Effect of tree mortality on structure of Brant'soak (Quercus brantii) forests of Ilam province of Iran

Document Type : Research article

Authors

1 Ph.D. student, Dept. of Forestry, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University

2 Associate professor, Dept. of Forestry, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University

3 Assistant professor, Research Institute of Forests and Rangelands

4 Associate professor, Faculty of Forest Sciences and Wood Technology, Gorgan University of Agriculture and Natural Resources

Abstract

The aim of the study was to investigate the effects of tree mortality on structural characteristics of an oak stand named Shalam Forest, with 670 ha area, located 10 km south east Ilam city of I.R. Iran. The structural characteristics consisted of stand density, basal area, canopy cover density, species composition, silvicultural form and distribution pattern of dead trees density and basal area and different diameter classes. The studied area was divided to 20 homogeneous topographical units in which three circular plots with 1000m2 area were located to measure diameter at breast height (dbh), minimum and maximum diameter of tree's crown, percentage of dried crown, trees origin and silvicultural form of each species separately and record the data. The results showed that the trees and shrubs density was reduced at 15.7%, in which 97.65% belonged to Quercus brantii. Basal area reduced at 14.23%, in which 95.29% belonged to Q. brantii. Mortality was found at most of the diameter classes, but the greatest amount was found at 10 to 25 cm classes and the maximum rate was found at 5, 60 and 75 cm classes. In addition, the maximum reduction rate of basal area was found at 25 to 45 cm classes. Although density of the most trees and shrubs species reduced and their mixture percentage changed, but the species composition was almost stable. Crown density reduction was about 12.88%. Tree mortality at coppice forest type was more than the standard type, but mortality rate at standard forest was more than the coppice one. DCA analysis defined the sample plots distribution according to their circumstances and situation and showed that there is a relationship between tree decline and dbh variable. Overall, tree mortality at the studied area caused great changes in stand structure of Q. brantii, for instance different tree characteristics changed, particularly dbh, which separated tree population before and after their mortality. The results might be used for conservational and protectional management of the dried and declined forest of Zagros region of I.R. Iran.

Keywords

References

- Allen, C.D. and Breshears, D.D., 1998. Drought-induced shift of a forest-woodland ecotone: rapid landscape to climate variation. Proceedings of the National Academy of Science, 95: 14839-14842.
- Anonymous, 2010. Ilam climate data report. Meteorogical Organization of Iran, 51 p.
- Dodge, S.L., 1997. Successional trends in a mixed oak forest on high Mountain New Jersey. Journal of the Torrey Botanical Society, 124(4): 312-317.
- Elliott, K.J. and Swank, W.T., 1994. Impacts of drought on tree mortality and growth in a mixed hardwood forest. Journal of Vegetation Science, 5: 229-236.
- Fensham, R.J. and Holman, J.E., 1999. Temporal and spatial patterns in drought-related tree dieback in Australian savanna. Journal of Applied Ecology, 36: 1035–1060.
- Ferrell, G.T., Otrosina, W.J. and Demars, C.J., 1994. Predicting susceptibility of white fir during a drought-associated outbreak of the fir engraver, Scolytus ventralis, in California. Can. J. For. Res., 24: 302–305.
- Floyd, M.L., Clifford, M., Cobb, N.S., Hanna, D., Delph, R., Ford, P. and Turner, D., 2009. Relationship of stand characteristics to drought-induced mortality in three Southwestern piñon–juniper woodlands. Ecological Applications, 19(5): 1223-1230.
- Franklin, J.F., Shugart, H.H., and Harmon, M.E., 1987. Tree death as an ecological process. BioScience, 37: 550-556.
- Fule´, P.Z., Korb, J.E. and Wuc, R., 2009. Changes in forest structure of a mixed conifer forest, southwestern Colorado, USA. Forest Ecology and Management, 258: 1200–1210.
- Greenwood, D. L. and Weisberg, P. J., 2008. Density-dependent tree mortality in Pinyon-juniper woodlands. Forest Ecol. Manage., 255(7): 2129-2137.
- Guarın, A. and Taylor, A.H., 2005. Drought triggered tree mortality in mixed conifer forests in Yosemite National Park, California, USA. Forest Ecology and Management, 218: 229–244.
- Hamzehpour, M., Kia-Daliri, H. and Bordbar, K., 2011. Preliminary study of manna oak (Quercus brantii Lindl.) tree decline in Dashte-Barm of Kazeroon, Fars province. Iranian journal of Forest and Poplar Research, 19(2): 352-363.
- Harris, L.D., 1984. The fragmented forest: Island Biogeography Theory and the Preservation of Biotic Diversity. University of Chicago Press, Chicago, 230 p.
- Kabrick, J.M., Dey, D.C., Jensen, R.G. and Wallendorf, M., 2008. The role of environmental factors in oak decline and mortality in the Ozark Highlands. Forest Ecology and Management, 255(5-6): 1409-1417.
- Linares, J.C., Camarero, J.J., Bowker, M.A., Ochoa, V. and Carreira J.A., 2010. Stand-structural effects on Heterobasidion abietinum-related mortality following drought events in Abies pinsapo. Oecologia, 164:1107–1119.
-McComb, W.C., Spies, T.A., and Emmingham, W.H., 1993. Douglas-fir forests: managing for timber and mature-forest habitat. J. For., 91: 31-42.
-Nepstad, D.C., Tohver, I.M., Ray, D., Moutinho, P. and Cardinot, G., 2007. Mortality of large trees and lianas following experimental drought in an Amazon forest. Ecology, 88(9): 2259-2269.
-Palik, B.J. and Pederson, N., 1996. Over story mortality and canopy disturbances in longleaf pine ecosystems. Can. J. For. Res., 26: 2035-2047.
-Peet, R.K., and Christensen, N.L., 1987. Competition and tree death. BioScience, 37: 586-595.
- Shaw, J.D., Steed, B.E. and DeBlander, L.T., 2005. Forest inventory and analysis (FIA) annual inventory answers the question: what is happening to Pinyon–juniper woodlands? Journal of Forestry, 103:280–285.
- Speer, J.H., Swetnamn, T.W., Wockman, B.F. and Youngblood, A., 2001. Changes in Pandora moth outbreak dynamics during the last 622 years. 82: 679–697.
- Starkey, D.A., Oak, S.W., Ryan, G.W., Tainter, F.H., Redmond, C. and Brown, H.D., 1988. Evaluation of oak decline areas in the south. Protection Publication, R8-PR 17. Atlanta, GA: U.S. Dept. of Agriculture, Forest Service, Southern Region, 36 p.
- Stringer, J.W., 2002. Oak regeneration using the two-age system. USDA Forest Service, General Technical Report, SRS-48: 379-382.
- Williamson, G.B., Laurance, W.F., Oliveira, A.A., Delamoˆnica, P., Gascon, C., Lovejoy, T.E. and Pohl, L., 2000. Amazonian tree mortality during the 1997 El Nin˜o drought. Conserv. Biol., 14: 1538–1542.
Iranian Journal of Forest and Poplar Research
Volume 20, Issue 4 - Serial Number 50
December 2013
Pages 577-565

Files

Share

How to cite

Statistics