title: Experimental evidence for the immediate impact of fertilization and irrigation upon the plant and invertebrate communities of mountain grasslands.
abstract: The response of montane and subalpine hay meadow plant and arthropod communities to the application of liquid manure and aerial irrigation - two novel, rapidly spreading management practices - remains poorly understood, which hampers the formulation of best practice management recommendations for both hay production and biodiversity preservation. In these nutrient-poor mountain grasslands, a moderate management regime could enhance overall conditions for biodiversity. This study experimentally assessed, at the site scale, among low-input montane and subalpine meadows, the short-term effects (1 year) of a moderate intensification (slurry fertilization: 26.7-53.3 kg N·ha(-1)·year(-1); irrigation with sprinklers: 20 mm·week(-1); singly or combined together) on plant species richness, vegetation structure, hay production, and arthropod abundance and biomass in the inner European Alps (Valais, SW Switzerland). Results show that (1) montane and subalpine hay meadow ecological communities respond very rapidly to an intensification of management practices; (2) on a short-term basis, a moderate intensification of very low-input hay meadows has positive effects on plant species richness, vegetation structure, hay production, and arthropod abundance and biomass; (3) vegetation structure is likely to be the key factor limiting arthropod abundance and biomass. Our ongoing experiments will in the longer term identify which level of management intensity achieves an optimal balance between biodiversity and hay production.
authors.affiliation: Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern 3012, Bern, Switzerland.
authors.forename: Aline
authors.initials: A
authors.lastname: Andrey
authors.affiliation: Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern 3012, Bern, Switzerland.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Humbert
authors.affiliation: Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern 3012, Bern, Switzerland ; Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice La Tour du Valat, Le Sambuc, 13200, Arles, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Pernollet
authors.affiliation: Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern 3012, Bern, Switzerland ; Swiss Ornithological Institute Valais Field Station, Rue du Rhône 11, 1950, Sion, Switzerland.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Arlettaz
keywords: Agriculture; arthropods; grassland management; hump-shaped model; liquid manure; vegetation heterogeneity