Alejandra Vázquez-Acosta, Jacinto Treviño-Carreón, B. Estrada-Drouaillet, Martha Lucrecia García-Alanis, María Concepción Herrera-Monsiváis, Virginia Vargas Tristán
The blue agave (Agave tequilana Weber variety azul) is a species that is widely used to produce tequila. For this reason, in the last decade, large extensions of terrain have been established for its cultivation. However, much of this land has been abandoned in a short time because at the beginning it was not known that at least six years were needed before the agave could be harvested. However, when the growers wanted to reintegrate some of these crops into the productive process, their exact age and the cultural activities needed for harvesting the agave were unknown because information regarding its vegetative development relative to its age was lacking. The hypothesis of this work was: If the morphological properties reflect the development state of the population individuals, then the properties height, basal area, rosette diameter, the north, south, east and west leaf, leaves number and foliar verticil will help to characterize the age categories in Agave tequilana Weber variety azul population under cultivated conditions. To this end, six plots with plants of different ages (one to six years) were selected in the municipality of Llera, Tamaulipas, Mexico. In each plot, 60 individuals were selected at random, and their morphological properties (height, basal area, rosette diameter, northern leaf, southern leaf, eastern leaf, western leaf; number of leaves and leaf whorl) were measured. With these data, a principal component analysis was performed to determine which of these properties explains the most variation of the data. The results indicate that height and basal area are the properties that are most closely associated with plant age. It is also for the first time demonstrated that harvest time can be reduced by one or two years, which favors producers economically because it could generate savings in production costs.
{"title":"Morphological Characterization of Agave tequilana Weber Variety azul (Asparagaceae) under Cultivation in the Municipality of Llera, Tamaulipas, Mexico","authors":"Alejandra Vázquez-Acosta, Jacinto Treviño-Carreón, B. Estrada-Drouaillet, Martha Lucrecia García-Alanis, María Concepción Herrera-Monsiváis, Virginia Vargas Tristán","doi":"10.4236/ojf.2020.102017","DOIUrl":"https://doi.org/10.4236/ojf.2020.102017","url":null,"abstract":"The blue agave (Agave tequilana Weber variety azul) is a species that is widely used to produce tequila. For this reason, in the last decade, large extensions of terrain have been established for its cultivation. However, much of this land has been abandoned in a short time because at the beginning it was not known that at least six years were needed before the agave could be harvested. However, when the growers wanted to reintegrate some of these crops into the productive process, their exact age and the cultural activities needed for harvesting the agave were unknown because information regarding its vegetative development relative to its age was lacking. The hypothesis of this work was: If the morphological properties reflect the development state of the population individuals, then the properties height, basal area, rosette diameter, the north, south, east and west leaf, leaves number and foliar verticil will help to characterize the age categories in Agave tequilana Weber variety azul population under cultivated conditions. To this end, six plots with plants of different ages (one to six years) were selected in the municipality of Llera, Tamaulipas, Mexico. In each plot, 60 individuals were selected at random, and their morphological properties (height, basal area, rosette diameter, northern leaf, southern leaf, eastern leaf, western leaf; number of leaves and leaf whorl) were measured. With these data, a principal component analysis was performed to determine which of these properties explains the most variation of the data. The results indicate that height and basal area are the properties that are most closely associated with plant age. It is also for the first time demonstrated that harvest time can be reduced by one or two years, which favors producers economically because it could generate savings in production costs.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47562059","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}
This study was conducted within a distance of three to five kilometres around Lake Burigi as a study area in the Burigi-Chato National Park for the purpose of documenting the diversity of plants, identifying invasive and rare species for enhancing conservation in the park. Lake Burigi was purposively sampled as a study area for plant identification due to its potential as a tourist destination. No study has been conducted in the study area to reveal plants diversity, with a focus on documenting invasive and rare species, thus necessitating undertaking of this study to inform the park authority to take urgent control measures in avoiding widespread of invasive species and proper planning for conservation of rare species. The methods involved included field observation; plant identification using field guide books, indigenous and professional knowledge; field mapping using GPS receiver and literature review. Analysis of meteorological data and soil sample were also used among other methods. Meteorological data were analysed using Microsoft Excel and SPSS v.20 to determine the relationship between variables. A total of 102 plant species of different growth forms of trees, shrubs, grasses, sedges, forbs, and herbs were identified and recorded. Tegetes minuta and Argemone mexicana were recorded as invasive plant species, while six rare plant species potential for pharmaceutical industry; Zanthoxylum usambarense, Gardenia ternifolia, Faidherbia albida, Harrisonia abyssinica, Anona senegalensis, and, Pappea capensis were also recorded. Scars of wildfires were observed in the study area. The study area received an average rainfall of 964.36 mm per year, the highest peak recorded in 1951. The trend of rainfall showed that many years had rainfall below the average while the temperature was found to increase from year to year, the situation which suggests the existence of climate change in the study area. There was a weak negative relationship between temperature and wind speed. Soil nutrients and disturbances in the area were found to favour the growth of Tegetes minuta. Findings of this study would help ecological unit in the park to conduct regular ecological assessment for the purpose of controlling invasive plant species, which if left to flourish are likely to reduce habitat suitability for ungulates to utilize the area. Moreover, knowing which plant species are rare, adds value to the area as a destination to visitors interested in plants. The findings also allow the park authority to keep record of species rarity and thus easily take control of them to avoid unintended exploitation. Based on the findings, it was concluded that a number of disturbances, meteorological and edaphic factors favour the growth of invasive species. Urgent measures are to be taken to control the observed invasive plant species before they are left to spread in the park to avoid destruction of the habitat suitability and incurring unnecessary expenses and time in combating t
{"title":"Plants Biodiversity of the Burigi-Chato National Park: Rare and Invasive Species","authors":"J. Makunga, Alfred Gobolo","doi":"10.4236/ojf.2020.102016","DOIUrl":"https://doi.org/10.4236/ojf.2020.102016","url":null,"abstract":"This study was conducted within a distance of three to five kilometres around Lake Burigi as a study area in the Burigi-Chato National Park for the purpose of documenting the diversity of plants, identifying invasive and rare species for enhancing conservation in the park. Lake Burigi was purposively sampled as a study area for plant identification due to its potential as a tourist destination. No study has been conducted in the study area to reveal plants diversity, with a focus on documenting invasive and rare species, thus necessitating undertaking of this study to inform the park authority to take urgent control measures in avoiding widespread of invasive species and proper planning for conservation of rare species. The methods involved included field observation; plant identification using field guide books, indigenous and professional knowledge; field mapping using GPS receiver and literature review. Analysis of meteorological data and soil sample were also used among other methods. Meteorological data were analysed using Microsoft Excel and SPSS v.20 to determine the relationship between variables. A total of 102 plant species of different growth forms of trees, shrubs, grasses, sedges, forbs, and herbs were identified and recorded. Tegetes minuta and Argemone mexicana were recorded as invasive plant species, while six rare plant species potential for pharmaceutical industry; Zanthoxylum usambarense, Gardenia ternifolia, Faidherbia albida, Harrisonia abyssinica, Anona senegalensis, and, Pappea capensis were also recorded. Scars of wildfires were observed in the study area. The study area received an average rainfall of 964.36 mm per year, the highest peak recorded in 1951. The trend of rainfall showed that many years had rainfall below the average while the temperature was found to increase from year to year, the situation which suggests the existence of climate change in the study area. There was a weak negative relationship between temperature and wind speed. Soil nutrients and disturbances in the area were found to favour the growth of Tegetes minuta. Findings of this study would help ecological unit in the park to conduct regular ecological assessment for the purpose of controlling invasive plant species, which if left to flourish are likely to reduce habitat suitability for ungulates to utilize the area. Moreover, knowing which plant species are rare, adds value to the area as a destination to visitors interested in plants. The findings also allow the park authority to keep record of species rarity and thus easily take control of them to avoid unintended exploitation. Based on the findings, it was concluded that a number of disturbances, meteorological and edaphic factors favour the growth of invasive species. Urgent measures are to be taken to control the observed invasive plant species before they are left to spread in the park to avoid destruction of the habitat suitability and incurring unnecessary expenses and time in combating t","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47984998","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}
Assessment of forest recovery following disturbance is enhanced by the use of biological indicators. One such indicator, the abundance of understory species, was examined in coast redwood (Sequoia sempervirens) forests using non-metric multiple dimensional scaling (NMDS) and indicator species analysis (ISA). Randomly distributed 10 m diameter circular plots were employed to record the abundance of all understory species across three treatments: actively managed (0 - 45 years since harvest); mature second-growth (~80 - 120 years since harvest); and unharvested old-growth stands. NMDS with perMANOVA analysis signified separation between treatments with the shade tolerant herbaceous species Trillium ovatum, Viola sempervirens, and Oxalis oregana positively correlated with mature second-growth and old-growth treatments. ISA supported the inclusion of T. ovatum, with the addition of Prosartes hookerii, as indicators of mature second-growth and old-growth. Both NMDS and ISA specified associations for Ceanothus thyrsiflorus and Stachys bullata with actively-managed stands. Occurrence of non-natives was low across treatments, though significantly higher on actively managed stands, with the shade intolerant invasive plants, Cortaderia sp. and Myosotis latifolia, occurring exclusively in actively-managed sites.
{"title":"Herbaceous Understory Indicators of Post-Harvest Recovery in Coast Redwood (Sequoia sempervirens) Forests","authors":"W. Russell","doi":"10.4236/ojf.2020.102014","DOIUrl":"https://doi.org/10.4236/ojf.2020.102014","url":null,"abstract":"Assessment of forest \u0000recovery following disturbance is enhanced by the use of biological indicators. \u0000One such indicator, the abundance of understory species, was examined in coast \u0000redwood (Sequoia sempervirens) \u0000forests using non-metric multiple dimensional scaling (NMDS) and indicator \u0000species analysis (ISA). Randomly distributed 10 m diameter circular plots were \u0000employed to record the abundance of all understory species across three \u0000treatments: actively managed (0 - 45 years since harvest); mature second-growth (~80 - 120 years \u0000since harvest); and unharvested old-growth stands. NMDS with perMANOVA analysis \u0000signified separation between treatments with the shade tolerant herbaceous \u0000species Trillium ovatum, Viola sempervirens, and Oxalis oregana positively correlated with mature second-growth and old-growth treatments. \u0000ISA supported the inclusion of T. ovatum, with the addition of Prosartes hookerii, as indicators of mature second-growth and \u0000old-growth. Both NMDS and ISA specified associations for Ceanothus thyrsiflorus and Stachys \u0000bullata with actively-managed stands. Occurrence of non-natives was low across treatments, though significantly higher \u0000on actively managed stands, with the shade intolerant invasive plants, Cortaderia sp. and Myosotis latifolia, occurring exclusively in actively-managed \u0000sites.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46702934","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. Hossain, M. Siddique, S. Abdullah, C. Saha, S. Islam, Md. Zaheer Iqbal, M. Akhter
Allometric biomass models are efficient tools to estimate biomass of trees and forest stands in a non-destructive way. Development of species-specific allometric biomass models requires extensive fieldwork and time. Our study aimed to generate species-specific allometric biomass models for the most common fuelwood and timber species of Bangladesh. We also wanted to evaluate the performances of our models relative to the performances of regional and commonly used pan-tropical biomass models. We used semi-destructive method that incorporates tree-level volume, species-specific biomass expansion factor (BEF), and wood density. We considered four base models, 1) Ln (biomass) = a + bLn (D); 2) Ln (biomass) = a + bLn (H); 3) Ln (Biomass) = a + bLn (D^2H); 4) Ln (Biomass) = a + bLn (D) + cLn (H) to develop species-specific best-fitted models for Total Above-Ground Biomass (TAGB) and stem biomass. The best-fitted model for each species was selected by the lowest value of Akaike Information Criterion (AIC), Residual Standard Error (RSE) and Root Mean Square Error (RMSE). The derived best-fitted models were then evaluated with respect to regional and pan-tropical models using a separate set of observed data. This evaluation was conducted by computing ME (Model Efficiency) and MPE (Model Prediction Error). The best-fitted allometric biomass models have shown higher model efficiency (0.85 to 0.99 at scale 1) and the lowest model prediction error (-8.94% to 5.27%) compared to the regional and pan-tropical models. All the examined regional and pan-tropical biomass models showed different magnitude of ME and MPE. Some models showed higher level (>0.90 at scale 1) of ME compared to the best-fitted specific species biomass model.
{"title":"Development and Evaluation of Species-Specific Biomass Models for Most Common Timber and Fuelwood Species of Bangladesh","authors":"M. Hossain, M. Siddique, S. Abdullah, C. Saha, S. Islam, Md. Zaheer Iqbal, M. Akhter","doi":"10.4236/ojf.2020.101012","DOIUrl":"https://doi.org/10.4236/ojf.2020.101012","url":null,"abstract":"Allometric biomass models are efficient tools to estimate biomass of trees and forest stands in a non-destructive way. Development of species-specific allometric biomass models requires extensive fieldwork and time. Our study aimed to generate species-specific allometric biomass models for the most common fuelwood and timber species of Bangladesh. We also wanted to evaluate the performances of our models relative to the performances of regional and commonly used pan-tropical biomass models. We used semi-destructive method that incorporates tree-level volume, species-specific biomass expansion factor (BEF), and wood density. We considered four base models, 1) Ln (biomass) = a + bLn (D); 2) Ln (biomass) = a + bLn (H); 3) Ln (Biomass) = a + bLn (D^2H); 4) Ln (Biomass) = a + bLn (D) + cLn (H) to develop species-specific best-fitted models for Total Above-Ground Biomass (TAGB) and stem biomass. The best-fitted model for each species was selected by the lowest value of Akaike Information Criterion (AIC), Residual Standard Error (RSE) and Root Mean Square Error (RMSE). The derived best-fitted models were then evaluated with respect to regional and pan-tropical models using a separate set of observed data. This evaluation was conducted by computing ME (Model Efficiency) and MPE (Model Prediction Error). The best-fitted allometric biomass models have shown higher model efficiency (0.85 to 0.99 at scale 1) and the lowest model prediction error (-8.94% to 5.27%) compared to the regional and pan-tropical models. All the examined regional and pan-tropical biomass models showed different magnitude of ME and MPE. Some models showed higher level (>0.90 at scale 1) of ME compared to the best-fitted specific species biomass model.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43921958","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}
The paper will present climate change, (global warming), and what is most important, the lasting consequences for planet Earth, which will be reflected for 500 years and maybe even before that deadline, the greatest environmental catastrophe that has not hit planet Earth since its inception will be felt. This will actually be the end of life on planet Earth and for the modern man (Homo sapiens Lat.). Measures that will be proposed in the work, as possible mitigation of the consequences of catastrophic consequences on planet Earth and life on it, in fact, they can only prolong or slightly reduce the end of life on planet earth that is imminent. The Titanic people only had 2.5 hours to live. “WE WILL HAVE A 500 YEARS”.
{"title":"A Vision of the Planet of the Earth in the Next 300 - 500 Years under Climate Change with Proposed Measures to Mitigate the Effects of Climate Change","authors":"S. Šikanja","doi":"10.4236/ojf.2020.101011","DOIUrl":"https://doi.org/10.4236/ojf.2020.101011","url":null,"abstract":"The paper will present climate change, (global warming), and what is most important, the lasting consequences for planet Earth, which will be reflected for 500 years and maybe even before that deadline, the greatest environmental catastrophe that has not hit planet Earth since its inception will be felt. This will actually be the end of life on planet Earth and for the modern man (Homo sapiens Lat.). Measures that will be proposed in the work, as possible mitigation of the consequences of catastrophic consequences on planet Earth and life on it, in fact, they can only prolong or slightly reduce the end of life on planet earth that is imminent. The Titanic people only had 2.5 hours to live. “WE WILL HAVE A 500 YEARS”.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41916725","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}
The limited number of studies on mixed plantations makes it difficult to accurately predict success of mixed-species combination especially with regards to growth, undergrowth diversity and carbon sequestration potentials. This study therefore provides information on the effects of Ceiba pentandra, Terminalia superba, Cedrela odorata and Khaya anthotheca in three different stand combinations on growth, undergrowth diversity and carbon sequestration potential. A 15-year-old coupe of 32 ha of mixed tree species stand combinations was selected for the study. The coupe was stratified based on the species combinations. Nested sub-plots (25 m × 25 m) were randomly laid in different species stand combinations for growth data collection. In each nested sub-plot, 1 m × 1 m plots were also randomly laid for undergrowth diversity study. The results revealed that two species stand combination of Ceiba pentandra and Terminalia superba performed better in terms of growth, carbon sequestration and carbon content as compared to the other species stand combinations. The saplings on the other hand, were more diverse under the three species stand combination plots. Also, the effective number of species, species richness, evenness, and dominance were higher in the four species stand combination plots. Generally, Ceiba pentandra and Terminalia superba are compatible as it produced the highest growth and carbon sequestration potential.
由于对混交林的研究数量有限，很难准确预测混交林的成功，特别是在生长、林下多样性和固碳潜力方面。本研究探讨了三种不同林分组合下五角木、冬绵、香柏木和花茶对林分生长、林下多样性和固碳潜力的影响。选择15年32公顷的混合树种林分组合作为研究对象。根据种属组合对种群进行分层。巢式样地(25 m × 25 m)随机设置在不同的种林分组合中，收集生长数据。在每个巢状样地随机设置1 m × 1 m样地，进行林下植物多样性研究。结果表明，五角木和毛缕木两种林分组合在生长、固碳和含碳量方面均优于其他林分组合。而三种林分组合样地的树苗多样性更高。4种林分组合样地的有效种数、物种丰富度、均匀度和优势度均较高。通常情况下，五角木和毛缕草是相容的，因为它具有最高的生长和碳固存潜力。
{"title":"Growth Performance, Undergrowth Diversity and Carbon Sequestration Potentials of Tree Species Stand Combinations, Ghana","authors":"Samuel Novor, S. Abugre","doi":"10.4236/ojf.2020.101010","DOIUrl":"https://doi.org/10.4236/ojf.2020.101010","url":null,"abstract":"The limited number of studies on mixed plantations makes it difficult to accurately predict success of mixed-species combination especially with regards to growth, undergrowth diversity and carbon sequestration potentials. This study therefore provides information on the effects of Ceiba pentandra, Terminalia superba, Cedrela odorata and Khaya anthotheca in three different stand combinations on growth, undergrowth diversity and carbon sequestration potential. A 15-year-old coupe of 32 ha of mixed tree species stand combinations was selected for the study. The coupe was stratified based on the species combinations. Nested sub-plots (25 m × 25 m) were randomly laid in different species stand combinations for growth data collection. In each nested sub-plot, 1 m × 1 m plots were also randomly laid for undergrowth diversity study. The results revealed that two species stand combination of Ceiba pentandra and Terminalia superba performed better in terms of growth, carbon sequestration and carbon content as compared to the other species stand combinations. The saplings on the other hand, were more diverse under the three species stand combination plots. Also, the effective number of species, species richness, evenness, and dominance were higher in the four species stand combination plots. Generally, Ceiba pentandra and Terminalia superba are compatible as it produced the highest growth and carbon sequestration potential.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45668107","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}
The dynamic tree stability assessment technique allows trees to be measured efficiently, under realistic weather conditions. In this study, the stability of four trees, including two conifers and two broad-leaved species was assessed in the Botanical Gardens of the University of Sopron, Hungary. The examined trees included Horse chestnut, Japanese zelkova, Douglas fir and Giant sequoia. Each tree was measured in various weather and seasonal conditions. Results show that the seasons affected the stability of broadleaved trees significantly, due to considerable changes in the crown surface area, while this difference was much lower in softwoods. Rainy weather loosens the topsoil, which adversely affects the stability of trees with relatively shallow roots. Lower layers take longer to saturate, and therefore trees with very deep roots are usually unaffected by the looser topsoil, while the increased weight of the top layer compacts the lower layers and improves stability, as evidenced by results measured on Sequoia. Snow accumulation on the branches increases the inertia of the tree, which imposes higher torque on the root collar, decreasing stability. In the meantime, the increased resistance offered by frozen ground stabilizes the tree, which more-or-less counterbalances this effect. A more extensive database of tree stability under different conditions is being built to allow for more comprehensive analysis of various factors, like wind direction, tree health and morphology, shading, etc.
{"title":"Investigating the Effect of Weather and Seasonal Factors on Root Stability Using Dynamic Measurements","authors":"Shadabeh Fathi, L. Bejó, F. Divos","doi":"10.4236/ojf.2020.101009","DOIUrl":"https://doi.org/10.4236/ojf.2020.101009","url":null,"abstract":"The dynamic tree stability assessment technique allows trees to be measured efficiently, under realistic weather conditions. In this study, the stability of four trees, including two conifers and two broad-leaved species was assessed in the Botanical Gardens of the University of Sopron, Hungary. The examined trees included Horse chestnut, Japanese zelkova, Douglas fir and Giant sequoia. Each tree was measured in various weather and seasonal conditions. Results show that the seasons affected the stability of broadleaved trees significantly, due to considerable changes in the crown surface area, while this difference was much lower in softwoods. Rainy weather loosens the topsoil, which adversely affects the stability of trees with relatively shallow roots. Lower layers take longer to saturate, and therefore trees with very deep roots are usually unaffected by the looser topsoil, while the increased weight of the top layer compacts the lower layers and improves stability, as evidenced by results measured on Sequoia. Snow accumulation on the branches increases the inertia of the tree, which imposes higher torque on the root collar, decreasing stability. In the meantime, the increased resistance offered by frozen ground stabilizes the tree, which more-or-less counterbalances this effect. A more extensive database of tree stability under different conditions is being built to allow for more comprehensive analysis of various factors, like wind direction, tree health and morphology, shading, etc.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41350164","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. Holmström, Ellen Nordström, D. Larivière, I. Wallin
Changes in clearcut management over time were evaluated using aerial photographs taken between 1960 and 2010. Temporal changes were analysed in two different climatic zones in Sweden: a typical boreal forest zone (the coast of Västerbotten County), and the hemi-boreal zone of southern Sweden (represented by Kronoberg County). The study covers the periods before and after the paradigm shift in Swedish forestry caused by the equalization of the production and nature conservation objectives specified in the first paragraph of the Swedish Forestry Act. Photographs were processed to determine clearcut size and shape and to register solitary retention trees and groups of retention trees. Small but significant changes in clearcut size were detected over time. The number of retention trees increased over time, a result that was also found in other studies using different methodologies. The results demonstrate that measurable structural changes have occurred in Swedish forests over the 25 years since the paradigm shift. Results from this study also show that digital detection of green tree retention could be a future complement to field inventory and monitoring.
{"title":"Detection of Retention Trees on Clearcuts, a 50-Year Perspective","authors":"E. Holmström, Ellen Nordström, D. Larivière, I. Wallin","doi":"10.4236/ojf.2020.101008","DOIUrl":"https://doi.org/10.4236/ojf.2020.101008","url":null,"abstract":"Changes in clearcut management over time were evaluated using aerial photographs taken between 1960 and 2010. Temporal changes were analysed in two different climatic zones in Sweden: a typical boreal forest zone (the coast of Västerbotten County), and the hemi-boreal zone of southern Sweden (represented by Kronoberg County). The study covers the periods before and after the paradigm shift in Swedish forestry caused by the equalization of the production and nature conservation objectives specified in the first paragraph of the Swedish Forestry Act. Photographs were processed to determine clearcut size and shape and to register solitary retention trees and groups of retention trees. Small but significant changes in clearcut size were detected over time. The number of retention trees increased over time, a result that was also found in other studies using different methodologies. The results demonstrate that measurable structural changes have occurred in Swedish forests over the 25 years since the paradigm shift. Results from this study also show that digital detection of green tree retention could be a future complement to field inventory and monitoring.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42755265","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}
Christopher F. Hansen, P. Schaberg, A. Strong, Shelly A Rayback, G. Hawley
Light detection and ranging (LiDAR) data can provide detailed information about three-dimensional forest structure. However, links between forest structure and tree function have not been fully evaluated using LiDAR. We assessed the relationship of LiDAR-derived structural categories to tree health and productivity on 36 hardwood plots at the Hubbard Brook Experimental Forest, New Hampshire, USA. We established nine plot replicates for each of four LiDAR-based vegetation categories: 1) high crown and high understory closure; 2) high crown and low understory closure; 3) low crown and high understory closure; and 4) low crown and low understory closure. Ground-based measures of canopy structure, site, stand and individual tree measures were collected on plots during summer 2012. Significant differences among LiDAR categories were found for several response variables. Lower basal area increment for sugar maple (Acer saccharum), decreased foliar nutrition for yellow birch (Betula alleghaniensis), and lower overall crown health were all associated with high understory closure provided that overstory closure was also high. These results suggest that LiDAR measures can be used to assess competitive interactions between overstory and understory vegetation, and that LiDAR shows promise for identifying stands with reduced health and productivity due to factors such as competition or overstocking.
{"title":"LiDAR Helps Differentiate Stand Health and Productivity Levels within a Northern Hardwood Forest","authors":"Christopher F. Hansen, P. Schaberg, A. Strong, Shelly A Rayback, G. Hawley","doi":"10.4236/ojf.2020.101006","DOIUrl":"https://doi.org/10.4236/ojf.2020.101006","url":null,"abstract":"Light detection and ranging (LiDAR) data can provide detailed information about three-dimensional forest structure. However, links between forest structure and tree function have not been fully evaluated using LiDAR. We assessed the relationship of LiDAR-derived structural categories to tree health and productivity on 36 hardwood plots at the Hubbard Brook Experimental Forest, New Hampshire, USA. We established nine plot replicates for each of four LiDAR-based vegetation categories: 1) high crown and high understory closure; 2) high crown and low understory closure; 3) low crown and high understory closure; and 4) low crown and low understory closure. Ground-based measures of canopy structure, site, stand and individual tree measures were collected on plots during summer 2012. Significant differences among LiDAR categories were found for several response variables. Lower basal area increment for sugar maple (Acer saccharum), decreased foliar nutrition for yellow birch (Betula alleghaniensis), and lower overall crown health were all associated with high understory closure provided that overstory closure was also high. These results suggest that LiDAR measures can be used to assess competitive interactions between overstory and understory vegetation, and that LiDAR shows promise for identifying stands with reduced health and productivity due to factors such as competition or overstocking.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70639430","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}
Tree growth is affected by environmental factors, climate condition and tree age. The objective of this study was to evaluate the growth patterns of Chamaecyparis obtusa (C. obtusa) stand in the Gyeongnam province. Data was collected from two cities and one county by using sample quadrats of 20 * 20 m. A total of 11 quadrats were used to collect tree height, diameter at the breast height (DBH), annual growth rings and soil data. The data analysis of soil moisture content, pH, organic matter (%), EC (cmol + /kg of soil), and available phosphorous was conducted. Growth ring was analyzed by using computer based software and the ages of the trees were identified. Average growth of height and DBH was computed from the surveyed data and annual growth of each tree was assessed by computer based reading of annual growth rings. The results of the study revealed that tree growth showed a reducing trend along the longevity. It was identified that soil pH, age, variation in annual average temperature, and altitude were the main factors related with growth of C. obtusa trees along the life of the stand.
{"title":"The Growth Pattern of Chamaecyparis obtuse Stand along Longevity in Gyeongnam Province, South Korea","authors":"Moon Hyun Shik, T. Solomon","doi":"10.4236/OJF.2020.104023","DOIUrl":"https://doi.org/10.4236/OJF.2020.104023","url":null,"abstract":"Tree growth is affected by environmental factors, climate condition and tree age. The objective of this study was to evaluate the growth patterns of Chamaecyparis obtusa (C. obtusa) stand in the Gyeongnam province. Data was collected from two cities and one county by using sample quadrats of 20 * 20 m. A total of 11 quadrats were used to collect tree height, diameter at the breast height (DBH), annual growth rings and soil data. The data analysis of soil moisture content, pH, organic matter (%), EC (cmol + /kg of soil), and available phosphorous was conducted. Growth ring was analyzed by using computer based software and the ages of the trees were identified. Average growth of height and DBH was computed from the surveyed data and annual growth of each tree was assessed by computer based reading of annual growth rings. The results of the study revealed that tree growth showed a reducing trend along the longevity. It was identified that soil pH, age, variation in annual average temperature, and altitude were the main factors related with growth of C. obtusa trees along the life of the stand.","PeriodicalId":63552,"journal":{"name":"林学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70639506","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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