کاربرد شاخص‌های آماری در انتخاب طول مناسب ترانسکت، برای اندازه‌گیری پوشش گیاهی (مطالعه موردی: مراتع نیمه استپی آریز سنندج)

نوع مقاله: مقاله پژوهشی

نویسندگان

1 استادیار، گروه مرتع و آبخیزداری، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج، ایران

2 دانش‌آموخته کارشناسی ارشد مرتع‌داری، گروه مرتع و آبخیزداری، دانشکده منابع طبیعی، دانشگاه کردستان، سنندج، ایران

چکیده

     برای مدیریت صحیح و برنامه‌ریزی مناسب در مرتع، نیاز به جمع‌آوری اطلاعات کمی می‌باشد. از راه‌های دسترسی به این اطلاعات، انتخاب روش‌های مناسب نمونه‌برداری و تعیین طول مناسب ترانسکت برای اندازه‌گیری پوشش گیاهیست. با این دیدگاه، این پژوهش در مراتع آریز واقع در شمال‌غربی سنندج در فصل رویش سال 1395 انجام شد. برای این منظور، ترانسکت‌هایی با طول 20، 50، 100، 150، 200،300 و 400 متر، با چهار تکرار، در دو جهت عمود بر شیب و موازی شیب در تیپ گیاهی Festuca ovina- Bromus tomentellus مستقر شد. ترانسکت 400 متری به‌عنوان ترانسکت شاهد برای کنترل محاسبات در نظر گرفته شد. نتایج حاصل از نمونه‌برداری به‌وسیله طول‌های مختلف ترانسکت با نتایج قطعات شاهد، توسط آزمون تجزیه واریانس مقایسه شد. نتایج حاصل از طول‌های مختلف ترانسکت نیز با استفاده از شاخص دقت ((E%)2×T) با یکدیگر مقایسه شدند. مقایسات میانگین درصد پوشش گیاهی ترانسکت‌ها، با استفاده از آزمون تی انجام شد. نتایج نشان داد که ترانسکت‌های 20، 50، 100 و 150 متری با ترانسکت شاهد (400 متری) به لحاظ شاخص دقت دارای اختلاف معنی‌دار هستند. همچنین تفاوتی بین ترانسکت‌های با طول 200، 300 و 400 متری از نظر شاخص دقت وجود نداشت. بنابراین با توجه به در نظر گرفتن دقت و زمان صرف شده، کاربرد ترانسکت‌های 200 متری برای اندازه‌گیری پوشش گیاهی مراتع مورد پژوهش توصیه می‌شود.

کلیدواژه‌ها


عنوان مقاله [English]

Application of statistical indices in selecting appropriate transect length for measurement of vegetation cover (Case Study: semi-steppe rangelands of Ariz, Sanandaj)

نویسندگان [English]

  • Bahram Gholinejad 1
  • Arian Farhadi 2
  • Parviz Karami 1
1 Assistant Professor, Department of Range and Watershed Management, Faculty of Natural Resources, University of Kurdistan, Iran
2 Former M.Sc. Student in Range Management, Faculty of Natural Resources, University of Kurdistan, Iran
چکیده [English]

Collection of appropriate quantitative data is necessary for proper management and planning in rangelands. One of the ways to access this information is choosing the appropriate methods of sampling and determining the appropriate length of transect for vegetation cover measurement. Therefore, this study was conducted in 2016 in Ariz rangelands located in the northwestern of Sanandaj city. For this purpose, transects with a length of 20, 50, 100, 150, 200, 300 and 400 meters, each with four replications were established perpendicular to slope and parallel to slope in the vegetation type of Bromus tomentellus - Festuca ovina. The 400-m transect was considered as a control for calculations. The obtained data from sampling were compared by ANOVA. The obtained results from different transect lengths were also compared by (E%) 2×T factor. The mean comparisons of vegetation cover percentage of transects were performed using t-student test. According to the results of this study, the transects of 20, 50, 100 and 150m length showed a significant difference with the control transect (400 m) in terms of accuracy index ((E%) 2 × T). However, there was no significant difference among the transects of 200, 300 and 400 meters length for the accuracy index. Therefore, the application of 200-meter transect is recommended regarding the cost and time.

کلیدواژه‌ها [English]

  • Vegetation cover
  • transect length
  • Ariz rangelands
  • accuracy index
  • Sanandaj

 

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