Temporal changes in species composition in permanent plots across the Shawnee National Forest, Illinois, USA1

2009 ◽  
Vol 136 (4) ◽  
pp. 487-499 ◽  
Author(s):  
Shibi Chandy ◽  
Yohanes A. K. Honu ◽  
David J. Gibson
Keyword(s):  
Species Composition ◽  
Temporal Changes ◽  
Permanent Plots ◽  
National Forest ◽  
Shawnee National Forest

Hardwood Density and Species Composition in Bottomland Areas Treated for Regeneration

1980 ◽  
Vol 4 (3) ◽  
pp. 122-127
Author(s):  
George A. Hurst ◽  
Thomas R. Bourland
Keyword(s):  
Species Composition ◽  
Abundant Species ◽  
National Forest ◽  
Green Ash ◽  
Commercial Species ◽  
Sapling Density

Abstract Seedling and sapling density of high- and low-commercial species varied from 994 to 2,792/acre on regenerated areas, age three to eight years, on the Delta National Forest, Mississippi. The highest densities were in the oldest regenerated stands, on low flat sites and on areas that had been hand-injected. Most seedlings and saplings were not suppressed by vines and the number growing in the open increased with age. The most abundant species were green ash, water hickory, overcup oak, sugarberry, Nuttall oak, and persimmon. The highest densities of subcommercial species were on sheared areas.

scholarly journals Floristic composition and similarity of 15 hectares in Central Amazon, Brazil

2018 ◽  
pp. 1927-1938
Author(s):  
Kátia Emidio da Silva ◽  
Sebastião Venancio Martins ◽  
Carlos Antonio Alvares Soares Ribeiro ◽  
Nerilson Terra Santos ◽  
Celso Paulo De Azevedo ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Rare Species ◽  
Diversity Index ◽  
Mantel Test ◽  
Permanent Plots ◽  
Terra Firme ◽  
Floristic Similarity ◽  
Forest Diversity ◽  
Number Of Individuals

The Amazon region is one of the most diverse areas in the world. Research on high tropical forest diversity brings up relevant contributions to understand the mechanisms that result and support such diversity. In the present study we describe the species composition and diversity of 15 one-ha plots in the Amazonian terra firme dense forest in Brazil, and compare the floristic similarity of these plots with other nine one-ha plots. The 15 plots studied were randomly selected from permanent plots at the Embrapa Experimental site, Amazonas State in 2005. The diversity was analysed by using species richness and Shannon’s index, and by applying the Sorensen’s index for similarity and unweighted pair-group average (UPGMA) as clustering method. Mantel test was performed to study whether the differences in species composition between sites could be explained by the geographic distance between them. Overall, we identified 8 771 individuals, 264 species and 51 plant families. Most of the species were concentrated in few families and few had large number of individuals. Families presenting the highest species richness were Fabaceae (Faboideae: 22spp., Mimosoideae: 22spp.), Sapotaceae: 22spp., Lecythidaceae: 15 and Lauraceae: 13. Burseraceae had the largest number of individuals with 11.8% of the total. The ten most abundant species were: Protium hebetatum (1 037 individuals), Eschweilera coriacea (471), Licania oblongifolia (310), Pouteria minima (293), Ocotea cernua (258), Scleronema micranthum (197), Eschweilera collina (176), Licania apelata (172), Naucleopsis caloneura (170) and Psidium araca (152), which represented 36.5% of all individuals. Approximately 49% of species had up to ten individuals and 13% appeared only once in all sampled plots, showing a large occurrence of rare species. Our study area is on a forest presenting a high tree species diversity with Shannon’s diversity index of 4.49. The dendrogram showed two groups of plots with low similarity between them (less than 0.25), and the closer the plots were one to another, more similar in species composition (Mantel R=0.3627, p<0.01). The 15 plots in our study area share more than 50% of their species composition and represent the group of plots that have the shortest distance between each other. Overall, our results highlight the high local and regional heterogeneity of environments in terra firme forests, and the high occurrence of rare species, which should be considered in management and conservation programs in the Amazon rainforest, in order to maintain its structure on the long run.

scholarly journals Remote-sensing support for the Estonian National Forest Inventory, facilitating the construction of maps for forest height, standing-wood volume, and tree species composition

2020 ◽  
Vol 73 (1) ◽  
pp. 77-97
Author(s):  
Mait Lang ◽  
Allan Sims ◽  
Kalev Pärna ◽  
Raul Kangro ◽  
Märt Möls ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Species Composition ◽  
Tree Species ◽  
Forest Inventory ◽  
Point Clouds ◽  
National Forest Inventory ◽  
National Forest ◽  
Tree Species Composition ◽  
Wood Volume ◽  
Forest Height

Abstract Since 1999, Estonia has conducted the National Forest Inventory (NFI) on the basis of sample plots. This paper presents a new module, incorporating remote-sensing feature variables from airborne laser scanning (ALS) and from multispectral satellite images, for the construction of maps of forest height, standing-wood volume, and tree species composition for the entire country. The models for sparse ALS point clouds yield coefficients of determination of 89.5–94.8% for stand height and 84.2–91.7% for wood volume. For the tree species prediction, the models yield Cohen's kappa values (taking 95% confidence intervals) of 0.69–0.72 upon comparing model results against a previous map, and values of 0.51–0.54 upon comparing model results against NFI sample plots. This paper additionally examines the influence of foliage phenology on the predictions and discusses options for further enhancement of the system.

scholarly journals REPRESENTATIVIDADE E PRECISÃO NA ESTIMATIVA DA DENSIDADE E ÁREA BASAL NA FLORESTA NACIONAL DO TAPAJÓS

Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 312
Author(s):  
Tatiana Da Cunha Castro ◽  
Ademir Roberto Ruschel ◽  
João Olegário Pereira de Carvalho ◽  
Edson Marcos Leal Soares Ramos ◽  
Jaqueline Macedo Gomes
Keyword(s):  
Random Process ◽  
Sampling Error ◽  
Basal Area ◽  
Permanent Plots ◽  
National Forest ◽  
Sampling Efficiency ◽  
Error Limit ◽  
Tree Diameter ◽  
Actual Error ◽  
High Level

O objetivo do estudo foi avaliar a eficiência de parcelas na estimativa da densidade e área basal de uma floresta manejada na Amazônia. A densidade e área basal foram calculadas utilizando dados de um censo florestal realizado em 144 ha e dos dados de medição realizada em 48 parcelas permanentes de 0,25 ha cada (amostra de 12 ha), instaladas nos 144 ha segundo um processo aleatório simples. Para testar a eficiência amostral na estimativa dessas variáveis foram calculados o erro real relativo, o erro de amostragem e a intensidade amostral para diferentes níveis de inclusão de diâmetro mínimo das árvores no inventário. O erro real foi calculado para seis níveis de inclusão de DAP, considerando árvores com diâmetro a partir de 25 cm, o erro de amostragem foi calculado para 10 níveis de inclusão de DAP, considerando árvores com diâmetro a partir de 5 cm; e o cálculo da intensidade amostral foi realizado para populações finitas. O limite de erro amostral admissível foi de 10%. A amostragem utilizada na área foi suficiente para gerar resultados com alto nível de precisão, podendo ser aplicada em florestas densas com densidade e área basal semelhantes às da floresta estudada.Palavras-chave: censo florestal, unidades amostrais, erro amostral, eficiência amostral. REPRESENTATIVENESS AND PRECISION IN THE ESTIMATION OF DENSITY AND BASAL AREA IN THE TAPAJÓS NATIONAL FOREST ABSTRACT:The objective of the study was to evaluate the efficiency of plots in the estimation of the density and basal area of a managed area in Amazon. The density and basal area were calculated from data of a forest census carried out in 144 ha and data from a measurement carried out in 48 permanent plots of 0.25 ha each (12 ha sample), installed in the same144 ha according to a simple random process. In order to test the sampling efficiency in the estimation of these variables, we calculated the actual relative error, the sampling error and the sample intensity for different inclusion levels of minimum tree diameter in the inventory. The actual error was calculated for six inclusion levels, considering trees with diameter from 25 cm, the sampling error was calculated for 10 inclusion levels, considering trees with diameter from 5 cm, and the calculation of the sampling intensity was performed for finite populations. The admissible sampling error limit was 10%. The sampling used in the area was sufficient to generate results with a high level of precision, being able to be applied in dense forests with density and basal area similar to those of the studied forest.Keywords: forest census, sampling units, sampling error, sample efficiency.

scholarly journals Bryophyte Conservation in Managed Boreal Landscapes: Fourteen-Year Impacts of Partial Cuts on Epixylic Bryophytes

2021 ◽  
Vol 4 ◽  
Author(s):  
Jeffrey Opoku-Nyame ◽  
Alain Leduc ◽  
Nicole J. Fenton
Keyword(s):  
Species Composition ◽  
Coarse Woody Debris ◽  
Black Spruce ◽  
Woody Debris ◽  
Permanent Plots ◽  
Old Growth ◽  
Clear Cut ◽  
Old Growth Forest ◽  
Old Growth Forests ◽  
Over Time

Clear cut harvest simplifies and eliminates old growth forest structure, negatively impacting biodiversity. Partial cut harvest has been hypothesized (1) to have less impact on biodiversity than clear cut harvest, and (2) to encourage old growth forest structures. Long-term studies are required to test this hypothesis as most studies are conducted soon after harvest. Using epixylic bryophytes as indicators, this study addresses this knowledge gap. Fourteen years after harvest, we examined changes in epixylic bryophyte community composition richness and traits, and their microhabitats (coarse woody debris characteristics and microclimate) along an unharvested, partial cuts and clear cuts harvest treatment in 30 permanent plots established in the boreal black spruce (Picea mariana) forests of northwestern Quebec, Canada. Our results were compared to those of an initial post-harvest study (year 5) and to a chronosequence of old growth forests to examine species changes over time and the similarity of bryophyte communities in partial cut and old growth forests. Coarse woody debris (CWD) volume by decay class varied among harvest treatments with partial cuts and clear cuts recording lower volumes of early decay CWD. The epixylic community was richer in partial cuts than in mature unharvested forests and clear cuts. In addition, species richness and overall abundance doubled in partial and clear cuts between years 5 and 14. Species composition also differed among treatments between years 5 and 14. Furthermore, conditions in partial cut stands supported small, drought sensitive, and old growth confined species that are threatened by conditions in clear cut stands. Lastly, over time, species composition in partial cuts became more similar to old growth forests. Partial cuts reduced harvest impacts by continuing to provide favorable microhabitat conditions that support epixylic bryophytes. Also, partial cut harvest has the potential to encourage old growth species assemblages, which has been a major concern for biodiversity conservation in managed forest landscapes. Our findings support the promotion of partial cut harvest as an effective strategy to achieve species and habitat conservation goals.

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