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Desertification Indicator System for Mediterranean Europe


1. Definition

Name

AREA OF MATORRAL

Brief definition

The percentage of total matorral surface vs. the total forested surface

Unit of measure

%

Spatial scale

 

Temporal scale

 

2. Position within the logical framework DPSIR

Type of Indicator

Driving Force/State

3. Target and political pertinence

Objective

The indicator defines the average surface cover of matorral that represents a degradation stage of the evergreen forest. The indicator contributes to quantifying the process of deforestation in a defined area, mainly due to repeated fires.

Importance with respect to desertification

Most of the natural vegetation in the area is a degradation stage of the evergreen forest, consisting of shrubby formations, which are called matorral by Tomaselli (1981). His definition of matorral is: "a formation of woody plants, whose aerial parts are not differentiated into trunk and branches, but much ramified from the base, and are of shrubby habit". Further discrimination of matorral can be made by height and density.

The highest matorral type is named high matorral or maquis (Tomaselli, 1981). Maquis is a very characteristic Mediterranean vegetation type. It consists of dense and impenetrable thickets of tall shrubs, 2-5 m high. The shrubs have densely twiggy branches and small dark green leathery leaves. Under certain conditions, maquis is considered to be the climax vegetation (primary maquis), but usually it is the result of man's activity (secondary maquis) (Polunin and Huxley, 1972).

Another characteristic vegetation type of the Mediterranean is middle matorral or garrigue (0.6-2 m high). Garrigue consists of low scattered bushes with bare patches of rock, sand or stony ground between. Many of the shrubs are spiny and have small leathery heather-like leaves often covered with woolly grey hairs (Polunin and Huxley, 1972).

Many studies have shown that the variation in runoff and sediment yields in drainage basins is attributed to the vegetation cover and land use management changes (Douglas, 1969; Reed, 1971; Williams and Reed, 1972; Patton and Schumm, 1975; Newson, 1985; Bryan and Campbell, 1986). On the other hand, it has been demonstrated that in a wide range of environments both runoff and sediment loss decrease exponentially as the percentage of vegetation cover increases (Elwell and Stocking, 1976; Lee and Skogerboe, 1985; Francis and Thornes, 1990).

International Conventions and agreements

The UNCCD recognises the particular conditions of the Mediterranean. The desertification process is associated with extensive forest coverage losses due to different causes (deforestation, frequent wildfires, intensive grazing etc) (Convention text as of September 1994 and as of September 2001 )

Secondary objectives of the indicator

This is an indicator of the impact of degradation on forest surfaces. Information about desertification can help in addressing political measures to recognise the loss of cover vegetation in an area and to organise efficient control mechanisms, and indirectly reduce desertification processes in the territory.

4. Methodological description and basic definitions

Definitions and basic concepts

Data are available for matorral areas for different periods and territory level (FAO;EUROSTAT, ISTAT, CFS). Detailed multi-temporal analyses of satellite data show that degradation of forest is a highly dynamic process of clearing, abandonment and re-clearing, and the rates at which land is cleared or abandoned are related to the land use and management system the forest farmers employ. The scientists use a combination of satellite-based earth observation and intensive field data collection to estimate degradation processes in a defined territory and for different types of vegetation (forest, shrubs, grasslands).

Benchmarks Indication of the values/ranges of value
  • <=10% of total matorral surface/total forested surface = low incidence
  • >10 -30% of total matorral surface/total forested surface = moderate incidence
  • >30 - 60% of total matorral surface/total forested surface = high incidence
  • >60 % of total matorral surface/total forested surface = very high incidence

Methods of measurement

Ratio between total matorral surface and the total forested surface

Limits of the indicator

The limit of the indicator is the difficulty in finding statistic forest data and homogeneous data on mattoral areas for different European countries, especially at a municipality level.

Linkages with other indicators

Forest fragmentation, Deforested area, Biodiversity conservation, Forest productivity, Forest management quality

5. Evaluation of data needs and availability

Data required to calculate the indicator

Total matorral surface; total forested surface

Data sources National and European Forest Statistics (ISTAT, EUROSTAT), National Forest Inventories. E.O. data

Availability of data from national and international sources

Data on forest surface can be provided by the Eurostat and National Statistic Organizations. Satellite data can also be used to measure matorral cover.

6. Institutions that have participated in developing the indicator

Main institutions responsible

University of Basilicata, Potenza, Italy

Other contributing organizations

 

7. Additional information

Bibliography

Bryan, R,B. and Campbell, I.A., 1986. Runoff and sediment discharge in a semi-arid drainage basin. Zeit fuer Geomorph., 58:121-143.

Douglas, I., 1969. Sediment yields from forested and agricultural lands, Proc. Symp. on "The Role of Water in Agriculture", University of Wales (Aberystwyth), Memorandum No. 12, E1-E22

Elwell, H. A. and Stocking M.A., 1976. Vegetal cover to estimate soil erosion hazard in Rhodesia. Geoderma, 15:61-70.

Francis, C. F. and Thornes, J.B., 1990. Runoff hydrographs from three Mediterranean vegetation cover types. In: J.B. Thornes (editor), Vegetation and Erosion, Processes and Environments. J. Wiley & Sons, Chichester, pp. 363-384.

Lee, C.R. and Skogerboe, J.G., 1985. Quantification of erosion control by vegetation on problem soils. In: Al Swaify, W. C. Moldenhauer and A. Lo (editors), Soil Erosion and Conservation. Soil Conservation Soc. of America, pp. 437-444.

Newson, M.D., 1985. Forestry and water on the uplands of Britain-the background of hydrological research and options for harmonious land use. J. Forestry, 79:113-120.

Reed, L.A., 1971. Hydrological and sedimentation of Corey Creek and Elk Run Basins, North-Central Pennsylvania. US Geol. Surv. Water Supply Paper.

Tomaselli, R., 1981. Main Physiognomic Types and Geographic Distribution of Shrub Systems Related to Mediterranean Climates. Ecosystems of the World 11: Mediterranean-type Shrublands (F. di Castri, D.W. Goodall & R.L. Specht, editors), Elsevier, Amsterdam, pp. 95-106.

Patton, P.C. and Schumm, S. A., 1975. Gully erosion, Northwestern Colorado: a threshold phenomenon. Geology, 3:83-90.

Polunin, O. & A. Huxley, 1972. Flowers of the Mediterranean. Chatto and Windus, London, 260 pp.

Williams, K.F. and Reed, L.A., 1972. Appraisal of stream sedimentation in the Susquehanna River basin. US Geol. Surv. Water Supply Paper.

Other references

 

Contacts Name and address

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