Overview of study sites in cropland

Authors: Constantinos Kosmas, Katerina Kounalaki, Mina Karamesouti, Giovanni Quaranta, Rosanna Salvia, Honghu Liu, Artemio Cerda, Michiel Curfs, Anton Imeson

Editor's note 3May2012: Text extracted from D711 section 7.4

Five cropland study sites have been selected; four of them are located in Mediterranean Europe and one in China. These are: (a) Messara Valley (Greece), (b) Alento River basin (Italy), (c) Canyoles River Basin (Spain), (d) Western Andévalo (Spain), and (e) Zhang Jiachong area (China). The selected study sites present a variety of environmental and socio-economic characteristics, various degrees of land degradation and desertification and particular responses to LEDD. An overview of the principal characteristics of the cropland study sites is given below.

Locations of the LEDDRA cropland study sites

In terms of their biophysical characteristics, the study sites of Messara Valley, Canyoles River Basin, and Western Andévalo are drier than the Alento River basin and the Zhang Jiachong area with a rainfall ranging between 250 mm to 800 mm, and 950 mm to 1590 mm, respectively (Table 1). Most of the rain in the European study sites falls between October and April, while in the China study site between June and September. The topography of the sites shows a variety of altitudes ranging from 0 m to up to 2453 m with a variety of slope gradients changing from almost flat (slope gradient 0-2%) to very steep (slope gradient >65%). The soils are characterized from very shallow (soil depth 15-30 cm) to deep (soil depth>100cm), formed on a variety of parent materials such as limestone, marl, schist, shale, sandstone, flysch, diorite, lava, alluvial deposits, etc. They are classified mainly as Leptosols, Cambisols, Fluvisols, and Luvisols.

Table 1. Main characteristics of the biophysical system of the study sites

The study sites constitute a variety of agro-ecosystems such as cultivated land (mainly with olives, vines, annuals, oranges, and vegetables), dryland, and some inclusions of forest and mountainous ecosystems. The type of agriculture is characterized mainly as intensive, including ploughing, irrigation, fertilization, as well as less intensive agriculture for rainfed crops. The Italian study site belongs to the National Park of Cilento and Vallo di Diano which is a UNESCO site of World Heritage and includes sites of Community Interest and Special Protected Areas.

The population of the study sites shows various trends in the last decades. In the China study site, the population increased until 1990 and then decreased. In the other study sites, population remained stable or decreased slightly (Table 2). There was a movement of population to main cities or in areas with higher economic activity such as along the coast causing significant depopulation of rural areas. Local population has been affected by the contemporary migratory flows. In many cases, more migrants come to the areas than emigrants leave. The population pyramids, especially in the last two decades, show a consistent reduction in young population accompanied by a decrease of birth rates in the Mediterranean Europe study sites except. In China the birth rates were high until 1990 and then decreased in almost equal rates.

Table 2. Main characteristics of the human system of the study sites

The agricultural sector has suffered the most, with a consistent decline in employment in the last decades. Even though the decline in agriculture remains the most important issue, other economic sectors such as tourism, services, transportation, manufacturing, etc. have developed in all study sites in recent decades. The construction of the Three Gorges Dam in the China study site in the last decade has greatly affected the structure of agriculture and the socio-economic characteristics of the area.

The selected study sites face various problems of land and ecosystem degradation and desertification (LEDD). The most important environmental and socio-economic impacts of LEDD are summarized in Table 3. Soil erosion constitutes a major issue in all study sites causing loss of fertile soil, loss in organic matter content, loss in soil water storage capacity, loss in crop production and farmer’s income, infrastructure damages, etc. In addition, land desertification and biodiversity loss is a major issue especially for the study sites located in Mediterranean Europe. Aquifer depletion accompanied in many cases by water pollution or/and soil salinization is a major issue for the study sites of Canyoles River Basin river and Messara Valley.

Table 3. Important land and ecosystem degradation and desertification (LEDD) issues identified in the cropland study sites

The main drivers of land degradation and desertification in all study sites are: fires for expansion of agricultural land, reduction of agricultural area due to low land productivity or urban expansion, intensification of crop production and concentration in productive soils, low prices of agricultural products especially in olive oil, expansion of tourism especially in the coastal areas, EU and national subsidies, and climate variability. One of the most important drivers of agricultural reform in the Yangtze River Basins was the increase in water availability.

Several physical/technological and institutional types of responses have been identified at the various study sites (Table 4). The main physical/technological responses to LEDD are: land terracing and terrace maintenance, understory annual vegetation in olive groves, no or minimum tillage, contour farming, intercropping, mixed cultivation, crop rotation, unsustainable farming, expansion of agriculture in natural areas, fires in natural and agricultural areas, organic farming, traditional flood irrigation, monoculture of certain plantations, land abandonment, etc. The main institutional responses are: national legislation for environmental protection, National Action Plans for combating land desertification, National Park Management Plans, Watershed Management Plans, Rural Development Programmes, NATURA 2000 Network, cross-compliance, afforestation schemes, etc. The main research or educational responses to LEDD are: environmental awareness raising, local education seminars on land degradation, research projects funded by EU or national funds, etc.

Table 4. Important planned and unplanned responses to LEDD in the cropland study sites

Cross-references need to be checked and links re made.

Messara Valley, Crete
Alento, Italy
Zhang Jiachong, China
Canyoles River Basin, Spain
Western Andévalo, Spain