Comparative study of additive basal area of conifers in forest ecosystems along elevational gradients

2007 ◽  
Vol 22 (3) ◽  
pp. 439-450 ◽  
Author(s):  
Shin-ichiro Aiba ◽  
Goro Hanya ◽  
Riyou Tsujino ◽  
Masaaki Takyu ◽  
Tatsuyuki Seino ◽  
...  
Keyword(s):  
Comparative Study ◽  
Forest Ecosystems ◽  
Basal Area ◽  
Elevational Gradients ◽  
Additive Basal Area

Elevational gradients of bryophyte diversity, life forms, and community assemblage in the southern Appalachian Mountains

2010 ◽  
Vol 40 (11) ◽  
pp. 2164-2174 ◽  
Author(s):  
Sarah E. Stehn ◽  
Christopher R. Webster ◽  
Janice M. Glime ◽  
Michael A. Jenkins
Keyword(s):  
Community Composition ◽  
Elevation Gradient ◽  
Light Availability ◽  
Basal Area ◽  
Life Forms ◽  
High Elevation ◽  
Canopy Openness ◽  
Fine Scale ◽  
Elevational Gradients ◽  
Community Assemblage

We investigated the influence of fine-scale elevational gradients and overstory disturbance on bryophyte distribution, diversity, and community composition. Bryophyte species cover and richness were sampled across 60 randomly selected plots within high-elevation spruce–fir ( Picea – Abies ) forests of Great Smoky Mountains National Park. Ordination and regression analyses revealed a fine-scale elevation gradient (700 m) in bryophyte community composition. Observed changes in bryophyte diversity and community composition were also associated with variation in deciduous basal area and thus litter composition, the prevalence of herbaceous plants, and the degree of canopy openness resulting from balsam woolly adelgid ( Adelges piceae Ratz.) infestation. Although overstory disturbances, such as those caused by the adelgid, create suitable substrate for bryophyte colonization, the corresponding increase in light availability and deciduous basal area may alter bryophyte diversity and community assemblages.

Lack of disturbance as an explanation for the additive basal area phenomenon in a stratified Afrotemperate forest

2006 ◽  
Vol 31 (4) ◽  
pp. 471-477 ◽  
Author(s):  
M. J. LAWES ◽  
J. J. MIDGLEY ◽  
S. BOUDREAU ◽  
M. E. GRIFFITHS
Keyword(s):  
Basal Area ◽  
Additive Basal Area

Competition among canopy trees in indigenous forests: An analysis of the 'additive basal area' phenomenon

2002 ◽  
Vol 27 (3) ◽  
pp. 269-272 ◽  
Author(s):  
J. J. Midgley ◽  
R. Parker ◽  
H. Laurie ◽  
A. Seydack
Keyword(s):  
Basal Area ◽  
Canopy Trees ◽  
Additive Basal Area

scholarly journals DINÂMICA DA VEGETAÇÃO COLONIZADORA EM TRÊS ÁREAS DEGRADADAS PELO GARIMPO NA SERRA DO ESPINHAÇO MERIDIONAL

Nativa ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 231
Author(s):  
Wander Gladson Amaral ◽  
Israel Marinho Pereira ◽  
Danielle Piuzana Mucida ◽  
Evandro Luiz Mendonça Machado ◽  
Michele Aparecida Pereira da Silva
Keyword(s):  
Gold Mining ◽  
Forest Ecosystems ◽  
Human Impacts ◽  
Basal Area ◽  
Floristic Composition ◽  
Plant Succession ◽  
Successional Stage ◽  
Recovery Strategies ◽  
Structural Indicators ◽  
Number Of Individuals

A avaliação do processo de sucessão vegetal em locais degradados constitui uma importante ferramenta para se definirem estratégias de recuperação. Assim, considerando-se o quadro atual de degradação nos ecossistemas florestais, o presente trabalho objetivou estudar a dinâmica da composição florística da vegetação colonizadora, em três áreas degradadas em processo de regeneração natural, na Serra do Espinhaço Meridional. No primeiro inventário, foram amostrados todos os indivíduos arbóreo-arbustivo com DAS30 ≥ 3 cm. No segundo inventário, foram registrados os indivíduos mortos, remensurados os sobreviventes e mensurados e identificados os indivíduos recrutados (DAS30 ≥ 3 cm). Foram calculadas as taxas de dinâmica: mortalidade, recrutamento, ganho e perda em área basal e número de indivíduos para cada área. Os valores de H’ obtidos para as áreas foram comparados aos pares pelo teste de t de Hutcheson. O padrão observado nas três áreas foi semelhante e as alterações mais expressivas durante os dois inventários foram o aumento significativo da densidade e o rápido aumento da área basal total. Todos os indicadores estruturais analisados mostraram que as áreas estão em processo de construção inicial, porém a área degradada pelo garimpo de ouro encontra-se em estágio sucessional mais avançado quando comparada à área degradada pelo processo de voçorocamento e à área degradada pelo garimpo de diamante.Palavras-chave: composição florística; impactos antrópicos; heterogeneidade temporal; sucessão ecológica. COLONIZING VEGETATION DYNAMICS IN THREE AREAS DEGRADED BY MININGIN SOUTHERN SERRA DO ESPINHAÇO ABSTRACT: The evaluation of the process of plant succession in degraded places is an important tool to define recovery strategies. Thus, considering the current situation of degradation in forest ecosystems, the present study aimed to study the dynamics of the floristic composition of the colonizing vegetation, in three degraded areas in the process of natural regeneration, in the Serra do Espinhaço Meridional. In the first inventory, all tree-shrub individuals with DAS30 ≥ 3 cm were sampled. In the second inventory, dead individuals were recorded, survivors were remeasured and recruited individuals were measured and identified (DAS30 ≥ 3 cm). The dynamics rates were calculated: mortality, recruitment, gain and loss in the basal area and number of individuals for each area. The H 'values obtained for the areas were compared in pairs by the Hutcheson t test. The pattern observed in the three areas was similar and the most significant changes during the two inventories were the significant increase in density and the rapid increase in the total basal area. All the structural indicators analyzed showed that the areas are in the process of initial construction, but the area degraded by gold mining is in a more advanced successional stage when compared to the area degraded by the voçorocamento process and the area degraded by diamond mining.Keywords: floristic composition; human impacts; temporal heterogeneity; ecological succession.

scholarly journals Application of the BDq method to complex tropical mixed forest ecosystems in Nigeria

2021 ◽  
Vol 349 ◽  
pp. 41-54
Author(s):  
Friday Nwabueze OGANA ◽  
José Javier GORGOSO-VARELA ◽  
Alfred Ossai ONEFELI
Keyword(s):  
Forest Ecosystems ◽  
Management Practice ◽  
Mixed Forest ◽  
Basal Area ◽  
Selection Method ◽  
Maximum Diameter ◽  
Mixed Stands ◽  
Mixed Forests ◽  
Breast Height ◽  
Silvicultural Treatments

The absence of management practice/silvicultural treatments in the complex tropical mixed forests of Nigeria has led to uncontrolled logging in natural forest stands and loss of biodiversity. To sustain production, protection and conservation in these complex tropical mixed stands, this study proposes the application of a selection method – the BDq method (B: basal area, D: maximum diameter, q-ratio) to manage these stands. Two strata were used as a pilot test: stratum 1 consisted of 15 plots and stratum 2 of 7 plots, each with an area of 0.25 ha. Only trees with a diameter at breast height (d) ≥ 10.0 cm were considered in this study. Harvesting with the BDq method was quantified, by setting B at 20 m2, 25 m2 and 30 m2/ha corresponding respectively to intensive, medium and light harvesting regimes. D was set at 65 cm and the q-ratio was computed for each plot. The results showed that the three BDq regimes prescribed (intensive, medium and light) yielded reasonable felling intensities (FI), derived as the percentage of extracted volume (Vext) and biomass (Wext). The Vext and FI for stratum 1 ranged from 39.94-62.30 m3/ha and 11.22-18.18%; the results for stratum 2 were 30.44-51.33 m3/ha and 10.02-17.57%. For biomass, the Wext and FI ranged from 18.46-29.82 t/ha and 9.40-15.95% for stratum 1 and 14.16-24.82 t/ha and 9.73-17.50% for stratum 2. These findings show that applying the BDq method to the complex tropical mixed forests of Nigeria would yield attractive stands.

scholarly journals Genesis and characteristics of the soil in A-R stage in forest ecosystems of NP 'Tara'

2009 ◽  
pp. 75-89 ◽  
Author(s):  
Milan Knezevic ◽  
Olivera Kosanin
Keyword(s):  
Scots Pine ◽  
Soil Type ◽  
Forest Ecosystems ◽  
Specific Effect ◽  
Basal Area ◽  
Physical Characteristics ◽  
Average Volume ◽  
Humid Climate ◽  
Different Types ◽  
Volume Current

Different types of soil in A-R stage formed on limestone and serpentinite in forest ecosystems in NP 'Tara' were researched. Based on the specific effect of limestone on the soil genesis and evolution, two types of calcareous limestone bedrocks were distinguished: dense limestones, and soft, marly limestones. Three subtypes of black earth were studied on dense limestones. They are: organogenic, organo-mineral and brownised soils. One soil type was researched on soft, marly limestones: rendzina, the leached variety. One soil type was researched on serpentinites, within the A-R stage: humus-siliceous soil (ranker), subtype eutric ranker. This paper also presents the evaluation of ecological and productive characteristics of the study soils. If the soil is observed separately, regardless of the tree species growing on it, the soils in A-R stage in NP 'Tara' cannot be evaluated as highly productive. However, in all plant communities on the soils in A-R stage on limestone, the values of average volume, current volume increment, and basal area were high. The unfavourable physical characteristics of the soil in the area of NP 'Tara' are compensated by the effect of humid climate. On the study eutric humus siliceous soils in the area of NP 'Tara', in the natural and artificially established stands of Scots pine and Austrian pine, the ecological and productive value is conditioned by numerous factors and it is mainly limited by unfavourable physical characteristics. Regardless of the unfavourable ecological and productive characteristics of the soil, the natural and artificially established stands of Scots pine and Austrian pine are in the coeno-ecological optimum.

scholarly journals Stand Composition, Tree-Related Microhabitats and Birds—A Network of Relationships in a Managed Forest

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 103
Author(s):  
Łukasz Piechnik ◽  
Jan Holeksa ◽  
Mateusz Ledwoń ◽  
Przemysław Kurek ◽  
Grażyna Szarek-Łukaszewska ◽  
...  
Keyword(s):  
Species Richness ◽  
Temperate Forest ◽  
Forest Ecosystems ◽  
Biological Diversity ◽  
Bird Species ◽  
Basal Area ◽  
Deciduous Trees ◽  
Managed Forest ◽  
Tree Stand ◽  
Cavity Nesters

Forest ecosystems contain many tree-related microhabitats (TreMs), which are used by various groups of organisms. Birds use TreMs for shelter, foraging and breeding. The abundance and variability of TreMs is related to tree stand composition and age. Over the last few centuries there has been a drastic decline in the structural and biological diversity of temperate forests over large areas of the Northern Hemisphere. These changes have reduced the diversity and quantity of TreMs. In this study we showed the relationships between stand composition, the abundance of TreMs, and the species richness of birds in a managed forest. We focused on TreMs that are important to birds: woodpecker breeding cavities, rot holes, dead branches, broken treetops, and perennial polypores. Our study was performed in a managed lowland temperate forest. In 94 plots (10 ha each) we made bird surveys and inventoried the stand composition and TreMs. Our results show that the tree stand composition of a managed forest affects the abundance of TreMs. The share of deciduous trees in the stand favors the occurrence of such TreMs as dead branches, rot holes and perennial polypores. The overall richness of bird species and the species richness of primary cavity nesters depended on the total basal area of oak, hornbeam and birch, whereas the species richness of secondary cavity nesters increased with the total basal area of birch and oak.

scholarly journals Assessing Biotic and Abiotic Effects on Biodiversity Index Using Machine Learning

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 461
Author(s):  
Mahmoud Bayat ◽  
Harold Burkhart ◽  
Manouchehr Namiranian ◽  
Seyedeh Kosar Hamidi ◽  
Sahar Heidari ◽  
...  
Keyword(s):  
Machine Learning ◽  
Random Forest ◽  
Forest Ecosystems ◽  
Abiotic Factors ◽  
Basal Area ◽  
Tree Diversity ◽  
Additive Models ◽  
Slope Aspect ◽  
Biotic And Abiotic Factors ◽  
The Relationship

Forest ecosystems play multiple important roles in meeting the habitat needs of different organisms and providing a variety of services to humans. Biodiversity is one of the structural features in dynamic and complex forest ecosystems. One of the most challenging issues in assessing forest ecosystems is understanding the relationship between biodiversity and environmental factors. The aim of this study was to investigate the effect of biotic and abiotic factors on tree diversity of Hyrcanian forests in northern Iran. For this purpose, we analyzed tree diversity in 8 forest sites in different locations from east to west of the Caspian Sea. 15,988 trees were measured in 655 circular permanent sample plots (0.1 ha). A combination of machine learning methods was used for modeling and investigating the relationship between tree diversity and biotic and abiotic factors. Machine learning models included generalized additive models (GAMs), support vector machine (SVM), random forest (RF) and K-nearest–neighbor (KNN). To determine the most important factors related to tree diversity we used from variables such as the average diameter at breast height (DBH) in the plot, basal area in largest trees (BAL), basal area (BA), number of trees per hectare, tree species, slope, aspect and elevation. A comparison of RMSEs, relative RMSEs, and the coefficients of determination of the different methods, showed that the random forest (RF) method resulted in the best models among all those tested. Based on the results of the RF method, elevation, BA and BAL were recognized as the most influential factors defining variation of tree diversity.

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