Table 1. Examples of North Atlantic Oscillation (NAO)-ecology relationships categorised by type of effect. Asterisks indicate studies invoking the NAO in their mechanisms. Although we have tried to include as many papers of this category as possible, the list should not be regarded as complete. Other cited works describe mechanisms which we suggest to be influenced by the NAO

Ecological descriptor Type of effect Parameter related to the NAO Suggested mechanism Reference
UK and US birds Direct Timing of egg laying Alteration of physiological rates (temperature effect) Crick et al. (1997); *Forchhammer et al. (1998a); McCleery and Perrins (1998); Crick and Sparks (1999); *Forchhammer and Post (2000); Sćther et al. (2000); *Wuethrich (2000)
UK amphibians Direct Timing of spawning Alteration of physiological rates (temperature effect) Beebee (1995); *Forchhammer et al. (1998a); *Forchhammer and Post (2000)
Terrestrial plants Direct Timing of blooming/length of production season Alteration of physiological rates (temperature, precipitation) Myneni et al. (1997); Menzel and Fabian (1999); *Post and Stenseth (1999)
African terrestrial plants Direct Vegetation productivity Alteration of physiological rates (precipitation) *G. Oba et al. (2001)
Zooplankton (Daphnia), central Europe Direct Abundance Alteration of physiological rates (temperature) *Straile and Geller (1998); *Straile (2000); Straile and Adrian (2000)
Barents Sea cod and haddock Direct Growth rate in early stages Alteration of physiological rates in larval and juvenile stages Loeng et al. (1995); Ottersen and Loeng (2000)
Sea trout fry, Lake District, UK Direct Date of fry emergence Unknown but linked to temperature *Elliott et al. (2000)
Barents Sea cod and haddock Direct/indirect Recruitment levels Regulates inflow of Atlantic water to the Barents Sea, influencing temperature and food availability for the larval and juvenile stages Ottersen et al. (1994); Ottersen and Sundby (1995); Ottersen (1996)
UK wheat Direct/indirect Quality Delayed effect through rainfall during August (?) *Kettlewell et al. (1999)
North Sea cod and plaice Direct/indirect Recruitment levels Unknown but linked to climate and temperature. Possibly modification of the timing of spawning, and alteration of the bioenergetic balance between metabolic requirements and food availability Svendsen et al. (1995); *Dippner (1998a, 1998b); Planque and Frédou (1999); C.J. Fox, B. Planque, C.D. Darby, unpublished data
Marine polychaetes Direct?/indirect Abundance Effect of winter temperature on a predatory polychaete followed by changes in predation rates on two prey polychaete species Beukema et al. (2000)
North Sea zooplankton: Calanus species Indirect Abundance Modification of the competition balance through alteration of phytoplankton production and change in sea surface temperature *Fromentin and Planque (1996)
North Sea zooplankton: Calanus finmarchicus Indirect Abundance Alteration of the circulation and transport of individuals to the North Sea Backhaus et al. (1994); *Planque and Taylor (1998); Stephens et al. (1998); Heath et al. (1999)
European flycatchers (birds) Indirect Abundance Modification of the competition balance between pied and collared flycatchers *Sćtre et al. (1999)
UK tits (birds) Indirect Abundance Effect of early spring temperature on population density through juvenile survival rate, possibly related to migration and/or territorial behaviour Slagsvold (1975)
UK birds Indirect Spatial distribution Migration northward in response to migration of prey (butterflies) in response to temperature increase Thomas and Lennon (1999)
Netherlands birds Indirect Timing of egg laying Phenotypic selection on early-laying birds in response to earlier timing of food availability Visser et al. (1998)
Norwegian red deer Indirect Growth, breeding, density, and sex ratios Combination of alteration of physiological rates, changes in the timing and availability of food, delayed effects through density-dependent mechanisms, in utero growth, fecundity *Post et al. (1997, 1999a, 1999b, 1999c); *Forchhammer et al. (1998b); *Loison et al. (1999); *Post and Stenseth (1999); *Mysterud et al. (2000, in press)
Soay sheep (Scotland) Indirect Abundance Winter survival combined with density-dependent processes *Milner et al. (1999); *Post and Stenseth (1999)
Macrofaunal community Indirect Abundance Effect on surface primary production transferred to the bottom macrofaunal community (Tunberg) or unspecified effect of temperature (Kröncke) *Kröncke et al. (1998); *Tunberg and Nelson (1998)
European sardine and herring Indirect Abundance Changes in temperature and wind patterns causing regime shifts. Changes in the pattern of transport of herring in the North Sea *Alheit and Hagen (1997); *Corten (1999)
Salmon (rivers, coastal waters, open ocean) Indirect/integrated Salmon environment Various effects on rivers, coastal waters and thermal habitat in oceanic waters (again, little is known about the mechanisms) Friedland et al. (*1993, 1998); *Dickson and Turrell (1999); *Reid and Planque (1999)
Canadian lynx Indirect/ integrated Population phenology Uncertain; possibly alteration of trophic interactions *Stenseth et al. (1999)
Moose and white-tailed deer Indirect/ integrated Population dynamics Effect on winter survival and density-dependent processes *Post and Stenseth (1998)
Wolf predation and moose dynamics Indirect/cascading Winter pack size Increased pack size and deeper snow lead to higher kill rates and declines in moose density *Post et al. (1999c)
Southern Norway dipper (Cinclus cinclus) birds Indirect/integrated Population dynamics Population dynamics and carrying capacity respond to temperature Sćther et al. (2000)
Phytoplankton (fjord, lake, open ocean) Indirect/integrated Abundance and production Unknown (in Reid et al., the environmental factors which might be responsible are given but no clear mechanism is proposed); mechanism(s) under study *Reid et al. (1998a, 1998b); *Belgrano et al. (1999); *Weyhenmeyer et al. (1999)
Benthic foraminifera, Gullmar Fjord, Sweden Indirect/integrated Changes in faunal composition Effects of changes in oxygen concentrations; mechanism(s) not clear *Nordberg et al. (2000)
North Sea zooplankton: Calanus finmarchicus Integrated Abundance Reduction in the volume of Norwegian Sea Deep Water where C. finmarchicus overwinters *Heath et al. (1999)