بررسی ترکیب بانک بذر خاک محدوده مرزی و قسمت‌های مرکزی رویشگاه جنگلی (مطالعه موردی: حوضه واز در استان مازندران)

نوع مقاله: علمی- پژوهشی

نویسندگان

1 استادیار، دانشکده منابع طبیعی و علوم دریایی دانشگاه تربیت مدرس

2 دانش آموخته کارشناسی ارشد مرتع‌داری، دانشکده منابع طبیعی و علوم دریایی دانشگاه تربیت مدرس

چکیده

 
تحقیق حاضر با هدف مقایسه خصوصیات بانک بذر خاک (تراکم، تشابه بانک بذر خاک با پوشش روزمینی و تنوع گونه­ای) قسمتهای مرکزی رویشگاه جنگلی و محدوده مرزی آن (مرز بین جنگل و مرتع) به‌عنوان دو رویشگاه با تراکم تاج‌پوشش درختی متفاوت انجام شد. در هر رویشگاه هفت ترانسکت با فاصله 25 متر از یکدیگر مستقر شدند. سپس نمونه­های خاک از اعماق 5-0 و 10-5 سانتی‌متری از داخل پلاتهای 2 مترمربعی برداشت و پس از اعمال تیمار سرما به گلخانه منتقل و کشت شدند. بذرهای ظهور یافته هر دو هفته یکبار شناسایی و حذف گردید. تشابه بانک بذر با پوشش روزمینی با استفاده از شاخص تشابه سورنسون و تنوع گونه­ای با استفاده از شاخص تنوع شانون- وینر محاسبه گردید. در نهایت خصوصیات بانک بذر خاک (تراکم، تشابه بانک بذر خاک با پوشش روزمینی و تنوع گونه‌ای) با استفاده از آزمون t مستقل بین دو رویشگاه مقایسه شد. نتایج نشان داد که تراکم، تنوع گونه­ای بانک بذر خاک در منطقه مرزی به‌طور معنی­داری بیشتر از منطقه مرکزی جنگلی بود. در هر دو رویشگاه تشابه ضعیفی بین بانک بذر خاک با پوشش روزمینی وجود داشت. ضمن اینکه تشابه بانک بذر خاک با پوشش روزمینی عمق سطحی در منطقه جنگلی به‌طور معنی­داری بیشتر از محدوده جنگل- مرتع بود. تراکم و تنوع گونه­ای بانک بذر نیز در عمق سطحی به‌طور معنی­داری بیشتر از عمق پایینی بود. به‌طور کلی می­توان گفت که منطقه مرزی به‌علت داشتن فضای بازتر تاج‌پوشش درختی، موقعیت قرارگیری و تنوع گونه­ای بیشتر نسبت به قسمتهای داخلی مرکزی دارای بانک بذر غنی­تری می­باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Investigation of soil seed bank composition in boundary and interior of forest habitat (case study: Vaz watershed in Mazandaran province)

نویسندگان [English]

  • Reza Erfanzadeh 1
  • Sayyed Hamze Hosseini Kahnuj 2
1 Assistant professor, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University
2 M.Sc. graduated, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University
چکیده [English]

This study aimed to compare soil seed bank characteristics (density, species diversity and similarity with above ground vegetation) between the boundary and interior of forest habitat. Boundary and interior of forest habitat were different in term of the cover percentage of woody plants. Therefore, the zone between forest and rangeland was selected as non-dense forest (Ecotone) with less cover percentage of woody plants and the interior of forest adjacent to the ecotone was selected as dense forest habitat with higher cover percentage of woody plants. In each habitat, seven transects were established with 25 m distance between transects. Then, soil sampling was done using quadrates in two depths: 0-5 and 5-10 cm. After the chilling treatment, soil samples were transferred and spread in the greenhouse. Germinated plant species were identified, counted and then removed. On the other hand, the percentage cover of plant species in each plot was recorded in the growth season. Finally, the number of seeds germinated in the greenhouse was recalculated per square meter and then the similarity between seed bank and aboveground vegetation was calculated in each plot using Sorenson’s similarity index. Non-paired t-test was applied to compare soil seed bank characteristics between the two depths and between the two habitats. The results showed that seed density and species diversity were significantly higher in the ecotone than the dense forest. The density and species diversity of soil seed bank was significantly higher in the upper layer than the deeper layer. There was low similarity between soil seed bank and aboveground vegetation in the both habitats. However, the similarity between seed bank related to upper layer was significantly higher in the dense forest than the ecotone. It can be concluded that ecotone zone has more enrichment from interior part of the forest due to more open crown cover, position and more species diversity.

کلیدواژه‌ها [English]

  • Seed density
  • Canopy cover density
  • species diversity
  • above ground vegetation
  • Sorenson’s similarity index
  • ecotone zone
- Akbarzadeh, M., 2005. Study on changing of above ground vegetation and soil seed bank in steppic and semi-steppic region. Ph.D. Thesis, Tehran University, 153p.

- Augusto, L., Dupouey, J.L., Picard, J.F. and Ranger, J., 2001. Potential contribution of the seed bank in coniferous plantations to the restoration of native deciduous forest vegetation. Acta Oecologica, 22: 87-98.

- Baskin, C.C., 1998. Seeds: ecology, biogeography and evolution of dormancy and germination. Academic Press, New York, 2: 204-205.

- Bertiller, M. and Aloia, A., 1997. Seed bank strategies in Patagonia semi-arid grasslands in relation to their management and conservation. Biodiversity and Conservation, 6(4): 639-650.

- Bossuyt, B. and Hermy, M., 2001. Influence of land use history on seed banks in European temperate forest ecosystems: a review. Ecography, 24: 225-238.

- Bossuyt, B., Heyn, M. and Hermy, M., 2002. Seed bank and vegetation composition of forest stands of varying age in central Belgium: consequences for regeneration of ancient forest vegetation. Plant Ecology, 162: 33-48.

- Chaideftou, E., Thanos, C.A., Bergmeier, E.A. and Kallimanis, P., 2009. Seed bank composition and above-ground vegetation in response to grazing in sub Mediterranean oak forests (NW Greece). Plant Ecology, 201: 255-265.

- Chen J., Franklin, J.F. and Spies, T.A., 1995. Growing-season microclimatic gradients from clear cut edges into old-growth douglasfir forests. Ecological Applications, 5: 74-86.

- Daïnoua, K., Bauduina, A., Bourlanda, N., Franc, J., Gillet, O., Fétékéa, F. and Douceta, J.L., 2011. Soil seed bank characteristics in Cameroonian rainforests and implications for post-logging forest recovery. Ecological Engineering, 37(10): 1499-1506.

- Devlaeminck, P., Bossuyt, B. and Hermy, M., 2005. Inflow of seeds through the forest edge: evidence from seed bank and vegetation patterns. Plant Ecology, 176: 1-17.

- Erfanzadeh, E., Gurbutt, A., Petillon, J., Maelfati, J.P. and Hoffmann, M., 2009. Factors affecting the success of early salt-marsh colonizers: seed availability rather than site suitability and dispersal traits. Plant Ecology, 206: 335-345.

- Erfanzadeh, E., Gurbutt, A., Petillon, J., Maelfati, J.P. and Hoffmann, M., 2010 Factors affecting the success of early salt-marsh colonizers: seed availability rather than site suitability and dispersal traits. Plant Ecology, 206: 335-345.

- Gehlhausen, S.M., Schwartz, M.W. and Augspruger, C.K., 2000. Vegetation and microclimatic edge effects in two mixed-mesophytic forest fragments. Plant Ecology, 147: 21-35.

- Godefroid, S., Phatyal, Sh.S. and Koedam, N., 2006. Depth distribution and composition of seed banks under different tree layers in a managed temperate forest ecosystem. Acta Oecologia, 5: 1437-1443.

- Gross, K.L., 1990. A comparison of methods for estimating seed numbers in the soil. Journal of Ecology, 78(4): 1079-1093.

- Hegazy, A.K., Hammouda, O., Lovett-Doust, J. and Gomaa, N.H., 2009. Variations of the germinable soil seed bank along the altitudinal gradient in the north western Red Sea region. Acta Ecologica Sinica, 29: 20-29.

- Honnay, O., Verheyen, K. and Hermy, M., 2001. Permeability of ancient forest edges for weedy plant species invasion. Forest Ecology and Management, 161: 109-122.

- Khaleghi, P., 1998. The profile of the Caspian forests. Research Institute of Forests and Rangelands, Tehran, 380 p.

- Kamali, P., Erfanzadeh, R. and Ghelichniya, H. 2011. Role of soil seed bank in recovering of the degraded vegetation in Vaz watershed. Pajuhesh & Sazandegi, In press.

- Kellerman, M.J.S., 2004. Seed bank dynamics of selected vegetation types in Maputaland, South Africa. M.S. Thesis, Faculty of Natural and Agricultural Sci., Univ. of Pretoria, 107 p.

- Leckie, S., Vellend, V., Bell, G., Waterway, J.W. and Lechowicz, M.J., 2000. The seed bank in an old-growth, temperate deciduous forest. Canadian Journal of Botany, 78: 181-192.

- Lunt, I.D., 1997. Germinable soil seed banks of anthropogenic native grasslands and grassy forest remnants in temperate south-eastern Australia. Plant Ecology, 130: 21-34.

- Matlack, G.R., 1994. Plant species migration in a mixed-history forest landscape in eastern North America. Ecology, 75: 1491-1502.

- Moles, A. and Drake, D.R., 1999. Potential contribution of the seed rain and seed bank to regeneration of native forest under plantation pine in New Zealand. New Zealand Botany, 37: 83-93.

- Peterson, C.J. and Carson, W.P., 1996. Generalising forest regeneration models: the dependence of propagule availability on disturbance history and stand size. Canadian Journal of Forest Research, 26: 45-52.

- Shabazian, R., 2012. The effect of shrub lands on seed bank characteristics of mountain grasslands in Vaz watershed. M.Sc. Thesis, Tarbiat Modares University, 76 p.

- Thompson, K., 1992. The functional ecology of seed banks. In the ecology of regeneration in plant communities. CAB International, London, U.K: 231-258.

- Weathers, K.C., Cadenasso, M.L. and Pickett, S.T.A., 2001. Forest edges as nutrient and pollutant concentrators: potential synergisms between fragmentation forest canopies and the atmosphere. Conservation Biology, 15: 1506-1514.

- Zobel, M., Kalamees, R., Kersti, P., Roosaluste, E. and Mari, M., 2007. Soil seed bank and vegetation in mixed coniferous forest stands with different disturbance regimes. Forest Ecology and Management, 250: 71-76.