آيا تغيير اقليم فرصت است يا تهديد؟ (ارزيابي دگرگوني‌هاي محتمل اقليمي بر محدوده كشت درختان مناطق گرمسيري ايران، مطالعه موردي؛ نخل خرما)

Whether climate change is an opportunity or a threat? Evaluation of Potential Climate Change on Tropical Trees of Iran, Case Study: Palm Dates

بخش كشاورزي و زيربخش باغباني، يكي از حساسترين و آسيب پذيرترين بخشها نسبت به تغييرات آب و هوايي محسوب مي شود. تحقيق حاضر در صدد پاسخ به اين سوال تحقيق بوده كه آيا تغييرات آب و هوايي براي درختان نواحي گرمسيري ميتواند فرصت باشد يا تهديد. در اين راستا، در ابتدا محدوده كشت نخل خرما در دوره حاضر در ايران براساس اطلاعات اقليمي مشخص شد. در ادامه روند بلند مدت مناطق كشت نخل براساس شاخص هاي اقليم كشاورزي موثر بررسي شد. در ادامه براساس مدلهاي CMIP5 در پايگاه MarksimGCM براساس دو خط سير واداشتي بدبينانه و حد وسط RCP8.5 و RCP4.5، پيش نگري وضعيت آب و هواي دوره آينده در مقايسه با دوره پايه مشخص گرديد. نتايج نشان داد كه براساس تحليل روند فراسنج هاي اقليمي موثر، روند افزايشي معني داري در مناطق كشت نخل ايران در دوره پايه وجود دارد. اين روند افزايشي براي مولفه هاي دمايي مانند دماي كمينه و بيشينه، روزهاي داغ و انباشت گرمايي در آستانه هاي زيستي و رويشي نخل خرما حائز اهميت مي باشد. براساس داده پيش نگري شده و افزايش دماي هوا در مناطق مجاور نخل خرما و عرضهاي بالاتر در فلات مركزي ايران نشان داد كه در اين مناطق پتانسيل گرمايي از نظر دماي كمينه، بيشينه و توان گرمايي براي رشد و نمو در آستانه هاي زيستي و رويشي درختان خرما وجود دارد. بنابراين تغييرات آّب و هوايي براي درخت گرمسيري نخل خرما در مناطق عرضهاي بالاتر و مجاور در نواحي داخلي و شرقي ايران، فرصت لازم براي رشد و نمو را فراهم مي سازد. بنابراين مناطق كويري و بياباني در نواحي داخلي كشور ايران، پتانسيل اقليمي لازم براي كشت درختان خرما را دارا مي باشد. تغيير برنامه هاي راهبردي در جهت توسعه اين محصول ارزشمند در اين نواحي حائز اهميت مي باشد...

Introuction Climate is one of the most important factors in human history and less agricultural activity that does not deal with one or more meteorological factors during the day. This is due to the important role climate that plays in human life, especially agricultural production. Climate plays a key role in the growth and production of crops and its changes directly affect the planting and cultivation of crops. Since the last two decades of the 20th century, the issue of climate change has become one of the most important challenges for mankind. Concerns about the decline in crop yields and food security are among the issues that have raised the issue worldwide. Long-term forecasts of climate change have been considered by various experts to inform the extent of the changes and thus take the necessary measures to mitigate the adverse effects of climate change. In general, the present study seeks to answer this research question; could climate change be a threat or an opportunity under the conditions of future climate change, and the effects on date palm? Matrial and Methods The present study seeks to answer the question of whether climate change can be an opportunity or threat for tropical trees. In this regard, at first, the date palm cultivation areas in Iran was determined based on climatic data. The long-term trend of palm cultivation areas was then evaluated based on effective agro-climatic indices. Then, based on the CMIP5 models at MarksimGCM database, based on the two radiative forcing RCP8.5 and RCP4.5, the projection of future climate conditions was compared with the baseline period. Results The results showed that based on the analysis of effective climatic parameters, there was a significant increasing trend in the area of palm cultivation in Iran. This incremental trend is important for temperature components such as minimum and maximum temperatures, hot days, and thermal accumulation in the palm tree's biological and vegetative thresholds. Based on the projected data and the increase in air temperature in the adjacent areas of date palm and higher latitudes in the central plateau of Iran showed that in these areas the thermal potential in terms of minimum temperature, maximum temperature and thermal accumulation for growth and development in the palm tree's biological and vegetative thresholds. Therefore, climate change for the palm tropical tree in higher latitudes and adjacent areas in the inner and eastern parts of Iran provides the opportunity for growth. Therefore, desert areas in the interior of Iran have the potential of climatic conditions for palm tree cultivation. It is important to change the strategic plans to develop this valuable product in these areas. Discussion In general, the results of the present study showed that: With the increase of air temperature and higher thermal accumulation in high latitudes and adjacent areas and similar to the palm cultivation zones in Iran, in fact new zones of central zones, climatic conditions and temperature potential for cultivation are needed. The palm will enjoy. Conclusion The results showed that according to the observation data of date palm cultivation areas in the baseline period (1985-2015), there is a significant increasing trend in effective climatic parameters. Evaluation of thermal accumulation at the palm biomass and vegetative thresholds showed that there was an increasing trend in the long-term thermal accumulation series at the baseline period. Evaluation of effective climatic parameters (minimum and maximum temperature and thermal accumulation in date palm biomass and vegetation) based on projected data in adjacent regions and higher latitudes in the central Iranian plateau showed that in these areas, the thermal potential in terms of minimum temperature, maximum and there is the potential for heat to grow in the palm tree's biomass. Therefore, climate change for the palm tropical tree in higher latitudes and adjacent areas in the inner and eastern parts of Iran provides the opportunity for growth.