The marginal cost of structural diversity of mixed uneven-aged hard maple forests

2002 ◽  
Vol 32 (4) ◽  
pp. 616-628 ◽  
Author(s):  
Shashi Kant
Keyword(s):  
Growth Model ◽  
Acer Saccharum ◽  
Marginal Cost ◽  
Structural Diversity ◽  
Shannon Index ◽  
Forest Stand ◽  
Simpson Index ◽  
Southern Ontario ◽  
Theoretical Concepts ◽  
Size Diversity

Theoretical concepts pertaining to the marginal cost (MC) of the structural diversity of a forest stand are developed. A matrix growth model is estimated for mixed uneven-aged forest stands of hard maple (Acer saccharum Marsh.) from southern Ontario. The estimated growth model is used to derive the MC equations for the Shannon and the Simpson indices of total structural diversity (TSD), species diversity (SD), and tree-size diversity (TD). The effects of exclusion and inclusion of the opportunity cost (OC) on the MC of the TSD are compared. The contributions of SD and TD to the MC of the TSD are disaggregated. The MCs of TSD, SD, and TD for the Shannon and the Simpson indices are iso-elastic. The elasticity of the MC of the TSD for the inclusion of OC is greater than the elasticity of MC of the TSD for the exclusion of OC. The elasticities of MC of TSD, SD, and TD for the Shannon index are greater than the elasticities of MC of TSD, SD, and TD, respectively, for the Simpson index. The elasticities of MC of SD are smaller than the elasticities of MC of TD, for both indices. However, these results are specific to the hard maple forests of southern Ontario and cannot be generalized. Some general features of MC equations of structural diversity are discussed.

scholarly journals Structural diversity and regeneration patterns of the Norway spruce (Picea abies (L.) Karst) dominated virgin forest in NNR Zadná Poľana

Beskydy ◽  
2013 ◽  
Vol 6 (2) ◽  
pp. 127-134 ◽  
Author(s):  
M. Saniga ◽  
Miroslav Balanda ◽  
J. Pittner ◽  
S. Kucbel ◽  
P. Jaloviar
Keyword(s):  
Gini Index ◽  
Nature Reserve ◽  
Structural Diversity ◽  
Height Growth ◽  
Forest Stand ◽  
Virgin Forest ◽  
Old Growth Forest ◽  
Tree Generation ◽  
Evans Index ◽  
Structural Indices

The paper analyzes the structural diversity of the spruce dominated old-growth forest in National Nature Reserve (NNR) Zadná Poľana on the series of three permanent research plots (PRP) with the area of 0.5 ha each. The height and diameter diversity as well as the spatial distribution were expressed using standard structural indices (Füldner’s TH and TD index, Gini index, Clark-Evans index). Obtained results confirmed the low structural diversity regardless of the developmental stage of investigated forest. The extensive ungulate browsing retards the height growth of the subsequent tree generation and leads toward to the structural homogenization of the future forest stand.

scholarly journals How Size Matters: Designing Diverse Fragment Libraries for Novel Drug Discovery

Proceedings ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 107
Author(s):  
Yun Shi ◽  
Mark von Itzstein
Keyword(s):  
Drug Discovery ◽  
Chemical Space ◽  
Structural Diversity ◽  
Optimal Size ◽  
Zinc Database ◽  
Fragment Library ◽  
Size Diversity ◽  
Efficient Exploration ◽  
Novel Drug ◽  
Fragment Libraries

Fragment-based drug discovery (FBDD) has become a major strategy to derive novel lead candidates for both new and established therapeutic targets, as it promises efficient exploration of chemical space by employing fragment-sized (MW 300) compounds. One of the first challenges in implementing a FBDD approach is the design of a fragment library, and more specifically, the choice of its size and individual members. In order to construct a library that maximises the chances of discovering novel chemical matter, a large number of fragments with sufficient structural diversity are often sought. However, the exact diversity of a certain collection of fragments remains elusive, which hinders direct comparisons among different selections of fragments. Building upon structural fingerprints that are commonly utilised in cheminformatics, we herein introduced quantitative measures for the structural diversity of fragment libraries. Structures of commercially available fragments were retrieved from the ZINC database and filtered by physicochemical properties, after which they were subject to selections with library sizes ranging from 100 to 100,000 compounds. The selected libraries were evaluated and compared quantitatively, resulting in interesting size-diversity relationships. Our results suggested the existence of an optimal size for structural diversity and demonstrated that such quantitative measures can guide the design of diverse fragment libraries under various circumstances

scholarly journals PHYTOSOCIOLOGY AND STRUCTURAL CHARACTERIZATION OF WOODY REGENERATION FROM A REFORESTATION WITH NATIVE SPECIES IN SOUTHEASTERN BRAZIL

2016 ◽  
Vol 40 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Michel Anderson Almeida Colmanetti ◽  
Luiz Mauro Barbosa ◽  
Regina Tomoko Shirasuna ◽  
Hilton Thadeu Zarate do Couto
Keyword(s):  
Native Species ◽  
Sao Paulo ◽  
Shannon Index ◽  
Southeastern Brazil ◽  
São Paulo ◽  
Simpson Index ◽  
Paulo State ◽  
São Paulo State ◽  
High Diversity

ABSTRACT In Brazil, specifically in São Paulo State, there are guidelines based on the high diversity of tropical forests that instructs the restoration projects in the state (current SMA 32/2014). The main goal of this study was verify the importance and effectiveness of the high diversity of arboreal species originated from a reforestation, and its influence in a woody regenerating composition. We developed a phytosociologic study in a woody regenerating stratum of a nine year old reforestation at a Private Reserve of Natural Heritage (RPPN), in Mogi-Guaçu, São Paulo State. All specimens with height > 30 cm and Diameter at Breast Height (DBH) < 5 cm were evaluated. The woody regenerating diversity was smaller than the overstory diversity and the species composition was similar to the overstory. The Simpson index (1-D) was 0.85, Shannon index (H') was 2.46 and the Pielou index (J') was 0.60. The zoochoric dispersion syndrome was major among the species. Our results suggest that the use of high diversity of native seedlings in a reforestation leads to high diversity of species in woody regeneration stratum, after one decade of planting.

scholarly journals Gut Microbiota Play an Essential Role in the Antidiabetic Effects of Rhein

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ruifeng Wang ◽  
Pu Zang ◽  
Junxiu Chen ◽  
Fei Wu ◽  
Zhouqin Zheng ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Essential Role ◽  
Fasting Blood Glucose ◽  
Shannon Index ◽  
Simpson Index ◽  
Significant Difference ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Host Metabolism ◽  
Antidiabetic Effects

It is clear that the gut microbiota can affect host metabolism and alterations of the gut microbiota can link with metabolic disease. Rhein has been used in traditional Chinese medicine with putative antidiabetic effects. Here we show that oral administration of rhein for 6 weeks can significantly reduce fasting blood glucose (FBG) level (8.30 ± 4.52 mmol/l versus 18.89 ± 6.06 mmol/l, p < 0.01), elevate the active glucagon-like peptide 1 (GLP-1) level (22.21 ± 2.61 pmol/l verss 14.46 ± 5.22 pmol/l, p < 0.05), and increase the number of L-cells in the terminal ileum. The antidiabetic effect of rhein is abrogated in db/db mice treated with rhein in combination with broad-spectrum antibiotics. We observed that the abundance of the Bacteroidetes is increased in mice treated with rhein (0.361±0.022 versus 0.185 ± 0.055, p < 0.05,). In addition, there is no significant difference in diversity between rhein-treated groups and the controls (Shannon index: p = 0.88; Simpson index: p = 0.86). Taken together, our results indicate that modulation of the gut microbiota may play an essential role in the antidiabetic effects of rhein.

scholarly journals On the way to continuous cover forest at middle elevations – the question of forest structure and specific site characteristics

2013 ◽  
Vol 59 (No. 10) ◽  
pp. 391-397 ◽  
Author(s):  
L. Bílek ◽  
J. Remeš ◽  
O. Švec ◽  
D. Zahradník
Keyword(s):  
Species Diversity ◽  
Gini Index ◽  
Structural Diversity ◽  
Transformation Process ◽  
Special Focus ◽  
Simpson Index ◽  
Forest Stands ◽  
Site Characteristics ◽  
Evenness Index ◽  
Diameter Differentiation

The transformation process of even-aged forest stands to irregular forest stands on waterlogged sites after 20 years effort was analysed. Data from two 1-ha PRP was analysed with special focus on structural (Shannon Evenness Index, Simpson Index and Gini Index) and species (Shannon Evenness Index and Simpson Index) diversity. Different development on study plots confirmed that the highest structural diversity is not often compatible with the concept of species diversity. On PRP 1 high diameter differentiation has led to lower values of species diversity, while on PRP 2 rather moderate diameter differentiation supported higher species diversity in lower DBH classes. The Gini Index was confirmed to be the best indicator for monitoring the diameter differentiation in the course of stand transformation.

scholarly journals Results of monitoring of the population of Blumeria graminis f.sp. hordei in Latvia in 2009-2010

2012 ◽  
Vol 66 (1-2) ◽  
pp. 41-47
Author(s):  
Inese Kokina ◽  
Isaak Rashal
Keyword(s):  
Blumeria Graminis ◽  
Shannon Index ◽  
Simpson Index ◽  
Pathogen Population ◽  
Random Samples ◽  
Barley Powdery Mildew ◽  
North Eastern ◽  
Pathogen Populations ◽  
North Western ◽  
High Diversity

Results of monitoring of the population ofBlumeria graminisf.sp.hordeiin Latvia in 2009-2010In 2009-2010, random samples of the causal agent of barley powdery mildew were collected in Daugavpils (south-eastern Latvia, Latgale region), Stende (north-western Latvia, Kurzeme region) and Priekuļi (north-eastern Latvia, Vidzeme region). Virulence frequency, complexity and pathotypes were calculated in the pathogen populations. Significant differences of virulence detected by the genesVa1, Va3and Va13occurred among samples of the pathogen population collected in different parts of Latvia. Nei index, Müller's index, Kosman index, Shannon index and Simpson index showed considerably higher diversity in Daugavpils and Stende during 2009-2010. In Daugavpils, the population ofBlumeria graminisf.sp.hordei was particularly characterised by high diversity.

Notes on the Biology of the Pitted Ambrosia Beetle, Corthylus punctatissimus (Coleoptera: Scolytidae), in Ontario and Quebec

1967 ◽  
Vol 99 (1) ◽  
pp. 49-54 ◽  
Author(s):  
R. J. Finnegan
Keyword(s):  
Life History ◽  
Host Plant ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
Ambrosia Beetle ◽  
Southern Ontario

AbstractThe pitted ambrosia beetle, Corthylus punctatissimus (Zimm.), was studied during widespread infestations in sugar maple (Acer saccharum Marsh.) stands of southern Ontario and Quebec. A brief description of each stage of the insect is given, and its life history and habits, as well as the damage caused to the host plant are discussed.

Holocene history of forest trees in southern Ontario

1987 ◽  
Vol 65 (9) ◽  
pp. 1792-1801 ◽  
Author(s):  
K. D. Bennett
Keyword(s):  
Acer Saccharum ◽  
Pinus Banksiana ◽  
Late Holocene ◽  
Accumulation Rate ◽  
Pinus Strobus ◽  
Fagus Grandifolia ◽  
Forest Trees ◽  
Southern Ontario ◽  
History Of ◽  
Available Information

Three new Holocene pollen percentage and accumulation rate diagrams for southern Ontario are presented. They greatly increase the available information on the history of the area's forest trees and permit a discussion of the competitive interactions that have brought about the forest pattern seen today. In the earliest Holocene, the forests were dominated by Picea, which was replaced by first Pinus banksiana–resinosa and then Pinus strobus. In extreme southern Ontario, Pinus strobus was replaced by Acer saccharum and Fagus grandifolia, but in the area east of Georgian Bay, Tsuga canadensis became the dominant, and near Mattawa, Betula (probably lutea). Late Holocene stability of forests is considered to be a function of the lack of taxa better able to compete than those already present.

scholarly journals FITOSSOCIOLOGIA EM COMUNIDADES ARBÓREAS REMANESCENTES DE CERRADO SENSU STRICTO NO BRASIL CENTRAL

FLORESTA ◽  
2015 ◽  
Vol 45 (4) ◽  
pp. 769 ◽  
Author(s):  
Zenesio Finger ◽  
Felipe Augusto Finger
Keyword(s):  
Sensu Stricto ◽  
Shannon Index ◽  
Simpson Index ◽  
Total Height ◽  
Central Brazil ◽  
Caryocar Brasiliense ◽  
Curatella Americana

Este estudo teve como objetivo caracterizar o estrato arbóreo das comunidades de cerrado sensu stricto mediante avaliações da riqueza, estrutura e diversidade. Os dados da vegetação foram obtidos empregando-se o método de parcelas múltiplas, com tamanho de 20 x 20 m (400 m2). Em cada uma das 82 unidades amostrais foram obtidas a altura total e as circunferências de todas as plantas arbóreas com perímetro a 0,30 m do nível do solo (PAB) maior ou igual a 15,7 cm (DAB ³ 5,0 cm). A partir da parcela 60 (24.000 m2 da área amostrada) a curva estabilizou-se com a ocorrência de 106 espécies, distribuídas entre 81 gêneros e 36 famílias, indicando que a amostragem foi suficiente para caracterizar e avaliar as vegetações de cerrado sensu stricto estudadas. As espécies com maior VI foram: Qualea parviflora, Curatella americana, Davilla elliptica, Qualea grandiflora, Pterodon emarginatus, Lafoensia pacari, Diptychandra aurantiaca, Myrcia albo-tomentosa, Caryocar brasiliense, Byrsonima pachyphylla, Byrsonima coccolobifolia, Hymenaea stigonocarpa, Callisthene fasciculata, Luehea paniculata, Magonia pubescens, Terminalia argentea, Erythroxylum deciduum, Couepia grandiflora e Pouteria ramiflora. A diversidade da vegetação arbórea encontrada na área estudada foi de 4,033 nats/ind. pelo índice de Shannon e de 0,975 pelo de Simpson, indicando alta diversidade florística. AbstractPhytosociology of the arboreal communities remainders of sensu stricto cerrado in Central Brazil. This study has a objective to characterize the cerrado sensu stricto communities' arboreal stratum by evaluations of the richness, structures and diversity. Data of vegetation were obtained by the method of multiple plots, with size of 20 x 20 m (400 m2). In each one of the 82 patternless units were obtained the total height and the circumferences of all the arboreal plants with perimeter to 0.30 m from the level of the soil (PAB) larger or equal to 15.7 cm (DAB 5.0 cm). From the plot 60 (24.000 m2 out of the area used as sample) the curve is stabilized with the occurrence of 106 species, distributed between 81 genera and 36 families, indicating that the sampling was enough to characterize and to evaluate the vegetations of cerrado sensu stricto studied. The species with larger VI were: Qualea parviflora, Curatella americana, Davilla elliptica, Qualea grandiflora, Pterodon emarginatus, Lafoensia pacari, Diptychandra aurantiaca, Myrcia albo-tomentosa, Caryocar brasiliense, Byrsonima pachyphylla, Byrsonima coccolobifolia, Hymenaea stigonocarpa, Callisthene fasciculata, Luehea paniculata, Magonia pubescens, Terminalia argentea, Erythroxylum deciduum, Couepia grandiflora and Pouteria ramiflora. The diversity from the arboreal vegetation found in the area being studied was of 4.033 nats/ind. considering the Shannon Index and of 0.975 considering the Simpson Index, representing a great floristic diversity.Keywords: Phytosociological structures; richness; diversity.

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