检索结果-南通市图书馆

Journal of Forestry Research 2019年第4期30卷 1383-1394页

作者： Farzam Tavankar Angela Lo Monaco Mehrdad Nikooy Rachele Venanzi Amireslam Bonyad rodolfo picchio Department of Forestry Khalkhal BranchIslamic Azad UniversityKhalkhalIran Department of Agriculture and Forest Sciences(DAFNE) Tuscia UniversityVia S.Camillo de Lellis01100 ViterboItaly Department of Forestry Faculty of Natural ResourcesUniversity of GuilanSomehsaraIran

Snow damage on natural stands is an important problem concerning mountainous forest *** the present research,the frequency and intensity of heavy snow damage on natural stands and the relationship of damages with characteristics of trees,stand and topography were studied in mountainous forests of northern Iran.A systematic sampling design was applied to the study area(140 ha),with 122 circular *** grid dimension was100 m and each plot area was 1000 m^*** four types of snow damage to trees include:crown damage(8.6%),stem breakage(5.4%),uprooting(3.2%),and bending(1.4%).The frequency of crown damage grew with an increase inthe diameter at breast height(DBH),while the frequency of stem breakage,uprooting and bending decreased with an increase the *** frequency of crown damage,stem breakage,and total damages was related to tree species(p<0.01).Not all tree species were equally susceptible to snow *** amount of damage grew with increasing elevation and slope angle and decreased with increasing soil *** trees(DBH<25 cm)were more susceptible to snow damage than other *** damage decreased by as the trees in the stand became more mixed in *** susceptibility of trees to snow damage increased by height and slenderness *** adequate silvicultural operation,snow damage can be reduced to a minimum level in these natural forests.

关键词： Mixed forest Slenderness coefficient Snow damage Stem breakage Uprooting

Productivity and energy balance of forest plantation harvesting in Uganda

在线全文

学校读者我要写书评

暂无评论

Forestry Studies in China 2012年第4期14卷 276-282页

作者： Hussein BALIMUNSI Stefano GRIGOLATO rodolfo picchio Kenneth NYOMBI Raffaele CAVALLI College of Agricultural and Environmental Sciences Makerere University Department of Land EnvironmentAgriculture and ForestryUniversity of Padua Department of Environmental and Forestry Technologies Engineering and SciencesTuscia University

The study evaluated the productivity and energy balance of the harvesting and the extraction of wood in plantation of exotic tree species, i.e., Pinus patula （Schiede ex Schlectendahl et Chamisso） and Cupressus lusitanica （Mill.）. The harvesting and extraction operations concerned clear-cut felling on two different types of terrain （gentle and steep terrain） and two levels of prun- ing. The results show that cutting is not affected by the terrain gradient whereas the pruning condition shows a significant effect on the delimbing operation. The productivity of cutting is evaluated at 28.1 m3.d-1 for unpruned trees and at 30.2 m3.d t for pruned trees. For the extraction phase, rolling was significantly affected by terrain conditions. On steep terrain, the gross productivity can be evaluated at 22.5 m3.d 1 for an extraction distance of 40 m, while for the same distance on gentle terrain the productivity decreases to 14.1 m3.d~. As a result, the steep terrain condition showed higher energy efficiency, suggesting that it is the more efficient system of extraction. The productivity model and the energy balance resulting from the study provide a better understanding of the variables af- fecting motor-manual cutting and rolling extraction in exotic plantations in Uganda.

关键词： exotic tree plantation energy balance harvesting productivity clear-cut felling Uganda

Effect of moisture on physical parameters of timber from Turkey oak (Quercus cerris L.) coppice in Central Italy

在线全文

学校读者我要写书评

暂无评论

Forestry Studies in China 2011年第4期13卷 276-284页

作者： Angela LO MONACO Luigi TODARO Mara SARLATTO Raffaello SPINA Luca CALIENNO rodolfo picchio Department of Science and Technology for Agriculture Forests Nature and Energy University of Tuscia Department of Crop Systems Forestry and Environmental Sciences University of Basilicata Agricultural Research Council

This study aims to investigate wood density at different levels of moisture, basic density and shrinkage of timber from Turkey oak （Quercus cerris L.） coppice forests growing in Central Italy. We also studied the variability in density in the trees within and among sites. Density shows no significant statistical differences in the tested population. A higher variability in the shrinkage than in the density was found. Wood moisture is referred to as dry mass and fresh mass, which is related to many performance characteristics of wood, i.e., energy production. Trends in moisture and water content were studied because these physical parameters play an important role in the specific area of firewood which requires an accurate estimation of mass, volume and energy content. This work is a contribution to improve xylo-energy estimates of small and medium forestry issues.

关键词： wood density coppice moisture content Quercus cerris L. shrinkage

Stumpage value in the short wood system for the conversion into high forest of a oak coppice

在线全文

学校读者我要写书评

暂无评论

Forestry Studies in China 2011年第4期13卷 252-262页

作者： rodolfo picchio Raffaello SPINA Mauro MAESANO Francesco CARBONE Angela LO MONACO Enrico MARCHI Department of Agriculture Forests Nature and Energy (DAFNE) University of Tuscia Via San Camillo de Lellis Viterbo 01100 Italy EcoGeoFor Lab Department of Science and Technology for the Environment and Territory (STAT) University of Molise Contrada Fonte Lappone Isernia 86090 Italy Department of Ecology and Sustainable Economic Development University of Tuscia Via San Camillo de Lellis Viterbo 01100 Italy Department of Agricultural and Forest Economics Engineering Sciences and Technologies University of Florence Via San Bonaventura 13 Florence 50145 Italy

This study aims to analyze the factors affecting the costs of different logging systems, in particular considering three different bunching-extraction methods. Moreover the stumpage value of each plot was calculated, and a comparison analysis of the results is presented. The work was carried out in Central Italy, in an aged Quercus cerris L. coppice in hill zones, with a 45% average slope. Short wood system harvesting was applied. Felling and processing were performed by chainsaw, while extraction with three different methods： plot No. 1 with mules, plot No. 2 with a tractor with winch, plot No. 3 with polyethylene chute line. Transport of firewood from the forest track to the landing was made by a tractor loaded as a mule. In the plot No. 1 the costs per unit mass （30.76 ∈·t33% ^-1） were higher despite having the lower cost per hour （39.99∈·th^- 1）. The reason was the lower productivity （1.3 t33%·h^-1）. The plot No. 2 had the highest cost per hour （66.79 ∈·h^-1）. However, productivity was the highest （2.7 t33%·h^- 1）. This aspect was notable from the financial point of view （24.74 ∈·t33%^-1）. Plot No. 3 was the less expensive （23.92 ∈·t33%^-1）. Comparing the three methods, a reduction of the costs through more appropriate extraction systems may increase the stumpage value from 8.3 to 9.65 ∈·t33%^- 1.

关键词： extraction financial analysis stumpage value coppice