Báo cáo lâm nghiệp: "Effects of a clear-cut on the in situ nitrogen mineralisation and the nitrogen cycle in a 67-year-old Douglas-fir (Pseudotsuga menziesii (Mirb ) Franco) plantation" potx

... that the ratio between the size of the largest branch and the mean size of the other branches on a particular shoot of N. dombeyi depends on a number of factors such as the type of axis of the ... here affected the position of the most proximal branches on shoots. On the other hand, some kinds of traumas acting on a parent shoot at specifi...

Ngày tải lên: 08/08/2014, 00:22

... and thus more biomass was pro- duced by the same amount of leaf area. The rapid rise in LAR with decreasing light intensity (Tab. I) together with the ability to maintain a positive carbon balance ... cm 2 g –1 ) and leaf weight measured for each seedling, total leaf area (LA; cm 2 ) was calculated. Leaf area to total biomass ratio (LAR; cm 2 g –1 ) and leaf ar...

Ngày tải lên: 08/08/2014, 00:22

... ha) in size. Each plot was randomly assigned one of 6 vegetation manage- ment treatments that included combinations of herbicide release and site preparation (Tab. I), and each vegetation management ... planting and vegetation management in interior Alaska. Wood and von Althen [39] reported results similar to our study on a site near Matheson, Ontario. White and black sp...

Ngày tải lên: 08/08/2014, 01:21

... (indications of decline) and sil- vicultural management (uneven-aged stand or recent thinnings) were recorded based on visual inspection. In each stand, mean transmittance of radiation by the canopy ... végétation / plantation / essence 1. INTRODUCTION The development of human societies often has caused an overexploitation of forests and a decrease in their area. In...

Ngày tải lên: 08/08/2014, 01:21

... O., Casal M., Effect of high temperatures on cone opening and on the release and viability of Pinus pinaster and P. radiata seeds in NW Spain, Ann. For. Sci. 59 (200 2) 327–334. [37] Samo A. J., ... treatments where initial pine density was maintained, therophyte percent- age was the lowest. Once more, the increase in light intensity and decrease in competition...

Ngày tải lên: 08/08/2014, 01:22

... defined as the rate of photo- synthesis at ca = 150 Pa. The maximal rate of carboxylation (V c max ) was calculated according to Von Caemmerer and Farquhar (198 1) and Harley ... maritime pine seedlings. The main parameters of the biochemical model of CO 2 assimilation of Farquhar et al (198 0) were calculated. The contribution...

Ngày tải lên: 08/08/2014, 18:21

... and the Northern Research Station for raising the container seedlings, and the staff rooting volume held constant, has a strong influence on the growth and development of ... the Newton field station for planting and maintaining the field experiment. Ian Wright and Andrew Peace helped with the statistical analysis, and John Morgan...

Ngày tải lên: 09/08/2014, 04:20

... from reduced assimilation rates and a decrease in leaf area, and Borralho et aL (198 6) recently reported that non-irrigated E. globulus had a smaller surface area per unit of leaf ... using caliper measurements of leaf length and width and direct values of leaf areas obtained with a Li-cor leaf area meter. Gas exchange studies wer...

Ngày tải lên: 09/08/2014, 04:20

... out at the end of the stress application. Effects of saline stress on germination The application of saline stress led to a reduced germination rate. E. alba was the most ... Saline stress was applied at germination and to seedlings in a greenhouse. Materials and Methods Seeds wete collected in the natural range of the 3 specie...

Ngày tải lên: 09/08/2014, 04:20

... 1174-1181 Results Effects of cutting Cutting caused an immediate and steep decrease in stomatal conductance (g) and net C0 2 assimilation (A) (Fig. 1 and a rapid increase of water potential (!yw), ... were immediate (appearing after less than 1 min) and only transient, vanishing in about 1 h. A new steady state was reached thereafter, wit...

Ngày tải lên: 09/08/2014, 04:20