نوع مقاله : علمی - پژوهشی
نویسندگان
دانشگاه فردوسی مشهد
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Introduction
The concept of ecological footprint was first proposed by Rees (1992) and further developed by Wackernagel and Yount (2000). This is an index based on the land area needed for basic requirements and also the waste disposal of an individual in a specific geographic location and usually calculated on the basis of area per capita which is normally global hectare (Gha) per capita. Based on the report of World Wildlife Found, total world ecological footprint for the year 2010 has been estimated to be 18.2 billion global hectares (Gha) with a per capita 2.7 Gha. This index is reciprocal of carrying capacity.
During the last two decades ecological footprint accounting is used widely for evaluation of ecosystems sustainability. However, limited information is available about ecological footprint of Iran and its components. In this research the state of production and consumption of different food stuffs and ecological footprint of food were calculated for Iran and the results are compared with other countries.
Materials and Methods
Data was collected for different group of agriculture foods including cereals, oil crops, pulses, dairy products, meat, fruits and vegetables from Ministry of Jihad Agriculture, Ministry of Commerce and also from other published data in official databases in the country. Calculation was made by the method provided in the literature.
Based on these factors ecological foodprint for each food product (efi) on the bases of Gha can be calculated from equation 1.
Equation (1)
In which efi: is the foodprint for product i, Ai: is the land area required for the same product i and fe,i: is the conversion factor for product i (Gha per ha).
Calculation of foodprint
Equation (2)
Equation (3)
Where EF is total ecological footprint (Gha), ef: per capita ecological footprint in terms of Gha and N: total population of the country.
Results and Discussion
The amount of total food production and consumption in 2013 were estimated as 89.5 and 94.6 Mg, respectively with self-sufficiency coefficient (production: consumption ratio) of 0.87. Self-sufficiency of cereals, oil crops and sugar crops were calculated as 0.69, 0.12 and 0.48, respectively that shows these food groups are highly import-dependent. However, production of vegetables and fruits exceeded their consumption and for other food items consumption was balanced by production. Ecological footprint of food estimated as 0.88 Gha/person and increased to 1.04 ha/person when calculated based on local hectares. Component analysis showed that this difference was due to lower efficiency of cereal and meat and dairy production systems of the country compared to world averages. Meat and dairy products accounted for 48% of food footprint of Iran and 33% of this footprint was due to cereals. Based on our results, Iranian food footprint is higher than Asia (0.7 Gh/person) and is almost the same as the world average (0.9 Gh/peron). Moreover, footprint of food is increased over the country by 76% during years 2000-2013 and this trend could led to severe environmental consequences.
Conclusion
Except for vegetable oils, sugar and cereals, the production and consumption of other groups of food materials are in balance, even for some groups such as fruits and vegetables. There is a small surplus in production over consumption for some extent dairy products. Foodprint for Iran is higher than the value for Asia and is similar to average for the world. In general, foodprint differs significantly amongst the nation and as expected this value is higher in those countries with higher consumption of meat. Higher demand for consumption of meat has caused an increase in indirect consumption of cereals for meat production. It should be noted that since foodprint is based on global hectare, comparison between countries and regions are simply possible. In fact if yield of a crop at national level is increased but world mean yield does not change, foodprint based on global hectare remains unchanged but if it is calculated on the bases of local hectare, foodprint will decrease. Therefore, system efficiency can be evaluated at national level, by comparison of foodprint at two different scales of global hectare and local hectare.
Acknowledgement
This research (14920.1) was funded by vice chancellor for research of Ferdowsi University of Mashhad, which is hereby acknowledged.
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