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E. Fernández-Núñez et al. 2010. Eight years of development of a silvopastoral system: effects on floristic diversity
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Eight years of development of a silvopastoral system: effects on
floristic diversity
E. Fernández-Núñez 1 , A. Rigueiro-Rodríguez 2 & M.R. Mosquera-Losada 2
1 Mountain Research Centre (CIMO), ESA – Instituto Politécnico de Bragança, Campus
de Stª Apolónia, Apartado 1172, 53001-855 Bragança, Portugal
2 Crop Production Department, High Politechnic School, University of Santiago de
Compostela, Lugo Campus, 27002-Lugo, Spain
Abstract
Biodiversity is an important issue to promote agricultural sustainability, and usually depends on
vegetation management. One of the main reasons to maintain biodiversity is to enhance
productivity in extensive systems, due to the best complementarity between different species to
use soil resources. The objective of this study was to evaluate the effect of two different tree
species, an exotic (Pinus radiata D. Don) and a native (Betula alba L.) established at two
densities (833 and 2500 tree ha -1 ) and three types of fertilization (no fertilization, dairy sewage
sludge fertilization and mineral fertilization) on component, species richness and abundance
eight years later. The results showed an important reduction in species richness in the systems
established at high density under pine tree compared with birch fertilised with mineral or
without fertilisation. Shannon index was reduced when fertilization was applied under birch at
high density, mostly with dairy sludge, compared with no fertilisation. No effects on plant
diversity was detected when tree density was 833 trees ha -1 .
Keywords: pine, birch, species richness, Shannon index, fertilisation
1. Introduction
In the Northern Spain, where the study was carried out, important changes have occurred in
rural land use in the last decades. The traditional landscape, a heterogeneous mosaic of pastures
and native deciduous forests has been gradually substituted by plantations characterized by the
presence of a unique forest tree species (Eucaliptus spp and Pinus spp.). The lack of subsequent
management of these plantations has resulted in excessive FCC and very high tree densities that
hamper an adequate forest development. Silvopastoral systems may be a viable means to
promote multipurpose forest land use and obtain income from newly afforested. Areas managed
for silvopastoralism can reduce fire and erosion risk in forests (Rigueiro-Rodríguez et al. 2005),
and can enhance biodiversity and contribute to the preservation of many endangered species that
depend on ecotones between woodlands and open landscapes (Rois-Díaz et al. 2006). However,
these land use changes can cause important modifications to microclimatic conditions (soil,
interior temperature of the system...) and this can affect biodiversity in the short and medium
term. On the other hand, studies carried out in NW Spain have shown that fertilisation enhances
pasture production as well as tree growth in a silvopastoral systems established in very acidic
soils (López-Díaz et al. 2007), but reduces both in neutral soils (Mosquera-Losada et al. 2006)
but, it is important to study how this fertilisation affects to vascular plant biodiversity on a short
time. This study aims to evaluate the effect of Pinus radiata D. Don and Betula alba L.
established at two density with different soil fertilisation treatments on alpha biodiversity
over eight years.
Forest Landscapes and Global Change-New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.)
2010, Instituto Politécnico de Bragança, Bragança, Portugal.