Edgars Dubrovskis, J. Donis, Eduards Rācenis, Māra Kitenberga, Ā. Jansons
Abstract In Europe, salvage-logging is a common management activity to partially recover economic value from wind disturbed forests. In the near future, wind damage to forests is predicted to increase due to climate change. Therefore, an economic assessment of wind damage effects on recovered timber value is useful information in the decision-making process. In this study, we aim to assess the influence of different stem damage heights on the monetary value of recovered timber. We simulated stem breakage at three heights for the Scots pine (Pinus sylvestris L.): 3, 5, and 7 m. For comparison, we used an uprooted tree without stem breakage. Our results revealed that the most negative influence on the recovered timber value was stem breakage at 3 m, which decreased the monetary value by 35%. The stem breakage at 5 and 7 m decreased the recovered timber value by 9–10%. Over the analysed period (2006–2017), no significant differences in the monetary value of the recovered timber were found between uprooted lumber and stems with breakage at 5 and 7 m. The price fluctuations in the market have a significant influence on the recovered timber value, which might cause a larger decrease in monetary value than stem breakage.
{"title":"Wind-induced stem breakage height effect on potentially recovered timber value: case study of the Scots pine (Pinus sylvestris L.) in Latvia","authors":"Edgars Dubrovskis, J. Donis, Eduards Rācenis, Māra Kitenberga, Ā. Jansons","doi":"10.2478/fsmu-2018-0009","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0009","url":null,"abstract":"Abstract In Europe, salvage-logging is a common management activity to partially recover economic value from wind disturbed forests. In the near future, wind damage to forests is predicted to increase due to climate change. Therefore, an economic assessment of wind damage effects on recovered timber value is useful information in the decision-making process. In this study, we aim to assess the influence of different stem damage heights on the monetary value of recovered timber. We simulated stem breakage at three heights for the Scots pine (Pinus sylvestris L.): 3, 5, and 7 m. For comparison, we used an uprooted tree without stem breakage. Our results revealed that the most negative influence on the recovered timber value was stem breakage at 3 m, which decreased the monetary value by 35%. The stem breakage at 5 and 7 m decreased the recovered timber value by 9–10%. Over the analysed period (2006–2017), no significant differences in the monetary value of the recovered timber were found between uprooted lumber and stems with breakage at 5 and 7 m. The price fluctuations in the market have a significant influence on the recovered timber value, which might cause a larger decrease in monetary value than stem breakage.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79947184","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 is a comparative analysis of how the main quality indices of containerized and barerooted coniferous (Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.)) planting stock conform to the existing standards in Estonia, how the plantation development depends on planting stock and natural regeneration on soil scarification. The height of Scots pine containerized seedlings exceeded that of barerooted seedlings by 20%. The height of barerooted Norway spruce transplants exceeded that of containerized seedlings by 19%. The root-collar diameter of containerized pine stock formed 70% and the corresponding index of containerized spruce stock formed 48% of the diameter of the barerooted plants of the same species. Typically, containerized plants had better initial growth increment during the first two to three years after planting but this difference disappeared during the latter years. The growth of Scots pine barerooted and containerized seedlings was similar, while the growth of Norway spruce containerized seedlings was slightly inferior compared to barerooted plants. Survival of both test species was independent of planting stock used. After clear-cutting, certain areas of peatland and mineral areas were disc-trenched and inventoried at the end of the first growing season. The number of all woody plants was determined by microsites – untreated area, furrow, slope, and ridge. The same inventory was repeated 11 growing seasons later. After 11 growth years, a large number of Scots pine trees was found in Rhodococcum, Oxalis and Vaccinium myrtillus site types and drained peatlands. The number of pine plants on microsites on mineral soil was the greatest in furrows and on slopes (34% and 30%), and on peat soil on furrows and in untreated areas (47% and 53%). The number of naturally regenerated Norway spruce trees was the largest in Vaccinium myrtillus, Oxalis-Rhodococcum and Oxalis site types. With regard to microsites, spruce plants were the most abundant in furrows and ridges on mineral soil (31% and 24%) and in untreated areas and on slopes on peat soil (46% and 42%).
{"title":"The effect of planting stock and soil scarification on forest regeneration","authors":"Andres Jäärats, A. Tullus","doi":"10.2478/fsmu-2018-0013","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0013","url":null,"abstract":"Abstract The present research is a comparative analysis of how the main quality indices of containerized and barerooted coniferous (Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.)) planting stock conform to the existing standards in Estonia, how the plantation development depends on planting stock and natural regeneration on soil scarification. The height of Scots pine containerized seedlings exceeded that of barerooted seedlings by 20%. The height of barerooted Norway spruce transplants exceeded that of containerized seedlings by 19%. The root-collar diameter of containerized pine stock formed 70% and the corresponding index of containerized spruce stock formed 48% of the diameter of the barerooted plants of the same species. Typically, containerized plants had better initial growth increment during the first two to three years after planting but this difference disappeared during the latter years. The growth of Scots pine barerooted and containerized seedlings was similar, while the growth of Norway spruce containerized seedlings was slightly inferior compared to barerooted plants. Survival of both test species was independent of planting stock used. After clear-cutting, certain areas of peatland and mineral areas were disc-trenched and inventoried at the end of the first growing season. The number of all woody plants was determined by microsites – untreated area, furrow, slope, and ridge. The same inventory was repeated 11 growing seasons later. After 11 growth years, a large number of Scots pine trees was found in Rhodococcum, Oxalis and Vaccinium myrtillus site types and drained peatlands. The number of pine plants on microsites on mineral soil was the greatest in furrows and on slopes (34% and 30%), and on peat soil on furrows and in untreated areas (47% and 53%). The number of naturally regenerated Norway spruce trees was the largest in Vaccinium myrtillus, Oxalis-Rhodococcum and Oxalis site types. With regard to microsites, spruce plants were the most abundant in furrows and ridges on mineral soil (31% and 24%) and in untreated areas and on slopes on peat soil (46% and 42%).","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82971068","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 To investigate the ecosystems on dunes, five typical dunes were selected in the coastal area of the Baltic Sea in southwest Estonia. To study ground vegetation species richness, species composition and horizontal structure, 251 quadrats of 1 m2 in size were established and descriptions of vascular plants, bryophytes and lichen species were provided. Topographical factors, soil horizons, soil pH and electrical conductivity, soil nutrients, soil moisture conditions and light conditions were determined. In total, 42 vascular plant, 43 bryophyte and 48 lichen species were recorded on five dunes. Vascular plant species richness and composition on forested dunes was dependent on the absolute dune height, zone and aspect of the slope, soil nitrogen, potassium and phosphorus content, soil pH and moisture, the cover of the bryophyte-lichen layer and light conditions. Regarding bryophyte and lichen layer species composition, important factors were the aspect of the dune, vascular plant species cover, light conditions, the thickness of the moderately decomposed organic soil horizon, soil pH, electrical conductivity and volumetric water content. Lichen species richness was highest on the slopes of the dunes, while bryophyte species richness was higher at the bottoms and decreased towards the tops of the dunes. Ground vegetation species richness and species’ horizontal and vertical structure on forested dunes were highly dependent on topography-induced differences, aspect, height and zone of the dunes. The most important factors controlling the complex of ground vegetation were light conditions, soil water content, thickness of the moderately decomposed litter layer and soil potassium and calcium content.
{"title":"Ground vegetation diversity and geobotanical analysis in dune pine forests in southwest Estonia","authors":"M. Tilk, K. Ots, Tea Tullus, M. Mandre","doi":"10.2478/fsmu-2018-0012","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0012","url":null,"abstract":"Abstract To investigate the ecosystems on dunes, five typical dunes were selected in the coastal area of the Baltic Sea in southwest Estonia. To study ground vegetation species richness, species composition and horizontal structure, 251 quadrats of 1 m2 in size were established and descriptions of vascular plants, bryophytes and lichen species were provided. Topographical factors, soil horizons, soil pH and electrical conductivity, soil nutrients, soil moisture conditions and light conditions were determined. In total, 42 vascular plant, 43 bryophyte and 48 lichen species were recorded on five dunes. Vascular plant species richness and composition on forested dunes was dependent on the absolute dune height, zone and aspect of the slope, soil nitrogen, potassium and phosphorus content, soil pH and moisture, the cover of the bryophyte-lichen layer and light conditions. Regarding bryophyte and lichen layer species composition, important factors were the aspect of the dune, vascular plant species cover, light conditions, the thickness of the moderately decomposed organic soil horizon, soil pH, electrical conductivity and volumetric water content. Lichen species richness was highest on the slopes of the dunes, while bryophyte species richness was higher at the bottoms and decreased towards the tops of the dunes. Ground vegetation species richness and species’ horizontal and vertical structure on forested dunes were highly dependent on topography-induced differences, aspect, height and zone of the dunes. The most important factors controlling the complex of ground vegetation were light conditions, soil water content, thickness of the moderately decomposed litter layer and soil potassium and calcium content.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84637261","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}
Roberts Čakšs, Linda Robalte, I. Desaine, B. Džeriņa, Ā. Jansons
Abstract The long-term (50 years) effect of whole-tree harvesting (stump harvesting) on ground vegetation in experimental drained Norway spruce (Picea abies (L.) Karst.) stands was studied. We used a chronosequence approach to assess the long-term impact of whole-tree harvesting (WTH) on stands’ ground vegetation. WTH stands were compared with four control stands with different age and with the same forest type: young stand (15 years), middle-aged stand (45 years), mature stand (110 years) and over-mature stand (140 years). Species richness was similar between the WTH stand and middle-aged stand (61 and 60 species, respectively). Shannon-Wiener diversity indices in the WTH and middle-aged stand (3.40 and 3.19, respectively) indicated that the stands were similar to each other. A community similarity analysis showed that the composition of vegetation was similar between the WTH and middle-aged stand, although some species like Lycopodium clavatum and Diphasiastrum complanatum occurred only in the WTH stand. The study showed that a period of 50 years is sufficient for ground vegetation of a typical drained spruce forest to recover after WTH management.
{"title":"Ground vegetation composition and diversity in drained Norway spruce (Picea abies (L.) Karst.) stands 50 years after whole-tree harvesting management: case study in Latvia","authors":"Roberts Čakšs, Linda Robalte, I. Desaine, B. Džeriņa, Ā. Jansons","doi":"10.2478/fsmu-2018-0010","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0010","url":null,"abstract":"Abstract The long-term (50 years) effect of whole-tree harvesting (stump harvesting) on ground vegetation in experimental drained Norway spruce (Picea abies (L.) Karst.) stands was studied. We used a chronosequence approach to assess the long-term impact of whole-tree harvesting (WTH) on stands’ ground vegetation. WTH stands were compared with four control stands with different age and with the same forest type: young stand (15 years), middle-aged stand (45 years), mature stand (110 years) and over-mature stand (140 years). Species richness was similar between the WTH stand and middle-aged stand (61 and 60 species, respectively). Shannon-Wiener diversity indices in the WTH and middle-aged stand (3.40 and 3.19, respectively) indicated that the stands were similar to each other. A community similarity analysis showed that the composition of vegetation was similar between the WTH and middle-aged stand, although some species like Lycopodium clavatum and Diphasiastrum complanatum occurred only in the WTH stand. The study showed that a period of 50 years is sufficient for ground vegetation of a typical drained spruce forest to recover after WTH management.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79846567","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}
Lele Lu, Bin Zhang, Jianguo Zhang, A. Duan, Xiongqing Zhang
Abstract The most important issues in Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) management are the quantitative determination of stand density and the selection of appropriate density. Different stand density index models have advantages for special tree species, and this study aimed to estimate the carrying capacity of planted stands of Chinese fir and to select simple and reliable stand density indexes. Based on special experiment of different initial density, the maximum carrying capacity was estimated using Reineke’s self-thinning rule, Nilson’s sparsity theory, Beekhuis’s relative-spacing hypothesis, Zhang’s nutrient-competition rule, Curtis’s maximum stand basal area and Hui’s crowding degree based on mean tree distance. The restricted maximum likelihood method (REML) implemented with ‘nlme’ package in R software was used to refine the parameters of thinning age in Richard’s growth model. The results showed that stand density index models can describe the trends of stand density in response to tree growth: the higher the plantation initial density, the earlier age and stronger self-thinning capacity of stands. Reineke’s SDI and Zhang’s Z model are the most stable and suitable to estimate changes in the density of Chinese fir plantations, competition intensification, and the thinning age. The RD model can also be used, except at low Chinese fir densities. K, which can be affected by the mean crown width of trees, directly reflects the forest area of photosynthesis; this index is easy and simple to apply, but more research is needed to optimize the equation to evaluate whether a forest requires management and to determine the appropriate time for the first thinning and its intensity.
{"title":"Application of stand density indices for Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) plantation management","authors":"Lele Lu, Bin Zhang, Jianguo Zhang, A. Duan, Xiongqing Zhang","doi":"10.2478/fsmu-2018-0005","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0005","url":null,"abstract":"Abstract The most important issues in Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) management are the quantitative determination of stand density and the selection of appropriate density. Different stand density index models have advantages for special tree species, and this study aimed to estimate the carrying capacity of planted stands of Chinese fir and to select simple and reliable stand density indexes. Based on special experiment of different initial density, the maximum carrying capacity was estimated using Reineke’s self-thinning rule, Nilson’s sparsity theory, Beekhuis’s relative-spacing hypothesis, Zhang’s nutrient-competition rule, Curtis’s maximum stand basal area and Hui’s crowding degree based on mean tree distance. The restricted maximum likelihood method (REML) implemented with ‘nlme’ package in R software was used to refine the parameters of thinning age in Richard’s growth model. The results showed that stand density index models can describe the trends of stand density in response to tree growth: the higher the plantation initial density, the earlier age and stronger self-thinning capacity of stands. Reineke’s SDI and Zhang’s Z model are the most stable and suitable to estimate changes in the density of Chinese fir plantations, competition intensification, and the thinning age. The RD model can also be used, except at low Chinese fir densities. K, which can be affected by the mean crown width of trees, directly reflects the forest area of photosynthesis; this index is easy and simple to apply, but more research is needed to optimize the equation to evaluate whether a forest requires management and to determine the appropriate time for the first thinning and its intensity.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81151612","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}
Mohamed Zouidi, A. H. Borsali, Ayoub Allam, R. Gros
Abstract Arid zones are very harsh environments characterized by binding edaphic and climatic factors, their rainfall is low and irregular accentuated by high temperatures and their soils are fragile and vulnerable. In recent years, it has been noted that vegetation is regressing and that the majority of reforestation has been a failure. Our study aims to know the physico-chemical and microbiological characteristics of forest soils in the pinewoods of an area of the highlands of western Algeria (Naama). For this we analyzed several soil samples spread over five sampling stations in a forest of Aleppo pine. The results show that the forest soils of our study area are characterized by a generally sandy texture and an orange color for all the selected stations. They are characterized by: a very high C/N ratio that indicates a slow evolution of organic matter and a nitrogen deficiency that is necessary for carbon decomposition. The conductivity shows that the soil contains some salinity, its permeability is strong and its humidity fairly low with an alkaline pH (> 8) due to the increase in the limestone level in the area. Basal respiration is low compared to microbial biomass due to poor physico-chemical quality of soils and the effect of water stresses that slow down microbial activities. Soils in this arid forest are generally characterized by soil homogeneity sensitive to the influence of environmental factors mainly poverty into elements necessary for its proper functioning such as nitrogen and water that accentuate soil degradation of these forest formations, which results in the risk of degradation being triggered.
{"title":"Characterization of coniferous forest soils in the arid zone","authors":"Mohamed Zouidi, A. H. Borsali, Ayoub Allam, R. Gros","doi":"10.2478/fsmu-2018-0006","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0006","url":null,"abstract":"Abstract Arid zones are very harsh environments characterized by binding edaphic and climatic factors, their rainfall is low and irregular accentuated by high temperatures and their soils are fragile and vulnerable. In recent years, it has been noted that vegetation is regressing and that the majority of reforestation has been a failure. Our study aims to know the physico-chemical and microbiological characteristics of forest soils in the pinewoods of an area of the highlands of western Algeria (Naama). For this we analyzed several soil samples spread over five sampling stations in a forest of Aleppo pine. The results show that the forest soils of our study area are characterized by a generally sandy texture and an orange color for all the selected stations. They are characterized by: a very high C/N ratio that indicates a slow evolution of organic matter and a nitrogen deficiency that is necessary for carbon decomposition. The conductivity shows that the soil contains some salinity, its permeability is strong and its humidity fairly low with an alkaline pH (> 8) due to the increase in the limestone level in the area. Basal respiration is low compared to microbial biomass due to poor physico-chemical quality of soils and the effect of water stresses that slow down microbial activities. Soils in this arid forest are generally characterized by soil homogeneity sensitive to the influence of environmental factors mainly poverty into elements necessary for its proper functioning such as nitrogen and water that accentuate soil degradation of these forest formations, which results in the risk of degradation being triggered.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90509133","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 A study was conducted in an oak forest, to find out the relationship of stand structure, aspect and regeneration of species. Among all disturbance stands the density of banj oak Quercus leucotrichophora A. Camus individuals was peaked at 40–50 cm and 50–60 cm diameter at breast height (DBH) classes and low tree density was observed with the increasing DBH classes. North aspect showed higher density for most of girth classes as compared to south facing aspect. Among all the stands, low seedling density was recorded in undisturbed stand at south facing aspect as compared to the moderately and highly disturbed stands. The tree density of Q. leucotrichophora was higher in the undisturbed stand followed by moderately disturbed and highly disturbed stand. But in case of seedling density the higher density were observed at undisturbed and highly disturbed stand in both of the aspects.
{"title":"Effect of stand structure and aspect on the regeneration of banj oak (Quercus leucotrichophora A. Camus) forest along disturbance in Garhwal Himalaya, Uttarakhand, India","authors":"Vikaspal Singh, D. Chauhan, S. Dasgupta","doi":"10.2478/fsmu-2018-0003","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0003","url":null,"abstract":"Abstract A study was conducted in an oak forest, to find out the relationship of stand structure, aspect and regeneration of species. Among all disturbance stands the density of banj oak Quercus leucotrichophora A. Camus individuals was peaked at 40–50 cm and 50–60 cm diameter at breast height (DBH) classes and low tree density was observed with the increasing DBH classes. North aspect showed higher density for most of girth classes as compared to south facing aspect. Among all the stands, low seedling density was recorded in undisturbed stand at south facing aspect as compared to the moderately and highly disturbed stands. The tree density of Q. leucotrichophora was higher in the undisturbed stand followed by moderately disturbed and highly disturbed stand. But in case of seedling density the higher density were observed at undisturbed and highly disturbed stand in both of the aspects.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91140121","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 Thinning cuttings create moderate disturbances in forest stands. Thinning intensity indicates the amount of felled wood relative to the initial standing volume. We used sparse point clouds from airborne lidar measurements carried out in 2008 and 2012 at Aegviidu test site, Estonia, to study stand level relationships of thinning intensity to the changes in canopy cover and ALS-based wood volume estimates. Thinning intensity (Kr, HRV) was estimated from forest inventory data and harvester measurements of removed wood volume. The thinning intensity ranged from 17% to 56%. By raising threshold from 1.3 m to 8.0 m over ground surface we observed less canopy cover change, but stronger correlation with thinning intensity. Correlation between ALS-based and harvester-based thinning intensity was moderate. The ALS-based thinning intensity estimate was systematically smaller than Kr, HRV. Forest height growth compensates for a small decrease in canopy cover and intensity estimates for weak thinnings are not reliable using sparse point clouds and a four-year measurement interval.
{"title":"Assessment of forest thinning intensity using sparse point clouds from repeated airborne lidar measurements","authors":"Mait Lang, T. Arumäe","doi":"10.2478/fsmu-2018-0004","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0004","url":null,"abstract":"Abstract Thinning cuttings create moderate disturbances in forest stands. Thinning intensity indicates the amount of felled wood relative to the initial standing volume. We used sparse point clouds from airborne lidar measurements carried out in 2008 and 2012 at Aegviidu test site, Estonia, to study stand level relationships of thinning intensity to the changes in canopy cover and ALS-based wood volume estimates. Thinning intensity (Kr, HRV) was estimated from forest inventory data and harvester measurements of removed wood volume. The thinning intensity ranged from 17% to 56%. By raising threshold from 1.3 m to 8.0 m over ground surface we observed less canopy cover change, but stronger correlation with thinning intensity. Correlation between ALS-based and harvester-based thinning intensity was moderate. The ALS-based thinning intensity estimate was systematically smaller than Kr, HRV. Forest height growth compensates for a small decrease in canopy cover and intensity estimates for weak thinnings are not reliable using sparse point clouds and a four-year measurement interval.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83735911","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 In recent years, with the rapid development of human civilization, a variety of environmental problems have emerged. As the most important natural ecological system of terrestrial ecosystems, forest ecosystem plays a significant role in protecting the environment and beautifying cities. The landscape planning and design of botanical gardens is of great significance to the maintenance of the urban forest ecosystem. Taking the Nanshan botanical garden as the research object, this paper analysed the present situation of the garden and carried out the vegetation landscape planning transformation on it from the perspective of landscape ecology. Then, the landscape hierarchy analysis method was used to evaluate the landscape after the transformation, the results of which suggested that the comprehensive evaluation of the garden was the highest when the plant landscape was diversified and the structure level was reasonable, which provided a reference for the optimization of the urban forest ecosystem.
{"title":"Plant landscape planning and design of Nanshan Botanical Garden (China) based on forest ecological garden","authors":"Ren Wang","doi":"10.2478/fsmu-2018-0002","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0002","url":null,"abstract":"Abstract In recent years, with the rapid development of human civilization, a variety of environmental problems have emerged. As the most important natural ecological system of terrestrial ecosystems, forest ecosystem plays a significant role in protecting the environment and beautifying cities. The landscape planning and design of botanical gardens is of great significance to the maintenance of the urban forest ecosystem. Taking the Nanshan botanical garden as the research object, this paper analysed the present situation of the garden and carried out the vegetation landscape planning transformation on it from the perspective of landscape ecology. Then, the landscape hierarchy analysis method was used to evaluate the landscape after the transformation, the results of which suggested that the comprehensive evaluation of the garden was the highest when the plant landscape was diversified and the structure level was reasonable, which provided a reference for the optimization of the urban forest ecosystem.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83477093","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 Landsat-8 OLI and Sentinel-2 MSI images from years 2015 and 2016, a 1:10,000 digital soil map and a large number of reference samples were used with a random forest machine learning implementation in GRASS GIS to construct a tree species map for the entire territory of Estonia (42,755 km2). Class probabilities for seven main tree species, an extra class for other species and probability of the forest cover not conforming to the forest definition were assigned for each pixel. Validation of dominant species distribution by area showed very strong correlation at county level both in state forests (R2 = 0.98) and in private forests (R2 = 0.93). Validation of tree species composition using harvester measurement data from 2,045 regeneration felling areas showed also very strong correlation (R2 = 0.75) with the measured values of the proportion of coniferous trees. There was some tendency to underestimate the proportion of more common species and overestimation was found for the species with smaller proportion in the mixture. The accuracy for the proportion of deciduous species that were present in a smaller number of reference observations was substantially smaller. Validation of the results by using data from 659 large sample plots from the database of the Estonian Network of Forest Research Plots and 3,002 small sample plots from the National Forest Inventory (NFI) data base confirmed the findings based on harvester data. The NFI data revealed also a decrease of estimation error with the increase of forest age. Cohen’s kappa index of agreement for main species for NFI sample plots with main species proportion equal to or greater than 75% decreased from 0.69 to 0.66 when observations with forests younger than 20 years were included in the comparison. Overall, the constructed map provides valuable data about tree species composition for the forests where no up to date inventory data are available or for the projects that require continuous cover of tree species data of known quality over the entire Estonia.
{"title":"Construction of tree species composition map of Estonia using multispectral satellite images, soil map and a random forest algorithm","authors":"Mait Lang, Mihkel Kaha, D. Laarmann, A. Sims","doi":"10.2478/fsmu-2018-0001","DOIUrl":"https://doi.org/10.2478/fsmu-2018-0001","url":null,"abstract":"Abstract Landsat-8 OLI and Sentinel-2 MSI images from years 2015 and 2016, a 1:10,000 digital soil map and a large number of reference samples were used with a random forest machine learning implementation in GRASS GIS to construct a tree species map for the entire territory of Estonia (42,755 km2). Class probabilities for seven main tree species, an extra class for other species and probability of the forest cover not conforming to the forest definition were assigned for each pixel. Validation of dominant species distribution by area showed very strong correlation at county level both in state forests (R2 = 0.98) and in private forests (R2 = 0.93). Validation of tree species composition using harvester measurement data from 2,045 regeneration felling areas showed also very strong correlation (R2 = 0.75) with the measured values of the proportion of coniferous trees. There was some tendency to underestimate the proportion of more common species and overestimation was found for the species with smaller proportion in the mixture. The accuracy for the proportion of deciduous species that were present in a smaller number of reference observations was substantially smaller. Validation of the results by using data from 659 large sample plots from the database of the Estonian Network of Forest Research Plots and 3,002 small sample plots from the National Forest Inventory (NFI) data base confirmed the findings based on harvester data. The NFI data revealed also a decrease of estimation error with the increase of forest age. Cohen’s kappa index of agreement for main species for NFI sample plots with main species proportion equal to or greater than 75% decreased from 0.69 to 0.66 when observations with forests younger than 20 years were included in the comparison. Overall, the constructed map provides valuable data about tree species composition for the forests where no up to date inventory data are available or for the projects that require continuous cover of tree species data of known quality over the entire Estonia.","PeriodicalId":35353,"journal":{"name":"Forestry Studies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83562675","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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