نوع مقاله : مقاله پژوهشی
نویسندگان
1 بخش تحقیقات منابع طبیعی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی گلستان، گرگان، ایران
2 گروه جنگلداری، دانشکده منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، تهران، ایران
3 موسسه آموزش و ترویج کشاورزی، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
چکیده
کلیدواژه‌ها
موضوعات
Extended Abstract
Objectives
Certain regions of Golestan Province, particularly in the Gonbad-e Kavous county, experience semi-arid and arid climates influenced by the proximity to the Qaraqom Desert in Turkmenistan. These conditions have resulted in reduced quantity and quality of rangeland and tree cover. Climate change and decreasing precipitation, coupled with the mismanagement of water resources, have adversely impacted the livelihoods of local communities, leading to desertification and increased dust storms. To combat this situation, the development of tree cover through afforestation and agroforestry has been proposed as solutions for controlling desertification, expanding green spaces, and supporting local livelihoods.
Agroforestry programs are of significant importance, especially following the cessation of logging in the northern forests of the country, which previously met less than 15% of the wood industry’s demand. The country’s wood demand is approximately 14 million cubic meters, of which less than 3 million cubic meters are produced through agroforestry and orchards, with the remainder being imported. Golestan Province, with an annual wood demand exceeding 500,000 tons for industrial purposes, has the potential to meet this demand through the expansion of agroforestry.
Utilizing GIS techniques and multi-criteria analyses can aid in identifying suitable areas for agroforestry. This study employs these techniques and a weighted linear combination approach to determine suitable areas for agroforestry in the Gonbad-e Kavous county. Spatial modeling and multi-criteria evaluation can produce land suitability maps for agroforestry, highlighting the critical role of climatic factors in developing these maps.
Methods
Gonbad-e Kavous County, covering an area of 5008.55 square kilometers, accounts for 24.59% of Golestan Province. This county is located at 37°17' N latitude and 55°18' E longitude, sharing a border with Turkmenistan, with an average elevation of 50 meters above sea level. Annual rainfall varies between 200 and 400 millimeters, dropping below 250 millimeters in northern regions.
This descriptive-analytical study, using existing data and field surveys, aimed to identify suitable areas for cultivating Populus euphratica in Gonbad-e Kavous. Due to the uniformity of the topography, factors such as elevation, slope direction, and slope percentage were excluded from the modeling. Fourteen variables were considered, including climatic factors (minimum temperature, annual average temperature, maximum temperature, annual rainfall, growing season rainfall, average annual humidity, and number of frost days), soil factors (soil texture, pH, Electrical Conductivity (EC)), and four factors related to distance from surface water, roads, groundwater depth maps, and land use.
Climatic data were obtained from synoptic and climatology stations, soil characteristics from agricultural maps, distances from roads and surface water from the Ministry of Roads and Urban Development and the Regional Water Company, and land use maps from the General Department of Natural Resources and Watershed Management. Maps were analyzed using ArcGIS 10.8 and IDRISI TerrSet2020 software and converted to raster format with 50×50 meters dimensions.
Value standardization was performed using the fuzzy method, and criteria weighting was conducted using the Analytic Hierarchy Process (AHP). Weighting questionnaires were distributed to 10 agroforestry experts. To determine the potential for agroforestry, a weighted linear combination model was applied. Data standardization adjusted the layer values to a range between 0 and 255. The accuracy and validity of the weighting were assessed using the consistency index; a consistency ratio of 0.1 or less indicated correct weighting.
After determining the weight of each criterion, multi-criteria evaluation was performed by overlaying the layers in the GIS system, resulting in the final land suitability map for agroforestry.
Results
In this study, annual precipitation, with a weight of 0.1767, had the greatest impact among the factors examined. The northwestern regions of Gonbad-e Kavous exhibited the highest minimum, annual average, and maximum temperatures, and experienced the most prolonged frost periods. The average relative humidity in all areas was above 60%. The results indicated that climatic factors were the most critical for the success of agroforestry, with northern and northwestern areas facing significant challenges due to reduced rainfall, while southern areas benefitted from proximity to the Hyrcanian forests and a temperate climate.
The soil textures of silty clay loam and silty loam with a pH between 7 and 8.3 were found to be suitable for the growth of Populus euphratica, and soil EC was observed to be less than 4 dS/m in most regions. Proximity to surface water and groundwater depth also played important roles in the development of Populus euphratica agroforestry. Areas near perennial and seasonal rivers and regions with a high groundwater table could adequately meet the water requirements of this species. Conversely, northern regions, due to the lack of suitable water resources, were less suitable for agroforestry with this species.
The study revealed that while Populus euphratica exhibits high tolerance to temperature and EC, its growth is limited in areas with high temperatures and low precipitation. Overall, the southern and central regions of Gonbad-e Kavous were found to be more suitable for Populus euphratica agroforestry, whereas the northern and northwestern areas were less suitable due to drought stress and soil EC challenges.
Discussion
This study aimed to identify suitable areas for the cultivation of Populus euphratica in Gonbad-e Kavous. The climatic maps indicate that the northwestern and western regions of the county, including Incheh Borun, receive low precipitation. Despite the presence of the Atrak River, the potential for planting depends on the river's flow rate. Ten years of meteorological data reveal that the southern regions have better climatic conditions. Maps of proximity to surface water and groundwater depth also highlight the suitability of the southern regions. Due to the high-water demand of Populus euphratica, it is recommended that this species not be planted in areas experiencing significant drought stress. The central and southern regions of the county are more suitable for its cultivation.
The land suitability map for agroforestry shows that the southern and central regions, including the Masan and Haji Qushan areas, are suitable for the development of agroforestry. Soil EC in the northwestern regions is a significant challenge. Populus euphratica naturally grows in arid and semi-arid areas with nearby surface or subsurface water, conditions not present in the northern regions. Based on the research findings, focusing on areas with Suitable and Very Suitable potential identified in the map, along with providing financial facilities, guaranteed wood purchase, training of operators, and coordination between relevant institutions, can effectively accelerate the development of wood farming. Therefore, the following recommendations are made:
Pre-purchase wood products by particle board factories and reimburse owners and smallholders throughout the year to make wood products competitive with agricultural products.
For research articles with several authors, a short paragraph specifying their individual contributions must be provided. The following statements should be used “Conceptualization, X.X. and Y.Y.; methodology, X.X.; software, X.X.; validation, X.X., Y.Y. and Z.Z.; formal analysis, X.X.; investigation, X.X.; resources, X.X.; data curation, X.X.; writing—original draft preparation, X.X.; writing—review and editing, X.X.; visualization, X.X.; supervision, X.X.; project administration, X.X.; funding acquisition, Y.Y. All authors have read and agreed to the published version of the manuscript.” Please turn to the CRediT taxonomy for the term explanation. Authorship must be limited to those who have contributed substantially to the work re-ported.
All authors contributed equally to the conceptualization of the article and writing of the original and subsequent drafts.
In this section, please provide details regarding where data supporting reported results can be found, including links to publicly archived datasets analyzed or generated during the study (see examples). Data available on request from the authors.
If the study did not report any data, you might add “Not applicable” here.
The Acknowledgments section should be a few sentences at the end, but it is important to recognize those people (organizations and individuals) who made considerable impact on the research, provided significant help to the author to formulate and complete the experiment, and improved the research at any stage (from providing access to equipment or field sites to editing the manuscript). However, this is an optional section.
In this section, you can acknowledge any support given which is not covered by the author contribution or funding sections. This may include administrative and technical support, or donations in kind (e.g., materials used for experiments).
The authors would like to thank all participants of the present study.
The study was approved by the Ethics Committee of the University of ABCD (Ethical code: IR.UT.RES.2024.500). The authors avoided data fabrication, falsification, plagiarism, and misconduct.
The author declares no conflict of interest.
The author declares no conflict of interest.
)