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Desertification Indicator System for Mediterranean Europe

1. Definition



Brief definition

Biodiversity measured by species richness, density, and diversity.

Unit of measure

Number of species (or selected taxa) and their variations.

Spatial scale


Temporal scale


2. Position within the logical framework DPSIR

Type of Indicator

Driving Force/State

3. Target and political pertinence


The indicator indirectly contributes to define biodiversity measured by species richness, density, and diversity in natural environments threatened by desertification.

Importance with respect to desertification The UN Convention to Combat Desertification (1995) defines desertification as "land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities." These vulnerable drylands comprise about 40% of global lands, of which at least a quarter are already degraded. It is generally agreed that desertification most frequently results from development which is not sustainable, due to the mismanagement of biodiversity: overexploitation of vegetation cover leading to topsoil erosion and hence reduced productivity, or improper water use resulting in salinization. This affects not only crops but also rangeland and its biodiversity. When the transformation of rangeland to irrigated cropland results in desertification, the effect on biodiversity is in the loss of natural ecosystems. When the overexploitation of rangeland results in desertification, the effects on biodiversity are first expressed in the direct loss of plant species and the animals associated with them, and later in the loss of topsoil and the potential for rehabilitating biodiversity. These biodiversity losses, both in goods and services, further exacerbate desertification in the affected areas. They also affect adjacent and other areas, which used to enjoy some of the services, such as aquifer recharge for example. Biodiversity conservation and sustainable use of biological resources can hardly be achieved in arid and semi-arid areas without taking into account the underlying causes of desertification, which affects all natural resources. Similarly, desertification control activities and restoration processes in these areas should include wetlands conservation as a priority. Finally, availability of water resources in arid lands depends directly on the rainfall (and climate variations). Hence, the links between biodiversity, desertification, wetlands and climate change are part of the day-to-day life of millions of people living in the drylands.

International Conventions and agreements

The loss of biodiversity often reduces the stability of ecosystems, reducing their ability to provide goods and services that sustain human life. The protection of biodiversity is therefore in mankind's self-interest and has been recognized as a major aspect of sustainable development through the adoption of the Convention on Biological Diversity at the 1992 Earth Summit in Rio de Janeiro. The UNCCD recognised the particular conditions of the Mediterranean where the causes of desertification include the extensive forest coverage losses due to deforestation, frequent wildfires, intensive grazing etc. (Convention text as of September 1994 and as of September 2001).

Secondary objectives of the indicator

This is a fundamental indicator of the impact of degradation of the forest surface and, in general, of natural environments. Information about desertification can help in addressing political measures to recognise the loss of biodiversity an area and to organise efficient control, and indirectly to reduce desertification.

4. Methodological description and basic definitions

Definitions and basic concepts

Species richness is defined as the total number of species in an area measured by a standard protocol. It is one of the common measures for biodiversity which can be assessed on three levels: the species, the genetic and the ecosystem level. Species richness refers to the species level (plants, animals and micro-organisms). The assessment of species richness of an area should not be confused with species diversity measurements that include components of both species richness and the evenness or dominance among the species present. The assessment of species richness is closely related to the process of gathering data on the distribution, numbers, and/or composition of species groups and population monitoring.

Benchmarks Indication of the values/ranges of value

The loss of species richness in an area can be used as an indicator for pressures on the environment and can help to define conservation measures and to avoid further damage. Values of losses of species (or selected taxonomic groups) can be fixed with respect to local flora if available.

Losses in species number > = 15% = very high incidence
Losses in species number 7.5% < 15% = high incidence
Losses in species number 5 < 7.5% = medium incidence
Losses in species number < 5% = low incidence

Methods of measurement

Number of species per defined area.

Various methods are used for the enumeration and determination of species richness according to the different taxonomic groups investigated, as well as particular ecozones and ecosystems. In general, plant species are recorded through point, line, plot or plotless vegetation surveys. The consistency of the assessment method is extremely important with regard to the monitoring of species richness. The sampling methods must be adapted to the particular conditions. Heterogeneous habitats require more samples than homogenous habitats. Species richness can also be estimated and there are various methods existing, mainly based on a species-area correlation.

Limits of the indicator

It is difficult to obtain up-to date knowledge of the local flora. It should be stressed that species richness needs to be used in the context of further indices for biodiversity and changes of biodiversity. Different ecosystems naturally support different numbers of species and species richness is not necessarily an indicator of high ecological value or stability. It only represents a basic value for each site which can be used for the monitoring of species numbers within the same area or in relation to other variables, e.g. the percentage threatened species from the total number of species, etc. The identification, investigation and description of species can help to understand their roles in the ecosystems. The identification of species-rich areas can be helpful to determine priority areas for biodiversity preservation.

Linkages with other indicators

Land cover, Land use type, habitat fragmentation, habitat conversion, indicator species, colonization of habitat by invasive species.

5. Evaluation of data needs and availability

Data required to calculate the indicator

With regard to species inventories, the variety of living species in even a small area is so great that identifying all of the species present is generally impractical. The identification of described species often requires a high level of expertise. A complete inventory will therefore not be attainable even at a site-level, and the surveys will probably have to be limited to selected taxonomic groups.

Data sources

Global Plant Checklist: http://iopi.csu.edu.au/iopi/iopigpc1.html

Index Nominum Genericum (Plantarum): www.nmnh.si.edu/ing/

International Organisation for Plant Information: http://iopi.csu.edu.au/iopi

International Plant Name Index: www.ipni.org

Treebase: www.herbaria.harvard.edu/treebase/

Vascular Plants Type Catalogue: www.nybg.org/bsci/hcol/vasc/

Availability of data from national and international sources

Species 2000 is a "federation" of database organizations and has the objective of catalogueing all known species of plants, animals, fungi and microbes on earth as the baseline dataset for studies of global diversity. It was established in 1994 by several organizations and is being developed by a multi-national project team. Its homepage is accessible at www.species2000.org or www.sp2000.org.

DIVERSITAS is the International Programme of Biodiversity Science, hosted at the International Council for Science (ICSU) and sponsored by different organizations. It is currently working on the development of standardized methods for sampling, assessing and monitoring biodiversity for various taxa. Information can be obtained from their homepage www.icsu.org/diversitas.

The Information Center for the Environment (ICE), in cooperation with the United States Man and the Biosphere Programme (U.S. MAB) and the Man and the Biosphere (MAB) Programme of the United Nations Educational, Scientific, and Cultural Organization (UNESCO), has produced standardized databases containing species inventories of plants and animals reported from Biosphere Reserves. The searchable database is accessible at http://www.arcbc.org/arcbcweb/biodiversitylinks/default.asp? catid=2&pagetitle=WWW_Databases

6. Institutions that have participated in developing the indicator

Main institutions responsible

University of Basilicata

Other contributing organizations


7. Additional information


Many efforts have also been made on a regional level to develop standard guidelines. A good example is the development of manuals by the Resources Inventory Committee of the Ministry of Environment, Lands and Parks of British Columbia. Forty-one manuals describing particular measurement methods for different species groups are available online at www.for.gov.bc.ca/ric/pubs/teBioDiv/index.htm

Other references


Contacts Name and address

Prof. Agostino Ferrara
University of Basilicata
Via dell'Ateneo Lucano
85100 Potenza, Italy
e-mail: ferrara@unibas.it