Number and projected area estimates of coarse woody debris by line intersect sampling (case study: chafroud forests)

Subject Areas : forest

farshad keivan behjo ¹ , zeynab poorgholi ²

1 - University of Mohaghegh Ardabili, Ardabil, I.R. Iran
2 - , University of Mohaghegh Ardabili, Ardabil, I.R. Iran.

Received: 2017-09-01 Accepted : 2018-02-26 Published : 2018-06-21

Keywords: Number and projected area estimates, coarse woody debris, Line intersect sampling, probability theory,

Abstract :

To determine a suitable method, based on precision and cost of inventory for estimates of residuals in Caspian Forests, a transect method based on probability theory, were selected for comparison. Parameters evaluated were number and projected area per hectare. Considering all the sampling factors, a grid of 100*100m were determined for randomized systematic sampling. Length of transect was determined as 100m in transect method. To compare the results of these method with the real population statistical parameters, a 100% survey of coarse woody debris was take over 107 hectares including three compartments. The results of t-test show that the population mean was similar to means of transect method based on probability theory for all parameters, the means being within the range of confidence intervals. However in this method and in all cases, the inventory errors were greater than those at the acceptable level (10%). This can be cocluded that transect method based on probability theory is a suitable method for estimating of coarse woody debris in Caspian forests.

References:

 

Refrences:

1. Forest and Rangeland Organization, Guilan Province Natural Resources Office, Bookfinder of Forestry Scheme 2, Chafroud Shanderman, 1996, (In persian).

2. Mansoor Far, Karim, 1997. Statistical Methods, Tehran University Press, (In persian).

3. Marshall.P. L.&G.Davis,2000. Using line intersect sampling for coarse woody debris , Technical report, P.1-34.

4. Marshall.P. L. & G.Davis, 2002, Measuring the length of coarse woody debris, Technical report,5p.

5. Taimuri, Isaac, 1379. Comparison of random systematic statistical method with circular sample pieces and transect method in terms of accuracy and cost in West oak forests, Master thesis, Karaj Natural Resources Faculty, Tehran University, (In persian).

6. Taylor. S. W. 1997. A field estimation procedure for downed coarse woody debris, technical transfer note2, pacific forestry centere, canadian forest services, 11pp.

7. Warren, W.G. & P.F.Olsen, 1964, A line intersect technique for assessing logging waste, Forest science, 10:267_276

8. Wagner,V.C.E. & A.L.Wilson, 1976. Diameter measurement in the line intersect method, Forest science, P; 230-232

9. Yazdi Samadi. Bahman Rezaei. Abdul Majid, Valizadeh. Mohsen, 2002. Statistical Models in Agricultural Research, Tehran University Press, (In persian).

10. Zabiri, Mahmoud, 1381. Bioethics (forest biometry), Tehran University Press, (In persian).