Báo cáo lâm nghiệp: "Variation in the composition and content of ellagitannins in the heartwood of European oaks (Quercus robur and Q petraea) A comparison of two French forests and variation with heartwood age" ppt

... colour Original article Variation in the composition and content of ellagitannins in the heartwood of European oaks (Quercus robur and Q petraea). A comparison of two French forests and ... relating the total soluble ellagitannins and heartwood age was calculated. In a second study two heartwood samples were tak...

Ngày tải lên: 08/08/2014, 18:21

... 10). The comparison of means, using the analysis of variance, showed that when the effect of dbh and height was eliminated the mean values of tapering of individual partial populations did ... is index is a relative measure of density elaborated for even-aged stands, and it is determined on the basis of the number of trees per hectare (TPH) and the...

Ngày tải lên: 07/08/2014, 10:22

... durability of Scots pine wood. The variation in the in vitro decay rate, and in the extractive content and sorp- tion of water by the sapwood and inner and outer heartwood of mature Scots pine stems ... that the mass loss in the periphery part of the heartwood was lower than that in the centre of the heartwood. The other marked dif- fer...

Ngày tải lên: 08/08/2014, 01:21

... soil-water balance Fig. 1 shows the strong decrease in sto- matal resistance with leaf age, expressed as the ratio of actual leaf area to its maxi- mal area. All these values ... h0" alt="" Variation of stomatal resistance with leaf age in Quercus petraea: effect on the soil-water balance of an oak forest J. Nizinski, D. Morand B. Saugi...

Ngày tải lên: 09/08/2014, 04:20

... conducting area – CA. Mean area of early wood per single annual ring was defined as the conducting area of a ring – CAar. Relative con- ducting area (CA.k –1 ) was calculated as a quotient of conducting ... Conducting area (CA) and ring conducting area (CAar) seem to be the values that may describe the relationships between conducting area and the size of the assi...

Ngày tải lên: 07/08/2014, 10:21

... morphological types of terrain: in lowlands and ta- blelands with the slope of terrain to 15% 15 m/ha by obtainable efficiency 90% and average geometrical skidding distance 170 m; in highlands 22 m/ha ... optimal forest and forest stand management is their reasonable opening by a forest road network. e basic frameworks of forest road network are forest transport ro...

Ngày tải lên: 07/08/2014, 10:21

... a continuous forest of 700 ha, consisting mostly of naturally regenerated mixed stands of Q. petraea and Q. robur. The sampled stand covers approx- imately 5 ha with a total of 286 standing trees. ... consists of three ecological zones: a small valley, a plateau and a regular intermediate slope. The plateau is covered by a well drained soil and composed o...

Ngày tải lên: 07/08/2014, 16:20

... to thank: Björn Hannrup for initiating and leading the project; Tapio Järvinen, Tapio Nevalainen and Kari Sauvala for sample prepara- tion and determing MOE and MOR; Irmeli Luovula for analysing the FTIR ... Norway spruce [19]. The grain angle (spiral grain) was measured by pulling a needle attached to an arm along the pith- and bark facing side of the boards. The ne...

Ngày tải lên: 07/08/2014, 16:21

... focused on quantifying the possible change in photosynthetic capacity with increasing tree age. Declining nutrient availability during stand development adversely affects tree leaf area and leaf photosynthesis ... stands either for the quantum use efficiency (α) or dark Table II. Characteristics of the sampled trees in each maritime pine stand. The tree leaf area was calcula...

Ngày tải lên: 08/08/2014, 00:22

... on the variations in growth and quality characteristics of Pinus pinaster Ait. prove- nance trials in Turkey, Ormancilik Arastirma Enstitusu Yayinlari, Ankara, 1985. [52] Vendramin G.G., Anzidei ... objective of the present work is the analysis of the variation in morphological traits within and among Moroccan maritime pine populations. In addition, we are interest...

Ngày tải lên: 08/08/2014, 00:22