Economic valuation of the ecosystem services of Mashhad’s Parks

Urbanization creates significant changes in global ecosystems, while urban agro-ecosystems can provide valuable and desirable ecosystem services for human society. Understanding these services and taking them into account is necessary for the urban management of both today’s society and future generations. This study was conducted in 2015 in Mashhad parks. To evaluate services like carbon sequestration, oxygen production and pollutant removal, plant data in plots was entered in itree software and their values were calculated according to international gas tax and also social values. In order to evaluate services such as diversity in landscapes, water storage, soil formation, biological pest control and cultural services, a questionnaire was designed using a choice experiment method and the average of willingness of landscape experts to pay was analyzed. The urban forest of Mashhad has tree cover of 41. 6 percent; the three most common species are Acer negundo (17. 4%), Platanus orientalis (15. 6%) and Robinia pseudoacacia (11. 7%). The percentage of young trees was greater than others and, so, the ecosystem services of parks come mostly from younger trees. The population of exotic tree species was more than native ones, with most exotic tree species having their origins in North America (at 44. 1%) and 15. 9% with Asian origins. The gross carbon sequestration of trees was 1. 0387 tons per hectare per year, most of which belonged to Platanus orientalis. Oxygen production was 0. 24656 and pollutant removal was 0. 041 ton/ha/year, with carbon storage per hectare at 22. 769 tons. Results showed that the value of regulatory services like (carbon sequestration, oxygen production and pollutant removal) in Mashhad parks was 4 million Rials annually per hectare and carbon storage was 61 million Rials per hectare. As the atmosphere is a huge source of oxygen, this gas was not calculated in the monitory valuation. The amount of oxygen production in all parks was 290 tons which can provide for the needs of 115 persons. Species richness was 38 with a value of 22 million Rials. Total value of other regulatory services such as (landscape diversity, water storage, soil formation, biological pest control and cultural services) was negative and, of these services, the responders only have a willingness to pay 365 million Rials per ha annually for cultural and water storage services. From this amount, 240 million Rials was for cultural services and 133 thousand Rials was for water storage. There was no willingness to pay for the other services which they consider to be part of the Municipality’s tasks. More budget is needed for increasing ecosystem services and for saving the urban ecosystem.