Báo cáo lâm nghiệp: "Evaluation of three methods for estimating the Weibull distribution parameters of Chinese pine (Pinus tabulaeformis)" pps

... leiycai@yahoo.com 566 J. FOR. SCI., 54, 2008 (12): 566–571 JOURNAL OF FOREST SCIENCE, 54, 2008 (12): 566–571 Evaluation of three methods for estimating the Weibull distribution parameters of Chinese pine (Pinus ... on the basis of the mean square error (MSE) and sample size. For these sample plots, the moment method was superior for estimating th...

Ngày tải lên: 07/08/2014, 10:22

... started in the eighties, at the time of the culmination of air-pollution disaster. In that period, within the programme of the gene conservation of indigenous forest tree species in the Krkonoše ... generation. e selection of individuals for further growing was performed on the basis of the complex evaluation of parent trees (the health status was the...

Ngày tải lên: 07/08/2014, 03:22

... light on the pro- cesses and trends of squared timber and log pro- duction and the relations between them in the Hyr- canian Forests of Iran during the last 20 years. MATERIALS AND METHODS Areas ... METHODS Areas under Study Located in the northern part of Iran, the study areas are known as the Northern Forests or Hyr- canian Forests and are distributed across three...

Ngày tải lên: 07/08/2014, 10:21

... was 44.24% of the size of the area of interest. Commercial zone had only begun to appear there in 1988, when they ac- counted for 0.16% of the area. At the same time, the area of forest vegetation ... di- rect occupation of biotopes. Gradual increase in acreage of forest vegetation in the surroundings of the D1 motorway was found. Forests accounted for 14....

Ngày tải lên: 07/08/2014, 10:21

... years of age.  e deterioration of the condition of some young forest outplantings currently arouses a question whether sorting in a forest nursery did not cause the undesirable narrowing of the ... temperatures the highest damage to the assimilatory apparatus (the highest drop in the values of F v /F m ratio) was found out in spruces of the “large” variant, f...

Ngày tải lên: 07/08/2014, 10:21

... found to be the slow- est growing. Mode 2 (crown in the upper third of the stem) entirely prevails for the type of branching. Only in the case of provenance 30 the majority of the stems were ... results of the stem shape evaluation document that fi ve provenances of sessile oak and four prov- enances of pedunculate oak had the highest propor- tion of strai...

Ngày tải lên: 07/08/2014, 10:21

... frequency distribution of bootstrap means of the measured and predicted data were rather similar for the FRB values calculated on the basis of tree height (Fig. 2). For the mesic woodland site the ... dis- tribution of rFRB. The results showed that for the xeric wood- land site, using tree height to define the spread and distribution of roots explained a muc...

Ngày tải lên: 07/08/2014, 16:20

... means that for whole-tree harvesting there would be critical losses for P, K and Ca, in the case of radiate pine, and for K in the case of maritime pine. Even in the traditional harvest of no debarked logs, ... indicates the critical role of P in the nu- trient dynamics of pine stands [45]. The high amounts of soil nitrogen content and nitrogen fixation in th...

Ngày tải lên: 07/08/2014, 16:21

... reduces the growth of other (subject) trees. In the absence of significant collinearity with the indices for other species, this is indicated by the size of the regression coeffi- cient for the species’ ... in their compet- itive effect on the subject tree. The analysis also estimates the neigh- bourhood area as a fraction of the maximum neighbourhood radius (8 m)....

Ngày tải lên: 07/08/2014, 16:21

... with the retention of a portion of the stand in the final cutting, and the extension of rotation to fulfill these non-timber producing objectives in the other case. The results for one stand of ... but also others involving the preservation of biodiversity and the landscape, etc., are the lengthening of the rotation, retention of part of the trees in fi...

Ngày tải lên: 08/08/2014, 01:22