Investigation and Comparison of the Economic Value of Carbon Sequestration Function of Vegetation Cover in Biological Operations (Case study: Sarbishe Rangelands-South Khorasan Province)

One of the most important ecological functions of rangelands especially destroyed rangelands is the high potential of carbon sequestration as the most important greenhouse gasses. Restoration of destroyed Irans’ dry lands has an important role in environmental plans. So this study was aimed to investigate the effect of range plants vegetation recovery operations on the economic value of carbon sequestration. For this purpose, three types of restoration plans, the construction of shrub planting, seeding and crescent waterfall, besides control sited were identified. The carbon tax policy method was used to estimate the amount of carbon sequestrated. According to the results, the carbon capture rate in the rangelands of the study area was estimated at 774 tons. The value of each hectare of the rangelands for carbon sequestration function estimated at $17.35 (equivalent to $ 60,744). According to the results, management factors such as recovery operations have played an important role in controlling carbon sequestration. Also, the treatment of carbon sequestration activity of the brush planting, significantly improved the ecological indices and the value of carbon sequestration compared to the control areas.
Introduction:
Rangeland ecosystems have high capability in carbon sequestration, because they have taken half of the surface of the earth and their carbon storage accounts for 10% of the total carbon stock of biomass in ecosystems and 30% of total soil carbon stock. However, carbon sequestration capacity in rangelands is less than forests, but due to the large extent of these ecosystems, management of these areas plays an important role in the carbon cycle. For this reason carbon sequestration in addition to the protective value has an economic value and it can be as an additional benefit of destruction operation of destroyed lands. Destruction operations such as restoration and protection of vegetation of pastures to increase carbon sequestration in soil and plant has other benefits such as ecosystem services. To increase carbon sequestration in arid and semi-arid regions planting methods are usually used. Using bush plants by deep root can absorb water from deep soil which normally is not available by existing plants in this areas. Su-Yong and Zao (2003), Hill et al (2003); Schuman and Derner (2007) stated management factors has an important role in soil carbon sequestration and the result of their research showed that under managed range management systems, total soil carbon sequestration, has increased significantly in biomass, litter and soil. So, increasing carbon sequestration through vegetation regeneration is equivalent to increasing plant biomass, increase production and improving land fertility. For this reason, in addition to basic and protective values, has also economically value. Considering the growing importance of greenhouse gases in the world and the importance issue of global warming and increasing co2 is not applicable to a particular country, there are a lot of ambiguous issues related to the ability of the types and different range plants in soil carbon sequestration and their economic value. Responding to these issues depends on extensive researches. Therefore, the present study aims to estimate and comparison the economic value of succeeded aboveground biomass of range plants.

Materials & Methods
Hossein-Abad basin is located 40 km away from Sarbishe city, in the south khorasan province adjacent to the Afghanistan border. In order to compare destruction operation 3 sites were selected. The sites located at Hossein-Abad in 79° 90' - 80° 55' E and 36° 01' and 36° 04' N, Abbas-Abad in 78° 65' - 78° 79' E and 36° 08'- 36° 11 N', Janat Abad in 78° 20'-78° 50' E and 36° 07'- 36° 09' N were selected. The average elevation of the area is 1830 m. Hossein-Abad rangelands receives an annual precipitation of 188 mm and its average annual temperature approximate 14.5 C°. To measure carbon sequestration in plant, 3 transect 200 m at a distance of 30 meters from each other were established. 10 (3m2) were established in each transect. Specified herbaceous species and their density were measured. To determine the coefficient of carbon sequestration of species into organic carbon, the combustion method was used. The ash of the samples was weighed after cooling in the desiccator. By determining the weight of the ash and with the weight of the original and the ratio of organic carbon to organic matter the amount of organic carbon in each of the plant organs was calculated separately. For valuing carbon sequestration function, carbon tax policy and the cost of emissions was used as a shadow value for carbon sequestration.

Discussion of Results
There was a significant difference in comparison of the mean of destruction operations with control area in terms of percentage of vegetation, forage production and litter indicators table (1), (2) and (3).

Table (1)- t test results for shrub destruction operations and control area
Feature Degrees of freedom
t

Plant vegetation cover 58 17.1**
Forage production 58 10.8**
Litter percentage 58 19**

Table (2)- t test results for crescent waterfall destruction operations and control area
Feature Degrees of freedom
t

Plant vegetation cover 58 13.9**
Forage production 58 11.3**
Litter percentage 58 9.3**

Table (3)- t test results for seeding operations and control area
Feature Degrees of freedom
t

Plant vegetation cover 58 13.6**
Forage production 58 7.3**
Litter percentage 58 13.1**


The results of the variance analysis between destruction operations and control sites forage production showed that there was significant difference between the sites of carbon sequestration project and the control site.

Table (4)- Analysis of variance of site type and destruction operations on organic carbon
Feature Degrees of freedom Mean squares
F
Site 1 7670.1 **378.5
Kinds of destruction operations 2 172.5 8.5*
error 176 20.2

- Carbon sequestration in plant
Results of carbon sequestration in plant has shown in table (5). In organic carbon construction operation, dominant plants in shrub planting operation were Atriplex canescen, Haloxylon persicum, Artemisia sieberi, Zygophyllum atripoides.
Table (5)-
sites Kind of operation Area (ha) Dominant plant Density (ha) Average carbon in plants (gr) Total organic carbon in plant (ha)
organic carbon (kg/ha)
carbon sequestration
($/ton) Total organic carbon (ton)
Destruction operation site Shrub
planting 1472 A.Canesces 209 133.61 27.92 343 8.67 504.8
P. Haloxylon 213 254.81 54.27
A.sieberi 10520 21.2 223
z. atripoides 268 141.1 37.81
Crescent waterfall 1311 A.Canesces 155 129.6 20.08 220 5.56 288.4
P. Haloxylon 218 238.3 51.94
A.sieberi 7150 20.7 148
Seeding 370 P. Haloxylon 280 240.6 67.3 171 4.32 63.2
A.sieberi 6030 17.2 103.7
Sum 856.4
Control site Shrub
planting 1472 A.sieberi 1653 9.4 15.53 41.75 10.5 61.4
A.camelorum 2081 12.6 26.22
Crescent waterfall 1311 A.sieberi 652 6.5 4.23 12.64 3.18 16.57
A.camelorum 956 8.8 8.41
Seeding 370 A.sieberi 709 7.2 5.1 11.79 2.9 4.36
A.camelorum 1015 6.6 6.69
sum 82.33

- Valuing Carbon sequestration in plant
Table (6)- Comparison of carbon sequestration levels and its economic value
sites Total organic carbon (ton) Total Economic value of C ($/ton/yr) Total Economic value of C (Rial/ton/yr) Economic value of C sequestration (Rial/ha/yr)
Destruction operation site 856.4 60547.48 211916180 67210.96
Control site 82.33 5820.73 203725550 64613.24
Carbon sequestrated weigh 774 5421.8 191526300 60744.15
Conclusions
In this study, to estimate the amount of carbon sequestrated in the plant, considering the cost of measurement, only the dominant species of rangelands of the region were measured. So, it is recommended to measure a whole plant species c sequestration in the region. Also, in selecting suitable species for destruction operations the ability of species in carbon sequestration is one of the indices for selecting the appropriate specie. Considering different valuation methods, it is suggested that the economic value of carbon sequestration in the study area compare with other methods of economic valuation and their results with each other.