Báo cáo lâm nghiệp: "Modeling the impact of thinning on height development of dominant and codominant loblolly pine trees" pot

... growth of dominant and codominant loblolly pine trees, the mean value of total height of dominant and codominant trees was calculated for each unthinned and once thinned stand at each location (site) ... right hand side of Equation (8) for a given set of variables. The integral of Equation (8) can also be computed online [16]. 4. CONCLUSIONS This study show...

Ngày tải lên: 08/08/2014, 00:22

... compares the square root of the means of the estimates s 2 y st.post.uncond for the conditional vari- ance (1), the means of s 2 y st.post.cond as estimates for the unconditional variance ... by far, and the conditional and uncondi- tional variance estimators, on an average, exhibit no remarkable differences. us, the component of variability associated...

Ngày tải lên: 07/08/2014, 03:22

... defines the stable diameter distribution and, consequently, the long-term dynamics of the non harvested populations. On the other hand, and assuming that condition (C1) holds, conditions (C2) and ... distribution. Condition (C3), to- gether with conditions (C1) and (C2), define the harvesting strategy for the model, and are formulated as follows: (C1) A necessary condit...

Ngày tải lên: 07/08/2014, 16:21

... influences more the occurrence and the length of the zones than the axes composition of each zone. The length of every zone was modeled as a function of the length of the whole annual shoot. These parameters ... of the stem measured below the branch at the height h i+1 , r i is the radius of the stem measured above the branch at the height h i a...

Ngày tải lên: 07/08/2014, 16:21

... basal area. Therefore, the reliabil- ity of the projections done after thinning may be questioned. On the other hand, some studies on Scots pine suggest that the post -thinning growth of trees can ... between stand age and the ratio of the mean diameter between post- and pre -thinning stand. However, the effect of timber prices on the timing and inten-...

Ngày tải lên: 07/08/2014, 16:21

... combination of DVs was fed into the simulator, which simulated cuttings and the development of the stand, and from these results the value of the objective function was calculated. The objective ... itera- tively. The direct search starts from an initial point. A better solution is sought both along the DVs, to discover the pattern of the objective function,...

Ngày tải lên: 08/08/2014, 00:21

... is crossed once more as the season of the year changes. In the context of the inter-relationship between the tree and its environment, it is of interest to discover which of the many potentially informative ... in response to any one of these variable alone [9]. The seasonal cycles of growth and development of temper- ate tree species are responses to variat...

Ngày tải lên: 08/08/2014, 00:22

... the integration of the risk of forest fires in the decision- making process of forestry. In this context, the stand level offers the first meaningful level of decision making where the risk of fire ... However, these studies only evaluated the effect of the risk of fires on the optimal rotation age of the stand. In all these stud- ies thinnings were ignor...

Ngày tải lên: 08/08/2014, 00:22

... The closer the eigenvalues of the m first axes of CCA are to the m first axes of CA, the greater the efficiency of environmental variables and the closer e m is to 1. The efficiency of the different ... ordination axis of CCA or CA and e m can be considered as the empirical index that measures the efficiency of the ecological variables used in E for...

Ngày tải lên: 08/08/2014, 00:22

... depends on this particular variable. The concentration of the yield on large timber and consequentially the minimising of small timber is deemed to be one of the biggest advantages of the plenter ... otherwise the standing volume would increase and change the relation- ship of growth. The distribution pattern of the removal rate over the d-class depends...

Ngày tải lên: 08/08/2014, 00:22