presentation of Ingrowth models and determination of biotic and abiotic factors affecting regeneration in the Hyrcanian forests

Document Type : Research Paper

Authors

Abstract

Background and objectives: Hyrcanian is a productive region near the southern coast of Caspian Sea. Her forests are mostly uneven-aged beach-dominated hardwood mixtures. There is increasing willingness to treat these forests without clear-felling, following the ideas of continuous cover management. This paper examines the possible ecological controls on ingrowth in a high-elevation forest in northern Iran. Natural regeneration is one of the most important affecting factors in survival and stability of natural forests. Understanding the factors that affecting the forest species regeneration can be helpful to understand the ecosystem succession stages. Recently, due to complexity of factors that affecting natural regeneration, using the growing models in order to determine affecting factors is very common.
Materials and methods: The Kheyrud forest covers 80 km2 near the port city of Nowshahr. The elevation of the Kheyrud forest varies from 10 m to 2200 m above sea level Ingrowth model was used to estimate the diameter increment in oriental beech at fixed sample plots level over a period of 9 years (2003-2012) In this study the impact of biotic and abiotic variables like competition, energy of sunlight in the growing season, topographic wetness index, highest point to nearest of drainage area, wind speed from ground-complex process models and other variables which are considered to be achieved for the first time on natural regeneration were investigated using fixed plots in Hyrcanian forests.
Results: Results showed that the mean number of regeneration in the unit area (hectares) are very low and equal to approximately 15 trees per hectare (up to a diameter of 7 cm) in a period of 9 years. The simplest way to predict and simulate ingrowth is to use the mean values for all stands. However, this is not biologically justified since ingrowth should eventually start decreasing with increasing stand basal area. The beech trees are of the most number of regeneration per hectare which represents the suitability of environmental and biological conditions for these valuable trees in the Hyrcanian forests. Basel area per hectare was the main affecting factor on regeneration in study area which defines about 40 percent of regeneration.
Conclusion: Humidity and temperature and the amount of solar radiation were the most important variables in the number of regeneration in Hyrcanian Forests. Consequently methods that used in this study are new and also can be used in other forested area in Iran. Finally, this research is trying to explain changes of ingrowth and abiotic and biotic variables in the fixed sample plots.

Keywords

Main Subjects


1. Atri, M. 1997. Phytosociology (Sociology plant). Research Institute of Forests and
Rangelands press. 384p. (In Persian)
2. Bang, C., Sabo, J.L., and Faeth, SH. 2010. Reduced wind speed improves plant growth in a
desert city. PLoS One, 5(6): 1-12.
3. Basiri, R. 2003. Growth area ecological study of Quercus Libani using analysis
environmental factors in the region of Marivan (northern Zagros). Ph.D. thesis. Natural
Resources. (In Persian)
4. Bassow, S.L., and Bazzaz, F.A. 1998. How environmental conditions affect canopy leaflevel
photosynthesis in four deciduous tree species. Ecology, 79(8): 2660-2675.
5. Bayat, M., Pukkala, T., Namiranian, M., and Zobeiri, M. 2013. Productivity and optimal
management of the uneven-aged hardwood forests of Hyrcania. European Journal of Forest
Research, 132: 851-864.
6. Bayat, M., Namiranian, M., Zobeiry, M., and Pukkala, T. 2015. Growth Models using to
Simulate and Investigate Different Forest Management Methods (Case Study: Gorazbon
District in Kheyroud Forest, North of Iran), Journal of Forest and Wood product, 67(4): 595-
612. (In Persian)
7. Bottero, A., Garbarino, M., Long, J.N., and Motta, R. 2013. The interacting ecological
effects of large-scale disturbances and salvage logging on montane spruce forest
regeneration in the western European Alps. Forest Ecology and Management, 292: 19–28.
8. Bourque, CP-A., and Matin, MA. 2012. Seasonal snow cover in the Qilian Mountains of
Northwest China: Its dependence on oasis seasonal evolution and lowland production of
water vapour. Journal of Hydrology, 454-455: 141-151.
9. Buffum, B., Gratzer, G., and Tenzin, Y. 2009. Forest Grazing and Natural Regeneration in a
Late Successional Broadleaved Community Forest in Bhutan. Mountain Research and
Development, 29(1): 30–35.
10. Campbell, G.S., and Norman, J.M. 1998. An introduction to environmental biophysics (2nd
Ed.). Springer-Verlag, New York, 306p.
11. Chavez, P.S. 1988. An improved dark-object subtraction technique for atmospheric
scattering correction of multispectral data. Remote Sensing of Environment, 24: 459-479.
12. Daubenmire, R.F. 1976. The use of vegetation in assessing the productivity of forest lands.
Botanical Review. 42: 115-143.
13. Endara Agramont, A.R., Maass, S.F., Bernal, G.N., Valdez Hernández, J.I., and
Fredericksen, T.S. 2012. Effect of human disturbance on the structure and regeneration of
forests in the Nevado de Toluca National Park, Mexico. Journal of Forestry Research, 23(1):
39−44.
14. Geiger, R. 1965. The climate near the ground. Harvard University Press, Cambridge,
Massachusetts, 611p. Lutz, JA and Halpern, CB. 2006. Tree mortality during early forest
development: along-term study of rates, causes, and consequences. Ecological Monographs,
76: 257–275.
15. Kamler, J., Dobrovolny, L., Drimaj, J., Kadav y, J., Kneifl, M., Adamec, Z., Knott, R.,
Martinik, R., Plhal, R., Zeman, J., and Hrbek, J. 2015. The impact of seed predation and
browsing on natural sessile oak regeneration under different light conditions in an over-aged
coppice stand. Journal iForest- Biogeosciences and Forestry. 9: 569-576.
16. Martinez Pastur, G.J., Esteban, R.S., Pulido, F., and Lencinas, M.V. 2013. Variable retention
harvesting influences biotic and abiotic drivers of regeneration in Nothofagus pumilio
southern Patagonian forests. Forest Ecology and Management, 289: 106–114.
17. Murphy, PNC., Ogilvie, J., Meng, F-R., White, B., and Bhatti, JS. 2011. Modelling and
mapping topographic variations in forest soils at high resolution: A case study. Ecological
Modelling, 222: 2314-2332.
18. Nagendra, H. 2001. Using remote sensing to assess biodiversity. International Journal of
Remote Sensing, 22(12): 2377-2400.
19. Nakashizuka, T. 2001. Species coexistence in temperate, mixed deciduous forests. Trends in
Ecology and Evolution, 16: 205–210.
20. Parhizkar, P., Sagheb-Talebi, K., Mataji, A., Nyland, R., and Namiranian, M. 2011.
Silvicultural characteristics of Oriental beech (Fagus orientalis Lipsky) rgeneration under
different RLI and positions within gaps. Forestry. 84: 2. 177–185.
21. Pausas, J.G., and Austin, M.P. 2001. Patterns of plant species richness in relation to different
environments: an appraisal. Journal of Vegetation Science, 12: 153-166.
22. Retuerto R., and Woodward FI. 1992. Effects of windspeed on the growth and biomass
allocation of white mustard Sinapis alba L. Oecologia, 92: 113-123. Zhang, J., Hao, Z., Sun,
IF., Song, B., and Ye, J. 2009. Density dependence on tree survival in an old-growth
temperate forest in northeastern China. Annuals of Forest Sciences, 66: 204.
23. Soriano, M., Kainer, K.A., Staudhammer, C., Marlene Soriano, E.S., Kainer, K.A.,
Staudhammer, C., and Soriano, E. 2012. Implementing multiple forest management in Brazil
nut-rich community forests: Effects of logging on natural regeneration and forest
disturbance. Forest Ecology and Management, 268: 92–102.
24. Tahmasebi, P. 2015. Ecology of plant communities. University of shahrekord Press. 247p.
(In Persian)- Volkov, I., Banavar, JR., He, FL., Hubbell, SP., and Maritan, A. 2005. Density
dependence explains tree species abundance and diversity in tropical forests. Nature, 438:
658–661.
25. Wang, X., Comita, L.S., Hao, Z., Davies, S.J., and Ye, J. 2012. Local-Scale Drivers of Tree
Survival in a Temperate Forest. PLoS ONE, 7(2): e29469.
26. Wassie, A., Sterck, F.J., Teketay, D., and Bongers, F. 2009. Effects of livestock exclusion on
tree regeneration in church forests of Ethiopia. Forest Ecology and Management, 257(3):
765–772.