چكيده لاتين :
According to importance of Environmental resource in preservation of natural ecosystems and human life, restriction on destruction is necessary. Miankaleh wetland in Mazandaran province is the settlement of animal and herbaceous rare species. This research will discuss determination of preservation value in Miankaleh international wetland and measure of individualʹs willingness to pay (WTP) for Preservation benefits based on contingent valuation (CV) and questionnaire dichotomous choice. For measuring the individualʹs WTP, Logit model was used. The estimation parameters are based on methods of maximum likelihood. Results show that 68.3% individuals have willing to pay for preservation of the Miankaleh wetland. According to the results, by increasing one unit in Bid, probability of acceptance is decreased equal to 0.924 percentages for preservation of Miankale Wetland. The annual mean of WTP for Preservation of this wetland is US $ 0.74 per household and US $ 2271.74 per hectare. Most important effective variables are bid quantity, individual income, sex, education and jobs for preservation of this wetland. It can be concluded that by application of the results of this study, a suitable price policy can be taken for preservation of Miankaleh.
The effective role of environmental resources on sustainable development trend has turned the focus of economists on the non market aspects of these resources. Due to the indirect role of environmental resources on supplying enormous benefits for society, it is needed to fully understand the function and services which have been provided by them. During last decades, several studies have been performed to evaluate natural resources values (Hadker and et al. 1997; Muramira, 2000; Lehtonen and et al. 2003; Amirnejad and et al. 2006; Shrestha and et al. 2007; Amirnejad, 2007; Amirnejad and Khalilian, 2006; Asgari and Mehregan, 200). In this regard, wetlands are considered as the most beneficial ecosystems in which have been dramatically damaged during the time.
There are several national and international wetlands in Iran in which Miankaleh is on of the most important one and is considered as a wild life sanctuary and was listed as a preserved area in 1969. Furthermore, regarding its ecological characteristics, this wetland has been chosen as a maternity site by many endangered animal and herbaceous species, specifically aquatic migrant birds. In fact, Miankaleh wetland and the Anzli wetland are two international wetlands in northern part of Iran. This wetland is benefiting from some specific natural characteristics and hence considering as one of the major fauna and flora habitat in Iran and even in the world. Meiankaleh as a preserved area is consist of both terrestrial and aquatic environment in total area of about 67349 ha, located in the far east of Mazandaran province and partially in wets of Golestan province. Contingent Valuation Method (CVM) is widely used for evaluation of environmental services and benefits. Such a method, determine the factor of willingness to pay (WTP) in form of virtual accessories (Lee and Han, 2002). CVM is based on referring to the public in order to determine the economical value of environmental services, hence, this method is known as preference method.
A person would be willing to pay for preservation of environmental resources provided that receives more benefits after payment compared with the time he/she do not pay. This can be stated mathematically in form of following equation
U(l, Income - Bid; S) + sl > U{0, Income; S) + £0 (1) Where
U= indirect benefits for every person Income= monthly income of every person Bid= debit amount for preservation s= socio-economical characteristics of people
e0 and sx = random variables with average of zero which have been equally and independently distributed
The application of Logit model is more convenient; thus, in this study it was used to determine the preservative value of Meiankaleh wetland and the effect of different descriptive variables on extent of WTP. Based on Logit model, possibility of Pi (i.e acceptance of any offer by person i) is expressed in form of
equation 2 :
Pi=FTJ(AU) = 1
l + exp(-At/) 1
(2)
1 + exp{ -(a - p.Bid + y.Income + 0.S)}
Where
FJ?(AU) = accumulative distribution function with a standard logistic difference
j3, y and 6 = predetermined coefficients which it is expected that /? < 0 ʹ ^ > 0 j 0 > 0
Expected amount of WTP can be calculated by numeric integral between zero up to maximum bid (M) in form of formula 3 as below;
M
E(WTP) = ^(AUjdBid
o
M
= f(-\-)dBid
J 1 + exp Ha + 6.Bid)}
Where
E (WTP)= Expected amount of WTP for every person
a* = The adjusted intercept which was added by the socio-economic term to the original intercept term of a
With attention to the aim of this study, evaluation of preservative value of Miankaleh wetland was not limited only to the city of Behshar, rather questionnaires were collected from different cities (Sari, Qaemshahr, Babol, Amol, Neka, Babolsar, Novshahr and Chalous) of Mazandaran province by random sampling method. The highest percentage (56.5%) of tested people was related to staffs community and regarding to the education level, the highest level (41.3%) was belonging to the undergraduate people. According to the results, out of 230 samples, 104 people (45.2%) did not accepted to pay the first offer (1.09 US Dollars per month) for preservation of Miankaleh wetland whereas 126 people (54.8%) did accept the offer. Regarding the second offer (0.54 US Dollars per month), apart from 73 people (31.7%) who did not accepted the offer and suggested to lower the offered price, the rest (31 people) were agreed with the offer. In case of those who accepted the first offer, they were questioned if they would be ready to pay 1.63 US Dollars monthly (as third offer) for preservation of Miankaleh wetland. In response, 67 people (29.1%) were agreed with the third offer while 59 people (25.7%) refused to pay more. Out of 31.7% people who were not willing to pay for preservation of Miankaleh wetland, 19.9% were believed that these expenses should be supplied by government, 8.4% asserted that who get benefit of wetland should pay and 3.4% believed that because of their short income, they are not able to afford the wetland preservation related prices. According to the results of Logit model, determined coefficient of bid variable, which is considered as the most important descriptive variable of WTP for preservation of Miankaleh wetland, indicated that bid variable is significant at confidence level of 99%. The negative sign shows that under presumption market situation, if the offered prices increase the possibility of its acceptance by people will decrease and vise versa. By one percent increase in people income, the acceptance possibility of offered prices will increase by 0.101% and 1.07 x 107 unit, respectively. Considering the significant effect of sex variable at a = 5%, it can be concluded that by addition of one percent or one person in male population, the acceptance possibility of offered priced for preservation of Miankaleh wetland will increase by 0.136% and 0.189%, respectively. In terms of specialty level and proficiency of sample people, by one percent or one professional person increase, the acceptance possibility of offered prices with increase by 0.760% and 0.132 unit, respectively. With attention to the determined tension of education level, by increase of one unit in education level, the possibility of payment acceptance will increase by 0.703 units. Based on percentage of anticipation statistic item which has been calculated as 94.7%, determined model has successfully anticipated high percentage of dependent variables. After determination of Logit model, the expected amount of average WTP for preservation of Miankaleh wetland based on numeric integral method between zero and maximum offer (16.3043 US Dollars) was determined equal to 0.7368 US Dollars per month. This number comes to 82543.2 per year. Knowing this fact that Miankaleh wetland is a national and international wetland, if we assume that this price can be extended to every Iranian family, with attention to the number of 17495646 Iranian family and area of Miankaleh wetland (68800 ha), annual preservative value of this wetland per each hectare, was approximately determined as 2271.74 US Dollars.
Due to the importance of natural resources in survival of nature and maintenance of sustainable development, the preservation of these resources needs to be considered. In this regard, Miankaleh wetland as one of the two international wetland in north of Iran, plays a key role in survival of natural ecosystems. After determination of model, the average WTP of every individual family for preservation of this wetland was calculated as 0.7476 US Dollars per month, which can be used as a base to optimize the financial policy making process in Mazandaran province. With attention to this value, the annual preservative value of this wetland would be about 2271.74 US Dollar per hectare.
