Geography in Dublin
Botany | Geology | Zoology |
Dublin and its Vicinity
The city and suburbs of Dublin (Self Catering, Dublin, Ireland) are interesting as being the headquarters of two rare plants-Sisymbrium Irio, unknown elsewhere in Ireland, and Mercurialis anmia, which, though frequently occurring about other towns in the southern half of the country, is much more abundant here than elsewhere. Neither of these plants is indigenous in Ireland.
The two canals which enter Dublin (Hotels, Dublin, Ireland) from the west have been the means of bringing within the city a number of plants of the Central Plain. The harbour is the home of a sedge and a grass both very local in Ireland-Carex divisa and Glyceria Borreri. A few miles to the northward the Kamtschatkan Artemisia 
Stelleriana, has established itself on sand-dunes. The banks of the River Liffey for some miles above the city are the only Irish home of Scrophularia umbrosa. The Ragwort Senecio erucifolius, which everywhere haunts the environs, is in this country scarcely found beyond the limits of the county of Dublin. It will be observed that these characteristic Dublin plants have widely separated homes, and that many of them are introductions.
Dublin is, indeed, the focus of the alien flora of Ireland. This is no doubt mainly the result of climate and soil, which conform more nearly than other parts of Ireland to those of more southern regions, to which the bulk of the introduced flora belongs. But it is, also, no doubt in part the result of early settlement and of many centuries of trade and intercourse.
Howth and Lambay.
The promontory of Howth and the island of Lambay, both situated in the county of Dublin (Accommodation, Dublin, Ireland), form two conspicuous projections on the coast of Leinster. Both are comparatively high (400- 600 ft.) and rocky, Howth being formed of Cambrian rocks, and Lambay mostly of volcanic material and the heathery uplands which both of them present, contrast strongly with the low drift-covered, highly tilled plain of the adjoining mainland. Howth has a flora which for Ireland is remarkably large-about 510 species of Phanerogams on an area of 2670 acres. This area includes the Cambrian headland, the limestones on their north-eastern side, and the low neck of gravel (raised beach), which joins them to the mainland. A number of the rarer Leinster plants are found here: Sisymbrium Irio Senecio viscosus Raphanus maritimus S. erucifolius Viola hirta Artemisia maritima Lavatera arborea Salvia Verbenaca Trifolium scabruni Atriplex portulacoides Trigonella ornithopodioides Zostera nana Ornithopus perpusillus Festuca uniglumis. The most interesting flora is that which is developed along the, steep sea-banks of the cast and south shores. Here, although the rocks are non-calcareous, lime, is present in the shelly limestone gravel-drift that is plastered against the face of the 
slopes. Here are quantities of Spergnlaria rupestris Inula crithmoides Geranium sanguincmn Carlina vnlgaris Erodium maritimnm Statice oecidentalis Crithmum maritimum Beta maritima Kubia peregrina Scilla verna. On the similar sea-slopes of Lambay we again meet with, in abundance, most of the plants of this list; the other leading characters of the Howth flora are. repeated, but with an absence of most of the rarest of the Howth plants. In compensation for this, we find in Lambay some plants locally rare, such as Geranium pusillum, Agrimonia, odorata, and Juncus obtusiflurus
The occurrence of marine shells in the Glacial deposits of Co. Wicklow was for a long time naturally regarded as evidence of submergence beneath the sea. The striations, however, that are found on the rock-floor show that ice sheets traversed the whole country, and the uplift of materials from lower to higher layers of moving ice may now be regarded as well established. Much of our knowledge of tin-history of East Leinster in Glacial times is due to the pioneer-observer Maxwell H. Close, whose work in the Dublin district has been completed by G. W. Lamplugh. The latter geologist also showed how such immature ravines as the Scalp south of Dublin, which is cut across a granite spur, and the Glen of the Downs in Co. Wicklow already recognised by Close as post-glacial are due to torrential waters set free by the melting of the ice-fronts. The gravels accumulated in subglacial channels form grass-covered mounds and ridges (eskers) in the Lucan and Tallaght area of the plain, and the Norman Tymon Castle stands on a small typical esker near Babrothery. Evidence from Europe shows that a dry age followed the final melting of the glaciers. Then came the milder years when bogs gathered in the plain, and- even across the crests of The Leinster Chain, from which they are now being washed or blown away. The tree-stems found in the mountain bogs indicate at least one forest epoch, when the slopes were clad with conifers to heights of 1800 ft. or more.
The floor of the Irish Sea, when freed from ice, very probably rose for a time as land, and channels may have been carved out in it by denudation of the glacial drifts. Peat and forests spread outward from the present coastline. A submergence allowed blue, marine muds to accumulate over these terrestrial beds, and a final elevation brought the drowned peat again near to the tidemarks. The coast between Bray and Killiney records these changes, and a raised beach connects Howth with the mainland, and is traceable under the east of Dublin city. The falls of the Liffey at Leixlip may be ascribed to this last uplift the river, like so many in East Leinster, has since sought its former channel through a deep covering of drift. The general drift-platform, indeed, raised the surface over which the rivers ran, and the return of the sea to about its pre-Glacial level has allowed them to cut ravines in the boulder-clays and gravels. The steep banks of the Liffey below Lucan or the Dodder at Tallaght and Kathfarnham afford fine examples of excavation. A pre-glacial northerly course has been indicated for the Liffey and for its important tributary, the Kings River, under the Slievethoul range, and down the Slade of Saggart into the plain. The rockravine at the Pollaphuca waterfall is clearly post-glacial, and the drift tilled hollow above the barrier traversed by it has been ascribed to glacial scour.
Liffy River
Foxes (Cams vulpcs), Otters {Ultra vulgaris), Badgers (Melcs taxus), and Martens (Mustelo. martes), are found in various parts of the area, the order of frequency being roughly at in which they are quoted.
As elsewhere in Ireland, the Irish Stoat (Putorius Jnbernicus) is frequent, as also the Alpine Hare (Lepus variabilis}. The Squirrel (Sciurus vulgaris), believed to have been introduced into Ireland in Wicklow about 1820, is now widespread in Leinster.
A point of much interest in connection with the marine fauna is that the Great Grey 
Seal (Halichaerus grypus) breeds within a few miles of Dublin (Bed and Breakfasts, Dublin, Ireland) , the only breeding-place known for this large animal in the British Isles which is not situated on the open Atlantic. Except for a great scarcity of lakes and of lowland bogs, eastern Leinster offers a wide range of habitat for bird life. Woods and streams are present in sufficient variety. The long sandy coast-line, broken by marshy inlets, offers a home for shore-breeding species. The rocky island of Lambay, now carefully preserved, is a sanctuary for cliff-breeding birds, and further south, the Great Saltee supports vast colonies of many species ; and the Wicklow mountains provide a wide area of bog and rock for the moorland breeders.
The shingle beaches of the Leinster sea-board are tenanted by Ringed Plover, Oyster- catchers, three species of Tern, and protection has largely increased some of the colonies. The cliff ledges, slopes, and banks of the Great Saltee in Wexford, are the home of innumerable Herring-Gulls, Lams Kittiwakes, Guillemots, Razorbills, Puffins, Cormorants, and Shags, also in smaller quantity Lesser Black-backed Gulls, Great Black-backed Gulls, Manx Shearwaters, Rock-Doves, and other species. All of these also breed on Lambay on the Dublin coast.
Dublin (Holiday Apartments, Dublin, Ireland) has long been a centre of ornithological study, and as a result, a large number of rare stragglers have been recorded from its vicinity and the surrounding counties. Among them are the only Irish specimens of the following:–Dartford Warbler, (Tuskar Rock) : Reed-Warbler, (Tuskar Rock and Rockabill) ; Icterine Warbler, (near Dublin) ; Woodchat Shrike, (Blackwater Bank lightship) ; Pallass Grasshopper-Warbler, (Rock- abill) ; Richards Pipit, (Dublin and Lucan) ; Tree-Pipit, (Tuskar Rock and Rockabill) ; Water-Pipit, (Rockabill) ; Little Bunting, (Rockabill) ; Shore- Lark, (Wicklow Head); Serin, (near Dublin) ; Red-footed Falcon, (Co. Wicklow) ; Lesser Kestrel, (Co. Dublin) ; Sociable Plover, (Navan, Co. Meath) ; Kentish Plover, (Dublin coast, several) ; Whiskered Tern (Dublin).
Attention may be drawn to the increase in this as in other Irish districts of certain species, and to the decrease of others. The increasing species, all of which breed in the district, include the Mistle Thrush, (unknown in Ireland before the nineteenth century, now common) ; Blackcap, Starling, (has greatly extended its breeding range, and immigrates in vast numbers in winter) ; Magpie, (which first reached Ireland in the seventeenth century); Jackdaw, Jay, (now abundant in Wexford) ; Stock-Dove, (first recorded from Ireland in 1875, now widespread); Woodcock, (now breeds throughout Ireland).