Estimating the volume of coarse woody debris of forest floor using sampling with probability proportional methods

Document Type : Research article

Authors

1 M. Sc. Forestry, Natural Resources and Marine Science Faculty, Tarbiat Modares University, Noor, Iran

2 Assistant Prof., Natural Resources and Marine Science Faculty, Tarbiat Modares University, Noor, Iran

Abstract

A variety of new methods have been proposed by ecologists and biologists for data collection on different attributes of coarse woody debris (CWD). Amongst others methods based on probability proportional to size are the newest techniques. These approaches are based on selecting individual logs into the sample unite using some forms of unequal probability sampling. In the present study, we aimed to introduce “Distance Limited Sampling” (DLS) and “Sausage protocol” of “Fixed Area Method” as well as assessing their precision and accuracy for estimating volume of CWD. These methods select individual logs into the samples using probability proportional to length of the logs. To collect the data, a set of attributes including location, top and bottom diameter and length of all logs in a 250×250 m plot in an un-harvested temperate forest were fully inventoried, and the location of logs were mapped. Then different methods with different sample unit sizes were simulated in R programming language environment using SampSurf package. Results indicated that both methods are unbiased. Considering precision of the estimates, Sausage protocol of fixed area sampling led to more precise estimates of volume of the loges than those estimated by DLS. Consequently, Sausage protocol is concluded for further usage as a promising method in the field due to its unbiasedness and production of highly-precise estimates.

Keywords


- Affleck, D.L.R., 2008. A line intersect distance sampling strategy for downed wood inventory. Canadian Journal of Forest Research, 38(8): 2262-2273.
- Anonymus, 1992. Forest Planning and Management, District 46. Forest, Range, and Watershed Management, Mazandaran Province, 126p (In Persian).
- Anonymus, 2011.  R: A Language and Environment for Statistical Computing. Development Core Team, R Foundation for Statistical Computing, Vienna, Austria.
- Bowman, J., Sleep, D., Forbes, G. and Edwards, M., 2000. The association of small mammals with coarse woody debris at log and stand scales. Forest Ecology and Management, 129 (2000): 119-124.
- Bunnell, F. and Houde, I., 2010. Down wood and biodiversity – implications to forest practices. Environmental Reviews, 18: 397-421.
- Gove, J.H., 2012. Sampling Surface Simulation for Areal Sampling Methods, R Packages. 178p.
- Gove, J.H., Ducey, M.J., Ståhl, G. and Ringvall, A., 2001. Point relascope sampling: A new way to assess downed coarse woody debris. Forestry, 99: 4-11.   
- Gove, J.H., Ducey, M.J., Valentine, H.T. and Williams, M.S., 2012. A distance limited method for sampling downed coarse woody debris. Forest Ecology and Management, 282: 53-62.
- Gove, J.H., and Van Deusen, P.C., 2011. On fixed-area plot sampling for downed coarse woody debris. International Journal of Forest Research, 84(2): 109-117.
- Harmon, M. and Franklin, J., 1989. Tree seedlings on logs in Picea–Tsuga forests of Oregon and Washington. Ecology, 70: 48-59.
- Haji Mirza Aghayee, S., Jalilvand, H., Pormajidian, M.R. and Kooch, Y., 2011. Herbal species diversity around of logs and snags in Sardabrood Forests, Chalous. Journal of the Iranian Biology, 24(1): 54-64 (In Persian).
- Harmon, M.E. and Sexton, J., 1996. Guidelines for Measurements of Woody Detritus in Forest Ecosystems. USLTER Network Office, University of Washington, Seattle, 20p.
- Heidari, R.H., Zobeiri, M., Namiranian, M. and Sobhani, H., 2009. Comparison of circular plot and transect sampling methods in the Zagros oak Forests (Case study: Educational and research forest of Razi University, Kermanshah province). Iranian Journal of Forest and Poplar Research, 17(3): 359-368 (In Persian).
- Jordan, G.J., Ducey, M.J. and Gove, J.H., 2004. Comparing line-intersect, fixed-area, and point relascope sampling for dead and downed coarse woody material in a managed northern hard wood forest. Canadian Journal Forest Research, 34(8): 1766-1775.
- Keivan Behjo, F., Sobhani, H. and Zobeiri, M., 2007. Volume and weight assessment of residuals by line intersect sampling (Case study: Chafroud watershed). Iranian Journal of Natural Resources, 60(1): 103-114 (In Persian).
- Pedlar, J.H., Pearce, J.L., Venier, L.A. and McKenny, D.W., 2002. Coarse woody debris in relation to disturbance and forest type in boreal Canada. Forest Ecology and Management, 158(1):189-194.
- Pouska, V., and Svoboda, M.A.L., 2010. The diversity of wood-decaying fungi in relation to changing site conditions in an old-growth mountain spruce forest, central Europe. European Journal of Forest Research, 129: 219-231.
- Sefidi, K. and Marvie Mohajer, M.R., 2010. Characteristics of coarse woody debris in successional stage of natural beech (Fagus orientalis) forests of Northern Iran. Journal of Forest Science, 56(1): 7-17.
- Sefidi, K., Mohadjer, M.R., Zobeiri, M. and Etemad, V., 2007. Investigation on dead trees effects on natural regeneration of oriental beech and hornbeam in a mixed beech forest. Iranian Journal of Forest and Poplar Research, 15(4): 365-373 (In Persian).
- Ståhl, G., 1998. Transect relascope sampling- a method for the quantification of coarse woody debris. Forest Science, 44(1): 58-63.
- Warren, W.G. and Olsen, P.F., 1964. A line intersect method for assessing logging waste. Forest Science, 3: 267-276.
- Williams, M.S. and Gove, J.H., 2003. Perpendicular distance sampling: an alternative method for sampling downed coarse woody debris. Canadian Journal of Forest Research, 33(8): 1564-1579.
- Woldendorp, G., Keenan, R.J., Barry, S. and Spencer, R.D., 2004. Analysis of sampling methods for coarse woody debris. Forest Ecology and Management, 198(1): 133-148.