Plantation

West Galmorgan has a large amount of plantation forest mostly composed of conifers. The largest concentration is in Neath Port Talbot where half of the wooded area is plantation, comprising 20% of the total land area. The most common species planted in these forest is Sitka Spruce (Picea sitchensis), a native of the cool humid coastal forests of the Pacific Northwest in North America, which grows rapidly in the cool temperate climate of south Wales. Until recently Japanese Larch (Larix kaempferi or its hybrid, Larix x marschlinsii) was also a major component of these plantations but the devastating spread of Ramorum Disease in Larch, caused by the Oomyce (Phytophthora ramorum), led to the felling and removal of all plantation larch in the region. Norway Spruce (Picea abies), Pines, particularly Scots Pine (Pinus sylvestris ssp. sylvestris) and Lodgepole Pine (Pinus contorta) have also been planted widley. Other species include Corsican Pine (Pinus nigra ssp. laricio), Macedonian Pine (Pinus peuce), Douglas Fir (Pseudotsuga menziesii), Western Hemlock (Tsuga heterophylla), Western Red-cedar (Thuja plicata), Lawson's Cypress (Cupressus lawsoniana), Giant Fir (Abies grandis), Noble Fir (Abies procera), and Japanese Red-cedar (Cryptomeria japonica). European Silver Fir (Abies alba) and Coast Redwood (Sequoia sempervirens) are also there but rarely in large groups.

Conifer plantations are made up of forested areas where the trees are grown and non-forested (open) areas, such as roads, tracks, verges, ponds and quarries. Willow scrub, which develops along forest roads at the edges of coupes, is also an important habitat in this category. Several factors contribute to the ecological character of plantations. Among them are (1) they are intensively managed (2) they are enclosed and largely free of grazing by domestic animals but are grazed by wild animals such as deer and to a lesser extent rabbits (3) they occupy large, contiguous areas of upland landscape and (4) large plantations develop an ameliorated mesoclimate which can suitable for oceanic (and hyperoceanic) bryophytes and lichens. 

Forest Areas

Forest areas in plantations are divided into compartments called coupes which are managed in a rotating growth cycle. Trees are planted and grown as a monoculture for 30 to 60 years, then clear-felled for harvest after which the coupe is replanted for another cycle. During the cycle, young trees grow quickly to form an almost inpenetrable thicket and then thinned in order to give the crop enough space for the strong growth of straight trunks. Very little light reaches the ground under a thicket of conifers, except at the edges, so vascular plants and bryophytes are largely absent. However, the macroscopic fruiting bodoes of basidiomycete of saprophytic and ectomycorrhizal fungi may be frequent. After thinning and as the crop matures, the canopy is lifted away from the ground and more light penetrates the forest, particularly at the edges. 

The ground flora in mature Sitka Spruce coupes can be rather sparse, particularly in the drier sites, It is composed of the most shade-tolerant species, but species diversity is usually low, The species most commonly represented are Broad Buckler-fern (Dryopteris dilatata), Ivy (Hedera helix) and Wood Sorrel (Oxalis acetosella). Bryophytes such as Diplophyllum albicans, Campylopus flexuosus and Pseudotaxiphyllum elegans, which is paeticularly shade-tolerant, are often prominent. However, where trees have been planted on wetter, peat-rich ground, a diverse bryophyte flora can develop that is reminiscent of temperate rainforest. The lower branches of trees become draped in Hypnum andoi and Isothecium myosuroides and the ground is covered by species normally associated with upland sessile-oak woodland typically with large amounts of  Plagiothecium undulatum and Rhytidiadelphus loreus but also scattered populations of Dicranum majus, Hypnum jutlandicum, Mnium hornum, Polytrichum formosum, Thuidium tamariscinum, and Sphagnum palustre and occasionally Leucobryum juniperoideum.

Sitka Spruce coupes of all ages can have a divese macroscopic basidiomycete flora, with over 250 species found in British forests and more than 150 recorded in the forests of West Glamorgan. Common species such as Russula ochroleuca, Laccaria laccata and Amanita rubescens are well represented, but there is also a more specific assemblage which consists of species such as Calocera viscosa, Calocera pallidospathulata, Clitocybe vibecina, Cortinarius mucifluus, Cortinarius obtusus, Cortinarius stillatitius, Cystoderma jasonis, Entoloma cetratum, Hypholoma marginatum, Inocybe calimistrata, Inocybe napipes, Lactarius deterrimus, Lactarius rufus, Mycena cinerella, Mycena epipterygia, Mycena metata, Mycena leucocephala, Ripartites tricholoma, Russula emetica, Russula fuscorubroides and Tricholoma pessundatum. 

Decaying logs are common in mature Sitka Spruce forests and they usually support a rich assemblage of bryophytes. Cepahalozia curvifolia is usually abundant along with other species such as Lophocolea heterophylla and Tetraphis pellucida and occasionally scarcer species such as Riccardia latifrons, Riccardia palmata and Schistochilopsis incisa. Sematophyllum substrumulosum has also been recorded on logs in recent years and may expanding its western range in Sitka Spruce forests West Glamorgan.

Pine is not a very important commercial crop in Wales any more. Large amounts of Scots Pine have been planted but lots of coupes have failed as a result of insect attack and disease. However, many have survived and grown into mature stands. Unlike Sitka Spruce forests, a dense undergrowth usually develops under Scots Pine often giving rise to interesting recombinant communities. Bilberry (Vaccinium myrtillus) and Heather (Calluna vulgaris) often form a significant dwarf shrub layer and nature stands inevitably develop an understory composed of Sessile-oak (Quercus petraea), Birch (Betula spp.), willows (Salix spp.), Rowan (Sorbus aucuparia) and Holly (Ilex aquifolium), giving the appearance of an upland sessile-oak woodland growing under a canopy of pine. Lodgepole Pine has been planted widely on higher, peaty ground but has either failed as a crop or produced unsuitable trees. In some areas large amounts of Lodgepole Pine has been removed, along with other Pine species.

Pine forests often have diverse assemblages of mycorrhizal basidiomycetes such Lactarius deliciosus, Russula sanguinea, Russula sardonia, Russula xerampelina, Suillus bovinus, Suillus granulatus, and Suillus luteus and saprophytes such as Baeospora myosura on female cones and Mycena vulgaris on needle litter.

Japanese Larch (or its hybrid) was widely cultivated in extensive coupes in West Glamorgan before the spread of ramorum disease. Larch is deciduous and larch coupes allow the penetration of more light than spruce, fir and hemlock stands. This allows them to support a diverse vernal flora with species like Bluebell (Hyacinthoides non-scripta) as well as providing breeding habitat for birds like wood warbler. In that way they can function almost like a surrogate oak woodland. Like pine, larch has a suite of mycorrhrizal fungi associated with which includes Gomphidius maculatus, Suillus grevillei, Suillus viscidus and Tricholoma psammopus.

Removal of larch has resulted in the creation of large areas of clearfell, many of which are undergoing rapid succession and after ten years they often support diverse, recombinant communities composed of birch and willow scrub mixed with Sessile-oak, Sycamore and regenerating conifer species, including larch, Sitka Spruce, Western Hemlock and Lodgepole Pine.

Non-forest Areas

Non-forest areas contribute the major proportion of biodiversity in plantations. Much of it occurs along the edges of the coupes and as such is largely defined by the structure and extent of forest roads and tracks. These areas include willow scrub that develops along roads, roadside verges, ditches, streams, ponds and quarries. Remnants of the pre-plantation landscape such as patches of semi-natural oak woodland, dwarf shrub heath and moorland are also part of the non-forest component. 

Willows that grow along the edges of coupes support lots of bryophytes and lichens. In the more humid areas there can be very diverse, epiphytic assemblages of mosses and liverworts such as  Colura calyptrifolia, Lejeunea patens, Metzgeria consanguinea, Metzgeria violacea, Radula complanata, Cryphaea heteromalla, Daltonia splachnoides, Hypnum andoi, Isothecium myosuroides, Orthotrichum pulchellum and Zygodon conoideus. The lichen flora is no less significant with lots of common foliose species such as Parmotrema perlata, often an abundance of Peltigera membranacea plus small squamules of Normandina pulchella and tiny bright orange apothecia of Dimerella lutea growing among the pleurocarpous mosses. The recent discoveries of some Atlantic lichens here, such as Pannaria rubiginosa, Scytinium subtile, Sticta limbata and Sticta rubiginosa (s.l.) is notable.