Glengarra, Co. Tipperary; Ecological Report
1. INTRODUCTION
This report is an ecological survey of parts of Glengarra Wood,
Co. Tipperary destined to be the location for a Millennium
Forest, including
· inventory of flora, fauna and habitats, especially items
of special conservation value covered by National or EU legislation
· management advice to protect key habitats and species
· recommendations to enhance the biodiversity of the whole
site
The site was visited in August 2000 and subsequently discussed
with Mr Dan Lynch, the Coillte Site Manager.
2. DESCRIPTION OF AREA
Glengarra is a long valley running into the southern side of the
Galtee Mountains some 12km west of Cahir. The river, the Burncourt,
divides into two at Mountain Lodge (a Youth Hostel) with one branch
coming from the vicinity of Galtybeg and the other from Greenane.
Flow is torrential in the river channels which are lined by clean
sandstone rocks from the slopes above. The valley has a long history
of afforestation and even when mapped in 1841 was a mixture of
deciduous and coniferous trees (Map 1). Firs, pines, redwoods
and cypresses persist from those times when Rhododendron and laurel
were also introduced. The latter shrubs have spread extensively
along the rivers extending from the entrance on the N8 to considerably
beyond Mountain Lodge.
Glengarra is cut in Old Red Sandstone rocks with conglomerate
and finer grained sandstones mixed in the river bed. Silurian
slates occur north of the summit ridge and find their way also
into the rivers in places.
3. VEGETATION & FLORA
The upper slopes of the valley are steep and a heathland rather
than a bog vegetation was the natural cover for them before afforestation.
Large deciduous trees (oak and ash) have persisted along the river
channels and there are places where finer sediment accumulates,
producing nutrient-rich sites locally.
Much of the area is under sitka spruce but where heathland can
develop it is based on autumn gorse Ulex gallii, heather Calluna
vulgaris, bell heather Erica cinerea with the level of moorgrass
Molinia caerulea and bracken Pteridium aquilinum depending on
former management. Common bent Agrostis capillaris, sweet vernal
grass Anthoxanthum odoratum and heath rush Juncus squarrosus are
frequent and there is some sheep's fescue Festuca ovina, St John's
wort Hypericum pulchrum, milkwort Polygala serpyllifolia and green-ribbed
sedge Carex binervis. Mosses such as Dicranum scoparium, Campylopus
introflexus and C.flexuosus are ubiquitous. Any disturbance is
followed by the appearance of foxglove Digitalis purpurea and
sheep's sorrel Rumex acetosella while ragwort Senecio jacobaea
and bramble Rubus fruticosus are not far behind.
3.1 Upper forest
The site includes both sides of the eastern branch of the river
above Mountain Lodge and has been felled for several years. There
is still branch debris and some bare ground with species such
as sheep's sorrel Rumex acetosella, foxglove Digitalis purpurea,
soft rush Juncus effusus and bramble Rubus fruticosus taking advantage
of it. Otherwise there is an open growth of ling heather Calluna
vulgaris, heath rush Juncus squarrosus, fraochan Vaccinium myrtillus,
heath bedstraw Galium saxatile and bell heather Erica cinerea
re-establishing itself after the shade of the previous tree crop.
Green-ribbed sedge Carex binervis, star sedge C.echinata and heath
woodrush Luzula multiflora are notable in frequency but it is
a sparse flora in general and one that can only diversify with
the growth of the new forest.
The river channel itself is partly gorge with sheets of rock on
the sides and in the bed of the river. In other places it is more
open and filled with boulders and rocks of different sizes. Oak
trees cling to the side slopes with greater woodrush Luzula sylvatica
beneath them while relatively old ash grow at the base. Hazel
Corylus avellana, holly Ilex aquifolium, rowan Sorbus aucuparia
and grey willow Salix cinerea are also found in small numbers
along with Rhododendron ponticum. Sandy and even muddy ground
occurs locally and supports additional species, such as
Oxalis acetosella wood sorrel
Cardamine flexuosa wavy bittercress
Stellaria uliginosa bog stitchwort
Lysimachia nemorum yellow pimpernel
Anemone nemorosa wood anemone
Veronica chamaedrys germander speedwell
Geranium robertianum herb robert
Viola riviniana violet
Chrysosplenium oppositifolium golden saxifrage
Stellaria holostea greater stitchwort
Juncus conglomeratus compact rush
J.bulbosus bulbous rush
Angelica sylvestris wild angelica
Hookeria lucens a moss
Atrichum undulatum ,,
Plagiomnium undulatum ,,
Rhizomnium punctatum ,,
Thamnobryum alopecuroides ,,
There are also small patches of grassland by the river with creeping
bent Agrostis stolonifera and creeping buttercup Ranunculus repens.
Exposed rock and shallow peat promotes the growth of ferns and
mosses and buckler fern Dryopteris dilatata, hay-scented buckler
fern D.aemula, male fern D.affinis and hard fern Blechnum spicant
are constantly present. A considerable amount of filmy fern Hymenophyllum
tunbridgense grows on near-vertical surfaces in shade though it
is being inhibited by Rhododendron in places. Mosses and liverworts
are ubiquitous and the species include
Dicranum scoparium
D.majus
Plagiothecium undulatum
Hypnum cupressiforme
Polytrichum formosum
P.commune
Thuidium tamariscinum
Rhytidiadelphus loreus
R.triquetrus
Isothecium myosuroides
Isopterygium elegans
Hyocomium flagellare
Pseudoscleropodium purum
Sphagnum quinquefarium
Diplophyllum albicans
Saccogyna viticulosa
Lophocolea cuspidata
The liverwort Pellia epiphylla is conspicuous beside the river
while old records exist for Lophozia incisa, Lophozia ventricosa
and Marchantia polymorpha in 'Glengarra Wood' (N.Lockhart, pers.comm.).
3.2 Lower forest
The lower forest lacks the habitat diversity of the upper and
is confined to the eastern side of the river below Mountain Lodge.
Its surface is an even though steep slope with relatively few
oak Quercus petraea and Scot's pine and also some spruce and Douglas
fir still in the lower part. Hairy birch Betula pubescens and
alder Alnus glutinosa grow by the main river with some oak. Here
on stable ground there is fraochan Vaccinium myrtillus, greater
woodrush Luzula sylvatica, ling heather Calluna vulgaris, hay-scented
buckler fern Dryopteris aemula, common buckler fern D.dilatata
and hard fern Blechnum spicant with the moss Racomitrium lanuginosum
in places. At the base of the site distant sedge Carex remota,
smooth-stalked sedge C.laevigata, yellow pimpernel Lysimachia
nemorum and bittercress Cardamine flexuosa grow on soft river-borne
sediment.
Silver birch Betula pendula is a feature of the rest of the site
and there is a scatter of trees in the southern part and also
in a stream valley which descends the slope obliquely. Here they
grow with Scot's pine Pinus sylvestris, ash Fraxinus excelsior
and grey willow Salix cinerea with single trees of sweet chestnut
Castanea sativa, wych elm Ulmus glabra, rowan Sorbus aucuparia
and sycamore Acer pseudoplatanus. Rhododendron and laurel Prunus
laurocerasus have invaded here so that the underlying flora is
reduced. Fraochan Vaccinium myrtillus, moorgrass Molinia caerulea,
tormentil Potentilla erecta, soft rush Juncus effusus, greater
woodrush Luzula sylvatica, hard fern Blechnum spicant and lady
fern Athyrium filix-femina still occur however.
In the open foxglove Digitalis purpurea, bramble Rubus fruticosus,
soft rush Juncus effusus, bulbous rush J.bulbosus, common bent
Agrostis capillaris form the major part of the vegetation though
there is still some open ground present. There are odd plants
too of heath woodrush Luzula multiflora, wood sorrel Oxalis acetosella,
male fern Dryopteris affinis and red fescue Festuca rubra with
the mosses Polytrichum juniperinum, Dicranum scoparium, Campylopus
introflexus and Thuidium tamariscinum - the latter on stable ground
beside the tree stumps.
The upper path along the eastern side of the plot has a distinct,
grassy vegetation because of better drainage and fertility. Yorkshire
fog Holcus lanatus, red fescue Festuca rubra, sweet vernal grass
Anthoxanthum odoratum and common bent Agrostis capillaris grow
with
Galium saxatile heath bedstraw
Senecio jacobaea ragwort
Cerastium fontanum mouse-ear
Viola riviniana common violet
Potentilla erecta tormentil
Taraxacum officinale dandelion
Epilobium brunnescens New Zealand willowherb
4. FAUNA
The fauna of the actual cleared patches is small as there is insufficient
cover for most species of mammal or bird. However there was evidence
of hare in one place and clear signs of deer along the upper valley.
Pygmy shrew was heard in an adjacent area and the habitat is suitable
also for fox, red squirrel and pine marten. Bat species would
be most common in the lower part of the valley where the large
conifers and other trees occur and would seldom penetrate to these
plots, at least at present.
The only birds seen on site were meadow pipit, wren and grey wagtail
though willow warbler and goldcrest would be expected in summer,
together with dipper. The isolated trees left standing also could
provide suitable nest sites for hooded crow and kestrel. Treecreeper,
chiffchaff, blackcap, spotted flycatcher, great tit, coal tit,
long-tailed tit, mistle thrush, jay and long-eared owl occur in
the lower valley and may be expected to visit these sites at times.
As the new planting develops these species are likely to make
some use of the areas as feeding habitat.
Only migrant butterflies were seen in the site - tortoiseshell
and red admiral - and it unlikely to be important for any species
at present. In view of the removal of trees the invertebrate fauna
would still be adapting to the change. Holly blue and purple hairstreak
butterflies may occur lower down the valley as they are in the
general area.
5. EVALUATION
The greater part of the two plots in Glengarra Wood have little
inherent interest being the typical product of recent felling
of conifers in a mountain area. They occur at the transition point
between woodland and heath (or common Ulex europaeus to autumn
gorse U.gallii) so have a relatively limited flora of mixed affinities.
Recent felling has compounded this picture and encouraged the
spread of a few species that respond to disturbance.
However the river valley in the upper site is rich in species
despite some influence of Rhododendron. It contains abundant filmy
fern Hymenophyllum (which is already known from the Galtees but
is rare in the County) and a seemingly good selection of bryophytes.
There are fragments of a mountain oakwood community with plants
such as greater woodrush Luzula sylvatica, hard fern Blechnum
spicant, the mosses Plagiothecium undulatum and Sphagnum quinquefarium
with the possibility of some interesting lichens.
The lower site is chiefly remarkable for the prevalence of silver
birch Betula pendula but this is likely to have had an artificial
source. It is generally considered native only on lakeshores in
the west and on eskers or around raised bogs in central Ireland.
No features of the fauna stand out though the presence of deer
will be a major factor in establishing new broadleaves.
6. COMMENTS ON FUTURE MANAGEMENT
The natural woodland in this location is likely to be oak above
holly and hazel with ash and elm Ulmus glabra along the rivers
and rowan and birch sprinkled throughout. The ground layer would
contain much fraochan Vaccinium myrtillus and woodrush Luzula
sylvatica with ling heather Calluna vulgaris, bracken Pteridium
aquilinum and several other ferns. The planting of oak should
be seen as the first step to creating a new ecology open to further
colonisation and diversification.
The abundance of Rhododendron and laurel is an ongoing and obvious
threat to the future of the new stands which will require management.
Spraying the canopy has detrimental effects on the existing flora,
especially in the upper valley where there is more diversity than
elsewhere, and should be discontinued. Further clearance should
be done by cutting individual bushes and spraying the regrowth.
Any steps to control and eliminate these shrubs elsewhere in the
valley should be encouraged as this will reduce the risk to the
Millennium plots. Control by volunteers in the summer such as
occurs in Killarney should be considered.
The other introduced species, particularly sycamore, should be
removed in the same way.
Because of the fencing, grazing will be excluded from the plots
and this will tend to favour the spread of brambles. Natural regeneration
of holly, birch and willow should be encouraged to curtail this
by cutting down light penetration. Grazing animals should be reintroduced
as soon as possible in limited numbers as they are a part of a
natural ecology and increase habitat diversity.
Pedestrian access should not be encouraged along the river channel
in the upper plot to avoid physical damage to the sheets of Hymenophyllum
and mosses in these steep surroundings. Bridges and viewing places
would be more suitable than a linear path.
APPENDIX
List of plant species recorded in 2000
Acer pseudoplatanus
Agrostis capillaris
Agrostis stolonifera
Alnus glutinosa
Anemone nemorosa
Angelica sylvestris
Anthoxanthum odoratum
Athyrium filix-femina
Betula pendula
Betula pubescens
Blechnum spicant
Calluna vulgaris
Cardamine flexuosa
Carex binervis
Carex echinata
Carex laevigata
Carex remota
Castanea sativa
Cerastium fontanum
Chrysosplenium oppositifolium
Corylus avellana
Digitalis purpurea
Dryopteris aemula
Dryopteris affinis
Dryopteris dilatata
Epilobium brunnescens
Erica cinerea
Festuca ovina
Festuca rubra
Fraxinus excelsior
Galium saxatile
Geranium robertianum
Holcus lanatus
Hymenophyllum tunbridgense
Hypericum pulchrum
Ilex aquifolium
Juncus bulbosus
Juncus conglomeratus
Juncus effusus
Juncus squarrosus
Luzula multiflora
Luzula sylvatica
Lysimachia nemorum
Molinia caerulea
Oxalis acetosella
Pinus sylvestris
Polygala serpyllifolia
Potentilla erecta
Prunus laurocerasus
Pteridium aquilinum
Quercus petraea
Ranunculus repens.
Rhododendron ponticum
Rubus fruticosus
Rumex acetosella
Salix cinerea
Senecio jacobaea
Sorbus aucuparia
Stellaria holostea
Stellaria uliginosa
Taraxacum officinale
Ulex gallii
Ulmus glabra
Vaccinium myrtillus
Veronica chamaedrys
Viola riviniana
BRYOPHYTES
Atrichum
undulatum
Campylopus flexuosus
Campylopus introflexus
Campylopus introflexus
Dicranum majus
Dicranum scoparium
Dicranum scoparium
Dicranum scoparium
Diplophyllum albicans
Hookeria lucens
Hyocomium flagellare
Hypnum cupressiforme
Isopterygium elegans
Isothecium myosuroides
Lophocolea cuspidata
Marchantia polymorpha
Pellia epiphylla
Plagiomnium undulatum
Plagiothecium undulatum
Polytrichum commune
Polytrichum formosum
Polytrichum juniperinum
Pseudoscleropodium purum
Racomitrium lanuginosum
Rhizomnium punctatum
Rhytidiadelphus loreus
Rhytidiadelphus triquetrus
Saccogyna viticulosa
Sphagnum quinquefarium
Thamnobryum alopecuroides
Thuidium tamariscinum
Ecological Survey of
Glengarra Wood, Co. Tipperary
Site of a Millennium Forest
Report for Coillte Ltd
October 2000
Roger Goodwillie & Associates
Lavistown House
Kilkenny
*Please note that it was not possible to reproduce figures for inclusion on the website version of the reports.