Báo cáo lâm nghiệp: " Optimising the management of uneven-aged Pinus sylvestris L and Pinus nigra Arn mixed stands in Catalonia, north-east Spain" pps

... ro- tation length (R) – Age of initial stand)/ (Number of thinnings + 1)): − Year of the first thinning: (Age of initial stand, Age of initial stand + 2I); Optimal management of Pinus sylvestris in Galicia ... MATERIALS AND METHODS The stand level offers the first meaningful level of decision mak- ing, and the results obtained for the stand level management...

Ngày tải lên: 07/08/2014, 16:21

... 747–758 © INRA, EDP Sciences, 2005 DOI: 10.1051/forest:2004071 Original article Optimising the management of uneven-aged Pinus sylvestris L. and Pinus nigra Arn. mixed stands in Catalonia, north-east ... initial point of 30 out of the 33 direct search runs for each problem. The effect of discounting rate and length of the cutting cycle on the...

Ngày tải lên: 08/08/2014, 00:21

... Miina J., Growth and yield model for uneven-aged mixtures of Pinus sylvestris L. and Pinus nigra Arn. in Catalonia, north-east Spain, Ann. For. Sci. 61 (2004) 9–24. [33] Valsta L. , Possibilities ... stand age when the first thinning occurs; years since previous thinning for the other thinnings; remaining basal area. For the final cutting: years since the las...

Ngày tải lên: 08/08/2014, 00:22

... be independent of thinnings. When a thinning is simulated, half of the basal area is removed equally from all diameter classes, and the other half as a low thinning, starting with the smallest ... previous thinning, and the remaining stand basal area after each thinning. The system was used to find optimal management schedules of Pinus sylvestris stands on site ind...

Ngày tải lên: 08/08/2014, 01:21

... in surroundings of the studied localities since larch lacks. Model e importance of all explanatory variables, their significance and correlations with axes are presented in Fig. 1 and Table ... first canonical axis explains 38.8% of variability, both canonical axes explain 53% of variability (Table 2). All axes explain 100% of vari- ability. e whole model was statistica...

Ngày tải lên: 07/08/2014, 03:22

... independently of the original dis- tribution of the variable of interest. Here, although the estimate of the true mean is unbiased and the variance of the mean decreases (Tables 3 and 4) with increasing ... random sampling (Fig. 6b), gains in precision are only slightly larger. Probably, the little size and spatial distribution of connected areas of th...

Ngày tải lên: 07/08/2014, 03:22

... trees following thinning. Peterson et al. [10] found that loblolly pine trees in thinned stands quickly expanded their crowns horizontally starting the year following thinning along with the reduction ... During the dormant seasons of 1980– 1981 and 1981–1982, permanent plots were established in planted stands of loblolly pine (Pinus taeda L. ) through the native range...

Ngày tải lên: 08/08/2014, 00:22

... measured in cm at half of the length of the log) and the log length (in m) were used. The mid diameters of the logs lay between 45.0 and 77.0 cm (mean 57.13 cm) while the length had values from ... indirectly controlled by the properties of the goods. Solving the problem was therefore divided into two steps; the analysis of the buyers’ preference and...

Ngày tải lên: 08/08/2014, 00:22

... 2 log likelihood including only the constant of the complete model. The models in bold are the selected ones. The coefficients of the variables in italics are not significant using a probability ... pine and four potential competi- tors following thermal treatment. Finally, conclusions allow the development of management strategies to help regenerate Scots pine st...

Ngày tải lên: 08/08/2014, 01:21

... seedlings (< 10 cm tall), old seedlings (≥ 10 cm but < 50 cm tall), short saplings (≥ 50 cm but < 1.5 m tall), tall saplings (≥ 1.5 m tall but < 7 cm dbh). For the 86 Norway spruce plantations, ... soil pH. b Other trees are: Alnus glutinosa, Carpinus betulus, Fagus sylvatica, and Quercus robur. c Young seedlings (< 10 cm tall), old seedlings (≥ 10 cm but < 50 cm tall)...

Ngày tải lên: 08/08/2014, 01:22