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C. Carvalho-Santos 2010. Fine-scale mapping of High Nature Value farmlands
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farmland). The objective is thus not to identify HNVf vs. non-HNVf areas, but instead to
provide a hierarchic zoning of nature value. The parish-level HNVf map is obtained from the
area-weighted mean value of farmland patches inside the parish, and the final score is expressed
without considering the total extent of each parish.
3.3. Testing the new framework in Northern Portugal
The region chosen to test the methodology was the Baixo Tâmega, in the north of Portugal, a
mosaic of different agrarian systems and landscapes that have, in most cases, been suffering
abandonment in the last few decades. Nonetheless, there are some areas with more specialized
and intensive agricultural systems, mostly related to wine production along the Douro and
Tâmega valleys. There are also non-cultivated areas, mostly in mountain areas, with seminatural
vegetation associated with extensive grazing.
Due to the regular presence of semi-natural vegetation types, most of these farmlands are
classifiable as HNVf areas (Andersen et al. 2003). The final maps (figure 2) provide
complementary views of HNVf distribution in the area. In fact, the patch-level map identifies
HNVf areas in most of the study area except for the eastern mountain areas (where forestry
prevails), but the parish-level map identifies small farmland areas in these mountains as the ones
with the highest nature value.
4. Discussion
The concept of HNVf, areas associated with low intensity farming, has become very important
regarding agrobiodiversity protection under the Rural Development Programs. It is already used
in many European countries from different perspectives, and is starting to be more and more
included in the political agricultural context. This could mean economic support to these areas,
through European financial instruments.
Land cover, farming characteristics and species distribution data are the central datasets in the
common approach to the identification of HNVf at European and national levels. The
availability and the quality of farming and species datasets is a recurrent problem. In fact,
mapping methodologies using land cover datasets at different scales can provide very distinct
HNVf maps.
A new refined methodology based on land cover data, landscape features, farming attributes and
natural value/conservation data was designed to map HNVf at a local scale. The use of datasets
on nature value including information on the valuation of ecosystem services inferred from
land-use dataset is considered an advantage. In the literature, HNVf is stressed to promote
biodiversity in agroecosystems. In our novel methodology, we suggest a stronger emphasis on a
landscape perspective and on the ecosystem services provided by semi-natural areas close to
cropland.
This methodology appears as an important instrument in the identification of HNVf areas to
support policy implementation in the framework of agrobiodiversity protection. It can be used
either spatially, comparing the extent of potential HNVf areas among different regions, or
temporally, comparing changes in extent of HNVf in one region at different times as a
monitoring effort. Additionally, we expect with future research to check the possibility to adapt
this methodology in other EU countries, where local land cover datasets are usually available.
References
Andersen E., Baldock D., Bennet H., Beaufoy G., Bignal E., Brouwer F., Elbersen B., Eiden G.,
Godeschalk F., Jones G., MaCracken D., Nieuwenhuizen W., Eupen M., Hennekens S.
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.