scholarly journals Modelling early regeneration processes in mixed-species boreal forests of Alberta : 1999 - update /

1999 ◽  
Author(s):  
Daniel W. Gilmore ◽  
◽  
2020 ◽  
Vol 50 (11) ◽  
pp. 1138-1151
Author(s):  
Vesa-Pekka Parkatti ◽  
Olli Tahvonen

We study the management of mixed-species boreal forests and tree species composition in a stand-level economic–ecological, size-structured model. The model includes ecological tree species interaction, a detailed harvesting cost module, optimal harvest timing, and optimization between continuous cover and rotation forestry. Optimization is solved by applying a trilevel structure in which the optimal rotation is the highest-level problem, harvest timing is the mid-level problem, and thinning intensity is the lowest-level problem. Given realistic regeneration costs and a 3% interest rate, continuous cover forestry is optimal and may include up to a 40% fraction of broadleaves. A low interest rate and low regeneration cost together with the presence of light-demanding Scots pine (Pinus sylvestris L.) favours rotation forestry. Eurasian aspen (Populus tremula L.) decreases the bare-land value but is optimal to fell without utilization only when it has no commercial value. Overyielding in terms of cubic metre output does not reveal the economically preferable species combination. Managing single-species stands by removing other species that are naturally regenerated decreases the economic outcome by 35%–44%. Felling noncommercial trees without utilization shows that the economically optimal solution avoids high-grading. Maintaining the number of large-diameter trees beyond the level that maximizes profitability implies only minor losses. Omitting thinning decreases the bare-land value up to 73%.


2021 ◽  
Vol 479 ◽  
pp. 118558
Author(s):  
Saija Huuskonen ◽  
Timo Domisch ◽  
Leena Finér ◽  
Jarkko Hantula ◽  
Jari Hynynen ◽  
...  

2021 ◽  
Vol 284 ◽  
pp. 03010
Author(s):  
Zaynilabiddin Abdikayumov ◽  
Diloram Yulchieva

This scientific paper presents the results of experiments on the propagation of vegetatively propagated clone grafts of cherries from green cuttings. In the experiment, the effect of the concentration of indolymic acid (IMK), the time of preparation of green cuttings and the part of the stem from which the green cuttings were obtained, on the growth of vegetatively propagated stems of cherries from green cuttings was studied. The object of study was the weakly growing vegetatively propagated VSL-2 (Krimsky-5) and CAB-6P grafts of cherries. The cuttings were treated with water concentrations of 20, 40, 60, 80, 100 mg/l to determine the optimal concentration of the growth regulating agent - IMK. Rapid acceleration of rhizogenesis processes and high root yield (78-81%) in green cuttings of cherry clone grafts were noted in the variant treated with IMK 80 mg/l water concentration. The rapid and early regeneration processes in green cuttings using the optimal concentration of IMK ensured that their conditional body diameter reached a standard (6-7 mm) size by the time of cutting grafts. In this experimental variant, the amount of plants that can be grafted has reached about 89% of the total number of plants that have taken root.


2019 ◽  
Vol 39 (4) ◽  
pp. 429 ◽  
Author(s):  
Joshua J. Puhlick ◽  
Shawn Fraver ◽  
Ivan J. Fernandez ◽  
Aaron Teets ◽  
Aaron R. Weiskittel ◽  
...  

2020 ◽  
Vol 82 (4) ◽  
pp. 342-351
Author(s):  
Wilbert Valkinir Cabreira ◽  
Marcos Gervasio Pereira ◽  
Fabiano de Carvalho Balieiro ◽  
Eduardo da Silva Matos ◽  
Renato de Aragão Ribeiro Rodrigues ◽  
...  

2012 ◽  
pp. 109-134
Author(s):  
P. S. Shirokikh ◽  
A. M. Kunafin ◽  
V. B. Martynenko

The secondary birch and aspen forests of middle stages of succession of the central elevated part of the Southern Urals are studied. 4 subassociations, 1 community, and 7 variants in the alliances of Aconito-Piceion and Piceion excelsae are allocated. It is shown that the floristic composition of aspen and birch secondary forests in the age of 60—80 years is almost identical to the natural forests. However, a slight increase the coenotical role of light-requiring species of grasslands and hemiboreal forests in the secondary communities of the class Brachypodio-Betuletea was noticed as well as some reduction of role the shade-tolerant species of nemoral complex and species of boreal forests of the class Vaccinio-Piceetea. Dominant tree layer under the canopy of secondary series is marked by an active growth of natural tree species.


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