Howford Bridge

Site of Special Scientific Interest · 55.4984, -4.3548

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Also within

Ayrshire and Arran County

Condition (NatureScot)

Favourable (1)
UnitFeatureConditionArea (ha)Assessed
F1 Carboniferous - Permian Igneous Favourable — 2016-03-29

Habitats

Fast flowing river and stream

Geology & landscape

Geological Period: Carboniferous, Permian

Landscape processes: Volcanic / Igneous

Description

HOWFORD BRIDGE Howford Bridge, lying less than 1km from Catrine, adjacent to the River Ayr, contains rocks formed during the early Permian geological period (approximately 295 million years ago). The chemical composition of the Carboniferous-Permian igneous rocks of Scotland has been interpreted as showing complex, but systematic variations with time; this interpretation has far-reaching implications for determining the genesis of the volcanic activity. The youngest members of the assemblage, whose age can be demonstrated without question, are a sequence of lava flows found in the Mauchline Basin; they are unique not only in the timing of their eruption but also in their petrological character and thus provide irreplaceable evidence to any overall study of the volcanic activity. The rocks are well-seen at Howford Bridge.

Plant communities

A9 — Fast flowing river and stream, Marginal and inundation, Pond ditch and canal, Sluggish river and stream

Potamogeton natans community

Schoenoplectus lacustris, Juncus bulbosus, Sparganium angustifolium, Sparganium erectum, Sparganium minimum, Alisma plantago-aquatica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Elodea canadensis, Lemna minor, Lemna trisulca, Nymphaea alba, Callitriche platycarpa, Callitriche stagnalis, Littorella uniflora, Potamogeton natans, Ranunculus trichophyllus, Glyceria fluitans, Chara subspinosa

A14 — Fast flowing river and stream

Myriophyllum alterniflorum community

Isolepis fluitans, Juncus bulbosus, Fontinalis antipyretica, Lobelia dortmanna, Equisetum fluviatile, Myriophyllum alterniflorum, Lemna minor, Callitriche stagnalis, Littorella uniflora, Potamogeton filiformis, Potamogeton gramineus, Potamogeton natans, Ranunculus peltatus, Chara spp., Nitella hyalina

A17 — Chalk river and stream, Fast flowing river and stream

Ranunculus penicillatus ssp. pseudofluitans community

Berula erecta, Nasturtium officinale, Elodea canadensis, Lemna minor, Callitriche stagnalis, Veronica beccabunga, Polygonum amphibium, Polygonum hydropiper, Potamogeton crispus, Potamogeton pectinatus, Ranunculus penicillatus ssp. pseudofluitans

A18 — Fast flowing river and stream

Ranunculus fluitans community

Fontinalis antipyretica, Fontinalis squamosa var. curnowii, Myriophyllum alterniflorum, Myriophyllum spicatum, Elodea canadensis, Mentha aquatica, Lemna gibba, Lemna minor, Potamogeton perfoliatus, Ranunculus fluitans, Glyceria fluitans, Phalaris arundinacea