Following its origins in acid rain research, Llyn Brianne continues to make seminal contributions about factors affecting ecological recovery from this major ecological stressor.

R. A. Kowalik, D.M. Cooper, C. M. Evans & S. J. Ormerod (2007) Acid episodes retard the biological recovery of upland British streams from acidification. Global Change Biology. 13, 2439–2452.

Z. Masters, I Peteresen, A. G. Hildrew & S. J. Ormerod ( 2007) Insect dispersal does not limit the biological recovery of streams from acidification.  Aquatic Conservation: Marine and Freshwater Ecosystems, 17, 375-383

S J Ormerod & I Durance (2009) Restoration and recovery from acidification in upland Welsh streams over 25 years.  Journal of Applied Ecology, 46, 164-174

Acidification - helicopter2

Climate change

Some of the World’s first data on the effects on stream ecosystems of large-scale climate change and variation originated from Llyn Brianne.  Changes in stability, the composition of stream communities and local extinctions have all tracked warming effects.

D. C. Bradley, S. J. Ormerod (2001).  Community persistence among upland stream invertebrates tracks the North Atlantic Oscillation. Journal of Animal Ecology, 70, 987-996

I. Durance, S.  J. Ormerod (2007) Climate change effects on upland stream invertebrates over a 25 year period.  Global Change Biology, 13, 942-957

I. Durance, S. J. Ormerod (2010).  Evidence for the role of climate in the local extinction of a cool-water triclad.  Journal of the North American Benthological Society, 29, 1367-1378

Climate change - insect2

Land use

Land use at Llyn Brianne varies from rough grazing to conifer and deciduous woodland, while experiments have manipulated land-use at whole catchment scales.  In each case, consequences for stream organisms and ecosystems have been evaluated.

I. Petersen, Z.  Masters, A. G.  Hildrew, S. J. Ormerod (2004).  Dispersal of adult aquatic insects in catchments of differing land use.  Journal of Applied Ecology, 41, 934-950

D. C. Bradley & S. J. Ormerod (2002).  Long-term effects of catchment liming on invertebrates in upland streams.  Freshwater Biology, 47, 161-171

N. S. Weatherley, S. J. Ormerod (1990).  Forests and the temperature of upland streams:   a  modelling study of the biological consequences.   Freshwater Biology, 24, 109-122.

Climate change - broadleaf river2

Ecosystem services

Research into ecosystem services at Llyn Brianne follows major leadership provided by the National Ecosystem Assessment in which we were closely involved.  The NERC-funded DURESS project is now developing this theme further by investigating the role of stream biodiversity in the regulation of water quality  and in sustaining fish, river birds.

Maltby, E. & Ormerod, S.J. (2011) Freshwaters – Openwaters, Wetlands and Floodplains. In: The UK National Ecosystem Assessment Technical Report, pp. 285 295-360. UNEP-WCMC, Cambridge.

Ecosystem services - cut conifer2Ecosystem services 2


A wide range of organism groups have figured in research at Llyn Brianne from algae and bryophytes to invertebrates, fish and birds.  Methods range from conventional taxonomy to molecular  biology

H. C. Williams, S. J. Ormerod and M. W. Bruford (2006). Molecular Systematics and Phylogeography of the Cryptic Species Complex Baetis rhodani (Ephemeroptera, Baetidae).  Molecular Phylogenetics and Evolution, 40, 370-382,

S.  T. Buckton, P. A. Brewin, A. Lewis, P. Stevens & S. J. Ormerod (1998). The distribution of dippers Cinclus cinclus in the acid senstive region of upland Wales, 1984-1995.Freshwater Biology, 39, 387-396    

H. Hirst, I. Jüttner & S. J. Ormerod (2002)  Comparing the responses of diatoms and macroinvertebrates to metals in upland streams of Wales and Cornwall.  Freshwater Biology, 47, 1752-1765

biodiversity - dipper and bullhead2


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