niels martin schmidt impacts of wet grassland management and winter severity on wader breeding...
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![Page 1: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/1.jpg)
Niels Martin Schmidt
Impacts of wet grassland management and winter severity on wader breeding numbers in
Eastern Denmark
![Page 2: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/2.jpg)
Wader population development• Most wader populations are declining in Denmark,
and in Europe in general
From Jacobsen (2000)
Index of lapwing breeding in Denmark
0
10
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90
100
19
76
19
77
19
78
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79
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99
Bre
ed
ing
in
de
x
![Page 3: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/3.jpg)
Wader population conservation• Large efforts are being invested in reversing this
trend
=> mainly focused on wet grassland management
• Waders also respond strongly to winter severity
• Relative importance of grassland management and winter severity
![Page 4: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/4.jpg)
The Klydesø reserve• Area of national interest as wader breeding ground
Lapwing Redshank Avocet Ringed plover Oystercatcher
• Reclaimed from sea in 1945=> Situated below sea-level=> Large succesional changes=> Detoriation of costal meadow as wader
breeding ground
![Page 5: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/5.jpg)
Population development in the Klydesø reserve
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1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
Bre
edin
g p
airs
Lapwing Redshank Oystercatcher Avocet Ringed Plover
Grazing Winter flooding
![Page 6: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/6.jpg)
Management implements• Cattle grazing (app. one steer per ha, 38 - 270 ha)
• Winter flooding (app. 115 ha shallow water)
Expected effects = more breeding and foraging habitats
• Fox exclusion
Expected effect = less predation on nests
![Page 7: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/7.jpg)
Winter severity• Proxy of winter severity: NAO winter state
Expected effects of mild winters (high NAO)
• Improved survival when migrating and when on winter grounds
• Early onset of breeding in years following mild winters
• Changes in food availability on tidal flats
![Page 8: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/8.jpg)
Population models• Autoregressive analyses• Most parsimonoius model selected by AICc
Nt = Nt-1 Nt-2 GRAZING WINTER-FLOODING NAO
![Page 9: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/9.jpg)
Waders, management and climate
Nt-1 Nt-2 NAOt GRt-1 WFt R2
Lapwing ++ 0.80
Redshank ++ 0.62
Avocet -- ++ 0.82
Ringed plover - + 0.88
Oystercatcher + - 0.62
![Page 10: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/10.jpg)
Lapwings and winter severity
Nt-1 Nt-2 NAOt GRt-1 WFt R2
Lapwing
(Klydesø)++ 0.80
Lapwing (Tipperne)
++ 0.63
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Conclusions• Management implements did result in increased
(most) wader breeding pairs
• Multi-lateral conservation approach needed for ensure coastal meadow species diversity
• Winter severity may be more important when management effort is constant
![Page 12: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/12.jpg)
The Lapwing paradox
• High predation pressure on nests (c. 90%)=> too low production of young to maintain
population size
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1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
Bre
edin
g p
airs
• Where do the lapwings come from?
![Page 13: Niels Martin Schmidt Impacts of wet grassland management and winter severity on wader breeding numbers in Eastern Denmark](https://reader035.vdocument.in/reader035/viewer/2022062715/56649d795503460f94a5d6e3/html5/thumbnails/13.jpg)
The Lapwing paradox
• Underestimation of production of young?• Attract birds from other (declining) population?• Production of young in arable areas, e.g. cereals?