Báo cáo lâm nghiệp: "A model of with even-aged beech stands productivity process-based interpretations" doc

... part of a larger project aimed at modeling growth of pure even-aged stands of common beech, on the basis of a network of permanent plots observed since the turn of the ... generalization of Eichhorn’s rule The data analysis of the 3 previous sec- tions provides a model for the 3 compo- nents of productivity in even-aged beech...

Ngày tải lên: 08/08/2014, 18:21

... cut. We designed a model to predict photosynthe- sis of heterogeneous canopies and wood respiration. The output of the model to- gether with measurements of aerial growth enabled ... between the foliage of different trees until the end of the first year. The leaves in the model were distributed homogeneously within ellipsoids or fractions...

Ngày tải lên: 09/08/2014, 04:20

... Jablunkov Fig. 4. Content of chromium (median) (mg/kg) in soil profiles of spruce (left) and beech (right) stands Table 4. Median of contents of elements in both compared stands (mg/kg) N (g/kg) ... the area of the Pass. is is confirmed by the highest values of the median: Zn = 103 mg/kg in contrast with 70.6 mg/kg in spruce stands and 121 in contrast with 101 mg/kg...

Ngày tải lên: 07/08/2014, 10:21

... causes of the observed acceleration of forest growth: weather conditions, atmospheric concentration Figure 8. Variation of mean country Net Ecosystem Productivity with latitude of centre of country ... the effect of many more variables e.g. nitrogen deposition, than the ecosystem model which allowed a more detailed assessment of the relative importance of the variables a...

Ngày tải lên: 08/08/2014, 00:22

... total tree C pool at year of felling. In even-aged stands stem C pool can be modeled as a function of tree radius and its age. Conifer wood density can be a good proxy of radial increment [4, 18, 27]. ... abies (L.) Karst. even-aged stands. Tree age, height and wood density can be good proxies of stem C pool in conifer even-aged stands. i: Cross-section increment number n:...

Ngày tải lên: 08/08/2014, 01:22

... height model is a key com- ponent for obtaining good estimates of the growth and yield of ponderosa pine. Four variations of the logistic model were fit to the data. In each variation, the basic model ... before fitting the model with the lag-1 sample autocorrelation [29, p. 279] calculated from the residuals in model (1). A different value of φ was estimated for each plot...

Ngày tải lên: 08/08/2014, 01:22

... exponential function of the length of the photon pathway within the needle before reaching the point under consideration. Results Measured rates of photosynthesis of a shoot subjected ... case of a highly directional field, and the rate of photosyn- thesis per unit of intercepted radiation should logically be higher (cf. Oker-Blom, 1985). The...

Ngày tải lên: 09/08/2014, 04:20

... identification pro- cedure and guarantees the quality of the fitted parameters and the wide range of validity of the resulting constitutive model. 2.2. Simulation of the experimental tests The creep function ... between softwood and hardwood is obvious. The glass transition of softening temper- ature for wood depends on the physical method used and the constant of time. Neverthe...

Ngày tải lên: 08/08/2014, 00:22

... models e.g. [3, 23, 39, 40]. These results are consistent with the dynamic process of the intra-spe- cific competition and the natural mortality of even-aged stands [8, 13, 36, 37]. The use of ... number of plots without observed mortality over a period of t years and n 0 is the number of plots with observed mortality at the same period of time. The weight used was the...

Ngày tải lên: 08/08/2014, 01:21

... natural processes of plant succession instead of composition types. Opportunistic silviculture makes use of natural plant dynam- ics. In the long term, natural development produces somewhat regular stands of ... 40]. In addition, the possible problem of species alternation arises for ash and sycamore: pure stands offer more favourable conditions for the regeneration of the oth...

Ngày tải lên: 08/08/2014, 01:22