Pub Date : 2022-04-03DOI: 10.2989/20702620.2022.2105178
J. P. de Maçaneiro, L. Z. Oliveira, L. A. Schorn, F. Galvão, G. S. Grittz, A. L. de Gasper
The conversion of native forests into pastures is still a common practice in Brazil. Abandoned pastures have great potential for natural regeneration and therefore could play an important role in meeting the enormous demand for forest restoration. Few studies, however, have investigated the extent to which spatially-structured environmental variables and community structure are correlated with the variation in species abundance of regenerating forests on abandoned pastures. Therefore, we aimed to determine whether environmental and spatial variables were capable of explaining the variation in abundance of woody species on abandoned pastures in the subtropical Atlantic Forest. We systematically distributed 45 sample plots with size and inclusion criteria that changed according to the vegetation layer in three different abandoned pastures. In general, most of the variation in species abundance that our models were able to explain was correlated with spatially-unstructured physical-chemical soil properties. A smaller part of the variation was correlated with spatially-structured soil variables and topography-related variables. An even smaller portion of the variation was spatially-structured but was not correlated with spatially-structured environmental variables. Therefore, our results suggest that the variation in species abundance of regenerating subtropical Atlantic forests on abandoned pastures is more closely related to niche-based processes mediated by environmental variables than to stochastic spatial processes.
{"title":"Correlation of variations in species abundance of Atlantic forests regenerating on abandoned pastures with different environmental and spatial variables","authors":"J. P. de Maçaneiro, L. Z. Oliveira, L. A. Schorn, F. Galvão, G. S. Grittz, A. L. de Gasper","doi":"10.2989/20702620.2022.2105178","DOIUrl":"https://doi.org/10.2989/20702620.2022.2105178","url":null,"abstract":"The conversion of native forests into pastures is still a common practice in Brazil. Abandoned pastures have great potential for natural regeneration and therefore could play an important role in meeting the enormous demand for forest restoration. Few studies, however, have investigated the extent to which spatially-structured environmental variables and community structure are correlated with the variation in species abundance of regenerating forests on abandoned pastures. Therefore, we aimed to determine whether environmental and spatial variables were capable of explaining the variation in abundance of woody species on abandoned pastures in the subtropical Atlantic Forest. We systematically distributed 45 sample plots with size and inclusion criteria that changed according to the vegetation layer in three different abandoned pastures. In general, most of the variation in species abundance that our models were able to explain was correlated with spatially-unstructured physical-chemical soil properties. A smaller part of the variation was correlated with spatially-structured soil variables and topography-related variables. An even smaller portion of the variation was spatially-structured but was not correlated with spatially-structured environmental variables. Therefore, our results suggest that the variation in species abundance of regenerating subtropical Atlantic forests on abandoned pastures is more closely related to niche-based processes mediated by environmental variables than to stochastic spatial processes.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91269011","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}
Pub Date : 2022-04-03DOI: 10.2989/20702620.2022.2102452
M. F. Rodrigues, D. Rodrigues, A. Pellegrini, Elisandra Pocojeski
This study describes the effects of gradually increasing the intensity of machine traffic in timber harvesting of Pinus taeda L. in a cut-to-length system on the severity of compaction and changes in functionality of a subtropical Oxisol in southern Brazil. The study was conducted in an 11-year-old P. taeda stand. The composition (bulk density, BD; degree-of-compactness, DC; total porosity, TP; macroporosity, Mac; microporosity, Mic) and functionality (saturated hydraulic conductivity, Ks; mechanical resistance to penetration, PR) of the soil were evaluated at 0.00–0.10 m, 0.10–0.20 m, 0.20–0.30 m, and 0.30–0.40 m. The traffic intensities were pine stand before harvesting (PSF), after one pass of harvester followed by one (HV-FW1), three (HV-FW3), six (HV-FW6), and eight (HV-FW8) complete passes of the forwarder. The surface soil layer was more susceptible to compaction due to the change in BD and DC, but the pores were affected by machine traffic at depth (to at least 0.30 m). HV-FW1 provided the greatest changes in composition and functional properties compared to PSF. BD and DC at 0.00–0.10 m increased by approximately 20% in HV-FW1. Mac decreased and Mic increased in all layers, and the traffic effect decreased with increasing soil depth (to 0.30 m) and with increasing traffic intensity. Ks decreased in all layers after HV-FW1. An average decrease of 0.06 m3 m−3 in Mac in HV-FW1 provided a decrease in Ks of approximately 270 mm h−1 compared to PSF. Only the PR reached values considered limiting for plant growth (PR > 2.0 MPa). A gradual increase in the intensity of machine traffic affects soil properties, although the proportion of this effect generally decreased with increasing traffic intensity. Analysis of soil composition properties alone is not sufficient to assess the effects of traffic intensity on soil degradation because functional properties are more sensitive to the effects of machine traffic intensity.
{"title":"Gradual increase in the intensity of machine traffic in timber harvesting: effects on soil composition and functionality","authors":"M. F. Rodrigues, D. Rodrigues, A. Pellegrini, Elisandra Pocojeski","doi":"10.2989/20702620.2022.2102452","DOIUrl":"https://doi.org/10.2989/20702620.2022.2102452","url":null,"abstract":"This study describes the effects of gradually increasing the intensity of machine traffic in timber harvesting of Pinus taeda L. in a cut-to-length system on the severity of compaction and changes in functionality of a subtropical Oxisol in southern Brazil. The study was conducted in an 11-year-old P. taeda stand. The composition (bulk density, BD; degree-of-compactness, DC; total porosity, TP; macroporosity, Mac; microporosity, Mic) and functionality (saturated hydraulic conductivity, Ks; mechanical resistance to penetration, PR) of the soil were evaluated at 0.00–0.10 m, 0.10–0.20 m, 0.20–0.30 m, and 0.30–0.40 m. The traffic intensities were pine stand before harvesting (PSF), after one pass of harvester followed by one (HV-FW1), three (HV-FW3), six (HV-FW6), and eight (HV-FW8) complete passes of the forwarder. The surface soil layer was more susceptible to compaction due to the change in BD and DC, but the pores were affected by machine traffic at depth (to at least 0.30 m). HV-FW1 provided the greatest changes in composition and functional properties compared to PSF. BD and DC at 0.00–0.10 m increased by approximately 20% in HV-FW1. Mac decreased and Mic increased in all layers, and the traffic effect decreased with increasing soil depth (to 0.30 m) and with increasing traffic intensity. Ks decreased in all layers after HV-FW1. An average decrease of 0.06 m3 m−3 in Mac in HV-FW1 provided a decrease in Ks of approximately 270 mm h−1 compared to PSF. Only the PR reached values considered limiting for plant growth (PR > 2.0 MPa). A gradual increase in the intensity of machine traffic affects soil properties, although the proportion of this effect generally decreased with increasing traffic intensity. Analysis of soil composition properties alone is not sufficient to assess the effects of traffic intensity on soil degradation because functional properties are more sensitive to the effects of machine traffic intensity.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91040639","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}
Pub Date : 2022-04-03DOI: 10.2989/20702620.2022.2084353
S. Grobbelaar, R. Oosthuizen
Bibliometrics is used to determine patterns in published research. The aim of this paper is to illustrate the observable bibliometric patterns in the journal Southern Forests: a Journal of Forest Science. Frequency analysis and co-occurrence network analysis were performed to identify patterns. Natural Language Processing and Supervised Machine Learning were used to perform text classification. The objective of the text classification was to classify articles into 15 themes. Each article was categorised in terms of the two main themes associated with the article. The analysis included 1 574 publications from 1941 to 2020 and confirmed that the journal’s change in name and aims were successful in increasing the number of international researchers publishing in the journal. The research institute co-occurrence network diagram illustrates that there are two main research collaboration clusters. The one surrounds Stellenbosch University, and the other encompasses several South African universities and research institutes. Mondi and Sappi were the companies that collaborated the most with independent research institutes. The keywords and theme analysis confirmed that the journal’s aim and scope were supported in the publications. The theme analysis also identified themes or aspects with very few publications. The methods illustrated in this paper can be used to identify research strengths and weaknesses and may assist in strategic planning for future research prioritisation.
{"title":"A reflection on Southern Forests: a Journal of Forest Science using bibliometrics","authors":"S. Grobbelaar, R. Oosthuizen","doi":"10.2989/20702620.2022.2084353","DOIUrl":"https://doi.org/10.2989/20702620.2022.2084353","url":null,"abstract":"Bibliometrics is used to determine patterns in published research. The aim of this paper is to illustrate the observable bibliometric patterns in the journal Southern Forests: a Journal of Forest Science. Frequency analysis and co-occurrence network analysis were performed to identify patterns. Natural Language Processing and Supervised Machine Learning were used to perform text classification. The objective of the text classification was to classify articles into 15 themes. Each article was categorised in terms of the two main themes associated with the article. The analysis included 1 574 publications from 1941 to 2020 and confirmed that the journal’s change in name and aims were successful in increasing the number of international researchers publishing in the journal. The research institute co-occurrence network diagram illustrates that there are two main research collaboration clusters. The one surrounds Stellenbosch University, and the other encompasses several South African universities and research institutes. Mondi and Sappi were the companies that collaborated the most with independent research institutes. The keywords and theme analysis confirmed that the journal’s aim and scope were supported in the publications. The theme analysis also identified themes or aspects with very few publications. The methods illustrated in this paper can be used to identify research strengths and weaknesses and may assist in strategic planning for future research prioritisation.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77313387","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}
Pub Date : 2022-04-03DOI: 10.2989/20702620.2022.2078251
Rafael Oliveira Brown, Kauê Augusto Oliveira-Nascimento, R. Robert, Daniel DeArmond
Harvesting is a complex and expensive step within forestry operations. In mountainous terrain timber harvesting is complex due to the risks and limitations that the terrain imposes on traditional forms of wood extraction. The objective of this study was to evaluate the effective time of work cycle, productivity, operational costs, and production costs of tree extraction by means of a farm tractor with winch, in two work crew compositions: Crew A: one tractor operator and a choker setter; and Crew B: one tractor operator and two choker setters. The study was implemented in the Vale do Ribeira region of south-eastern Brazil, using a full tree-harvesting system through a time and motion study under different conditions of extraction distance (6–135 m), log yard (5–241 m), and ground slope (7–37°). To evaluate the cycles, a regression analysis was conducted for each treatment, and subsequently compared using the Graybill F-test. Next, a regression with a dummy variable was performed. Crew B showed an average productivity of 13.54 m3; per productive machine hour (PMH), which was higher than the 9.50 m3; PMH−1 of Crew A. The operational costs were US$33.52 PMH−1 for Crew A, and US$44.24 PMH−1 for Crew B. Despite the higher operational cost with Crew B, the increase in productivity resulted in a lower production cost up until the scenario of 120 m of winching distance.
采伐是林业作业中一个复杂而昂贵的步骤。在山区，由于地形对传统木材开采形式的风险和限制，木材采伐是复杂的。本研究的目的是评估使用农用拖拉机和绞车采油树的有效工作周期、生产率、操作成本和生产成本，在两种工作人员组成中:工作人员a:一名拖拉机操作员和一名吊带工;船员B:一名拖拉机操作员和两名吊带员。该研究在巴西东南部的Vale do Ribeira地区实施，采用完整的树木采伐系统，在不同的采伐距离(6-135 m)、原木场(5-241 m)和地面坡度(7-37°)条件下进行时间和运动研究。为了评估周期，对每个治疗进行回归分析，随后使用Graybill f检验进行比较。接下来，使用虚拟变量进行回归。机组B的平均生产率为13.54 m3;每生产机器小时(PMH)，高于9.50 m3;机组A的PMH−1为33.52美元，机组B的PMH−1为44.24美元。尽管机组B的操作成本较高，但在绞车距离为120米的情况下，生产率的提高导致生产成本较低。
{"title":"Wood extraction performance with a farm tractor in a mountainous region of Brazil: cycle time, productivity and costs of two different work crews","authors":"Rafael Oliveira Brown, Kauê Augusto Oliveira-Nascimento, R. Robert, Daniel DeArmond","doi":"10.2989/20702620.2022.2078251","DOIUrl":"https://doi.org/10.2989/20702620.2022.2078251","url":null,"abstract":"Harvesting is a complex and expensive step within forestry operations. In mountainous terrain timber harvesting is complex due to the risks and limitations that the terrain imposes on traditional forms of wood extraction. The objective of this study was to evaluate the effective time of work cycle, productivity, operational costs, and production costs of tree extraction by means of a farm tractor with winch, in two work crew compositions: Crew A: one tractor operator and a choker setter; and Crew B: one tractor operator and two choker setters. The study was implemented in the Vale do Ribeira region of south-eastern Brazil, using a full tree-harvesting system through a time and motion study under different conditions of extraction distance (6–135 m), log yard (5–241 m), and ground slope (7–37°). To evaluate the cycles, a regression analysis was conducted for each treatment, and subsequently compared using the Graybill F-test. Next, a regression with a dummy variable was performed. Crew B showed an average productivity of 13.54 m3; per productive machine hour (PMH), which was higher than the 9.50 m3; PMH−1 of Crew A. The operational costs were US$33.52 PMH−1 for Crew A, and US$44.24 PMH−1 for Crew B. Despite the higher operational cost with Crew B, the increase in productivity resulted in a lower production cost up until the scenario of 120 m of winching distance.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91088776","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}
Pub Date : 2022-04-03DOI: 10.2989/20702620.2022.2040925
Franciele Alba da Silva, S. P. Netto, A. Behling, H. Koehler, Ataídes Marinheski Filho, Cláudio Cerqueira
Nelder’s systematic design enables studies of tree plantation spacing in relatively small areas, which is of great interest for forest planning. However, dependence between observations can arise with this method, making it difficult to use classic statistics for evaluating an experiment. Therefore, our aims were to: evaluate the relationship between dendrometric variables (tree diameter, height and volume) and the available growing area; evaluate autocorrelation among the observations; and use multivariate analysis of the profiles of the clones for comparisons of the dendrometric variables. The data are from an experiment with four Nelder wheel plots of different Eucalyptus species clones of different ages, in the state of Tocantins, Brazil. Spearman’s rank correlation was applied to evaluate the relationship between the estimates of the studied variables and respective available growing area. Autocorrelation between the observations was evaluated with Moran’s I index. To analyse the profile behaviour of the clones, three questions were proposed: (1) Are there statistical differences between the estimations made for the different clones? (2) Are there differences between treatments applied in the experiment with the clones? (3) Is there interaction between clones and spacings? The main results show that multivariate profile analysis solved the autocorrelation problem in Nelder’s systematic design. Furthermore, we obtained answers as to differences between the growth variables diameter, volume and height among the clones at different spacings, whether there is a difference between the spacings for these variables, and whether there is an interaction between clones and spacings. The analysis method used for repeated measures is appropriate to evaluate trees in Nelder wheel trials.
{"title":"Density effect on growth variables of eucalypt clones in a Nelder wheel experiment","authors":"Franciele Alba da Silva, S. P. Netto, A. Behling, H. Koehler, Ataídes Marinheski Filho, Cláudio Cerqueira","doi":"10.2989/20702620.2022.2040925","DOIUrl":"https://doi.org/10.2989/20702620.2022.2040925","url":null,"abstract":"Nelder’s systematic design enables studies of tree plantation spacing in relatively small areas, which is of great interest for forest planning. However, dependence between observations can arise with this method, making it difficult to use classic statistics for evaluating an experiment. Therefore, our aims were to: evaluate the relationship between dendrometric variables (tree diameter, height and volume) and the available growing area; evaluate autocorrelation among the observations; and use multivariate analysis of the profiles of the clones for comparisons of the dendrometric variables. The data are from an experiment with four Nelder wheel plots of different Eucalyptus species clones of different ages, in the state of Tocantins, Brazil. Spearman’s rank correlation was applied to evaluate the relationship between the estimates of the studied variables and respective available growing area. Autocorrelation between the observations was evaluated with Moran’s I index. To analyse the profile behaviour of the clones, three questions were proposed: (1) Are there statistical differences between the estimations made for the different clones? (2) Are there differences between treatments applied in the experiment with the clones? (3) Is there interaction between clones and spacings? The main results show that multivariate profile analysis solved the autocorrelation problem in Nelder’s systematic design. Furthermore, we obtained answers as to differences between the growth variables diameter, volume and height among the clones at different spacings, whether there is a difference between the spacings for these variables, and whether there is an interaction between clones and spacings. The analysis method used for repeated measures is appropriate to evaluate trees in Nelder wheel trials.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76099437","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}
Pub Date : 2022-04-03DOI: 10.2989/20702620.2022.2066488
Alejandro González, J. Hernández, A. del Pino, A. Hirigoyen
The sustainability of forest production is based on an adequate balance between soil nutrient supply and its demand by forest plantations, which may vary depending on the species and the site. In Uruguay, the low to medium fertility of the soils under forest production makes this aspect relevant. The objectives of the study were: (a) to quantify the concentration and distribution of nutrients in the harvested biomass of Eucalyptus dunnii, Eucalyptus grandis and Eucalyptus globulus in the predominant soils of the zones of greater forestry aptitude of Uruguay; and (b) to compare the nutrient use efficiencies of the three mentioned species in different soil types, as a criterion to evaluate the sustainability of the productive system in the long term. In 29 sites located in the three main forest areas of the country, nine trees with average diameter at breast height (DBH) and height were harvested at eight to eleven years of age. The aerial biomass and nutrient uptake (nitrogen, phosphorus, potassium, calcium and magnesium) in commercial wood, bark, leaves and branches were quantified, and two nutrient use efficiency indexes (nutrient use efficiency and biological utilisation coefficient) were calculated. Although the zones offered different conditions for growth and nutrient uptake, E. dunnii presented the highest extraction of nutrients in commercial wood, considering all sites, these indexes being lower for E. dunnii. Therefore, when planting E. dunnii, its greater use of the soil’s resources must be considered, particularly in soils that are naturally less fertile. Likewise, E. grandis presented a greater extraction of cations than E. globulus because of more extensive growth.
{"title":"Nutrient use efficiency in commercial eucalypt plantations in different soils under temperate climate","authors":"Alejandro González, J. Hernández, A. del Pino, A. Hirigoyen","doi":"10.2989/20702620.2022.2066488","DOIUrl":"https://doi.org/10.2989/20702620.2022.2066488","url":null,"abstract":"The sustainability of forest production is based on an adequate balance between soil nutrient supply and its demand by forest plantations, which may vary depending on the species and the site. In Uruguay, the low to medium fertility of the soils under forest production makes this aspect relevant. The objectives of the study were: (a) to quantify the concentration and distribution of nutrients in the harvested biomass of Eucalyptus dunnii, Eucalyptus grandis and Eucalyptus globulus in the predominant soils of the zones of greater forestry aptitude of Uruguay; and (b) to compare the nutrient use efficiencies of the three mentioned species in different soil types, as a criterion to evaluate the sustainability of the productive system in the long term. In 29 sites located in the three main forest areas of the country, nine trees with average diameter at breast height (DBH) and height were harvested at eight to eleven years of age. The aerial biomass and nutrient uptake (nitrogen, phosphorus, potassium, calcium and magnesium) in commercial wood, bark, leaves and branches were quantified, and two nutrient use efficiency indexes (nutrient use efficiency and biological utilisation coefficient) were calculated. Although the zones offered different conditions for growth and nutrient uptake, E. dunnii presented the highest extraction of nutrients in commercial wood, considering all sites, these indexes being lower for E. dunnii. Therefore, when planting E. dunnii, its greater use of the soil’s resources must be considered, particularly in soils that are naturally less fertile. Likewise, E. grandis presented a greater extraction of cations than E. globulus because of more extensive growth.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87151761","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}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2021.2017761
G. T. D. O. S. Azevedo, A. M. Souza, G. B. D. Azevedo, P. Teodoro, L. P. Teodoro, José Raimundo Luduvico de Sousa
Establishing the optimal time for rooting permanence and evaluation of the rooting quality of eucalypt clones allows us to optimise the production process and increase the quality of the seedlings produced. This study aimed to determine the optimal time for rooting permanence and the rooting quality of three eucalypt clones. Minicuttings from the clones AEC 0144, GG100 and VM01 were propagated in a greenhouse and evaluated for six weeks. The percentages of callus- rooted, rooted and live minicuttings, the number of roots, root system length, and root dry mass were evaluated. The selected clones differed in the speed and rate of rooting, reflecting differences in the optimal time in the rooting house for the minicuttings. Clone VM01 presented the lowest rate and speed of rooting. We conclude that optimisation of the rooting process can be achieved using logistic model fitting and noting the intercept between the daily current increment and daily average increment curves of the rooting percentage, since the other variables are dependendent on this.
{"title":"Time of permanence and rooting quality of minicuttings of eucalypt clones","authors":"G. T. D. O. S. Azevedo, A. M. Souza, G. B. D. Azevedo, P. Teodoro, L. P. Teodoro, José Raimundo Luduvico de Sousa","doi":"10.2989/20702620.2021.2017761","DOIUrl":"https://doi.org/10.2989/20702620.2021.2017761","url":null,"abstract":"Establishing the optimal time for rooting permanence and evaluation of the rooting quality of eucalypt clones allows us to optimise the production process and increase the quality of the seedlings produced. This study aimed to determine the optimal time for rooting permanence and the rooting quality of three eucalypt clones. Minicuttings from the clones AEC 0144, GG100 and VM01 were propagated in a greenhouse and evaluated for six weeks. The percentages of callus- rooted, rooted and live minicuttings, the number of roots, root system length, and root dry mass were evaluated. The selected clones differed in the speed and rate of rooting, reflecting differences in the optimal time in the rooting house for the minicuttings. Clone VM01 presented the lowest rate and speed of rooting. We conclude that optimisation of the rooting process can be achieved using logistic model fitting and noting the intercept between the daily current increment and daily average increment curves of the rooting percentage, since the other variables are dependendent on this.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87074582","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}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2022.2037399
Phanesh Raghbor, Linisha Devi Seeruttun, C. Appadoo
Blue carbon has gained recognition as a strategy to mitigate climate change. Mangroves allow significant amounts of carbon to be sequestered and stored and are considered an important component in the offset of greenhouse gas emissions. Despite this, little is known about the ecosystem-level carbon storage of the mangrove stands of Mauritius, western Indian Ocean. We conducted an inventory of mangrove stands to characterise forest stand structure and estimate carbon stocks in terms of aboveground biomass and soil carbon at two sites, Ferney and Pointe d’Esny. Different allometric equations relative to species (for areas dominated by Rhizophora mucronata or Bruguiera gymnorrhiza) were used for aboveground biomass, and the loss-on-ignition method was used for estimating soil carbon. The results showed that aboveground biomass ranged from 54.57 Mg ha−1 to 328.71 Mg ha−1, and soil carbon from 99.11 ± 18.35 Mg ha−1 to 133.45 ± 30.35 Mg ha−1. The total ecosystem carbon stock ranged from 402.35 ± 19.29 Mg ha−1 to 427.81 ± 18.35 Mg ha−1 at Ferney, and from 188.03 ± 30.35 Mg ha−1 to 189.72 ± 19.27 Mg ha−1 at Pointe d’Esny. Our results underscore the importance of mangrove forest stands and highlight the need for in-depth and broader spatial-scope research on blue carbon ecosystems in Mauritius.
{"title":"First assessment of the blue carbon storage of Rhizophora and Bruguiera mangrove stands on the island of Mauritius (western Indian Ocean)","authors":"Phanesh Raghbor, Linisha Devi Seeruttun, C. Appadoo","doi":"10.2989/20702620.2022.2037399","DOIUrl":"https://doi.org/10.2989/20702620.2022.2037399","url":null,"abstract":"Blue carbon has gained recognition as a strategy to mitigate climate change. Mangroves allow significant amounts of carbon to be sequestered and stored and are considered an important component in the offset of greenhouse gas emissions. Despite this, little is known about the ecosystem-level carbon storage of the mangrove stands of Mauritius, western Indian Ocean. We conducted an inventory of mangrove stands to characterise forest stand structure and estimate carbon stocks in terms of aboveground biomass and soil carbon at two sites, Ferney and Pointe d’Esny. Different allometric equations relative to species (for areas dominated by Rhizophora mucronata or Bruguiera gymnorrhiza) were used for aboveground biomass, and the loss-on-ignition method was used for estimating soil carbon. The results showed that aboveground biomass ranged from 54.57 Mg ha−1 to 328.71 Mg ha−1, and soil carbon from 99.11 ± 18.35 Mg ha−1 to 133.45 ± 30.35 Mg ha−1. The total ecosystem carbon stock ranged from 402.35 ± 19.29 Mg ha−1 to 427.81 ± 18.35 Mg ha−1 at Ferney, and from 188.03 ± 30.35 Mg ha−1 to 189.72 ± 19.27 Mg ha−1 at Pointe d’Esny. Our results underscore the importance of mangrove forest stands and highlight the need for in-depth and broader spatial-scope research on blue carbon ecosystems in Mauritius.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91255277","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}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2021.2008779
E. Pasho, A. Alla
In the context of changing climate conditions, it is crucial to understand how trees maintain resistance and resilience to and recover from drought stress and management-related disturbances, and how management (intensive/extensive) modulates tree growth responses to climate. Dendrochronological methods were used to examine radial growth rates, to reconstruct disturbance history and to evaluate growth resistance and resilience to and recovery from disturbance events identified by pointer year analysis in two coexisting Quercus species (Q. macrolepis Kotschy and Q. trojana Webb). Moreover, a dendro-ecological approach was used to quantify climate–growth relationships, including a drought index, the Standardised Precipitation Index (SPI). Q. trojana/Q. macrolepis showed major/moderate growth releases and moderate growth suppression. Q. trojana demonstrated statistically lower growth recovery than Q. macrolepis. The climatic drivers of radial growth in Q. macrolepis were May, June, September precipitation, July temperatures and the SPI accumulated since the previous year (up to 18 months); whereas Q. trojana responded significantly to May and June precipitation, July temperatures and the SPI at mid-time scales (< 8 months). Under intensive management, both species were more responsive to precipitation, temperature and short to mid-time scale SPI than during the extensive management period where they showed loss of sensitivity to spring–summer precipitation, temperature and SPI. These results are relevant to understand species vulnerability to climate and management/ human-related disturbances, and the effects of intensive/extensive management in modulating climate (drought)–growth relationships in Q. macrolepis and Q. trojana trees.
{"title":"Impact of climate and management on radial growth dynamics of two coexisting Mediterranean Quercus species in south Albania","authors":"E. Pasho, A. Alla","doi":"10.2989/20702620.2021.2008779","DOIUrl":"https://doi.org/10.2989/20702620.2021.2008779","url":null,"abstract":"In the context of changing climate conditions, it is crucial to understand how trees maintain resistance and resilience to and recover from drought stress and management-related disturbances, and how management (intensive/extensive) modulates tree growth responses to climate. Dendrochronological methods were used to examine radial growth rates, to reconstruct disturbance history and to evaluate growth resistance and resilience to and recovery from disturbance events identified by pointer year analysis in two coexisting Quercus species (Q. macrolepis Kotschy and Q. trojana Webb). Moreover, a dendro-ecological approach was used to quantify climate–growth relationships, including a drought index, the Standardised Precipitation Index (SPI). Q. trojana/Q. macrolepis showed major/moderate growth releases and moderate growth suppression. Q. trojana demonstrated statistically lower growth recovery than Q. macrolepis. The climatic drivers of radial growth in Q. macrolepis were May, June, September precipitation, July temperatures and the SPI accumulated since the previous year (up to 18 months); whereas Q. trojana responded significantly to May and June precipitation, July temperatures and the SPI at mid-time scales (< 8 months). Under intensive management, both species were more responsive to precipitation, temperature and short to mid-time scale SPI than during the extensive management period where they showed loss of sensitivity to spring–summer precipitation, temperature and SPI. These results are relevant to understand species vulnerability to climate and management/ human-related disturbances, and the effects of intensive/extensive management in modulating climate (drought)–growth relationships in Q. macrolepis and Q. trojana trees.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82674056","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}
Pub Date : 2022-01-02DOI: 10.2989/20702620.2022.2039044
P. Gómez, S. Espinoza, P. Garrido, José San Martín, Yony Ormazábal
The endemic ruil (Nothofagus alessandrii Espinosa) forest is one of the most endangered forest ecosystems in central Chile, where its regeneration is challenged by factors such as low seedling germination capacity and recently by fire. In this study, we sampled 36 plots (625 m2 each) within the very restricted distribution range of N. alessandrii and quantified regeneration of the species from seed after a catastrophic large-scale fire event in 2017. By means of logistic regression, Path analysis, and non-metric multidimensional scaling, we related ruil seedling regeneration with percentage vegetative cover, number of ruil individuals, richness of native species, density of seedlings of the introduced species Pinus radiata D. Don, and fire severity. Our results indicate that fire severity was the most important variable explaining the probability of regeneration of N. alessandrii. Seedling recruitment was present in 65% of the sites with low fire severity, but no recruitment was observed in sites severely burned by fire. The ecological implications of these findings suggest that after a high-severity fire, efforts to restore N. alessandrii should be concentrated on reforestation activities; however, in areas of low-severity burn, efforts must be focused on the management and protection of the new recruits.
智利特有的森林(Nothofagus alessandrii Espinosa)是智利中部最濒危的森林生态系统之一，其再生受到幼苗发芽率低和最近的火灾等因素的挑战。在这项研究中，我们在2017年灾难性的大规模火灾事件后，在非常有限的分布范围内取样了36个样地(每个样地625 m2)，并量化了该物种的种子再生。通过logistic回归、通径分析和非度量多维尺度分析，将林分幼苗再生与植被覆盖度、林分个体数、本地种丰富度、引种种辐射松(Pinus radiata D. Don)幼苗密度和火灾程度等因素联系起来。结果表明，火灾严重程度是解释亚历山德兰再生概率的最重要变量。65%的低火烧点有苗木再生，而严重火烧点没有苗木再生。这些发现的生态学意义表明，在严重火灾发生后，亚历山德里亚的恢复工作应集中在重新造林活动上;然而，在烧伤程度较低的地区，必须把工作重点放在对新兵的管理和保护上。
{"title":"Post-fire tree regeneration from seed of the endangered Nothofagus alessandrii Espinosa in the Maule region of central Chile","authors":"P. Gómez, S. Espinoza, P. Garrido, José San Martín, Yony Ormazábal","doi":"10.2989/20702620.2022.2039044","DOIUrl":"https://doi.org/10.2989/20702620.2022.2039044","url":null,"abstract":"The endemic ruil (Nothofagus alessandrii Espinosa) forest is one of the most endangered forest ecosystems in central Chile, where its regeneration is challenged by factors such as low seedling germination capacity and recently by fire. In this study, we sampled 36 plots (625 m2 each) within the very restricted distribution range of N. alessandrii and quantified regeneration of the species from seed after a catastrophic large-scale fire event in 2017. By means of logistic regression, Path analysis, and non-metric multidimensional scaling, we related ruil seedling regeneration with percentage vegetative cover, number of ruil individuals, richness of native species, density of seedlings of the introduced species Pinus radiata D. Don, and fire severity. Our results indicate that fire severity was the most important variable explaining the probability of regeneration of N. alessandrii. Seedling recruitment was present in 65% of the sites with low fire severity, but no recruitment was observed in sites severely burned by fire. The ecological implications of these findings suggest that after a high-severity fire, efforts to restore N. alessandrii should be concentrated on reforestation activities; however, in areas of low-severity burn, efforts must be focused on the management and protection of the new recruits.","PeriodicalId":21939,"journal":{"name":"Southern Forests: a Journal of Forest Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87723156","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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