حساسیت دمایی نرخ دی‌اکسیدکربن متصاعد‌شده از خاک توده جنگلی راش- ممرز (پژوهش موردی: جنگل شصت‌کلاته گرگان)

نوع مقاله : علمی- پژوهشی

نویسندگان

1 دانشجوی دکتری جنگل‌شناسی و اکولوژی جنگل، دانشکده علوم جنگل، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران

2 دانشیار، دانشکده علوم جنگل، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران

3 دانشیار، بخش تحقیقات جنگل، مؤسسه تحقیقات جنگل‌ها و مراتع کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران

چکیده

چگونگی اثرات تغییر دما بر تنفس خاک از ناشناخته‌هایی است که موجب عدم قطعیت در پیش‌بینی وضعیت آینده چرخه جهانی کربن می‌شود. حساسیت دمایی تنفس خاک (Q10) مؤلفه‌ای کلیدی به‌منظور تخمین بازخورد تنفس خاک به گرمایش جهانی است. هدف از پژوهش پیش‌‌‌رو، بررسی حساسیت دمایی تنفس کل خاک براساس تغییرات سالانه دما و محتوای رطوبتی خاک در یک توده راش- ممرز بود. به‌منظور انجام این پژوهش، ابتدا 12 قطعه‌نمونه به ابعاد 3 × 3 متر (شش قطعه‌نمونه در زیر تاج‌پوشش و شش قطعه‌نمونه در روشنه) مشخص شد. سپس نمونه‌برداری در سه نقطه تصادفی از هر قطعه‌نمونه انجام شد. تنفس ماهانه خاک با استفاده از چمبر دینامیکی بسته در نقاط تعیین‌شده طی یک سال اندازه‌گیری شد. نتایج این پژوهش بیانگر همبستگی معنی‌دار بین حساسیت دمایی تنفس خاک و متغیرهای محیطی شامل دمای خاک، محتوای رطوبتی خاک و دمای هوا در سطوح اطمینان 95 و 99 درصد بود. همچنین، حساسیت دمایی تنفس خاک در قطعه‌نمونه‌های زیر تاج‌پوشش بیشتر از روشنه بود. در حالی‌که کمترین نرخ تنفس خاک در فصل زمستان مشاهده شد (0/94 میکرومول بر متر مربع در ثانیه)، بیشترین حساسیت دمایی تنفس خاک نیز به همین فصل و قطعه‌نمونه زیر تاج‌پوشش (4/23) اختصاص یافت. بر این‌ اساس، افزایش جزئی در دمای خاک به‌ویژه در فصل زمستان منجر به تغییر چشمگیری در نرخ تنفس کل خاک و به‌هم‌خوردن تعادل چرخه کربن در توده‌های جنگلی این منطقه خواهد شد.

کلیدواژه‌ها


عنوان مقاله [English]

Temperature sensitivity of soil carbon dioxide efflux in beech-hornbeam stand (Case study: Shast-kalateh Forest, Gorgan)

نویسندگان [English]

  • Fatemeh Rafiee 1
  • Hashem Habashi 2
  • Ramin Rahmani 2
  • Khosro Sagheb-Talebi 3
1 Ph.D. Student of Silvicultural and Forest Ecology, Faculty of Forest Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
2 Associate Prof., Faculty of Forest Science, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
3 Associate Prof., Research Institute of Forests and Rangelands, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
چکیده [English]

The way temperature affects the soil respiration remains still unknown, which causes uncertainties in predictions of future trajectories of the global carbon cycle. Temperature sensitivity of soil respiration (Q10) is a key indicator for estimating soil respiration feedback to global warming. The purpose of this study was to investigate the temperature sensitivity of total soil respiration based on temporal changes in soil temperature and moisture contents in a beech-hornbeam stand. Therefore, we first determined 12 sample plots (six sample plots in the gaps and six under canopy cover) with 3×3-meter dimension. Sampling was conducted in three randomized points of each sample plot. At each sample point, soil respiration was monthly measured using a closed dynamic chamber throughout the year. The results showed a significant correlation between Q10 and some environmental variables, including soil temperature and moisture contents and also air temperature (p < 0.05 and p < 0.01). In addition, the temperature sensitivity of soil respiration was higher under canopy cover plots than that of in gaps. Although the lowest soil respiration rate was observed in winter (0.94 mmol m-2 s-1), the highest temperature sensitivity of soil respiration in this season (4.23) was observed under canopy cover plots. Thus, a slight increase in soil temperature, especially in winter, would result in a significant change in the rate of respiration of the entire soil and the adoption of a carbon cycle equilibrium in the forest stands of this area.

کلیدواژه‌ها [English]

  • Climate changes
  • global warming
  • Q10
  • soil temperature and moisture contents
  • temperature sensitivity of soil respiration
- Ågren, G.I. and Wetterstedt, J.A.M., 2007. What determines the temperature response of soil organic matter decomposition? Soil Biology and Biochemistry, 39(7): 1794-1798.
- Bellassen, V. and Luyssaert, S., 2014. Carbon sequestration: managing forest in uncertain times. Nature, 506(7487): 153-155.
- Boone, R.D., Nadelhoffer, K.J., Canary, J.D. and Kaye, J.P., 1998. Roots exert a strong influence on the temperature sensitivity of soil respiration. Nature, 396: 570-572.
- Chen, B., Liu, S., Ge, J. and Chu, J., 2010. Annual and seasonal variations of Q10 soil respiration in the sub-alpine forests of the Eastern Qinghai-Tibet Plateau, China. Soil Biology and Biochemistry, 42(10): 1735-1742.
- Curiel Yuste, J., Janssens, I.A., Carrara, A. and Ceulemans, R., 2004. Annual Q10 of soil respiration reflects plant phonological patterns as well as temperature sensitivity. Global Change Biology, 10(2): 161-169.
- Davidson, E.A., Richardson, A.D., Savage, K.E. and Hollinger, D.Y., 2006. A distinct seasonal pattern of the ratio of soil respiration to total ecosystem respiration in a spruce-dominated forest. Global Change Biology, 12(2): 230-239.
- Davidson, E.A. and Janssens, I.A., 2006. Temperature sensitivity of soil carbon decomposition and feedbacks to climate change. Nature, 440(7081): 165-173.
- Fierer, N., Colman, B.P., Schimel, P.J and Jackson, R.B., 2006. Predicting the temperature dependence of microbial respiration in soil: A continental-scale analysis. Global Biogeochemical Cycles, 20(3): 1-10.
- Anonymous, 1995. Forest Management Plan. District 1 Dr. Bahramnia forest, Watershed 85. Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, 252p (In Persian).
- IPCC, 2007. Climate Change 2007: The Physical Sciences Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M.M.B. and Miller, H.L. (Eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 996p.
- Jafari Haghighi, M., 2003. Methods of Soil Analysis: Sampling and Important Physical & Chemical Analysis. Nedaye Zoha Press, Sari, 236p (In Persian).
- Janssens, I.A. and Pilegaard, K., 2003. Large seasonal changes in Q10 of soil respiration in a beech forest. Global Change Biology, 9(6): 911-918.
- Jiang, H., Deng, Q., Zhou, G., Hang, D., Zhang, D., Liu, S., Chu, G. and Li, J., 2013. Responses of soil respiration and its temperature/moisture sensitivity to precipitation in three subtropical forests in southern China. Biogeosciences, 10(2): 3963-3982.
- Joos, O., Hagedorn, F., Heim, A., Gilgen, A.K., Schmidt, M.W.I., Siegwolf, R.T.W. and Buchmann, N., 2010. Summer drought reduces total and litter-derived soil CO2 effluxes in temperate grassland - clues from a 13C litter addition experiment. Biogeosciences, 7: 1031-1041.
- Kuzyakov, Y. and Cheng, W., 2001. Photosynthesis controls of rhizosphere respiration and organic matter decomposition. Soil Biology and Biochemistry, 33(14): 1915-1925.
- Lal, R., 2005. Forest soil and carbon sequestration. Forest Ecology and Management, 220(1-3): 242-258.
- Marvie-Mohadjer, M.R., 2011. Silviculture. University of Tehran Press, Tehran, 418p (In Persian).
- Ma, Y., Piao, S., Sun, Z., Lin, X., Wang, T., Yue, C. and Yang, Y., 2014. Stand ages regulate the response of soil respiration to temperature in a Larix principis-rupprechtii plantation. Agricultural and Forest Meteorology, 184: 179-187.
- Mikan, C.J., Schimel, J.P. and Doyle, A.P., 2002. Temperature controls of microbial respiration in arctic tundra soils above and below freezing. Soil Biology and Biochemistry, 34(11): 1785-1795.
- Muscolo, A., Sidari, M. and Mercurio, R., 2007. Variations in soil chemical properties and microbial biomass in artificial gaps in silver fire stands. European Journal of Forest Research, 126(1): 59-65.
- Nadelhoffer, K.J., Giblin, A.E., Shaver, G.R. and Linkins, A.E., 1992. Microbial processes and plant nutrient availability in arctic soils: 281-300. In: Chapin III, F.S., Jefferies, R.L., Reynolds, J.F., Shaver, G.R. and Svoboda, J. (Eds.). Arctic Ecosystems in a Changing Climate: An Ecophysiological Perspective. Academic Press, San Diego, California, 468p.
- Piao, S., Ciais, P., Friedlingstein, P., Peylin, P., Reichstein, M., Luyssaert, S., Margolis, H., Fang, J., Barr, A., Chen, A., Grelle, A., Hollinger, D.Y., Laurila, T., Lindroth, A., Richardson, A.D. and Vesala, T., 2008. Net carbon dioxide losses of northern ecosystems in response to autumn warming. Nature, 451: 49-52.
- Rafiee, F., Habashi, H., Rahmani, R. and Sagheb-Talebi, Kh., 2017. Effect of selection system on variability of some soil microbiological parameters in mixed beech stand of Hyrcanian forests. Journal of Forest Research and Development, 3(3): 191-205 (In Persian).
- Raich, J.W. and Schlesinger, W.H., 1992. The global carbon dioxide flux in soil respiration and its relationship to vegetation and climate. Tellus B, 44(2): 81-99.
- Rasaneh, Y., Moshtagh Kahnamoie, M.H. and Salehi, P., 2001. Quantitative and qualitative investigation on forests of northern Iran. Proceedings of the National Conference on Management of Northern Forests and Sustainable Development. Ramsar, Iran, 6-7 Sep. 2001: 55-79 (In Persian).
- Sampson, D.A., Janssens, I.A., Curiel Yuste, J. and Ceulemans, R., 2007. Basal rates of soil respiration are correlated with photosynthesis in a mixed temperate forest. Global Change Biology, 13(9): 2008-2017.
- Subke, J.A. and Bahn, M., 2010. On the ‘temperature sensitivity’ of soil respiration: Can we use the immeasurable to predict the unknown? Soil Biology and Biochemistry, 42(9): 1653-1656.
- Suchewaboripont, V., Ando, M., Iimura, Y., Yoshitake, S. and Ohtsuka, T., 2015. The effect of canopy structure on soil respiration in an old-growth beech-oak forest in central Japan. Ecological Research, 30(5): 867-877.
- van’t Hoff, J.H., 1899. Lectures on Theoretical and Physical Chemistry. Edward Arnold Publishers Ltd, London, UK, 156p.
- Walkley, A. and Black, I.A., 1934. An examination of the Degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method. Soil Science, 37(1): 29-38.
- Wang, X., Piao, S., Ciais, P., Janssens, I.A., Reichstein, M., Peng, S. and Wang, T., 2010. Are ecological gradients in seasonal Q10 of soil respiration explained by climate or by vegetation seasonality? Soil Biology and Biochemistry, 42(10): 1728-1734.
- Xu, M. and Qi, Y., 2001. Spatial and seasonal variations of Q10 determined by soil respiration measurements at a Sierra Nevadan forest. Global Biogeochemical Cycles, 15(3): 687-696.
- Yu, S., Chen, Y., Zhao, J., Fu, S., Li, Z., Xia, H. and Zhou, L., 2017. Temperature sensitivity of total soil respiration and its heterotrophic and autotrophic components in six vegetation types of subtropical China. Science of the Total Environment, 607-608: 160-167.
- Zheng, Z.M., Yu, G.R., Fu, Y.L., Wang, Y.S., Sun, X.M. and Wang, Y.H., 2009. Temperature sensitivity of soil respiration is affected by prevailing climatic conditions and soil organic carbon content: A trans-China based case study. Soil Biology and Biochemistry, 41(7): 1531-1540.