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.
{"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}
Abstract The article presents research on the population density of the Eurasian beaver in the large, medium and small rivers of the Republic of Mordovia. The population density of the beaver in the large rivers of the region varies from 0.45 to 0.62 colonies per km (average 0.52). The population density in medium rivers ranges from 0.36 to 0.48 colonies per km (average 0.4). In small rivers, population density ranges from 0.2 to 0.94 colonies per km (average 0.46). The total number of beavers in the region is about 17,000 individuals as at 2016.
{"title":"Population density of the Eurasian beaver (Castor fiber L.) (Castoridae, Rodentia) in the Middle Volga of Russia","authors":"A. Andreychev","doi":"10.1515/fsmu-2017-0016","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0016","url":null,"abstract":"Abstract The article presents research on the population density of the Eurasian beaver in the large, medium and small rivers of the Republic of Mordovia. The population density of the beaver in the large rivers of the region varies from 0.45 to 0.62 colonies per km (average 0.52). The population density in medium rivers ranges from 0.36 to 0.48 colonies per km (average 0.4). In small rivers, population density ranges from 0.2 to 0.94 colonies per km (average 0.46). The total number of beavers in the region is about 17,000 individuals as at 2016.","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":"76065321","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}
D. Broz, Gastón Silverio Milanesi, D. Rossit, D. Rossit, F. Tohmé
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.
{"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}
E. Saadaoui, Kaouther Ben Yahia, S. Dhahri, M. L. Ben Jamâa, M. Khouja
Abstract Eucalyptus is a plant frequently present and cultivated in arid regions because of its high adaptation to drought. Furthermore, it is known by its numerous species which represents a great opportunity to choose several tolerant species with variable uses. Therefore, the choice of species, hybrids or genotypes resistant to aridity becomes a necessity before any plantation in regions and countries characterized by semi-arid, arid and Saharan climates. Our review shows an important effect of drought on anatomical, physiological and biochemical parameters of Eucalyptus spp. Indeed, water stress acts directly on growth, yield and response to pests. However, the response to drought varies significantly among species, genotypes, hybrids and clones. This result represents a field for the selection of eucalypts tolerant and adapted to water deficit or climate change.
{"title":"An overview of adaptative responses to drought stress in Eucalyptus spp.","authors":"E. Saadaoui, Kaouther Ben Yahia, S. Dhahri, M. L. Ben Jamâa, M. Khouja","doi":"10.1515/fsmu-2017-0014","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0014","url":null,"abstract":"Abstract Eucalyptus is a plant frequently present and cultivated in arid regions because of its high adaptation to drought. Furthermore, it is known by its numerous species which represents a great opportunity to choose several tolerant species with variable uses. Therefore, the choice of species, hybrids or genotypes resistant to aridity becomes a necessity before any plantation in regions and countries characterized by semi-arid, arid and Saharan climates. Our review shows an important effect of drought on anatomical, physiological and biochemical parameters of Eucalyptus spp. Indeed, water stress acts directly on growth, yield and response to pests. However, the response to drought varies significantly among species, genotypes, hybrids and clones. This result represents a field for the selection of eucalypts tolerant and adapted to water deficit or climate change.","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":"84965791","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}
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.
摘要本研究旨在连续三年定量和经济地评价山茱萸(Cornus mas L.)果实作为农村常住社区的非木材林产品。伊朗西北部Kalaleh村50公顷的森林(Arasbaran生物圈保护区)被选中。在估算出每公顷茎数后，确定了果实产出率。选取45个单株进行营养性状评价，包括总高(m)、冠高(m)、冠径(m)、胸径(mm)、幼芽数和年产果量(kg)。然后使用多元回归分析确定营养特征与果实产量之间的关系，以估计每公顷的总果实产量(每公顷的估计茎数x每茎的平均果实产量)。进行问卷调查和访谈，以确定利益相关者的人数、收获的水果数量及其收获方法;除了成本和收入的收获。结果表明，2012年、2013年和2014年，青松的年总产量和当地采收率分别为(i) 17 500、10 705和8 169 kg， (ii) 4 900、6 540和6 700 kg。销售水果的收入占家庭生计的3.6%至7.3%。山茱萸利用的平均经济租金和森林的平均预期价值分别为52.9美元和17.6美元，利用的平均销售边际为65.5%。我们认为，2014年的采伐率过高，超过了允许的配额，可能对森林的生存能力和可持续性构成重大威胁。总之，需要启动和执行包括树木驯化在内的非木材林产品项目，一方面有助于保护生物多样性，另一方面有助于可持续地管理自然资源。
{"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}
K. Ots, M. Orru, M. Tilk, Leno Kuura, Karin Aguraijuja
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.
{"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}
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.
{"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}
R. Drenkhan, K. Adamson, Tiia Drenkhan, A. Agan, Marili Laas
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.
{"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}
E. Bāders, J. Donis, G. Šņepsts, A. Adamovičs, Ā. Jansons
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).
{"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}
M. Zeps, S. Šēnhofa, M. Zadina, U. Neimane, Ā. Jansons
Abstract Solid wood production of hybrid aspen requires relative longer rotation periods, thus increasing risk of wood damages by pests and diseases. We compared damages by heart rot and poplar borer of 48 years old hybrid (Populus tremuloides Michx. × P. tremula L.) and European aspen in a progeny trial located in Eastern part of Latvia. Trees were harvested and rot patches and galleries were recorded and measured at a stump level. The number of galleries had positive relation on number of patches and total area of rot. The susceptibility of the rot and poplar borer was similar for both hybrid and European aspen. Yet, some differences among families were detected. No effect of pathogens damage was observed on the tree growth. Larger trees had smaller proportion and incidence of rot and galleries per unit of area as well as wider outer rot-free wood layer.
杂交白杨生产实木需要较长的轮作周期，从而增加了木材被病虫害破坏的风险。比较了48岁杂交白杨心腐病和白杨蛀虫的危害。× P. tremula L.)和欧洲白杨在拉脱维亚东部的子代试验。采伐树木，在树桩水平上记录和测量腐斑和腐廊。通道数与腐斑数和腐斑总面积成正相关，杂交杨树和欧洲杨树对腐斑和螟虫的易感性相似。然而，家庭之间也存在一些差异。未观察到病原菌对树木生长的影响。树木越大，单位面积腐烂率和气孔率越低，外无腐木层越宽。
{"title":"Stem damages caused by heart rot and large poplar borer on hybrid and European aspen","authors":"M. Zeps, S. Šēnhofa, M. Zadina, U. Neimane, Ā. Jansons","doi":"10.1515/fsmu-2017-0003","DOIUrl":"https://doi.org/10.1515/fsmu-2017-0003","url":null,"abstract":"Abstract Solid wood production of hybrid aspen requires relative longer rotation periods, thus increasing risk of wood damages by pests and diseases. We compared damages by heart rot and poplar borer of 48 years old hybrid (Populus tremuloides Michx. × P. tremula L.) and European aspen in a progeny trial located in Eastern part of Latvia. Trees were harvested and rot patches and galleries were recorded and measured at a stump level. The number of galleries had positive relation on number of patches and total area of rot. The susceptibility of the rot and poplar borer was similar for both hybrid and European aspen. Yet, some differences among families were detected. No effect of pathogens damage was observed on the tree growth. Larger trees had smaller proportion and incidence of rot and galleries per unit of area as well as wider outer rot-free wood layer.","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":"72428699","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}
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