Regular Article J F E S Journal of Forest and Environmental Science eISSN: 2288-9752 Journal of Forest and Environmental Science Vol. 31, No. 2, pp. 73-77, May, 2015 http://dx.doi.org/10.7747/JFES.2015.31.2.73 Ｐ＆Ｌｕｘ＆Ｋｔ｜＆Ｙｉｏ＆９７．８／２＆＝９３＝＝＆＆＆＆＆73 Easy and Quick Survey Method to Estimate Quantitative Characteristics in the Thin Forests Mehrdad Mirzaei*, Amir Eslam Bonyad, Mahboobeh Mohebi Bijarpas and Fatemeh Golmohamadi Faculty of Natural Resources, University of Guilan, Someh Sara 1144, Iran Abstract Acquiring accurate quantitative and qualitative information is necessary for the technical and scientific management of forest stands. In this study, stratification and systematic random sampling methods were used to estimation of quantitative characteristics in study area. The estimator (((E%) 2 xT)) was used to compare the systematic random and stratified sampling methods. 100 percent inventory was carried out in an area of 400 hectares; characteristics as: tree density, crown cover (canopy), and basal area were measured. Tree density of stands was compared through systemic random and stratified sampling methods. Findings of the study reveal that stratified sampling method gives a better representation of estimates than systematic random sampling. Key Words: inventory, systematic random, stratification, zagros forests Received: October 18, 2014. Revised: December 13, 2014. Accepted: December 16, 2014. Corresponding author: Mehrdad Mirzaei Faculty of Natural Resources, University of Guilan, Someh Sara 1144, Iran Tel: (98)9187429259, 1344323600, Fax: (98)9187429259, 1344323600, E-mail: mehrdadmirzaei28@gmail.com Introduction Among forest sciences, forest inventory and measure- ment are important, and the correct operation of forest in- ventory in each forestry plan regarding the goal of forestry plans is of great importance. Accurate and updated in- formation is needed for various purposes, including forest management, health monitoring, biodiversity, climate change, and the effects of various environmental factors (Holopainen 1998). This information is obtained by in- ventory or sampling in the forest area. The main objective of a forest inventory is to describe the structure and species composition of a given stand with maximum possible accu- racy and at a reasonable cost (Husch et al. 1982; Avery and Burkhart 2002). Inventory technique is very effective in obtaining current and accurate information for forest planning. It can remedy the defects of periodic inventory and provide data for scientific forest management and man- agement planning (Mingcan 1999). Sampling methods and plot design have to be adapted to the characteristics of the stands present in the country or region studied. It is necessary to decide which variables to measure and through which type of inventory method to measure them. It is also necessary to decide on a sampling intensity in order to meet the maximum acceptable error for the analyzed variables. In most cases, if a sampling method that is in harmony with the type of forest and forest management goals is chosen and performed correctly, the analysis proves to be more use- ful and acceptable than full calipering inventory. One meth- od that has proved its efficiency and practicability often in the last decades is double sampling for stratification (2st) (Cochran 1977; De Vries 1986; Schreuder et al. 1993; Sarndal et al. 2003; Gregoire and Valentine 2008; Mandallaz 2008). The theory of double sampling (or two phase sampling) was first formulated by Neyman (1938) in connection with collecting information on the strata weights