Acoustic inventory of Sri Lankan amphibians is still in a primitive stage. So far, only 20 amphibian species are known acoustically and are about 16% of the island amphibian fauna. Altogether, twelve publications provide primary acoustic characters, yet the majority of them are not quantitative. Bioacoustics is a powerful tool that can use in many disciplines, including taxonomy and conservation. This work emphasises that the current knowledge on the vocalisation of Sri Lankan amphibians is not adequate and highlighted its applications towards conservation and planning.
{"title":"Bioacoustics of Sri Lankan Amphibians: a Review of Current Knowledge and Conservation Significance","authors":"S. D. Silva, Nayana Wijayathilaka","doi":"10.31357/JTFE.V9I1.3944","DOIUrl":"https://doi.org/10.31357/JTFE.V9I1.3944","url":null,"abstract":"Acoustic inventory of Sri Lankan amphibians is still in a primitive stage. So far, only 20 amphibian species are known acoustically and are about 16% of the island amphibian fauna. Altogether, twelve publications provide primary acoustic characters, yet the majority of them are not quantitative. Bioacoustics is a powerful tool that can use in many disciplines, including taxonomy and conservation. This work emphasises that the current knowledge on the vocalisation of Sri Lankan amphibians is not adequate and highlighted its applications towards conservation and planning.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86216994","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 : 2019-08-03DOI: 10.31357/JTFE.V9I1.3950.G3117
D.V.S. Kaluthanthri, P. Dasanayaka
Sorghum (Sorghum bicolor (L.) Moench) is considered as the fifth most important cereal crop in the world. It is well adapted to a range of environmental conditions. This study was based on twenty six sorghum germplasm accessions conserved at the seed gene bank of Plant Genetic Resource Center, Gannoruwa, Sri Lanka. The evaluation of the morphological diversity was based on 14 qualitative morphological traits outlined by the International Plant Genetic Resources Institute. Qualitative data recorded from morphological traits were analyzed using PROC CLUSTER procedure of SAS software. The clustering pattern of studied sorghum accessions based on qualitative morphological markers comprised of seven major clusters. Clustering pattern based on the qualitative traits depicts the geographical origin of the studied accessions. This can be explained by the fact that qualitative traits are less influenced by the environment. In principle, qualitative data are expected to provide additional information on hierarchical units. Observation of a considerably high number of clusters consolidates that principle. There were 13 polymorphic qualitative morphological traits with respect to all the studied sorghum germplasm accessions. Cluster I, II, III, IV, V and VI had one or several features shared by all the member accessions those cannot be found in all the members of any other clusters. Also there were unique features restricted to cluster II, III, V and VI. This study reveals sufficient genetic relatedness of studied sorghum germplasm accessions which will meaningful in the conservation and breeding programs of the crops.
{"title":"Genetic Variability Assessment of Sorghum (Sorghum bicolor (L.) Moench) Germplasm Accessions using Qualitative Morphological Descriptors","authors":"D.V.S. Kaluthanthri, P. Dasanayaka","doi":"10.31357/JTFE.V9I1.3950.G3117","DOIUrl":"https://doi.org/10.31357/JTFE.V9I1.3950.G3117","url":null,"abstract":"Sorghum (Sorghum bicolor (L.) Moench) is considered as the fifth most important cereal crop in the world. It is well adapted to a range of environmental conditions. This study was based on twenty six sorghum germplasm accessions conserved at the seed gene bank of Plant Genetic Resource Center, Gannoruwa, Sri Lanka. The evaluation of the morphological diversity was based on 14 qualitative morphological traits outlined by the International Plant Genetic Resources Institute. Qualitative data recorded from morphological traits were analyzed using PROC CLUSTER procedure of SAS software. The clustering pattern of studied sorghum accessions based on qualitative morphological markers comprised of seven major clusters. Clustering pattern based on the qualitative traits depicts the geographical origin of the studied accessions. This can be explained by the fact that qualitative traits are less influenced by the environment. In principle, qualitative data are expected to provide additional information on hierarchical units. Observation of a considerably high number of clusters consolidates that principle. There were 13 polymorphic qualitative morphological traits with respect to all the studied sorghum germplasm accessions. Cluster I, II, III, IV, V and VI had one or several features shared by all the member accessions those cannot be found in all the members of any other clusters. Also there were unique features restricted to cluster II, III, V and VI. This study reveals sufficient genetic relatedness of studied sorghum germplasm accessions which will meaningful in the conservation and breeding programs of the crops.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76662505","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 Sinharaja Forest Reserve is located in the Southern as well as Sabaragamuwa provinces in the wet zone, between latitudes 6o21-6o26 N and longitudes 80o21-80o34 E is one of the biologically unique Tropical Forest in Sri Lanka. Although Sinharaja is considered a lowland rain forest, the Eastern part of the forest consists montane and sub-montane forests. Many scholars have already researched on reptiles in the lowland rain forests of Sri Lanka including Sinharaja, however, they have not significantly attended to the diversity of reptiles in the Eastern and Southern parts of the Sinharaja forest. Considering this gap, the research focuses on studying diversity of reptiles in diverse lowland rain forests, montane and sub-montane forests in the Southern and Eastern parts of Sinharaja. Giguruwa-Kosmulla and Pitadeniya sites in the Southern part, and Hadpanella and Morningside in the Eastern part are selected as study areas of the research. 16 line transects (as four from each site) and quadrate 16 samples (as four from each site) are used for primary data collecting. Lowland rain forests, montane and sub-montane forests are identified as biologically sensitive habitats of reptiles. High number of native reptile species are recorded in lowland rain forests than in montane and sub-montane forests. 36 reptile species are identified in Southern and Eastern parts of the Sinharaja forest and 19 species of them are endemic to Sri Lanka. Among them, 05 vulnerable species, 04 endangered species, 05 critically endangered species are recorded. Many threats have been found, however, among them issues of bio piracy loss of forest genetic resources and wildlife smuggling, illegal forest utilisation practices, gem mining, illegal forest encroachments and unethical tourism practices are major issues. Thus, state forest department and other responsible authorities must attend to minimize the effects of these negative human impact on these vulnerable areas to protect sensitive reptile species in their habitats in order to conserve their diversity.
{"title":"Diversity of Reptiles in the Eastern and Southern parts of the Sinharaja Rain Forest","authors":"V. Samarawickrama, H. Kumara, D. Samarawickrama","doi":"10.31357/JTFE.V9I1.3948","DOIUrl":"https://doi.org/10.31357/JTFE.V9I1.3948","url":null,"abstract":"The Sinharaja Forest Reserve is located in the Southern as well as Sabaragamuwa provinces in the wet zone, between latitudes 6o21-6o26 N and longitudes 80o21-80o34 E is one of the biologically unique Tropical Forest in Sri Lanka. Although Sinharaja is considered a lowland rain forest, the Eastern part of the forest consists montane and sub-montane forests. Many scholars have already researched on reptiles in the lowland rain forests of Sri Lanka including Sinharaja, however, they have not significantly attended to the diversity of reptiles in the Eastern and Southern parts of the Sinharaja forest. Considering this gap, the research focuses on studying diversity of reptiles in diverse lowland rain forests, montane and sub-montane forests in the Southern and Eastern parts of Sinharaja. Giguruwa-Kosmulla and Pitadeniya sites in the Southern part, and Hadpanella and Morningside in the Eastern part are selected as study areas of the research. 16 line transects (as four from each site) and quadrate 16 samples (as four from each site) are used for primary data collecting. Lowland rain forests, montane and sub-montane forests are identified as biologically sensitive habitats of reptiles. High number of native reptile species are recorded in lowland rain forests than in montane and sub-montane forests. 36 reptile species are identified in Southern and Eastern parts of the Sinharaja forest and 19 species of them are endemic to Sri Lanka. Among them, 05 vulnerable species, 04 endangered species, 05 critically endangered species are recorded. Many threats have been found, however, among them issues of bio piracy loss of forest genetic resources and wildlife smuggling, illegal forest utilisation practices, gem mining, illegal forest encroachments and unethical tourism practices are major issues. Thus, state forest department and other responsible authorities must attend to minimize the effects of these negative human impact on these vulnerable areas to protect sensitive reptile species in their habitats in order to conserve their diversity.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73140314","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}
Forest fragments in Arid and Semi-Arid Lands are key water catchment areas and provide important ecosystem services. However, uncontrolled human activities are fast altering their stem density basal area and diameter structure resulting into forest degradation. Besides, information regarding tree density and diameter size-class distribution of dryland forest fragments such as Museve and Mutuluni is lacking. Thus, the purpose of this study was to document key human activities in Museve and Mutuluni forest fragments in Kitui, Kenya and comparatively investigate their influences on stem density, basal area and stem diameter size-class distribution. Two belt transect of 20 m wide and 500 m long, with contiguous sample plots of 20 m by 20 m and subplots of 10 m by 10 m were established in each forest. Evidence of human activities, abundances and diameter measurements for mature trees were assessed in the 20 m by 20 m plots while abundances and diameter measurements for saplings were in the subplots. Mann-Whitney, t-test and logistic regression were used for data analysis. Mutuluni forest exhibited significantly (p<0.05) high stem density compared to Museve however, basal area density was not different (p<0.05). Introduction of exotic species enhanced basal area and stem density (p<0.05) in Museve forest. Tree cutting reduced both basal area and stem density in Museve forest and only stem density in Mutuluni. Stem-density diameter distribution in both forests followed a reverse J-curve but with more fluctuations and irregularities observed in Museve compared to Mutuluni forest. Diameter size-class distribution did not differ (p<0.05) across the two forests. Therefore human activities significantly impacted on tree density in both forest fragments with high impacts in Museve. This study recommends formulation of appropriate protection and conservation strategies, especially for Museve, to control tree cutting and increase tree density.
干旱半干旱区森林残片是重要的集水区，提供重要的生态系统服务。然而，不受控制的人类活动正在迅速改变它们的茎密度、基面积和直径结构，导致森林退化。此外，穆塞夫和穆图鲁尼等旱地森林碎片的乔木密度和直径大小级分布信息缺乏。因此，本研究的目的是记录肯尼亚基图伊Museve和Mutuluni森林碎片中的关键人类活动，并比较研究其对茎密度、基面积和茎直径大小类分布的影响。在每个森林内建立了宽20 m、长500 m的2个样带样带，样带样地为20 m × 20 m，样带样地为10 m × 10 m。人类活动的证据、成熟树木的丰度和直径测量值在20 m × 20 m样地进行评估，而树苗的丰度和直径测量值在子样地进行评估。采用Mann-Whitney检验、t检验和logistic回归进行数据分析。木腐林干密度显著高于木腐林(p<0.05)，但基片密度差异不显著(p<0.05)。外来种的引入增加了木栎林的基面积和茎密度(p<0.05)。树木采伐降低了木塞夫林的基面积和茎密度，而穆图鲁尼林仅降低了茎密度。两种森林的茎密度直径分布均遵循反j曲线，但穆塞夫林比穆图鲁尼林有更多的波动和不规则性。两种林分的径级分布无显著差异(p<0.05)。因此，人类活动显著影响了穆塞夫两个高影响森林片段的树木密度。本研究建议制定适当的保护和养护策略，特别是对木树，以控制树木砍伐和增加树木密度。
{"title":"Influences of Human Activities on Tree Density and Diameter Distribution in Museve and Mutuluni Dryland Forest Fragments; Kitui County, Kenya","authors":"J. M. Musau, J. Mugo","doi":"10.31357/JTFE.V9I1.3955","DOIUrl":"https://doi.org/10.31357/JTFE.V9I1.3955","url":null,"abstract":"Forest fragments in Arid and Semi-Arid Lands are key water catchment areas and provide important ecosystem services. However, uncontrolled human activities are fast altering their stem density basal area and diameter structure resulting into forest degradation. Besides, information regarding tree density and diameter size-class distribution of dryland forest fragments such as Museve and Mutuluni is lacking. Thus, the purpose of this study was to document key human activities in Museve and Mutuluni forest fragments in Kitui, Kenya and comparatively investigate their influences on stem density, basal area and stem diameter size-class distribution. Two belt transect of 20 m wide and 500 m long, with contiguous sample plots of 20 m by 20 m and subplots of 10 m by 10 m were established in each forest. Evidence of human activities, abundances and diameter measurements for mature trees were assessed in the 20 m by 20 m plots while abundances and diameter measurements for saplings were in the subplots. Mann-Whitney, t-test and logistic regression were used for data analysis. Mutuluni forest exhibited significantly (p<0.05) high stem density compared to Museve however, basal area density was not different (p<0.05). Introduction of exotic species enhanced basal area and stem density (p<0.05) in Museve forest. Tree cutting reduced both basal area and stem density in Museve forest and only stem density in Mutuluni. Stem-density diameter distribution in both forests followed a reverse J-curve but with more fluctuations and irregularities observed in Museve compared to Mutuluni forest. Diameter size-class distribution did not differ (p<0.05) across the two forests. Therefore human activities significantly impacted on tree density in both forest fragments with high impacts in Museve. This study recommends formulation of appropriate protection and conservation strategies, especially for Museve, to control tree cutting and increase tree density.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91436908","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 endemic endangered agamid lizard Calotes nigrilabris inhabits the grasslands of Horton Plains National Park (HPNP) and it is restricted to a few localities in the central highlands of Sri Lanka. In this study, the microhabitat utilisation of Calotes nigrilabris was investigated utilising line transects and quadrate method. The comparison of available microhabitat variables with occupied microhabitat variables revealed that there was a significant difference between some of the variables (Man-Whiteney U test, p<0.05) indicating that C. nigrilabris was selective in its microhabitat utilisation. Based on PCA analysis, amount and type of vegetation was the main determining factor of microhabitat preference of this species. Ulex sp. cover (PC1, 0.606) and Rhododendron sp. cover (PC2,-0.603) were significantly affecting the occupied microhabitat structure. Microhabitat utilisation varied in the temporal and spatial scales also indicating clear resource partitioning between different maturity stages. The results of this study indicate that C. nigrilabris actively selects and utilises the most suitable grassland microhabitats of HPNP and provide important insights for the conservation and management of the species as well as its natural habitat.
{"title":"Microhabitat Utilisation of Endemic Lizard Calotes nigrilabris in the Grasslands of Horton Plains National Park, Sri Lanka","authors":"Egdp Jayasekara, M. Prabhath, W. Mahaulpatha","doi":"10.31357/JTFE.V9I1.3952","DOIUrl":"https://doi.org/10.31357/JTFE.V9I1.3952","url":null,"abstract":"The endemic endangered agamid lizard Calotes nigrilabris inhabits the grasslands of Horton Plains National Park (HPNP) and it is restricted to a few localities in the central highlands of Sri Lanka. In this study, the microhabitat utilisation of Calotes nigrilabris was investigated utilising line transects and quadrate method. The comparison of available microhabitat variables with occupied microhabitat variables revealed that there was a significant difference between some of the variables (Man-Whiteney U test, p<0.05) indicating that C. nigrilabris was selective in its microhabitat utilisation. Based on PCA analysis, amount and type of vegetation was the main determining factor of microhabitat preference of this species. Ulex sp. cover (PC1, 0.606) and Rhododendron sp. cover (PC2,-0.603) were significantly affecting the occupied microhabitat structure. Microhabitat utilisation varied in the temporal and spatial scales also indicating clear resource partitioning between different maturity stages. The results of this study indicate that C. nigrilabris actively selects and utilises the most suitable grassland microhabitats of HPNP and provide important insights for the conservation and management of the species as well as its natural habitat.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73926073","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 at Ades forest in West Hararghe Zone, Ethiopia, for determining the woody species composition and regeneration status of the forest. Systematic sampling method was used to collect vegetation data from 48 (20 m×20 m) main sample plots for woody species that was established along a transect line and spaced at 10 m altitudinal drop, from top to the bottom of the natural forest. Inside the main plot (400 m2), subplots (5 m×5 m) were established to simplify the counting of seedlings and saplings. Species abundance and environmental variables were recorded in each sample plot. A total of 48 woody plant species belonging to 42 genera and 29 families were identified. Fabaceae family had the highest number of taxa followed by Rosaceae and Flacourtiaceae families. Woody plant species densities for mature individuals were 197.9 ha-1, saplings 420 ha-1and 849.5 ha-1for seedlings. Although over all regeneration status of woody plants of the Forest revealed good regeneration status, the presence of anthropogenic disturbance in the area necessitates the need for conservation action in order to ensure sustainable utilisation and management of the Forest.
{"title":"Woody Species Composition and Natural Regeneration Status of Ades Forest, Oromia Regional State, West Hararghe Zone, Ethiopia","authors":"O. Dereje, I. D. Duguma","doi":"10.31357/JTFE.V9I1.3947","DOIUrl":"https://doi.org/10.31357/JTFE.V9I1.3947","url":null,"abstract":"This study was conducted at Ades forest in West Hararghe Zone, Ethiopia, for determining the woody species composition and regeneration status of the forest. Systematic sampling method was used to collect vegetation data from 48 (20 m×20 m) main sample plots for woody species that was established along a transect line and spaced at 10 m altitudinal drop, from top to the bottom of the natural forest. Inside the main plot (400 m2), subplots (5 m×5 m) were established to simplify the counting of seedlings and saplings. Species abundance and environmental variables were recorded in each sample plot. A total of 48 woody plant species belonging to 42 genera and 29 families were identified. Fabaceae family had the highest number of taxa followed by Rosaceae and Flacourtiaceae families. Woody plant species densities for mature individuals were 197.9 ha-1, saplings 420 ha-1and 849.5 ha-1for seedlings. Although over all regeneration status of woody plants of the Forest revealed good regeneration status, the presence of anthropogenic disturbance in the area necessitates the need for conservation action in order to ensure sustainable utilisation and management of the Forest.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75191641","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}
Lateral shoot cuttings are used for multiplication of Leucaena leucocephala clones to control lodging in pulpwood plantations. Variability in rooting pattern was evaluated in lateral cuttings from four types of mother plants (a) sand beds in shade house (SH), (b) sand beds with overhead shade, (c) open sand beds and (d) open field hedges (CMA) in a commercial Leucaena clone. Rooting rate of SH cuttings varied significantly with propagation conditions across two mist chambers (87% in MC 1 versus 68% in MC 2). Rooting pattern also differed with 77% cuttings in MC 1 having long root zone (>2.5 cm length from stem base) compared to only 10% plants in MC 2. Application of rooting hormone (IBA 5000 ppm) increased number of roots by 46% and root zone length by 39% in SH cuttings. Rooting rate did not vary between winter and summer season. Lateral cuttings from open sand bed and CMA had comparatively thicker stem with anatomical configuration of larger pith region, large diameter vessels in low frequency and sclerenchyma bundles, compared to mother plants raised in shade (a and b). Rooting rate was high (83-87%) in covered sand beds (a and b) compared to those (c and d) in open sunlight (43-68%). Majority of cuttings from open sand bed (85%) and CMA (93%) had short root zone (<2.5 cm length) compared to covered sand beds (30%). Clonal propagules with good root system can be produced from Leucaena cuttings when mother plants are maintained in shade and provided suitable propagation conditions.
{"title":"Variation in Rooting Pattern of Leucaena leucocephala in Relation to Propagation System and Stock Mother Plants","authors":"P. Suraj, M. Suresh, P. R. Babu, M. Varghese","doi":"10.31357/JTFE.V9I1.3945","DOIUrl":"https://doi.org/10.31357/JTFE.V9I1.3945","url":null,"abstract":"Lateral shoot cuttings are used for multiplication of Leucaena leucocephala clones to control lodging in pulpwood plantations. Variability in rooting pattern was evaluated in lateral cuttings from four types of mother plants (a) sand beds in shade house (SH), (b) sand beds with overhead shade, (c) open sand beds and (d) open field hedges (CMA) in a commercial Leucaena clone. Rooting rate of SH cuttings varied significantly with propagation conditions across two mist chambers (87% in MC 1 versus 68% in MC 2). Rooting pattern also differed with 77% cuttings in MC 1 having long root zone (>2.5 cm length from stem base) compared to only 10% plants in MC 2. Application of rooting hormone (IBA 5000 ppm) increased number of roots by 46% and root zone length by 39% in SH cuttings. Rooting rate did not vary between winter and summer season. Lateral cuttings from open sand bed and CMA had comparatively thicker stem with anatomical configuration of larger pith region, large diameter vessels in low frequency and sclerenchyma bundles, compared to mother plants raised in shade (a and b). Rooting rate was high (83-87%) in covered sand beds (a and b) compared to those (c and d) in open sunlight (43-68%). Majority of cuttings from open sand bed (85%) and CMA (93%) had short root zone (<2.5 cm length) compared to covered sand beds (30%). Clonal propagules with good root system can be produced from Leucaena cuttings when mother plants are maintained in shade and provided suitable propagation conditions.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74050984","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 distribution of crown diameter is important for assessing crown social class, monitoring forest health and wildlife management. However, the direct measurement of crown diameter is relative difficult, and as such, it is often predicted from diameter at breast based on a simple relationship. Therefore, in this study, the crown diameter distribution of Parkia biglobosa was derived from Dbh using Weibull and Log-Logistic functions. A total of 284 trees were measured from Parkia biglobosa plantation in Makurdi, Nigeria. Four methods were used for Weibull distribution including maximum likelihood (MLE), moments, percentiles and cumulative distribution function regression (CDFreg). MLE and CDFreg were used for Log-Logistic function. Transformation technique was used to transform the Dbh to crown distribution based on a simple allometric relationship between the variables. Kolmogorov-Smirnov (Dn), Cramer-von Mises statistic (W2) and Reynolds error index (EI) were used to assess the derived crown diameter distribution. The result showed that the underlying diameter distribution followed Weibull and Log-Logistic distributions. The fitted allometric equation was of the form: . MLE and CDFreg were the best methods for Weibull and Log-Logistic functions, respectively. The Dn, W2 and EI were 0.071, 0.0265 and 0.3434, respectively for MLE; and 0.0931, 0.0367 and 0.4171, respectively for CDFreg. In all methods, the observed and derived crown distributions were not significant at 20% (Dα=0.339). Thus, given the diameter distribution, the tree crown distribution of Parkia biglobosa can be derived. This would be useful for determination of the crown social class.
{"title":"Deriving Tree Crown Distributions from Diameter at Breast Height","authors":"F. N. Ogana, J. H. Dau","doi":"10.31357/JTFE.V9I1.3954","DOIUrl":"https://doi.org/10.31357/JTFE.V9I1.3954","url":null,"abstract":"The distribution of crown diameter is important for assessing crown social class, monitoring forest health and wildlife management. However, the direct measurement of crown diameter is relative difficult, and as such, it is often predicted from diameter at breast based on a simple relationship. Therefore, in this study, the crown diameter distribution of Parkia biglobosa was derived from Dbh using Weibull and Log-Logistic functions. A total of 284 trees were measured from Parkia biglobosa plantation in Makurdi, Nigeria. Four methods were used for Weibull distribution including maximum likelihood (MLE), moments, percentiles and cumulative distribution function regression (CDFreg). MLE and CDFreg were used for Log-Logistic function. Transformation technique was used to transform the Dbh to crown distribution based on a simple allometric relationship between the variables. Kolmogorov-Smirnov (Dn), Cramer-von Mises statistic (W2) and Reynolds error index (EI) were used to assess the derived crown diameter distribution. The result showed that the underlying diameter distribution followed Weibull and Log-Logistic distributions. The fitted allometric equation was of the form: . MLE and CDFreg were the best methods for Weibull and Log-Logistic functions, respectively. The Dn, W2 and EI were 0.071, 0.0265 and 0.3434, respectively for MLE; and 0.0931, 0.0367 and 0.4171, respectively for CDFreg. In all methods, the observed and derived crown distributions were not significant at 20% (Dα=0.339). Thus, given the diameter distribution, the tree crown distribution of Parkia biglobosa can be derived. This would be useful for determination of the crown social class.","PeriodicalId":17445,"journal":{"name":"Journal of Tropical Forestry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83837849","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 : 2018-01-01DOI: 10.31357/jtfe.v8i2.3764.g2980
L. D. Wakawa, F. N. Ogana, T. Adeniy
Forests play a significant role in human existence and survival. Timely and reliable information on the status of a forest is essential for assessing the extent of regeneration and degradation. However, when such information is lacking effective forest management practices becomes impossible. Therefore, this study assessed the tree species diversity, richness and structure of Oluwa forest reserve with the view of ascertaining it present state which is crucial for management and conservation purposes. To achieved these, a systematic line transect was used in the laying of eight (8) temporary sample plots (TSPs) of size 50m x 50m. Trees with Dbh≥10cm in the selected plots were enumerated, identified and measured. The results indicate that 535 individual trees were enumerated cutting across 26 families and 58 species. The reserve has the Margalef's index of species richness, Shannon-Weiner diversity Index (H') and Pielou's Species Evenness Index (E H ) of 9.07, 3.43 and 0.84 respectively. The forest has a mean Dbh (cm), mean height (m), total basal area/ha (m 2 ) and total volume/ha (m 3 ) of 24.7, 16.9, 36.63 and 602.09 respectively. Majority of trees were found in the smaller diameter and height classes; giving rise to reverse J-shaped structure. The structure of Oluwa forest reserve has been altered significantly while the species diversity and richness seems to indicate a sign of improvement compared to previous studies. With proper management, the remaining fragmented forests could regenerate and replenish to save some of the original species composition of the reserve.
森林对人类的生存和发展起着重要的作用。关于森林状况的及时和可靠的资料对于评估森林再生和退化的程度是必不可少的。但是，如果缺乏这种资料，就不可能采取有效的森林管理措施。因此，本研究对奥卢瓦森林保护区的树种多样性、丰富度和结构进行了评估，以确定其现状，这对管理和保护具有重要意义。为了实现这些目标，在铺设大小为50m x 50m的8个临时样地(tsp)时使用了系统的线样带。对所选样地胸径≥10cm的乔木进行枚举、鉴定和测量。结果表明，共录得树木535株，分26科58种。保护区物种丰富度指数、Shannon-Weiner多样性指数和Pielou物种均匀度指数分别为9.07、3.43和0.84。平均胸径(cm) 24.7，平均高度(m) 16.9，总基带面积(m2) 36.63，总积(m3) 602.09。大多数树木分布在直径和高度较小的类别;形成反j型结构。奥卢瓦森林保护区的结构发生了明显的变化，物种多样性和丰富度与以往的研究相比似乎有改善的迹象。通过适当的管理，剩余的破碎森林可以再生和补充，以保存保护区的一些原始物种组成。
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Illegal exploitation of timber species in developing countries have increased over the years. Though, there is dearth of empirical models for describing the dimension, structure, quality and estimating quantity of a removed tree needed for assessment of damage due to catastrophic events, creating historical records of previous management activities and for conviction of illegal loggers. The objective of this study was to develop and test non-linear models that can effectively estimate individual tree merchantable height (Ht) from stump diameter (Ds) for Tectona grandis stands in Omo Forest Reserve, Nigeria, for timber valuation in case of illegal felling. Thirty-six temporary sample plots (TSPs) of size 25 m x 25 m were laid randomly in six age strata of T. grandis ; 26, 23, 22, 16, 14, and 12 years specifically. Diameter at breast height, Ht and Ds were measured for all living T. grandis trees within the 36 TSPs. Least square method was used to convert the counted stumps into harvested stem height. Four Ht-Ds models were fitted and evaluated. The Ht-Ds relationship was best described by square model which gave least values of root mean square error (0.083) and Akaike information criterion (-7578). This study revealed that height estimation was realistic even when the only information available was stump diameter. The square model was validated using independent data not used in the model calibration and was found to be appropriate for estimating the height of T. grandis stands in Omo Forest Reserve, Nigeria. Keywords: Tree height, Nonlinear model, Stump diameter, Square, Tectona grandis
多年来，发展中国家对木材的非法开采有所增加。然而，目前缺乏经验模型来描述被砍伐树木的尺寸、结构、质量和估计数量，这些都是评估灾难性事件造成的损害、创建以往管理活动的历史记录和对非法伐木者定罪所必需的。本研究的目的是开发和测试非线性模型，该模型可以有效地从树桩直径(Ds)估计尼日利亚奥莫森林保护区的大构造林的单株树木可买卖高度(Ht)，以便在非法砍伐的情况下对木材进行评估。随机设置36个25 m × 25 m的临时样地(tsp)，分布于大田鼠6个年龄层;26岁，23岁，22岁，16岁，14岁，具体是12岁。在36个tsp范围内，测量了所有活松的胸径、Ht和Ds。用最小二乘法将计算的树桩换算成收获的茎高。拟合并评价了4种Ht-Ds模型。均方根误差最小(0.083)，赤池信息准则最小(-7578)，均能较好地描述Ht-Ds关系。该研究表明，即使只有树桩直径的信息，高度估计也是现实的。使用模型校准中未使用的独立数据对平方模型进行了验证，发现该模型适用于估计尼日利亚Omo森林保护区的大白杨林分高度。关键词:树高;非线性模型;树桩直径
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