Linear programming approach for optimal forest plantation

The aim of this research was to identify species suitable for plantation. We first identified species for potentially suitable for plantation based on ecological capabilities regarding soil properties. We determined the area of plantation for different species based on ecological capabilities. Then, we collected relevant data such as growth patterns of different species, labor requirements for plantation and plantation cost. A linear programming model and two integer linear programming models were used for optimization. The appropriate species based on ecological capabilities were ash, elm, maple, oak and bald cypress. A linear programming model was used based on ecological capabilities classification to determine the land area of different species for plantation. Then, two integer linear programming models were employed to select the species for plantation. We set ecological properties unequal for all of the species in the first run of the integer programming model. Two groups were classified： group one included maple and ash; group two included bald cypress,oak and elm. The second integer programming model assumed equal ecological properties for all the species.Results of linear programming showed that maple and bald cypress were appropriate for plantation at the site and their plantation areas should be 151.3 and 355.3 ha, respectively. Results of the first integer linear programming model showed that maple and bald cypress would be economically profitable for plantation. The results of the second integer linear programming model showed that only bald cypress would be appropriate for plantation.

Biomass production of hybrid aspen growing on former farm land in Sweden

We construct dry weight equations for hybrid aspen growing on former farmland in Sweden. Dry weight equations for fractions of hybrid aspen trees were also made. We estimated biomass production in 24 stands. The stands were located in Sweden at latitudes ranging from 55 to 60o N. The mean age was 18 years （range 15-23）, the mean stand density 1090 stems·ha-1 （range 378 2374）, and the mean diameter at breast height （over bark） 178 mm （range 85 244 mm）. Soil types in the hybrid aspen stands were mainly clay （21 stands）, tills （2 stands） and other （1 stand）. The mean total standing dry weight above stump level （≈ 200 mm） for the hybrid aspen stands was 135±53 t·ha-1 with a range of 42 219 t·ha-1 . In addition to estimating conventional dry weights of trees and tree components, basic density, specific leaf area （SLA）, projected leaf area （PLA） and leaf area index （LAI） were estimated and were in agreement with published figures.

Endangered lowland oak forest steppe remnants keep unique bird species richness in Central Hungary

The biodiversity of natural or semi-natural native,old oak woodlands have high conservation importance,especially in landscapes of monocultural forest plantations and arable fields.With a wider variety of microhabitats and foraging sources,such old oak forests can provide essential habitat for native forest bird communities.We conducted a study using bird point counts to compare the forest bird communities of old pedunculate oak(Quercus robur)remnants with native and non-native plantations in central Hungary in a landscape of mostly arable fields,settlements,and monocultural plantations.Avian surveys were carried out in old oak forest remnants,middle-aged oak,white poplar(Populus alba),hybrid poplar(Populus×euramericana),black locust(Robinia pseudoacacia),and pine(Pinus spp.)plantations.Fieldwork has been carried out in nine study sites,where all six habitat types were represented(with a few exceptions),to determine total abundance,species richness,Shannon–Wiener diversity,species evenness,dominant and indicator species,and guild abundances.We found that old oak forest remnants were the most diverse habitats among the studied forest types,while hybrid poplar and pine plantations exhibited the lowest avian biodiversity.The avian guilds most sensitive to the loss of old oak forest remnants were ground foragers,bark foragers,cavity-nesters,residents,and Mediterranean migratory birds.Native habitats were more diverse than non-native plantations.Our results suggest that it is important to conserve all remaining high biodiversity old oak stands and to avoid clear-cutting of monocultural plantations in favour of practices such as mixed-species plantations,longer rotation lengths,or retention forestry.

Influence of Different Forest Management Techniques on the Quality of Wood

The issue of accelerated forestry plantation with high-quality wood using the best soils in terms of productivity,fertilizers,and intensive treatment has become quite relevant due to increased demand for forestry products and higher requirements for environmentally friendly use of forest resources.This paper presents the results of a study on the impact of various techniques for treating coniferous plantations,including thinning,fertilization,and herbicide processing,on wood quality key indicators.The paper examined the wood density,correlation of early and late wood zones,and the cell wall thickness for 38-year-old pine trees grown on the sample plots of Siversky leskhoz(Leningrad region,Gatchinskiy district)at different treatment and density control techniques.It has been established that the highest basis density of wood corresponds to the samples grown at the density variant of 1 t/ha and double herbicides treatment,and the lowest basis density value was recorded at the option of 4 t/ha with combined treatment.It has been shown that the increase of width index for early wood is influenced by the lower density of 1 t/ha and one-time herbicide treatment,for late wood–by the lower density of 1 t/ha and repeated treatment with herbicides.The increase in average cell wall thickness for early and late wood is observed when the density increases up to 4 t/ha and double herbicides treatment.The results obtained provide a valuable scientific contribution to general forestry knowledge and have practical value in plantation forestry.

Taxonomy and pathogenicity of Ceratocystis species on Eucalyptus trees in South China, including C. chinaeucensis sp. nov.

Commercial plantations of Eucalyptus species have been established in South China,especially during the past 20 years,to meet the needs of a rapidly growing national economy.As part of a survey of fungal diseases affecting Eucalyptus species in South China,Ceratocystis species were collected from Eucalyptus plantations in the GuangDong Province.The aims of this study were to identify these Ceratocystis isolates and to test their pathogenicity to Eucalyptus.The most aggressive isolates were also used to screen different species and clones of Eucalyptus for susceptibility to infection under field conditions.The fungi were identified based on morphology and through comparisons of DNA sequence data of the ITS,partialβ-tubulin and TEF-1αgene regions.Morphological and DNA sequence comparisons showed that isolates collected from Chinese Eucalyptus plantations represent two species,C.acaciivora in the C.fimbriata s.l.species complex and a previously undescribed species belonging to the C.moniliformis s.l.species complex,for which the name C.chinaeucensis sp.nov.is provided.In pathogenicity trials,both C.acaciivora and C.chinaeucensis gave rise to lesions on wounded Eucalyptus trees,and the former fungus was most pathogenic.Differences were also observed in the responses of different Eucalyptus clones to inoculation and this could be useful in reducing disease,if C.acaciivora should emerge as a pathogen in the future.