Forestry Studies最新文献_第10页

Estimation of change in forest height growth 森林高度生长变化的估计

Forestry Studies Pub Date : 2017-12-01 DOI: 10.1515/fsmu-2017-0009

Mait Lang, T. Arumäe, D. Laarmann, A. Kiviste

{"title":"Estimation of change in forest height growth","authors":"Mait Lang, T. Arumäe, D. Laarmann, A. Kiviste","doi":"10.1515/fsmu-2017-0009","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0009","url":null,"abstract":"Abstract Forest height increment rate is related to the forest growth conditions. Data bases of previous forest inventories contain information about forest heightage relationship on large number of forest stands while repeated measurements of permanent sample plots provide an excellent reference for comparison. Repeated airborne laser scanning of forest stands is an additional source for the estimation of change in forest structure. In this study, height growth of middle-aged and older forest stands for about 10 year period was compared to an algebraic difference model on permanent sample plots (66) and for a sample of forest stands with repeated airborne laser scanning data (61). The model was based on a large dataset of forest inventory records from the period of 1984–1993. Statistically significant increased forest height growth was found in permanent sample plots based on tree height measurements (9 cm yr−1) as well in stands with repeated laser scanning data (4.5 cm yr−1) in South-East Estonia compared to the algebraic difference model. The difference between the two data sets was explained by their mean age and site class, but the increased forest height growth compared to the old forest inventory data indicates improved growth conditions of forests in the test area. The results hint also that empirical data-based forest growth models need to be updated to avoid biased growth estimates.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81353817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Population density of the Eurasian beaver (Castor fiber L.) (Castoridae, Rodentia) in the Middle Volga of Russia 俄罗斯伏尔加河中部欧亚海狸(Castor fiber L.) (Castoridae，啮齿目)种群密度

Forestry Studies Pub Date : 2017-12-01 DOI: 10.1515/fsmu-2017-0016

A. Andreychev

引用次数: 6

Forest management decision making based on a real options approach: An application to a case in northeastern Argentina 基于实物期权方法的森林经营决策:在阿根廷东北部案例中的应用

Forestry Studies Pub Date : 2017-12-01 DOI: 10.1515/fsmu-2017-0015

D. Broz, Gastón Silverio Milanesi, D. Rossit, D. Rossit, F. Tohmé

{"title":"Forest management decision making based on a real options approach: An application to a case in northeastern Argentina","authors":"D. Broz, Gastón Silverio Milanesi, D. Rossit, D. Rossit, F. Tohmé","doi":"10.1515/fsmu-2017-0015","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0015","url":null,"abstract":"Abstract The Net Present Value (NPV) approach is widely applied to assess forest investments, but this method has serious shortcomings, which we propose to overcome by switching to the assessment through the Real Options Approach (ROA). The model in this paper starts with the simulation of the forest’s growth, combined with the projection of the products’ prices and valuing the assets using a binomial model. We include an option of postponement, determining the optimal period of felling. We find that ROA is more robust than the NPV approach because it relaxes the assumption of constancy of both the prices and the discount rate, allowing the determination of the optimal time of felling based on the growth rate of either the forest or the prices of its products. Contrary to the traditional NPV approach, the results obtained with ROA exhibit longer harvest turns and consequently higher profits. The key variable in the ROA, the Real Option Value (ROV) can be shown to be less (albeit moderately) sensitive to decreases of the discount rate than NPV. Moreover, ROV is moderately sensitive to decreases in the price of logs and is negligibly affected by rises in the costs of harvesting, loading and transporting rolls.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87532403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

An overview of adaptative responses to drought stress in Eucalyptus spp. 桉树对干旱胁迫的适应性反应综述。

Forestry Studies Pub Date : 2017-12-01 DOI: 10.1515/fsmu-2017-0014

E. Saadaoui, Kaouther Ben Yahia, S. Dhahri, M. L. Ben Jamâa, M. Khouja

引用次数: 30

Cornelian cherry (Cornus mas L.) fruit as a non-timber forest product of Arasbaran biosphere reserve forests in Northwest of Iran 山茱萸果实是伊朗西北部阿拉斯巴兰生物圈保护区的一种非木材林产品

Forestry Studies Pub Date : 2017-12-01 DOI: 10.1515/fsmu-2017-0013

A. Alijanpour

{"title":"Cornelian cherry (Cornus mas L.) fruit as a non-timber forest product of Arasbaran biosphere reserve forests in Northwest of Iran","authors":"A. Alijanpour","doi":"10.1515/fsmu-2017-0013","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0013","url":null,"abstract":"Abstract The present research aimed to quantitatively and economically evaluate Cornelian cherry (Cornus mas L.) fruit as a non-timber forest product for a resident rural community across three consecutive years. A forest stand of 50 hectares in Kalaleh village, Northwest of Iran (Arasbaran biosphere reserve), was selected. After estimating the number of stems per hectare, the rate of fruit production rate was determined. Forty five individuals were then selected and assessed for their vegetative characteristics, including total height (m), crown height (m), crown diameter (m), diameter at breast height (mm), number of coppice shoots and annual fruit production (kg). Relationships between the vegetative characteristics and fruit production were then determined using multiple regression analysis to estimate the total fruit production per ha (estimated number of stems per hectare x mean fruit production per stem). Questionnaires and interviews were conducted to determine the number of stakeholders, quantity of fruit harvested and their harvesting methods; in addition to the costs and revenues of the harvest. Our results indicated that in 2012, 2013 and 2014, the annual total fruit production and local harvesting rates were: (i) 17 500, 10 705 and 8 169 kg and (ii) 4 900, 6 540 and 6 700 kg respectively. The revenue from selling the fruit contributed from 3.6% to 7.3% to household livelihoods. Mean economic rent of Cornelian cherry utilization and the average expected value of the forest were US$ 52.9 and US$ 17.6 respectively, while the average marketing margin of utilization was 65.5%. We believe that the inflated harvest rate recorded in 2014, which was above the allowable quota, might be a crucial threat to viability and also the sustainability of the forest stand. In conclusion, launching and implementing non-timber forest products projects including tree domestication is required to help conserving biodiversity in one hand and to sustainably manage natural resources in the other hand.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80038813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Afforestation of cutaway peatlands: effect of wood ash on biomass formation and carbon balance 采伐泥炭地造林:木灰对生物量形成和碳平衡的影响

Forestry Studies Pub Date : 2017-12-01 DOI: 10.1515/fsmu-2017-0010

K. Ots, M. Orru, M. Tilk, Leno Kuura, Karin Aguraijuja

{"title":"Afforestation of cutaway peatlands: effect of wood ash on biomass formation and carbon balance","authors":"K. Ots, M. Orru, M. Tilk, Leno Kuura, Karin Aguraijuja","doi":"10.1515/fsmu-2017-0010","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0010","url":null,"abstract":"Abstract Alternatives to the restoration of cutaway peatlands include afforestation, energy forests, agricultural production, wetland restoration (restoration of peataccumulating function), reed canary grass (energy mower) or wild berries (blueberry, cranberry) cultivation, protected area for birds, and artificial lakes. Investigations made in several countries suggest that one of the most promising ways of regenerating cutaway peatlands is afforestation. The re-vegetation of Estonian cutaway peat production fields is mainly the result of natural processes, which are generally very slow: vegetation covers only 10–20% of a peat field. Carbon dioxide is not bound anymore in cutaway peatlands where vegetation layer has been destroyed and therefore photosynthetical processes no more occur. Using biofuel ashes (wood ash, etc.) for the afforestation of cutaway peatlands helps to balance the content of nutrients in peat substrate, which improves the survival of planted seedlings and significantly increases bioproduction. Drained and mined peatlands have become a significant source of CO2 but stimulated woody biomass production can be helpful to balance CO2 emission from cutaway peatlands. Because of the limited resources of fossil fuels and negative impacts on the environment in recent decades alternative sources of energy have been actively looked for. In Scandinavia a lot of attention has been paid to finding possibilities for using biofuels. The situation in Estonia is that only very few types of ashes (for example certified oil shale fly ash with product name Enefix) have been founded to be suitable for utilization and have been used for recycling in agriculture.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81279155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

The influence of forest management and timber use options on carbon sequestration and the consequences on biodiversity 森林管理和木材利用方案对固碳的影响及其对生物多样性的影响

Forestry Studies Pub Date : 2017-12-01 DOI: 10.1515/fsmu-2017-0011

Raul Rosenvald, K. Rosenvald

{"title":"The influence of forest management and timber use options on carbon sequestration and the consequences on biodiversity","authors":"Raul Rosenvald, K. Rosenvald","doi":"10.1515/fsmu-2017-0011","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0011","url":null,"abstract":"Abstract The results of scientific studies dealing with the influence of forest management on carbon dynamics are often controversial. Substituting fossil fuels with wood is not always a climate-friendly solution, and besides, it has often a negative impact on biodiversity. The current paper reviews the literature about the influence of different forest management and timber use options on climate change and brings out the accompanying consequences on biodiversity in temperate and boreal climate zones. The forest’s ability to sequestrate and store carbon can be enlarged by appropriate forest management planning and practices. Generally, for mitigation of climate change, the moderate (not intensive) forest management is most favourable, but intensification of management enhances global warming, since forest carbon storage in tree biomass and soil decreases. The mitigation of climate change is just one of the many roles of forest, and climate policy actions cannot come at the expense of species diversity. The complex studies dealing with several forest goals conclude that high carbon store and biodiversity protection do not contradict each other, but the achievement of maximum economic profit at the same time is not possible. The mitigation of climate change and wildlife protection is most effective when it is first of all the forests with a high biodiversity that are managed less intensively. Concerning climate change, the most negative forest biomass use is wood combustion. It is reasonable to burn only such biomass (cut and industrial residues) which cannot be used for producing goods holding carbon for a long time.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80816718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New problems in dendropathology – new and invasive pathogens 树木病理学的新问题——新的侵袭性病原体

Forestry Studies Pub Date : 2017-12-01 DOI: 10.1515/fsmu-2017-0012

R. Drenkhan, K. Adamson, Tiia Drenkhan, A. Agan, Marili Laas

{"title":"New problems in dendropathology – new and invasive pathogens","authors":"R. Drenkhan, K. Adamson, Tiia Drenkhan, A. Agan, Marili Laas","doi":"10.1515/fsmu-2017-0012","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0012","url":null,"abstract":"Abstract During the last decades, several new and invasive tree pathogens have arrived in the northern Europe, damaging forest and verdant trees. New and invasive species (e.g. Lecanosticta acicola, Dothistroma septosporum, Diplodia sapinea, Hymenoscyphus fraxineus) are considered to cause economic loss and be an important threat to biodiversity. Once the alien species have entered into ecosystem, then it is very difficult to eliminate them. Therefore, it is important to discover new and invasive pathogens from forests and from imported plant material as early as possible. For that reason, the research team of Estonian forest pathologists has worked out a survey strategy with permanent plots across Estonia – for early detection of new pathogens, which essentially includes molecular monitoring of pathogens. An important task in developing of early detection methods for new and invasive pathogens is working out of quick detection methods by creating original PCR primers. Crucial is also the analyses of pathogens biology, of their spreading and finding of all their potential hosts in new for them environment in northern Europe. In cooperation studies with our foreign partners, the Estonian forest pathologists have analysed populations of D. septosporum, L. acicola and H. fraxineus. The population genetic methods give data about the pathogens diversity, vitality and betray potential pathways of them to northern Europe. This information serves for building up the control strategy and helps to find and test resistant tree species progenies. Early detection, molecular monitoring and pathways detection of new and invasive pathogens are currently the most important research tasks of the forest pathology team working in Estonian University of Life Sciences.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89575636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Pruning effect on Norway spruce (Picea abies (L.) Karst.) growth and quality 挪威云杉(Picea abies, L.)的修剪效果喀斯特)生长和质量

Forestry Studies Pub Date : 2017-06-01 DOI: 10.1515/fsmu-2017-0005

E. Bāders, J. Donis, G. Šņepsts, A. Adamovičs, Ā. Jansons

{"title":"Pruning effect on Norway spruce (Picea abies (L.) Karst.) growth and quality","authors":"E. Bāders, J. Donis, G. Šņepsts, A. Adamovičs, Ā. Jansons","doi":"10.1515/fsmu-2017-0005","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0005","url":null,"abstract":"Abstract Pruning requires significant investment, therefore, the aim of the study was to characterize occlusion of branch wounds and changes in radial increment as well as frequency of browsing damages after pruning of Norway spruce (Picea abies (L.) Karst.) in order to provide data for financial calculations and recommendations for practical forestry. Altogether 1,614 pruned and 4,368 unpruned trees from 45 Norway spruce stands were measured and cored. Degree of wound occlusion and browsing damages were assessed, and additional volume increment estimated in each stand. Pruning resulted in significant increase of length of branch-free section: for unpruned trees it was 0.3 ± 0.07 m, but for pruned 3.4 ± 0.10 m. Branch wounds for most of the trees (68%) were filled with resin (occluded), for lower share of trees (31%) – still open, but for some trees (1%) completely occluded. Branch wound occlusion rate was not affected by differences in stand density, but was significantly affected by stand age: proportion of trees with occluded branch scars increased with age. Trees with occluded branch wounds had a significantly higher increase in tree ring width after the pruning in comparison to the period before pruning than trees with open branch wounds, emphasizing the importance of radial increment in development of branch-free layer of wood. Pruning resulted in minor (−7% or −0.28 ± 0.05 m3 ha−1) reduction of annual increment that was statistically significant only up to 3 years after this forest management activity for stands younger than 17 years and with mean height up to 10.5 m. Pruned trees were significantly more browsed than unpruned (6.1% and 2.7%, respectively).","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89111855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Stem damages caused by heart rot and large poplar borer on hybrid and European aspen 杂交杨树和欧洲杨树的心腐病和大杨树蛀虫对茎的危害

Forestry Studies Pub Date : 2017-06-01 DOI: 10.1515/fsmu-2017-0003

M. Zeps, S. Šēnhofa, M. Zadina, U. Neimane, Ā. Jansons

引用次数: 7