Castlearchdale, Co. Fermanagh; Ecological Report

Ecological Assessment of Plans for Castle Archdale, Co. Fermanagh

Report by: S.A. Wolfe-Murphy

WM Associates
Environmental Consultants
35 Rossmore Avenue
Ormeau Road
Belfast BT7 3 HB

Date: 31/08/2000

Ecological Assessment of Plans for Castle Archdale, Co. Fermanagh

Contents:

BACKGROUND 3
SUMMARY 3
SURVEY AND REPORTING PROTOCOL: 4
INTRODUCTION TO SITE AND PROPOSED PLANS: 5
ECOLOGICAL SURVEY OF SITE: 5
ASSESSMENT OF SITE: 13
RECOMMENDATIONS ON PROPOSED MANAGEMENT: 13
Acknowledgements 16
References 16
APPENDIX 1. SITE PHOTOGRAPHS 17

Background

The Millennium Forests Project is an all-Ireland initiative to restore and extend existing native woodlands, and to create new woodlands based upon appropriate native species. The project is intended to stimulate public interest in native woodland development and protection in Ireland.

Castle Archdale is one of 16 woodland sites that have been selected for enhancement.

This study aims to:

· Provide an ecological background to the project at Castle Archdale.

· Assess the proposed planting area in the context of relevant nature conservation legislation

· Provide management advice outlining the options to best enhance the natural history and biodiversity interest of the site.

Fieldwork was conducted 10/08/2000. The proposed planting area is currently grassland so this is a favourable time of year for the survey.

Summary

The site proposed for planting comprises entirely improved grassland of Rye grass, currently being farmed, so there is no possibility that planting would compromise existing scientific interest.

Two small plantations are already established adjacent to the proposed planting area and would be usefully linked. However, the type of planting in these areas is not considered optimum for wildlife or for landscape and amenity.

Recommendations are made to plant mixed species instead of mono-cultural blocks, using mainly native tree species and varying the planting pattern.

Survey and reporting protocol:

The areas were surveyed by zigzag walks across the site. Where vegetation quadrats were recorded, these describe the cover of plants within a (usually) 1 x 1m area of vegetation. The 'DOMIN' % cover class is used, as follows:

Domin % cover class

+ = a few individuals 6 = 25-33%
1 = 1-2% 7 = 33-50%
2 = <2% 8 = 50-75%
3 = 2-5% 9 = 75-90%
4 = 5-10% 10 = 90-100%
5 = 10-25%

In describing the status of plant species in a larger area, the qualitative DAFOR scale is sometimes used, where:

D = Dominant
A = Abundant
F = Frequent
O = Occasional
R = Rare

L = Local - to describe patchy distribution within an area.
V = 'very' ( as a prefix)

Where trees have been measured, their diameter at breast height (dbh) is given in cm.

Introduction to site and proposed plans:

Castle Archdale is an estate situated on the east shore of Lower Lough Erne in undulating drumlinoid country, mainly over Devonian old red sandstone from which the gleyed glacial till soils are derived. Most of the woodland on the estate is coniferous plantation managed for forestry, although there is a lake shore fringe of carr, and in places Birch co-dominate waterlogged soils.

The site is entirely pastoral farmland adjacent to the existing forestry. Here the clay loam soils have been substantially improved and are intensively farmed. Drainage over most of the planting area is improved by gradient - the site slopes to the centre along its northern and western edges.

A track linking the internal forestry track system to the site runs north-west to south-east, initially along the site boundary. Off this, another track runs downhill to the farm yard on the Lisnarrick road.

A certain amount of broad-leaf planting has already been undertaken in the local area and the site will link two existing plantations of Ash, Sycamore, Oak and Beech. It is assumed that the proposed new planting is of a similar nature.

Ecological survey of site:

Area 1i

Off site to the north Recent broad-leaved plantation into semi-improved neutral grassland of Creeping bent (Agrostis stolonifera) and Creeping buttercup (Ranunculus repens). See photo 1, with much of the rest of the site in the background.

Four species are planted, each in large mono-specific blocks: Ash (Fraxinus excelsior); Pedunculate oak (Quercus robur); Sycamore (Acer pseudoplatanus) and Beech (Fagus sylvatica).

Area 1ii

Mixed coniferous plantation including areas of Norway spruce (Picea abies), Douglas fir (Pseudotsuga menziesii), Scot's pine (Pinus sylvestris) and Lawson cypress (Chamaecyparis lawsoniana).

The plantation edge to the south (see photo 2) is interesting as it of naturally generated cover and harbours species that may spread through the proposed new plantation:

Species:
Elder (Sambucus nigra) F
Ash (Fraxinus excelsior) LF
Hazel (Corylus avellana) LF
Hawthorn (Crataegus monogyna) LF
Blackthorn (Prunus spinosa) O
Rosebay willowherb (Chamerion angustifolium)
Common nettle (Urtica dioica)
Remote sedge (Carex remota)
Foxglove (Digitalis purpurea)
Prickly sow-thistle (Sonchus asper)
Herb-robert (Geranium robertianum)
Common bent (Agrostis capillaris)
Opposite-leaved golden-saxifrage (Chrysosplenium oppositifolium)
Wood speedwell (Veronica montana)
Cleavers (Galium aparine)
Common dog-violet (Viola riviniana)
Enchanter's nightshade (Circaea lutetiana)
Primrose (Primula vulgaris)
Creeping buttercup (Ranunculus repens)
Bramble (Rubus agg.)
Short-fruited willowherb (Epilobium obscurum)
Meadowsweet (Filipendula ulmaria)
Meadow foxtail (Alopecurus pratensis)
Timothy (Phleum pratense)
Yellow iris (Iris pseudacorus)
Meadow vetchling (Lathyrus pratensis)
Bush vetch (Vicia sepium)
a moss (Eurhynchium striatum)
a liverwort (Lophocolea bidentata)
a moss (Eurhynchium praelongum)
a moss (Thuidium tamariscinum)
a moss (Plagiomnium undulatum)

Further inside the plantation Cherry laurel (Prunus laurocerasus) was noted at the trackside and further again Rhododendron (Rhododendron ponticum), Snowberry (Symphoricarpos alba) and Garden Solomon's-seal (Polygonatum hybridum).

Area 1iii

A small planted copse in improved grassland. All the saplings are thriving. Alder (Alnus glutinosa) is the main species, also:

Species:
Rowan (Sorbus aucuparia) R
Hazel (Corylus avellana) R
Ash (Fraxinus excelsior) R

Area 1 iv

To the south of the site a mature plantation that although recently-fenced, is grazed by the cattle from area 9.

The main trees are Intermediate oak (Quercus x rosacea) to 80 cm dbh, although there are also mature Sweet chestnut (Castanea sativa) roughly the same size. The trees are well-spaced, the canopy tall with a cover around 60%, so the ground is not shaded enough for a woodland ground flora to develop. Instead, typical species are Creeping bent (Agrostis stolonifera); Cock's-foot (Dactylis glomerata); Chickweed (Stellaria media); Common nettle (Urtica dioica) and Creeping buttercup (Ranunculus repens) (see photo 3).

Area 1 v

A recent plantation with a row of mature Ash (Fraxinus excelsior) running east to west across the centre. To the north is planted pure Sycamore (Acer pseudoplatanus) (see photo 4) and to the south, pure Pedunculate oak (Quercus robur). These planted into a semi-improved neutral grassland of:

Species:
Creeping bent (Agrostis stolonifera) D
Yorkshire-fog (Holcus lanatus) F
Perennial rye-grass (Lolium perenne)
Common nettle (Urtica dioica)
Marsh thistle (Cirsium palustre)
Broad-leaved dock (Rumex obtusifolius)
Creeping buttercup (Ranunculus repens)
etc…

Area 2

An improved field either very much dominated by Perennial rye-grass (Lolium perenne) or with Creeping bent (Agrostis stolonifera) as a co-dominant. Unlike the other improved grasslands in the site, this field is almost without White clover (Trifolium repens). Photo 5 is a view downslope towards the Lisnarrick road which runs beyond the farm buildings, and photo 6 is detail of the sward.

Ungrazed and tall at the time of the survey, but noted to have a cattle trough.

Species table:
spp. quadrat tot.
1 2 3 4 5

Creeping bent (Agrostis stolonifera) 8 8 5 7 5 V
Perennial rye-grass (Lolium perenne) 7 7 9 8 9 V
Chickweed (Stellaria media) 1 1 1 III
Rumex obtusifolius 1 1 1 III
Creeping buttercup (Ranunculus repens) 5 I
Annual meadow-grass (Poa annua) 3 3 II
White clover (Trifolium repens) 4 I
Marsh foxtail (Alopecurus geniculatus) 3 4 II

Other species:
Cock's-foot (Dactylis glomerata) R by track side
Redshank (Persicaria maculosa) VLO by gate
Wavy bitter-cress (Cardamine flexuosa) R
Dandelion (Taraxacum agg.) R
Creeping thistle (Cirsium arvense) VLO confined to trackside
Yorkshire-fog (Holcus lanatus) LF only by plantation
Hairy sedge (Carex hirta) VLF by plantation
Spear thistle (Cirsium vulgare) R
Common mouse-ear (Cerastium fontanum) VLF
Lesser spearwort (Ranunculus flammula) R
Creeping buttercup (Ranunculus repens) VLF
Meadow foxtail (Alopecurus pratensis) VLO by plantation
Soft-rush (Juncus effusus) VLO by plantation

Area 3

An 'L'-shaped shelterbelt planted alongside the track leading from the farm yard. Four rows of trees planted quite densely:

Row 1. Intermediate whitebeam (Sorbus intermedia) to 15 cm dbh inter-planted with low-growing St Lucie cherry (Prunus maheleb).

Row 2. European larch (Larix decidua) in the range 12-22 cm dbh.

Row 3. Beech (Fagus sylvatica) in the range 12-29 cm dbh.

Row 4. European larch (Larix decidua) in the range 12-22 cm dbh.

Although fenced, cattle have access to the plantation and there is just enough room between the trees for them to wear a muddy track between each of the rows.

Otherwise the grassland is of:

Species:
Creeping bent (Agrostis stolonifera) A
Yorkshire-fog (Holcus lanatus) A
Meadow foxtail (Alopecurus pratensis) O
Red fescue (Festuca rubra) VLF
Smooth hawk's-beard (Crepis capillaris)
Meadow buttercup (Ranunculus acris)
Marsh thistle (Cirsium palustre)
Soft-rush (Juncus effusus)
Creeping buttercup (Ranunculus repens)
Common mouse-ear (Cerastium fontanum)
White clover (Trifolium repens)
Spear thistle (Cirsium vulgare)
Common nettle (Urtica dioica)
Hairy sedge (Carex hirta)
Common sorrel (Rumex acetosa)
Annual meadow-grass (Poa annua)
Tall fescue (Festuca arundinacea) VLF
Sharp-flowered rush (Juncus acutiflorus) VLO
a moss (Brachythecium rutabulum)
a moss (Ulota crispa)
a moss (Thuidium tamariscinum)
a moss (Eurhynchium praelongum)

The bryophytes occur mainly on and around the tree bases.

Area 4

Grazed. At the time of the survey by just 3 cattle, but formerly more intensively (sheep?). Photo 7 is of this field with the shelterbelt to the left, and photo 8 is the sward detail.

Species:
Creeping bent (Agrostis stolonifera) F-A
Perennial rye-grass (Lolium perenne) A-D
Yorkshire-fog (Holcus lanatus) R
Marsh foxtail (Alopecurus geniculatus) O
Annual meadow-grass (Poa annua) F
Cuckooflower (Cardamine pratensis) R
White clover (Trifolium repens) VLF
Creeping buttercup (Ranunculus repens) OLF
Common mouse-ear (Cerastium fontanum) OLF
Broad-leaved dock (Rumex obtusifolius) O-F
Dandelion (Taraxacum agg.) O
Chickweed (Stellaria media) O-F
Lesser spearwort (Ranunculus flammula) R
Creeping thistle (Cirsium arvense) LO edge only
Spear thistle (Cirsium vulgare) R edge only
Thyme-leaved speedwell (Veronica serpyllifolia) R
a toadstool Panaeolus subbalteatus OLF

To the south of this field is the only other OS marked boundary in this compartment. Isolated but closely regular Hawthorn (Crataegus monogyna) bushes, inter-planted at the top of the slope with Wild cherry (Prunus avium). Rabbit burrows were noted alongside the hedge,

Species table:
spp. quadrat tot.
1 2 3 4 5

Creeping bent (Agrostis stolonifera) 8 8 8 7 7 V
Annual meadow-grass (Poa annua) 5 5 5 5 6 V
Perennial rye-grass (Lolium perenne) 6 6 8 8 8 V
Common mouse-ear (Cerastium fontanum) 1 2 2 III
Broad-leaved dock (Rumex obtusifolius) 1 1 3 3 5 V
Creeping buttercup (Ranunculus repens) 6 3 II
White clover (Trifolium repens) 4 I
Area 5

A small enclosure next to the track accommodating two water tanks, presumably headers for the cattle troughs that are installed in each field.

The sward around them is less comprehensively improved than the surrounding fields:

Species:
Creeping bent (Agrostis stolonifera) A
Perennial rye-grass (Lolium perenne) A
Annual meadow-grass (Poa annua) F
Smooth meadow-grass (Poa pratensis) O
Marsh foxtail (Alopecurus geniculatus) O
Marsh thistle (Cirsium palustre) F
Soft-rush (Juncus effusus) F
Curled dock (Rumex crispus) R
Hairy sedge (Carex hirta) LO
Common mouse-ear (Cerastium fontanum) O
Common nettle (Urtica dioica) R
Yorkshire-fog (Holcus lanatus) F
Creeping buttercup (Ranunculus repens) A
White clover (Trifolium repens) A
Meadow foxtail (Alopecurus pratensis) O
Meadow buttercup (Ranunculus acris) O
Crested dog's-tail (Cynosurus cristatus) VLF
Marsh ragwort (Senecio aquaticus) R
Meadow vetchling (Lathyrus pratensis) R
Procumbent pearlwort (Sagina procumbens) LO

Area 6

Very improved field overwhelmingly dominated by Perennial rye-grass (Lolium perenne) and White clover (Trifolium repens) cultivars. Grazed by 5 cattle at the time of survey (see photos 9 and 10).

Species table:
spp. quadrat tot.
1 2 3 4 5

Perennial rye-grass (Lolium perenne) 9 9 10 9 10 V
White clover (Trifolium repens) 7 8 5 8 7 V
Creeping bent (Agrostis stolonifera) 4 3 3 3 IV
Chickweed (Stellaria media) 1 I

Few other species:
Creeping buttercup (Ranunculus repens) R
Annual meadow-grass (Poa annua) O
Common mouse-ear (Cerastium fontanum) R
Yorkshire-fog (Holcus lanatus) R

Area 7

The southern section of the western site boundary links the end of the broken fence in Area 9 to the junction between fence and track by Area 5. Thus the new boundary as drawn, will dissect two fields in the south of the site. This area is a small section of one of those fields. It is comprehensively improved. At the time of survey it was not grazed and was assumed to be under second cut silage. Photo 11 is taken from the gate beside Area 5. The boundary internalising the track runs from the end of the just visible fence that runs to the tree'd boundary in the middle distance, across the open fields to a point ± 10m behind the point from which this photo was taken. Area 7 is a triangular segment of the field to the right.

Perennial rye-grass (Lolium perenne) and White clover (Trifolium repens) cultivars are overwhelmingly dominant to the virtual exclusion of other species, only Creeping buttercup (Ranunculus repens), Dandelion (Taraxacum agg.) and Broad-leaved dock (Rumex obtusifolius) were noted, none of them frequent.

Area 8

Ungrazed at the time of survey, but previously sheep grazed. A familiar species-poor improved sward (see photo 12):

Species:
Perennial rye-grass (Lolium perenne) D
White clover (Trifolium repens) A
Creeping buttercup (Ranunculus repens) O
Creeping bent (Agrostis stolonifera) OLA
Broad-leaved dock (Rumex obtusifolius) R

The boundary at the base of the slope to the north-east is of interest. It is part of an abandoned track that is now a linear weedy scrub feature that could be a source of invasive propagules once the plantation is established (see photo 13):

Species:
young Ash (Fraxinus excelsior) F
Hawthorn (Crataegus monogyna) A
Hazel (Corylus avellana) LA
Rusty willow (Salix cinerea ssp oleifolia) R
Blackthorn (Prunus spinosa) LF
Snowberry (Symphoricarpos alba) LA
Holly (Ilex aquifolium) O
Silver maple (Acer saccharinum) R 1 tree
Wych elm (Ulmus glabra) O

Ground-elder (Aegopodium podagraria) LA
Wood dock (Rumex sanguineus)
Ivy (Hedera helix)
Herb-robert (Geranium robertianum)
Selfheal (Prunella vulgaris)
Greater stitchwort (Stellaria holostea)
Wood speedwell (Veronica montana)
Male-fern (Dryopteris filix-mas)
Hart's-tongue (Phyllitis scolopendrium)
Bramble (Rubus agg.)
Wild angelica (Angelica sylvestris)
Creeping buttercup (Ranunculus repens) A
Enchanter's nightshade (Circaea lutetiana)
Montbretia (Crocosmia x crocosmiiflora)
Brooklime (Veronica beccabunga)
Chickweed (Stellaria media) F
Lesser burdock (Arctium minus ssp nemorosum)
Primrose (Primula vulgaris)

The boundary running south-west from the old track is also Ash, Hazel and thorns and includes young Sycamore (Acer pseudoplatanus).

Area 9

The fence from the southern boundary to the end of the track runs through this area but is broken and gappy (see photo 14). The large cattle herd runs over the fields to either side pasture (see photo 15). The western field is divided by the proposed site boundary linking the fence end to the junction by area 5.

The sward is an improved Perennial rye-grass (Lolium perenne):

Species:
Perennial rye-grass (Lolium perenne) D
Broad-leaved dock (Rumex obtusifolius) F
Creeping bent (Agrostis stolonifera) F
Chickweed (Stellaria media) R
Meadow buttercup (Ranunculus acris) R
Timothy (Phleum pratense) R
White clover (Trifolium repens) F
Creeping buttercup (Ranunculus repens) F
Marsh foxtail (Alopecurus geniculatus) O

The hedge to the west dips into a wetter hollow, in places with standing water in an associated ditch:

Species:
Rusty willow (Salix cinerea ssp oleifolia) A
Bramble (Rubus agg.) F-A
Hawthorn (Crataegus monogyna) F
Ash (Fraxinus excelsior) O
Blackthorn (Prunus spinosa) O
Ivy (Hedera helix)
Male-fern (Dryopteris filix-mas)
Yellow iris (Iris pseudacorus)

Fauna

Swallow
Wood pigeon
Hooded crow
Redwing

Green-veined white

Assessment of site:

The grasslands are all versions of the National Vegetation Classification MG7 Lolium perenne leys or related Lolio-Plantaginion grassland community (Rodwell 1992), and conform to the most 'improved' and species-poor Sub-community Lolium perenne-Trifolium repens leys.

The only unusual floristic feature is that Creeping bent (Agrostis stolonifera) and to a lesser extent Marsh foxtail (Alopecurus geniculatus) are widespread, the former sometimes abundant. This is an Atlantic variant due to high rainfall and only moderate drainage, and is not an indication of MG13 Agrostis stolonifera-Alopecurus geniculatus inundation grassland.

This is a very common grassland type in much of Ireland and is of very low intrinsic wildlife value. Rare, scarce or declining species of animal or plant will not be found here.

The presumably high nutrient status will have a bearing on the floristic development of the planted woodland. The prospect of developing a cover similar to that of an old, established, semi-natural woodland is probably poor without soil replacement, except in the very long-term.

Recommendations on proposed management:

· Woodland creation along the lines of previous planting of broad-leaved monocultures in Areas 1i and 1v, would not be appropriate to be funded under the Millennium Forests Project, especially where the plantation is of non-native species. Guidelines on the creation of native woodlands are given in Rodwell and Patterson (1994).

· The proposed planting site is of very limited intrinsic scientific interest comprising very improved grasslands with little semblance to semi-natural habitat. Planting with broad-leaved trees represents the easiest way to increase the value of the site for wildlife, particularly as it is adjacent to sources of recolonising species.

· Given the Millennium Forests Project's stated aims, the selected trees for planting should be at least largely restricted to native species and comprise Irish stock.

The planting should aim to create a semi-natural mixture of species. Some insight into what this may be here is gained from looking at the naturally established hedgerow species. Thus it seems that the predominant species chosen should be Ash (Fraxinus excelsior) and Hazel (Corylus avellana).

The appropriate target condition should be the typical Sub-community of NVC W9 Fraxinus excelsior-Sorbus aucuparia-Mercurialis perennis woodland.

Ash (Fraxinus excelsior) Predominant planting species
Hazel (Corylus avellana) Predominant planting species
Rowan (Sorbus aucuparia) Secondary species
Wych elm (Ulmus glabra) Secondary species
Downy birch (Betula pubescens) Secondary species
Bird cherry (Prunus padus) Trackside groups (of Irish stock)
Goat willow (Salix caprea) Occasional
Sycamore (Acer pseudoplatanus) Allow natural generation
Hawthorn (Crataegus monogyna) Allow natural generation
Holly (Ilex aquifolium) Allow natural generation

There is probably little variation is base status on the site, although there may be some flushing of bases downslope. Even so, there is the opportunity to impose a variation in the tree cover, even if it is not truly reflected in the soil conditions.

Oak clearly thrive in the area and either Sessile oak (Quercus petraea) or Pedunculate oak (Quercus robur) could be used extensively in the upslope section along the length of the site.

The target community here would be closer to W11 Quercus petraea-Betula pubescens-Oxalis acetosella woodland

Oak (Q. petraea or robur) Predominant planting species
Downy birch (Betula pubescens) Frequent species
Hazel (Corylus avellana) Secondary species
Rowan (Sorbus aucuparia) Secondary species
Ash (Fraxinus excelsior) Secondary species
Bird cherry (Prunus padus) Trackside groups (Irish stock)
Goat willow (Salix caprea) Occasional
Sycamore (Acer pseudoplatanus) Allow natural generation
Hawthorn (Crataegus monogyna) Allow natural generation
Holly (Ilex aquifolium) Allow natural generation

Given that highly modified woodland is characteristic of the Castle Archdale estate, there is latitude for the introduction of non-native species in small groups. Of these the most favoured are:

Species:
Southern beech (Nothofagus sp.)
Beech (Fagus sylvatica)
Scot's pine (Pinus sylvestris) (avoid any other conifers)
Sweet chestnut (Castanea sativa)
Hornbeam (Carpinus betulus)

· Desist from further fertilisation on planting. The ground is already fertile. There may be some requirement for vegetation control around planted saplings in the early stages of establishment. Initially Perennial rye-grass (Lolium perenne) will probably be slowly replaced by rank Yorkshire-fog (Holcus lanatus) and Creeping bent (Agrostis stolonifera) with much Broad-leaved dock (Rumex obtusifolius). On canopy formation expect a transition from rank grass to Common nettle (Urtica dioica), Chickweed (Stellaria media), Bramble (Rubus agg.) and Cleavers (Galium aparine).

· There are potentially invasive and undesirable alien shrub species in the adjacent habitats, particularly Cherry laurel (Prunus laurocerasus), but also Snowberry (Symphoricarpos alba) and Rhododendron (Rhododendron ponticum).

It will be substantially easier to keep the new plantation free of these species than it would be to clear them if they became well-established.

· FSNI have an 'open gate' policy for pedestrians (see photo 16). Woodland visitors are already well-serviced with access points and car parks.

The closest access point is the track immediately north of the site. There would be room to allocate a small car park to the left of this track, in area 1i, just before the stile.

· Electricity cables cross Area 4, 6 and 7 on telegraph poles. The easiest way to accommodate these would be in rides. Ride management, including occasional late summer mowing and enhancement planting, could increase diversity on site.

· Once the plantation is established, thin the windbreak trees of area 3. Although these are all non-native species, some of the Whitebeam and Beech should be allowed to mature. Remove the Larch and the Cherry completely.

· The value of this planting area could be improved if the adjacent coniferous plantation now largely in the last thinning phase, were eventually to be re-structured to broad-leaved cover. This would depend upon a long-term strategy for the whole of the Castle Archdale site.

Acknowledgements

I would like to thank Stan Milner of FSNI, and staff of the Castle Archdale Country Park for their support in this project.

References

Rodwell, J.S. (ed.) (1992)
British Plant Communities volume 3. Grasslands and montane communities.
Cambridge University Press, Cambridge.

Rodwell, J.S. and Patterson G.S. (1994)
Creating new native woodlands
Forestry Commission Bulletin 112. HMSO, London

Appendix 1. Site Photographs

*Please note that it was not possible to reproduce figures for inclusion on the website version of the reports.