The ecology and conservation of Llyn Idwal and Llyn Cwellyn (Snowdonia National Park, North Wales, UK)—two lakes proposed as special areas of conservation in Europe
✍ Scribed by C.A. Duigan; T.E.H. Allott; D.T. Monteith; S.T. Patrick; J. Lancaster; J.M. Seda
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 477 KB
- Volume
- 8
- Category
- Article
- ISSN
- 1052-7613
No coin nor oath required. For personal study only.
✦ Synopsis
-
This paper gives a comprehensive account of the ecology of Llyn Idwal and Llyn Cwellyn, two nationally well known and internationally important conservation lakes in Snowdonia National Park, North Wales. Idwal has a small but precipitous catchment with relatively large areas of heathland and base rich bare rock. Cwellyn has a larger catchment with a substantial proportion of woodland, including coniferous plantations, and a long history of human activity.
-
The chemistry of the waters in both lakes is indicative of nutrient-poor conditions but Idwal exhibits relatively high alkalinity and pH values.
-
The diatom floras are typical of nutrient-poor upland waters, with species composition reflecting the alkalinity differences. Isoetids form a dominant component of the macrophyte floras, with the most diverse assemblage recorded at Idwal. 4. The zooplankton communities are distinctive, with only a small number of species occurring in both lakes. The macroinvertebrate faunas are dominated by insect taxa typical of stony shores. Supplementary stocking of the Idwal trout population has been reported.
-
The conservation importance of the sites lies primarily in their representation of nutrient-poor mountain lake systems and the macrophyte assemblages which include a number of rare species. In addition, a genetically unique arctic charr population is present in Cwellyn.
-
Impoundment, water abstraction, acidification, eutrophication and the recreational use of the sites are identified as potential environmental impacts. The conservation management of the sites is related to the extent of the reserve boundaries and catchment activities. Aspects of the future