On the relationship between farmland biodiversity and land-use intensity in Europe.
Worldwide agriculture is one of the main drivers of biodiversity decline. Effective conservation strategies depend on the type of relationship between biodiversity and land-use intensity, but to date the shape of this relationship is unknown. We linked plant species richness with nitrogen (N) input as an indicator of land-use intensity on 130 grasslands and 141 arable fields in six European countries. Using Poisson regression, we found that plant species richness was significantly negatively related to N input on both field types after the effects of confounding environmental factors had been accounted for. Subsequent analyses showed that exponentially declining relationships provided a better fit than linear or unimodal relationships and that this was largely the result of the response of rare species (relative cover less than 1%). Our results indicate that conservation benefits are disproportionally more costly on high-intensity than on low-intensity farmland. For example, reducing N inputs from 75 to 0 and 400 to 60kgha-1yr-1 resulted in about the same estimated species gain for arable plants. Conservation initiatives are most (cost-)effective if they are preferentially implemented in extensively farmed areas that still support high levels of biodiversity.
Kleijn
D
D
Alterra, Centre for Ecosystem Studies, Droevendaalsesteeg 3, Wageningen, The Netherlands. david.kleijn@wur.nl
Kohler
F
F
Báldi
A
A
Batáry
P
P
Concepción
E D
ED
Clough
Y
Y
Díaz
M
M
Gabriel
D
D
Holzschuh
A
A
Knop
E
E
Kovács
A
A
Marshall
E J P
EJ
Tscharntke
T
T
Verhulst
J
J
D000383:Agriculture; D000818:Animals; D044822:Biodiversity; D003247:Conservation of Natural Resources; D005060:Europe; D009584:Nitrogen
D009584:Nitrogen