ESTIMATION OF PLANT DIVERSITY AT LANDSCAPE LEVEL:
A METHODOLOGICAL APPROACH APPLIED TO THREE SPANISH
RURAL AREAS
M. ORTEGA
1
, R. ELENA-ROSELLÓ
2
and J. M. GARCÍA DEL BARRIO
1∗
1
Centro de Investigación Forestal, Instituto Nacional de Investigación y Tecnología Agraria y
Alimentaria, CIFOR-INIA, Carretera de La Coruña KM 7,500, Madrid, Spain;
2
Departamento de
Silvopascicultura, Escuela Universitaria de Ingenieros Técnicos Forestales, Universidad
Politécnica de Madrid, Ciudad Universitaria s/n., Madrid, Spain
(
∗
author for correspondence, e-mail: jmgarcia@inia.es)
(Received 26 November 2002; accepted 9 May 2003)
Abstract. Approaches linking biodiversity assessment with landscape structure are necessary in the
framework of sustainable rural development. The present paper describes a methodology to estimate
plant diversity involving landscape structure as a proportional weight associated with different plant
communities found in the landscape mosaic. The area occupied by a plant community, its patch
number or its spatial distribution of patches are variables that could be expressed in gamma plant
diversity of a territory. The methodology applies (1) remote sensing information, to identify land
cover and land use types; (2) aspect, to discriminate composition of plant communities in each
land cover type; (3) multi-scale field techniques, to asses plant diversity; (4) affinity analysis of
plant community composition, to validate the stratified random sampling design and (5) the additive
model that partitions gamma diversity into its alpha and beta components. The method was applied to
three Spanish rural areas and was able to record 150–260 species per ha. Species richness, Shannon
information index and Simpson concentration index were used to measure diversity in each area. The
estimation using Shannon diversity index and the product of patch number and patch interspersion as
weighting of plant community diversity was found to be the most appropriate method of measuring
plant diversity at the landscape level.
Keywords: landscape, Mediterranean vegetation, metrics, plant diversity, remote sensing
Abbreviations: CUT(s): land cover and land use type(s); CUTA(s): land cover and land use type(s)
taking aspect (sun and shade) into consideration of each of CUT; DTM: Digital Terrain Model; GPS:
Global Position System; IJI: Interspersion and juxtaposition index.
1. Introduction
Sustainable rural development is one of the main objectives of the agricultural
policy of the European Union, as well as the maintenance or improvement of biod-
iversity from local to regional scales (Anon, 2000). Understanding and monitoring
the spatial distribution and patterns of biodiversity is a difficult task as it involves
the knowledge of species diversity of many different biological groups with com-
plex spatial and temporal distribution patterns, and information concerning trends
and changes at different spatial scales (Huston, 1999). The usefulness of various
Environmental Monitoring and Assessment 95: 97–116, 2004.
© 2004 Kluwer Academic Publishers. Printed in the Netherlands.