M. Anaya-Romero

Changes in land cover and vegetation carbon stocks in Andalusia, Southern Spain (1956-2007)

Land use has significantly changed during the recent decades at global and local scale, while the importance of ecosystems as sources/sinks of C has been highlighted, emphasizing the global impact of land use changes. Land use changes can increase C loss rates which are extremely difficult to reverse, in the short term, opposite to organic carbon (OC) which accumulates in soil in the long-term. The aim of this research is to improve and test methodologies to assess land cover change (LCC) dynamics and temporal and spatial variability in C stored in vegetation at a wide scale. LCCs between 1956 and 2007 in Andalusia (Southern Spain) were selected for this pilot study, assessed by comparison of spatial data from 1956 to 2007 and were reclassified following land cover flows (LCFs) reported in major areas in Europe. Carbon vegetation densities were related to land cover, and C vegetation stocks for 1956 and 2007 were calculated by multiplying C density for each land cover class with land cover areas. The study area has supported important changes during the studied period with significant consequences for vegetation C stocks, mainly due to afforestation and intensification of agriculture, resulting in a total vegetation C stock of 156.08Tg in 2007, with an increase of 17.24Tg since 1956. This study demonstrates the importance of LCC for C sequestration in vegetation from Mediterranean areas, highlighting possible directions for management policies in order to mitigate climate change as well as promoting land conservation. The methodologies and information generated in this project will be a useful basis for designing land management strategies helpful for decision makers.

Climate Change Impact on Bioclimatic Deficiency, Using MicroLEIS DSS in Ahar Soils, Iran

Regional impact studies of the future climate change effects are necessary because projected changes in meteorological variables differ from one region to another, and different climate systems can react in varied ways to the same changes. In this study, the effects of climate change on bioclimatic deficiency were compared in two cultivation methods (irrigated and rainfed) in a semi-arid region, Ahar (East Azarbaijan, IRAN). The agricultural land uses selected for evaluation were wheat ( Triticum aestivum ), alfalfa ( Medicago sativa ), sugar beet (Beta vulgaris ), potato ( Solanum tuberosum ), and maize ( Zea mays ). In this way, Terraza model included in the land evaluation decision support system, called MicroLEIS DSS, was used. Terraza gives a quantitative prediction of a site bioclimatic deficiency. Soil morphological and analytical data were obtained from 44 sampling points based on a grid survey. Agro-climatic data, referred to temperature and precipitation, were collected from weather stations located in Ahar region, which benefits from more than 20 consecutive years of weather data. A future scenario of climate change was calculated according to the Intergovernmental Panel on Climate Change (IPCC) on regions of Asia under scenario A1FI (highest future emission) for 2080s. Although, increasing of precipitation being available by climate change in the future scenario, humidity index will be reduced because of high temperature. The results showed that climate change is likely to cause severe water stress in irrigated cultivation of alfalfa, sugar beet, potato, and maize, the use of irrigation methods being essential to maintain agricultural productivity. Although irrigation is indicated as very important in this regime of semi-arid agriculture, cultivation of rainfed wheat can be possible instead of the irrigated one. Also, it is revealed that climate perturbation effects on rainfed conditions are more serious than those on the irrigated conditions in the area.

Evaluating soil contamination risks by using MicroLEIS DSS in El-Fayoum province, Egypt

The Agro-ecological Decision Support System, MicroLEIS DSS, was applied to investigate and predict soil degradation in the province of El-Fayoum, one of the western desert areas of the Arab Republic of Egypt, with an area of 149,300 ha approximately. The Pantanal land evaluation model as one constituents of this DSS, was used for evaluating contamination risks of phosphorus, nitrogen, heavy metals and pesticides. Pantanal is an expert system model based on three kinds of input data : I) monthly meteorological data contains average values of climate variables such as mean temperature, maximum and minimum rainfall, number of days of rain and humidity, for a consecutive period of 44 years, collected from the station of El- Fayoum; II) soil survey data collected from 46 soil profiles representative of the study area and stored in the MicroLEIS SDBm plus database; and III) agricultural information on soil use and management for major crops in the area, from scientific publications of the Ministry of Agriculture. The model application results are grouped in five vulnerability classes: V1-none, V2-low, V3-moderate, V4-high and V5-Extreme for each specific contaminant. Results obtained in El-Fayoum area show that 2.8%, 45.2% and 52% of total studied area were classified as V1, V3, and V4 vulnerable land due to phosphorous contamination. On the other hand 95.9 % and 4.1% of total studied area were classified as V3, and V4 vulnerable land due to nitrogen and heavy metals, and 6.1 %, 21.5 %, 68.8 % and 2.8% of total studied area were classified as V1, V2, V3, and V4 vulnerable land due to pesticides. Additionally, Typic Torripasamment soil has a high vulnerability classes for all the types of contaminants although it represents a residual area, of 2600 ha approximately. Finally hypothetical recommended scenarios were established for each soil types in order to formulate sustainable agriculture practices by reducing inputs use like water, fertilizers and pesticides, and so minimizing the risk of soil degradation due to contamination. In conclusion, MicroLEIS DSS appears to be a useful tool in this part of arid regions, such as north of Africa (Egypt), to formulate sustaining agro-ecological systems. Although information about land resources in this part of Africa is rather scarce, these innovative agro-ecological strategies can be applied and adapted in other agricultural provinces from the Arab Republic of Egypt in order to achieve a regional sustainable land management.