellow saxifrage and

yellow pimpernel along with many others.

W7 woodland tends to be a tangle of bramble and fallen trees

among waterlogged ground, thus a difficult terrain to traverse.

Appendix I National Vegetation Class (NVC) Woodland Types in Manx Oak/Hazel Woodlands (from Rodwell 1991)

W7 at Groudle Glen

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W8/9 Ash-Field Maple-Dog’s

Mercury/Ash-Rowan-Dog’s Mercury woodlands

These are the standard communities on the Island of

woodlands on somewhat base rich (though often still quite

acid) soils. Occurring in valley bottoms on colluvial soils or on

soils over less acid bedrock. While field maple and dog’s

mercury are not native to the Island, they are ably replaced

here by wych elm and enchanter’s nightshade respectively.

Similar to W7 they lack the species dependent on woodlands

in wet conditions such as opposite-leaved golden-saxifrage,

wood horsetail and alder and gain a suite of species that

demands more freely drained soil such as wood false brome,

bluebell and herb robert. Many species such as sanicle, remote

sedge, primrose, bugle and wood anemone are equally at

home in W7 and W8/9.

W8 and W9 are lumped together here as the differences are

slight, with W8 being the lowland counterpart to the upland

W9. As many glen woodlands start in the lowlands and climb

some 100m or more, the common situation is the lower part of

the glen is W8, normally the distinctive wild garlic dominated

sub-community and the upper part is W9 as garlic falls away

and ferns become more numerous. The dividing line is rarely

clear on the ground and the differences are slight hence the

reasons for lumping the communities together. Ballure Glen is

a useful Island example, with most of the woodland below the

reservoir W8 and the riverside woodland above the reservoir

W9.

Like W7, W8/W9 is a very species rich community, indeed,

even where wild garlic seems to overwhelmingly dominate,

there will still be significant species richness. This community

is also the most important for many of the rarer woodland

species such as wood speedwell, wood fescue and hard

shield-fern.

W10/W11 Pedunculate Oak-Bracken-Bramble/Sessile

Oak-Downy Birch-Wood Sorrel woodlands

These are the classic bluebell woodlands, most beloved on the

Island, with bluebells forming a dominant vegetation carpet in

spring. They occur on free draining, more acid and base poor

soils than that of W8/9.

The most common vegetation types found in oak/hazel

woodland, W10 is the lowland counterpart to the upland

W11. They are lumped together for the same reasons as W8

and W9, indeed the differences between the two communities

are so subtle as to be hardly noticeable, with an abundance of

wood sorrel that can be seen after the bluebell has died away

in W11 the main diagnostic feature that differentiates it from

W10.

The typical tree in the community is hybrid oak, but it only

locally dominates the canopy and where the community forms

secondary woodland adjacent to a glen it tends to be absent.

Sycamore, birch, beech (mostly planted) and planted conifers

and sweet chestnuts form the majority of the remainder of the

tree cover, though ash and wych elm do occur occasionally. In

some glens hazel is a common understorey, but holly or

bramble can be locally abundant or dominant, as can cherry

laurel and rhododendron.

As has been said, it is the dominance of bluebell that is most

distinctive in the ground flora, with male-ferns and broad

buckler-ferns also common, whilst other species such as

greater stitchwort are infrequent. As the bluebell dies off in the

summer the ground flora takes on a grassy look with sweet

vernal grass, Yorkshire fog and creeping soft-grass the more

common species. Greater woodrush can become a local

monoculture and while most common in this type of woodland

it can also form local monocultures in W7, W9 and W17.

While aesthetically very attractive the community is not

blessed with a great variety of vascular plants, though where

large mature oak trees are present a great deal of lower plant

and invertebrate interest is assumed.

W15 Beech-Wavy Hair-grass woodland

Created by the planting of beech trees over acid soils, it can be

considered a species poor type of W17 on the Isle of Man and

Typical W11 at Glen Helen

W i l d f l o w e r s o f M a n n P r o j e c t

Page 26

not an indigenous woodland community to Mann. Where

mature beech occurs near W17 woodland however, the

natural regeneration of beech into this community could

gradually convert the site to W15 as is happening in places

such as Ballaglass. The acid leaf litter also has the potential to

convert the more acid W10/11 sites to W15 in time.

These woodlands are open and attractive to people, and while

generally species poor they can develop an interesting fungal

assemblage.

W17 Sessile Oak-Downy Birch-Greater Fork Moss

woodlands

The woodland type on the most acid soils. This tends to occur

in the uplands, but at lower altitudes it can form small patches

on very thin soils over rock, so is not uncommon at the top of

narrow ravines, where it can form small patches above W8/9

woodland.

This woodland type is dominated by downy birch with

occasional oak, holly and rowan. Where this woodland type is

colonising open heath, rowan tends be the more common

pioneer species, often with some lodgepole pine where conifer

plantations are nearby. Beech readily seeds into this

community, but mature trees are planted in origin.

The ground flora looks very grassy or mossy with an absence

of showy species such as bluebell or wild garlic. The near

absence of bramble and dense scrub further add to the

pleasant aesthetic of the community. Pill sedge, hairy

woodrush, goldenrod, slender St Johns wort and wood sage

are the more noticeable vascular species. Bilberry, greater

woodrush and bracken can be locally dominant.

While found in most of the larger glens this is not a particularly

abundant vegetation type and tends to occur on the boundary

of glens and conifer plantations or open heath. While

considered species poor, its distinctive flora adds somewhat to

the diversity of the woodland where the vegetation type

occurs.

Bare Rock Ravine woodland

Sitting somewhat outside any NVC communities (though

perhaps closest to W11) the stone gouged humid rocks in

most glens support a rather consistent community. The bare

rocks are dominated by mosses and liverworts and the

frequent cracks between them contain species tolerant of the

acid rocks, and frequent base rich flushing. Many of these sites

are extremely shady thus the vascular plant flora can be

sparse but there is an interesting assemblage of

wet-demanding (such as lemon-scented fern and devil’s bit),

along side drought-tolerant (but humid dependent) species

such as hairy woodrush and wood sorrel. Other species

frequent here are tutsan, opposite leaved golden saxifrage,

greater woodrush and goldenrod. Hay-scented buckler-fern,

and beech fern are rarer Manx species that are most likely

found in this community.

Oak/hazel woodlands of the Isle of

Man is a report by the Wildflowers of Mann Project.

The Project undertakes all aspects of research, practical conservation,

consultancy and public engagement

in the field of Wildflowers and habitat conservation on the Isle of

Man. Part of its scope has been the creation of a showcase garden

open to the public, the publication of a best selling book, ‘The Wild-

flowers of Mann’, as well as

running a wildflower nursery producing native plants and seeds

to create new native woodlands, meadows, wetlands and other

habitats across the Island.

Run out of the Manx Wildlife Trust the Wildflowers of Mann is a

partnership project between Isle of Man Government departments and

local conservation organisations who together form a steering

committee for the Project chaired

by Bill Henderson MHK.

Andree Dubbeldam MIEEM has

been the Wildflowers of Mann Project Manager since 2002. Born

and brought up in Sussex he has been in work or education in the

field of conservation and the

countryside for 25 years.

As a forestry graduate from Bangor

University, ancient semi-natural woodland is an area of particular

expertise and interest.

Top: Brookdale; Middle: speckled wood butterfly in Ballure; horned stag-beetle in Dhoon; Bellow: Dr Keith Alexander showing David Bellamy an invertebrate sweep-net sample; native bluebell

Wildflowers of Mann Project