COBERTURA Y ESTRUCTURA DE LOS BOSQUES DE MANGLE EN LA BAJA GUAJIRA, CARIBE COLOMBIANO

cover and structural attributes of mangrove forests in the Baja Guajira were estimated and identified. Forest cover was estimated from ASTER images and aerial photographs. The forest structure was evaluated along transects which were 10 m broad and as long as the width of the mangrove fringe. In each transect mangrove trees were identified and counted. The total height and the diameter at breast height (DBH) of the trees were measured and subsequently the basal area, density and Importance Value Index (IVI) calculated. The estimated mangrove cover of the Baja Guajira was 59.9 ha. The most frequent and dominant species was Laguncularia racemosa (0.54 m2.ha-1). Rhizophora mangle was present in 75 % of the stations, while Avicennia germinans was only found in the north of the study area. The highest average heights and diameters for R. mangle, L. racemosa and A. germinans were determined in Rincón Mosquito (12.9±2.3 m and 22.4±11.2 cm), Puerto Brisa (12.2±5.3 m and 20.8±9.8 cm) and La Enea (13.8± 4.3 m and 23.8±14.8 cm), sectors with a constant fresh water supply. The less developed forest, a monospecific forest of Conocarpus erectus, was observed in Dibulla station, with height and diameter averages of 2.8±0.6 m and 3.0±0.9 cm. In terms of natural regeneration, L. racemosa presented the highest proportion of seedlings in the study area, R. mangle was found in stations partly flooded and A. germinans had the highest density of seedlings and propagules at La Enea station.

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Fitossociologia de manguezais em zonas urbanas: um estudo de caso em Aracaju, Sergipe

Revista Brasileira de Geografia Física ◽

10.26848/rbgf.v13.5.p2103-2113 ◽

2020 ◽

Vol 13 (5) ◽

pp. 2103

Author(s):

Jose Paulo Santana ◽

Eduardo Vinícius Da Silva Oliveira ◽

Túlio Vinícius Paes Dantas ◽

Myrna Friederichs Landim ◽

Patrício Adriano da Rocha

Keyword(s):

Urban Areas ◽

Rhizophora Mangle ◽

Floristic Composition ◽

Laguncularia Racemosa ◽

Mangrove Forests ◽

Importance Value Index ◽

Importance Value ◽

Conocarpus Erectus ◽

Avicennia Schaueriana

O objetivo deste estudo foi comparar a composição florística e a estrutura fitossociológica dos bosques de manguezais de áreas urbanas em Aracaju, estado de Sergipe, com diferentes tempos de regeneração e intensidades de impacto antrópico. Para o levantamento fitossociológico, foi adotado o método de parcelas múltiplas, sendo seis ou sete parcelas distribuídas equitativamente em dois transectos paralelos em quatro bosques de manguezais nos bairros 13 de julho, Porto Dantas, São Conrado e Mosqueiro. Destes, somente o bosque do Mosqueiro não apresentava tensores antrópicos contínuos como descarga de esgotos domésticos, retirada de madeira ou contribuição alóctone de sedimento. Para caracterizar a estrutura dos manguezais foram calculados os parâmetros densidade, frequência, dominância e o índice de valor de importância de cada espécie. Procedeu-se com a comparação estatística entre os bosques avaliados pelo teste de Kruskal-Wallis quanto a densidade geral e por espécie, diâmetro e altura geral dos indivíduos. Foram identificadas quatro espécies: Laguncularia racemosa, Avicennia schaueriana, Rhizophora mangle e Conocarpus erectus, que apresentaram diferenças de abundância e dominância entre os bosques analisados. De maneira geral, L. racemosa foi à espécie mais abundante e dominante nos bosques mais impactados, porém no bosque do Mosqueiro, R. mangle foi a mais dominante. Não houve diferenças significativas na densidade, diâmetro e altura geral dos indivíduos, porém a densidade de A. schaueriana e R. mangle diferiu entre os bosques. Em relação à altura, os bosques da 13 de julho e São Conrado apresentaram os maiores valores, ainda que possuíssem o menor tempo de regeneração pós-distúrbios.Phytosociology of mangroves in urban areas: a case study in Aracaju city, Sergipe stateA B S T R A C TThe aim of this paper was to compare the floristic composition and the phytosociological structure of the mangrove forests in urban areas with different levels of regeneration and intensities of anthropic impact. The study was performed in the municipality of Aracaju, Sergipe state, Brazil Northeast. For the phytosociological survey, the multiple plots method was adopted; so six or seven plots were equally distributed in two parallel transects in four mangrove forests in the neighborhoods 13 de Julho, Porto Dantas, São Conrado and Mosqueiro. Of these, only the Mosqueiro mangrove did not have continuous anthropic tensors such as discharge of domestic sewage, removal of wood or allochthonous contribution of sediment. To characterize the structure of the mangroves, the parameters density, frequency, dominance and the importance value index for each species were calculated. Statistical comparison was made among the mangroves evaluated using the Kruskal-Wallis test between general density and by species, diameter and general height of individuals. Four species were identified: Laguncularia racemosa, Avicennia schaueriana, Rhizophora mangle and Conocarpus erectus, which showed differences in abundance and dominance between the mangroves evaluated. In general, L. racemosa was the most abundant and dominant species in the most impacted mangrove, but in the Mosqueiro mangrove, R. mangle was more dominant. There were no significant differences in the density, diameter and general height of the individuals; however the density of A. schaueriana and R. mangle differed between mangroves. In relation to height, the forests of 13 de Julho and São Conrado presented the highest values, even though they had the shortest time of regeneration after disturbances.Keywords: ecotone, mangrove, forest structure, coastal zone, Brazil northeast.

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Community Composition and Distribution Pattern of Herbaceous Flora in Holi Area of District Chamba in Himachal Pradesh

International Journal of Economic Plants ◽

10.23910/2/2020.0354 ◽

2020 ◽

Vol 7 (1) ◽

pp. 013-020

Author(s):

Kehar Singh Thakur ◽

◽

Munesh Kumar ◽

Rajan Bawa ◽

Anita Kumari ◽

...

Keyword(s):

Distribution Pattern ◽

Dominant Species ◽

Basal Area ◽

Quantitative Information ◽

Himachal Pradesh ◽

Importance Value Index ◽

Importance Value ◽

North West ◽

The North ◽

The Mean

The present study was carried out in Holi Forest Range of district Chamba, which is the north-west district of Himachal Pradesh and is located between latitude 32o17’412’’ to 32o26’541’’N and longitude 76o31’504’’ to 76o35’385’’E. The territory is completely mountainous with altitude varying from about 2,000 feet (610 m) to about 21,000 feet (6,400 m) above the mean sea level. The quantitative information of herbs was collected from different sites i.e., Deol, Kut, Dal, Lahaud Dhar. Frequency (%), Density (plants m-2), Basal Area (cm2), Importance Value Index (IVI) and A/F ratio of plant species at different sites were recorded. Poa alpina was found to have highest frequency (90%) closely followed by Jurinea dolomiaea (80%) and Biebersteinia odora has the lowest frequency of 10%. Poa alpina has the highest density (60.6 plants m-2) at Dal followed by Gentiana kurrooa (35.8 plants m-2). Moschela esculenta was found to have highest basal area (1.234 cm2) at Kut. Viola serpens was the dominant species with highest value of IVI (78.77) closely followed by Poa alpina (65.91), Gentiana kurrooa (65.37) and Jurinea dolomiaea (65.36). Most of the species were distributed randomly followed by contagious pattern of distribution and least species were reported for regular distribution pattern.

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Fuel beds variation of coastal tropical freshwater forested wetlands in three disturbance regimes at La Encrucijada, Biosphere Reserve, Mexico

10.21203/rs.3.rs-42037/v1 ◽

2020 ◽

Author(s):

Romeo de Jesús Barrios Calderón ◽

Dulce Infante Mata ◽

José Germán Flores Garnica ◽

Jony Ramiro Torres Velázquez ◽

Zulia Mayari Sánchez-Mejía ◽

...

Keyword(s):

Forest Fires ◽

Biosphere Reserve ◽

Basal Area ◽

Forested Wetlands ◽

Material Surface ◽

Importance Value Index ◽

Importance Value ◽

High Accumulation ◽

Horizontal Structure ◽

Tropical Freshwater

Abstract Background: Tropical freshwater forested wetlands in coastal regions are rapidly disappearing, one of the causes is forest fires. This is caused by high accumulation of fuel beds that can vary in origin and type. Therefore, the objective of this study was to characterize the fuel beds in tropical freshwater forested wetlands with three different level of disturbance at El Castaño, La Encrucijada Biosphere Reserve.Methods: Seventeen sampling units were used to described the strates of forest fuel beds (canopy, sub-canopy and understory) in both the vertical and horizontal stratum. Quantity and quality of dead (fallen woody material, surface litterfall and fermented litterfall) fuels were characterized using the planars intersections technique.Results: A total of eight tree species, two shrubs, five lianas and two herbaceous species were found in tropical freshwater forested wetlands. The vertical structure concentrates the highest proportion of trees between 2 and 12 m high, including the first two defined height classes. The horizontal structure denotes a higher percentage of trees with a normal diameter between 2.5 to 7.5 cm (61.4%) of the total. The sites none disturbance presented the highest arboreal density (2,686 ind. ha− 1), however the highest basal area was found in the sites with medium disturbance (39.41 m2 ha− 1). The richness and diversity of species shows that the Fisher, Margalef, Shannon and Simpson α indices were higher in the sites undisturbed, while the Berger-Parker index shows greater dominance in the sites high disturbance. Pachira aquatica Aubl. was the species with the highest importance value index, and contributes the most to the fuel beds. The average accumulation of dead fuel beds was higher in sites with high disturbance (222.18 ± 33.62 t ha− 1), with the largest accumulations of woody fuels occurring in the 1 h, 10 h and 1000 h classes, the latter in a state of fermentation.Conclusions: It’s important to consider the probability of occurrence of surface fires is high. In these tropical freshwater forested wetlands, independent of disturbance, underground fires have the same probability and the intensity will depend on the depth of the organic matter layer. This study contributes define fire-prone areas in these ecosystems. The results are of great importance to design fire prevention strategies.

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Comparison of true mangrove stands in Dudepo and Ponelo Islands, North Gorontalo District, Indonesia

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d200142 ◽

2018 ◽

Vol 20 (1) ◽

pp. 259-266

Author(s):

FAIZAL KASIM ◽

MIFTAHUL KHAIR KADIM ◽

SITTI NURSINAR ◽

ZULKIFLI KARIM ◽

ALDIN LAMALANGO

Keyword(s):

Similarity Index ◽

Basal Area ◽

Current Status ◽

Survey Method ◽

Landsat 8 ◽

Importance Value Index ◽

Importance Value ◽

Mangrove Species ◽

Rhizophora Apiculata ◽

The Mean

Kasim F, Kadim MK, Nursinar S, Karim Z, Lamalango A. 2019. Comparison of true mangrove stands in Dudepo and Ponelo Islands, North Gorontalo District, Indonesia. Biodiversitas 20: 259-266. This study aimed to investigate and compare the current status of mangrove areas, as well as the composition and species diversity of mangrove stands in both regions of Dudepo and Ponelo Islands. The results showed that the mangrove areas calculated using the segmentation method in classifying image of Landsat-8 OLI (acquisition on September 2017) were 279.46 ha (Dudepo Island) and 113.35 ha (Ponelo Island) respectively. A total of 13 species of true mangrove were recorded from both islands, using survey method from 9 transect lines (TL), with a distance ranging from 40 to 210 meters (1-6 quadrats) per transect. The mean densities of trees were 2133 ± 329.78 ha-1 (Dudepo Island) and 2111 ± 234.28 ha-1 (Ponelo Island), while those of saplings and seedlings were 58 ± 13.48 ha-1 and 1425 ± 113.96 ha-1 (Dudepo Island), and 79 ± 14.51 ha-1 and 2963 ± 443.22 ha-1 (Ponelo Island). The mean diameter and basal area were 19.73 ± 10.65 cm and 84.22 ± 67.67 m2ha-1 (Dudepo Island), 17.04 ± 1.46 cm and 60.07 ± 15.12 m2ha-1 (Ponelo Island), respectively. The Importance Value Index (IVI) ranged between 3.97-114.87 (Dudepo Island) and 6.04-82.18 (Ponelo Island). The dominant and codominant species based on IVI in both islands were Rhizophora apiculata Blume and R. stylosa Griff. The indexes of diversity, richness, and evenness of mangrove species in both islands were 0.34-1.70, 0.48-1.18, 0.47-0.94 (trees), 0.00-1.10, 0.00-1.82, 0.00-1.00 (saplings), and 0.00.-1.48, 0.00-1.44, 0.72-1.00 (seedlings), respectively. The Bray-Curtis similarity index between Dudepo and Ponelo Islands, based on the overall values of community attributes, was 0.75.

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Geographic and environmental contributions to genomic divergence in mangrove forests

10.1101/2020.01.08.889717 ◽

2020 ◽

Cited By ~ 1

Author(s):

Michele Fernandes da Silva ◽

Mariana Vargas Cruz ◽

João de Deus Vidal Júnior ◽

Maria Imaculada Zucchi ◽

Gustavo Maruyama Mori ◽

...

Keyword(s):

Genetic Variation ◽

Avicennia Germinans ◽

Global Changes ◽

Mangrove Forests ◽

Tidal Variation ◽

Mangrove Species ◽

Coastal Species ◽

Precipitation Regimes ◽

Isolation By Environment ◽

Mangrove Trees

ABSTRACTAssessing the relative importance of geographic and environmental factors to the spatial distribution of genetic variation may provide relevant information about the processes that maintain genetic variation in natural populations. With a globally wide but very restricted habitat distribution, mangrove trees are an interesting model for studies aiming to understand the contributions of these factors. Mangroves occur along the continent-ocean interface of tropical and subtropical latitudes, regions considered inhospitable to many other plant types. Here, we used landscape genomics approaches to investigate the relative contributions of geographic and environmental variables to the genetic variation of two black mangrove species, Avicennia schaueriana and Avicennia germinans, along the South American coast. Using single nucleotide polymorphisms, our results revealed an important role of ocean currents in the gene flow of A. schaueriana and isolation by environment as the pattern that best explains the genetic differentiation of A. germinans. Additionally, for both species, we observed significant correlations between genetic variation with evidence of selection and precipitation regimes, tidal variation, solar radiation and temperature patterns. These discoveries expand our knowledge about the evolution of mangrove trees and provide important information to predict future responses of coastal species to the expected global changes for this century.

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Population status of the tree Sacoglottis holdridgei (Humiriaceae) at Isla del Coco National Park, Costa Rica

Revista de Biología Tropical ◽

10.15517/rbt.v64i1.23455 ◽

2016 ◽

Vol 64 (1) ◽

pp. 263

Author(s):

Luis Guillermo Acosta-Vargas

Keyword(s):

National Park ◽

Basal Area ◽

Forest Monitoring ◽

Diameter Distribution ◽

Population Status ◽

Importance Value Index ◽

Importance Value ◽

Data Points ◽

Using Data ◽

Annual Mortality

Isla del Coco is the only oceanic island in the Eastern Pacific with humid tropical climate. Its forests have a particular structure with a unique array of plant species and high endemism. There are few studies on the flora or forest monitoring on the island. The population structure of Sacoglottis holdridgei was analyzed using data from six years with data points taken in 2006 and 2012, including sampling of regeneration in 2012. Sacoglottis holdridgei was the most important tree species, presenting in 2012 the highest Importance Value Index (190.7±21.8), abundance (158.5±40.3 Nha-1 or 39.5 % of the forest) and basal area (15.6 m2ha-1 or 72.9 % of the forest). It was present in all three height strata with dominance in the highest. Annual mortality was reported at 3.3 % and recruitment at 1.2 %. The diameter distribution of forest fits the inverted J model, but not for the reported species of which only S. holdridgei tends to adjust for DBH>40 cm. Regeneration fitted the inverted J model with values below those reported for continental forests. Even though it was the dominant species, S. holdridgei showed low regeneration values. This particular condition, give way hypotheses related to the introduction of species, species biology and climate change which could influence the future development of S. holdridgei and forests of Isla del Coco.<div> </div>

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Structure and floristic composition of a tropical evergreen forest in south-west India

Journal of Tropical Ecology ◽

10.1017/s026646740000941x ◽

1996 ◽

Vol 12 (2) ◽

pp. 191-214 ◽

Cited By ~ 65

Author(s):

Jean-Pierre Pascal ◽

Raphael Pelissier

Keyword(s):

Western Ghats ◽

Basal Area ◽

Floristic Composition ◽

Evergreen Forest ◽

Systematic Sampling ◽

Importance Value Index ◽

Importance Value ◽

Tropical Evergreen Forest ◽

Western Ghats Of India ◽

The Western Ghats

ABSTRACTA permanent plot of 28 ha was established in a dense wet evergreen forest in the Western Ghats of India to study the functioning of the ecosystem. Since April 1990, 1981 trees of ≥30 cm gbh have been enumerated in a systematic sampling of five strips totalling 3.12 ha. This paper describes the main structural and floristic characteristics of the plot.The density (635 trees ≥30 cm gbh per hectare) and basal area (39.7 m2 ha−1) are high. Despite the high diversity (Simpson's D = 0.92 and Shannon's H' = 4.56), four species are distinctly, dominant in terms of an importance value index (relative density + relative basal area). Each of these four species occupies a different layer in the ecosystem: Humboldtia brunonis Wall. (Fabaceae) dominates the undergrowth, Myristica dactyloïdes Gaertn. (Myristicaceae) the intermediate strata, Valeria indica L. (Dipterocarpaceae) the higher canopy level and Dipterocarpus indicus Bedd. (Dipterocarpaceae) the emergents. This pronounced species hierarchy is one of the most important characteristics of the evergreen forests of the Western Ghats. The two dipterocarps account for 20.1% of the total number of trees and contribute 40.9% to the total basal area. This formation can, therefore, be considered as the westernmost lowland dipterocarp forest of Asia.Analysis of the spatial variations in the floristic composition and in the structure of the main species populations shows that two kinds of mature phases can be identified: where the topography is raised and gently sloping, the vertical structure of the stand is discontinuous, with Dipterocarpus indicus and Vateria indica forming an emergent layer above a dense undergrowth; on slopes, the stand is lower, vertically continuous and saturated with Valeria indica and Myristica dactyloïdes. The link between the structure of the stand and dynamic processes is discussed.

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Komposisi Jenis, Struktur Komunitas, dan Keanekaragaman Mangrove Asosiasi Langge Kabupaten Gorontalo Utara-Provinsi Gorontalo

Jurnal Ilmu Lingkungan ◽

10.14710/jil.17.1.181-188 ◽

2019 ◽

Vol 17 (1) ◽

pp. 181

Author(s):

Sukirman Rahim ◽

Dewi Wahyuni K Baderan

Keyword(s):

Community Structure ◽

Species Diversity ◽

Relative Density ◽

Relative Frequency ◽

Diversity Index ◽

Mangrove Forests ◽

Chromolaena Odorata ◽

Importance Value Index ◽

Importance Value ◽

Nypa Fruticans

Hutan mangrove Langge yang terdapat di Kecamatan Anggrek Kabupaten Gorontalo Utara memiliki keunikan dari pola zonasi dan keanekaragaman jenis. Hal ini yang menjadikan hutan mangrove di kawasan tersebut sebagai objek wisata tracking mangrove yang dikenal dengan nama “mangrove in love. Hutan mangrove memiliki berbagai fungsi ekologis yang sangat kompleks yakni sebagai daerah pemijahan (spawing ground), tempat asuhan (nursery ground), dan tempat mencari makan (feeding ground) biota laut yang beraneka jenis dan memiliki fungsi ekonomis diantaranya buah mangrove dapat diolah menjadi berbagai produk kue dan sumber pangan alternatif pengganti beras. Penelitian ini bertujuan untuk : 1) untuk mengetahui komposisi jenis mangrove asosiasi; 2) untuk mengetahui struktur komunitas dari hutan mangrove Langge; dan 3) nilai Indeks Keanekaragaman. Adapun metode yang digunakan dalam penelitian ini adalah metode jalur berpetak (kombinasi plot dan transek). Jumlah spesies yang ditemukan akan dilihat untuk menjadi dasar penentuan komposisi jenis. Untuk pengkuran struktur komunitas mangrove dengan melakukan perhitungan terhadap Kerapatan Relatif (KR) dan Frekuensi Relatif (FR). Selanjutnya data yang didapatkan ditabulasikan untuk memperoleh nilai Indeks Nilai Penting (INP). Perhitungan keanekaragaman jenis menggunakan rumus (Sannon-wienner). Hasil penelitian menemukan 12 spesies tumbuhan mangrove asosiasi yakni Acanthus spinosus, Chromolaena odorata, Crassocephalum sp, Calotropis gigantean, Ipomea pes-caprae, Ricinus communis Excoecaria agallocha, Scaevola taccada, Spinifex littoreus, Terminalia catappa, Derris trifoliate dan Nypa fruticans. Struktur komunitas menunjukkan Chromolaena odorata memiliki nilai INP sebesar 33,2%, Kerapatan Relatif sebesar 24,91%, dan Frekuensi Relatif sebesar 8,33%. Spesies dengan nilai INP terendah dimiliki oleh Nypa fruticans yaitu sebesar 9,14%, Kerapatan Relatif sebesar 0,81%, dan Frekuensi Relatif sebesar 8,33%. Nilai Indeks Keanekaragaman (H’) mangrove asosiasi sebesar 2,175 dan termasuk dalam kriteria tingkat keanekaragaman sedang. Data yang diperoleh ini dapat digunakan dalam pengelolaan hutan mangrove di Gorontalo Utara serta dapat menjadi database dalam usaha konservasi mangrove guna mengurangi efek pemanasan global.Langge mangrove forest located in the District of North Gorontalo District Orchid has a uniqueness of zoning patterns and keanekragaman types. This is what makes the mangrove forests in the region as a tourist attraction tracking mangrove known as the "mangrove in love. Mangrove forests have a variety of ecological functions is very complex which is a spawning area (spawing ground), point of care (nursery grounds), and foraging (feeding ground) various types of marine life and has the economic function of which pieces of mangrove can be processed into various products cake and alternative food sources instead of rice. This study aims to: 1) to determine the association of mangrove species composition; 2) to determine the community structure of mangrove forests Langge; and 3) the value of diversity index. The method used in this study is a terraced path method (combination of plots and transects). The composition of the types of views based on the number of species found. For sizing mangrove community structure by calculating the Relative Density (KR) and Relative Frequency (FR). Then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of twelve species of mangrove plants and the relative dominance (DR), then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of eight species of mangrove plants and the relative dominance (DR), then the data obtained are tabulated to get the value of Importance Value Index (IVI). Calculation of species diversity using the formula (Sannon-wienner). The study found an association of twelve species of mangrove plantsnamely Acanthus spinosus, Chromolaena odorata, Crassocephalum sp, Calotropis gigantean, Ipomea pes-caprae, Ricinus communis Excoecaria agallocha, Scaevola taccada, Spinifex littoreus, Terminalia catappa, Derris trifoliate dan Nypa fruticans. Community structure showed Chromolaena odorata has a value of IVI of 33,2%, amounting to 24,91% Relative Density and Relative Frequency of 8,33%. The species with the lowest IVI owned by Nypa fruticans that is equal to 9,14%, 0,81% Relative Density and Relative Frequency of 8,33%. Values Diversity Index (H ') at 2.175 and mangrove associates included in the criteria for a medium level of diversity. The data obtained can be used in the management of mangrove forests in North Gorontalo and can be a database of mangrove conservation efforts to reduce the effects of global warming.

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How Timber Harvest Affects the Structure and Diversity of a Montane Forest in Southern Mexico

Forests ◽

10.3390/f12070895 ◽

2021 ◽

Vol 12 (7) ◽

pp. 895

Author(s):

Nayely Martínez-Meléndez ◽

Neptalí Ramírez-Marcial ◽

Pablo Martínez-Zurimendi ◽

Manuel J. Cach-Pérez ◽

José G. García-Franco

Keyword(s):

Species Richness ◽

Dominant Species ◽

Basal Area ◽

Timber Harvest ◽

Montane Forest ◽

Control Treatment ◽

Importance Value Index ◽

Importance Value ◽

Southern Mexico ◽

Timber Extraction

Timber extraction directly affects forest structure by opening the canopy, reducing the density and volume of dominant species, and transforming the composition, diversity, and functioning of the forest. We analyze the richness, diversity, and basal area of tree species in a pine–oak montane forest under two stages of the Silvicultural Development Method (thinning and liberation cut treatments) in comparison with remnants of forest considered to be control treatment in the Ocotones forest. Timber extraction began 14 years previously but its effect on the tree structure has not been studied to date in this area. We quantified and measured all the trees with a diameter at breast height >5 cm in 12 0.1 ha circular plots in each treatment. Diversity (Hill numbers) and the importance value index were calculated in each treatment. Observed species richness did not differ between treatments; Pinus oocarpa Schiede ex Schltdl. and Quercus sapotifolia Liebm. were the dominant species regardless of treatment. The principal differences in density and basal area among the treatments were found between the small oaks and small pines. In general, tree density recovered in managed areas because of newly recruited pines and re-sprouting oaks. Although no significant reduction in species richness was detected between treatments, species composition and vegetation structure were modified by the extraction of pine timber and the permanence of many large oaks. Silvicultural treatments appear to create conditions favorable to the maintenance of species richness. The silvicultural interventions in the site meet the objectives of timber production, regeneration, and biodiversity conservation; however, the question of how long the forest can maintain its species diversity and structure after timber extraction remains to be addressed.

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Structure, composition and tree diversity in a temperate forest under management

Journal of Enviromental Sciences and Natural Resources ◽

10.35429/jesn.2019.15.5.29.35 ◽

2019 ◽

pp. 29-35

Author(s):

Antonio Mora-Santacruz ◽

María Leonor Román-Miranda ◽

Omar Nungaray-Villalobos ◽

Gerardo Alberto González-Cueva

Keyword(s):

Temperate Forest ◽

Cloud Forest ◽

Basal Area ◽

Diversity Indices ◽

Shannon Index ◽

Importance Value Index ◽

Importance Value ◽

A Value ◽

Normal Diameter ◽

Area And Volume

In order to study both diversity indices and structure of forests, which are an essential tool for decision-making in forest management, which show natural successional processes and effects for its management. So the objetive of this study was to evaluate structure and diversity of arboral species in a temperate forest of southern Jalisco state. Five permanent forestry research sites 50 x 50 (2.500 m2) were established, and a census of all tree species was carried out, with normal diameter greater than 7.5 cm. Each individual was measured: height and normal diameter, placing an aluminum plate for identification. We obtained the importance value index (IVI), indices of diversity, richness, and dasometric parameters. There were 17 species, 9 genera and 9 botanical families; the Fagaceae was dominant. Pinus douglasiana presented the highest IVI (57.93%); The Shannon index had a value of 2.0; the index of Margalef was 2.4; the forest has a density of 688 trees ha-1, being the most abundant Styrax ramirezii; Pinus herrerae obtained the highest values in basal area and volume with 30.77 m2 ha-1 and 357,325 m3 ha-1 respectively. The values of diversity are influenced by elements of the cloud forest

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