scholarly journals Structure and diversity of trees on post-fire regenerated areas in Sierra de Guerrero, Mexico

2020 ◽  
Vol 98 (2) ◽  
pp. 210-218
Author(s):  
Eduardo Alanís-Rodríguez ◽  
Laura Sánchez-Castillo ◽  
Cuauhtemoc Méndez-Osorio ◽  
Pamela Anabel Canizales Velázquez ◽  
Arturo Mora-Olivo ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Forest Fires ◽  
Forest Ecosystems ◽  
Control Area ◽  
Anthropogenic Influence ◽  
Importance Value Index ◽  
Importance Value ◽  
Data Description ◽  
Tree Communities ◽  
Over Time

Background: It is known that forest ecosystems have the capacity to regenerate over time. However, the anthropogenic influence over them arises the question on how different the original ecological conditions are after regeneration. Question: Do fires and agrochemicals have an influence on tree diversity in the study area? Studied species/ Data description/ Mathematical model: The structure and diversity data obtained from tree communities on four different areas were evaluated. The evaluated areas were a control area (mature forest without management) and three areas with different managements: reforested area, restored area and fumigated area. Study site and years of study: The study area was located in the Sierra de Guerrero, Mexico on areas affected by a fire that occurred in 2005. Seven years after the fire, in 2012, the investigation was performed. Methods: In each selected area a census of all tree species was carried out. The density, dominance, frequency, and importance value index were determined per species. Moreover, the diversity at community level and richness were estimated. Results: The control area showed highest values of density and dominance. The regenerated and reforested area showed highest values of specific richness and diversity. Conclusions: The evaluated areas showed significant differences when comparing diversity and structure indexes. It is recommended to implement reforestation actions in areas affected by forest fires.

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

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.

scholarly journals Does the severity of a forest fire modify the composition, diversity and structure of temperate forests in Jalisco?

2021 ◽  
Vol 28 (1) ◽  
pp. 3-20
Author(s):  
Daniel A. Cadena-Zamudio ◽  
◽  
José G. Flores-Garnica ◽  
Mónica E. Lomelí-Zavala ◽  
Ana G. Flores-Rodríguez ◽  
...  
Keyword(s):  
Forest Fire ◽  
Forest Fires ◽  
Temperate Forest ◽  
Temperate Forests ◽  
Diameter Class ◽  
Importance Value Index ◽  
Importance Value ◽  
Horizontal Structure ◽  
Moderate Severity ◽  
Composition Structure

Introduction: Forest fires are natural disturbances that influence structure, dynamics, performance, composition and diversity of species. Objective: To compare composition, structure and diversity of temperate forest vegetation affected by different levels of severity of a forest fire in Jalisco. Materials and methods: Composition, horizontal structure, importance value index (IVI), diameter class, diversity indexes of Shannon, Simpson, Margalef richness and Bray-Curtis similarity were evaluated in three regions (Bosque La Primavera and Sierra de Tapalpa and Sierra de Quila) of temperate forest with three levels of severity (no fire, moderate and extreme). Results: Twelve species from six families were recorded. Pinaceae and Fagaceae were the most dominant. Dominance ranged from 0.2 to 50 m2∙ha-1 in moderate and extreme severity sites. Pinus devoniana recorded the highest IVI (71 %) in Sierra de Tapalpa. The highest number of trees was recorded in diameter class ≤30 cm. Diversity and richness indices showed significant differences (P < 0.05) for Sierra de Tapalpa and Sierra de Quila and among fire levels; the highest indices were recorded in sites of moderate severity. Tree composition similarity between regions was low (<33 %). Conclusions: Moderate severity of forest fire favored composition, structure and diversity of vegetation in temperate forests of Jalisco, indicating that the level of severity influences resilience of forest ecosystem communities.

scholarly journals Identifikasi Jenis Epifit Dan Tumbuhan Yang Menjadi Penopangnya Di Blok Perlindungan Dalam Kawasan Taman Hutan Raya Wan Abdul Rachman

2014 ◽  
Vol 2 (3) ◽  
pp. 39
Author(s):  
Gesta Rama Noprian Nawawi ◽  
Indriyanto . ◽  
Duryat .
Keyword(s):  
Plant Species ◽  
Forest Ecosystems ◽  
The Other ◽  
Sample Plot ◽  
Importance Value Index ◽  
Importance Value ◽  
Forest Park ◽  
Alstonia Scholaris ◽  
Sampling Intensity ◽  
Area Of Protection

Epiphytic is one among the plants that attaches and grows on other plants for sunlight, water, air, and minerals.  The existence of epiphytes is very important for forest ecosystems due its ability to provide a place for the ants and the other organisme.  The objective of this study were to identify the species of epiphytes, species of cantilever plant, and to know the number of cantilever plant species associated with the species of epiphytes in Wan Abdul Rahman Great Forest Park.  This research was conducted at the protection block, Wan Abdul Rahman Great Forest Park, particularly in the area of Way Balau Sub-watershed.  This research was conducted during September to October 2013.  Epiphytes and cantilever plants species were inventoried in a sampling intensity of 0,2% taken from 796,50 ha of total area of protection blocks, therefore the large of sample plot is 1,593 ha. The size of each sample plot is 400 m2 or 20 m x 20 m, therefore the total number of sample plots are 40 plots.  Observed variables were the species and the number of epiphytes , species of cantilever plant and its number, and the importance alue index for each species.  The result of the study showed that plant are 7 species of epiphytes and 16 species of cantilever plant.  The highest importance value index (IVI) of epiphytes is paku sepat (59,14%).  The highest IVI of cantilever plant is pulai (30,91%).  The most abundant cantilever plant growed by epiphytes is pulai (Alstonia scholaris), pinangsi (Villebrunea rubescens), enau (Arenga pinnata), and medang gabong (Litsea firma).  Result of the study showed that epiphytic mostly found on the cantilever plant that has thicker bark, groove bark, stringy bark, and a tough bark.

scholarly journals EFEITO DAS ATIVIDADES ANTRÓPICAS NA COBERTURA VEGETAL NA RESERVA FLORESTAL DE MECUBÚRI, MOÇAMBIQUE

Nativa ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 588-593
Author(s):  
Aguinaldo Joaquim Mário ◽  
Sailon Augusto Roia Mesa ◽  
Caetano Miguel Lemos Serrote
Keyword(s):  
Forest Cover ◽  
Control Area ◽  
Dispersion Index ◽  
Natural Forests ◽  
Importance Value Index ◽  
Importance Value ◽  
Forest Reserve ◽  
Forest Coverage ◽  
Afzelia Quanzensis ◽  
Millettia Stuhlmannii

O estudo foi realizado na Reserva Florestal de Mecubúri, em Moçambiquee, visando avaliar os efeitos das atividades antrópicas sobre a cobertura florestal. Áreas de queimada, agrícola e de exploração florestal foram comparadas com uma área controle em termos de composição e fitossociologia. Em cada área, foram estabelecidas, de maneira sistemática, parcelas quadrangulares de 20 x 20 m, distantes 20 m uma da outra, sendo realizado o levantamento da vegetação adulta e da regeneração. Foram determinados índices de similaridade, diversidade e riqueza. Os resultados indicaram existir dissimilaridade entre as áreas, sendo que as espécies Julbernardia globiflora, Diplorhynchus condylocarpon, Brachystegia utilis, Millettia stuhlmannii, Afzelia quanzensis, Burkea africana e Cussonia arborea destacaram-se em termos de abundância, frequência, dominância, Índice de Valor de Importância (IVI) e regeneração. O maior número de árvores por hectare foi encontrado na área de controle e o menor número foi encontrado na área agrícola. Com base no índice de dispersão de Morisita, a maior parte das espécies distribui-se de forma aleatória e agrupada. A distribuição diamétrica das árvores seguiu o padrão de J-invertido, característico de florestas naturais.  As práticas de queimadas, agricultura e exploração florestal contribuem na redução da cobertura florestal na Reserva Florestal de Mecubúri. Palavras-chave: fitossociologia; conservação; desmatamento.   The effect of anthropic activities on forest coverage in the Mecubúri Forest Reserve, Mozambique   ABSTRACT: The study was carried out in the Mecubúri Forest Reserve, Mozambique, with the purpose of evaluating the effects of human activities on the forest cover. Burning, agricultural and logging areas were compared with a control area in terms of composition and phytosociology. In each area were systematically established 20 x 20 m quadrangular plots, 20 m apart from each other, in which were carried out the survey of adult vegetation and regeneration. The similarity, diversity and richness indices were determined. The results showed that there is dissimilarity between the areas and the species Julbernardia globiflora, Diplorhynchus condylocarpon, Brachystegia utilis, Millettia stuhlmannii, Afzelia quanzensis, Burkea africana e Cussonia arborea stood out in terms of abundance, frequency, dominance, Importance Value Index (IVI) and regeneration. The largest number of trees per hectare was found in the control area, and the smallest number was found in the agricultural area. Based on the Morisita dispersion index, most species have random and clustered distribution. The diametric structure of the trees followed the inverted-j, typical of natural forests. Burning, agriculture and logging contribute to the reduction of forest cover in the Mecubúri Forest Reserve. Keywords: phytosociology; conservation; deforestation.

Floristic Variation of Tree Communities and Their Association with Soil Properties in Pulau Jerejak, Penang, Peninsular Malaysia

2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Faezah Pardi
Keyword(s):  
Tree Species ◽  
Diversity Index ◽  
Basal Area ◽  
Peninsular Malaysia ◽  
Importance Value ◽  
Conservation Action ◽  
Endangered Tree ◽  
Endangered Tree Species ◽  
Tree Communities ◽  
Floristic Variation

This study was conducted at Pulau Jerejak, Penang to determine the floristic variation of its tree communities. A 0.5-hectare study plot was established and divided into 11 subplots. A total of 587 trees with diameter at breast height (DBH) of 5 cm and above were measured, identified and recorded. The tree communities comprised of 84 species, 63 genera and 32 families. The Myrtaceae was the most speciose family with 10 recorded species while Syzgium glaucum (Myrtaceae) was the most frequent species. The Myrtaceae recorded the highest density of 306 individuals while Syzgium glaucum (Myrtaceae) had the highest species density of 182 individuals. Total tree basal area (BA) was 21.47 m2/ha and family with the highest BA was Myrtaceae with 5.81 m2/ha while at species level, Syzgium glaucum (Myrtaceae) was the species with the highest total BA in the plot with value of 4.95 m2/ha. The Shannon˗Weiner Diversity Index of tree communities showed a value of 3.60 (H'max = 4.43) and Evenness Index of 0.81 which indicates high uniformity of tree species. The Margalef Richness Index (R') revealed that the tree species richness was 13.02. Myrtaceae had the highest Importance Value of 20.4%. The Canonical Correspondence Analysis (CCA) showed that Diospyros buxifolia (Ebenaceae) and Pouteria malaccensis (Sapotaceae) were strongly correlated to low pH. Dysoxylum cauliflorum (Meliaceae) and Eriobotrya bengalensis (Rosaceae) were correlated to phosphorus (P) and calcium ion (Ca2+), respectively. Therefore, the trees species composition at Pulau Jerejak showed that the biodiversity is high and conservation action should be implemented to protect endangered tree species. Keywords: Floristic variation; Tree communities; Trees composition; Pulau Jerejak; Species diversity

Struktur Makroalga Pada Ekosistem Lamun Di Kecamatan Tabukan Selatan, Kabupaten Kepulauan Sangihe, Sulawesi Utara (Structure of Macroalgae in Seagrass Ecosystems at South Tabukan District, Sangihe Islands Regency, North Sulawesi

2019 ◽  
Vol 9 (1) ◽  
pp. 44
Author(s):  
Irawaty Mertosono ◽  
Ratna Siahaan ◽  
Pience Maabuat
Keyword(s):  
Sampling Technique ◽  
Marine Macroalgae ◽  
Line Transect ◽  
Land Conversion ◽  
Importance Value Index ◽  
Importance Value ◽  
North Sulawesi ◽  
Sea Transportation ◽  
Seagrass Ecosystems ◽  
Biodiversity Decline

Struktur Makroalga Pada Ekosistem Lamun Di Kecamatan Tabukan Selatan, Kabupaten Kepulauan Sangihe, Sulawesi Utara(Structure of Macroalgae in Seagrass Ecosystems at South TabukanDistrict, Sangihe Islands Regency, North Sulawesi) Irawaty A. Mertosono1), Ratna Siahaan1*) Pience V. Maabuat1)1)Jurusan Biologi, Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Sam Ratulangi, Manado 95115*Email korespondensi:[email protected] Diterima  15 Februari 2019, diterima untuk dipublikasi 28 Februari  2019 Abstrak Makroalga laut merupakan tumbuhan laut yang tidak memiliki akar, batang, maupun daun sejati. Kegiatan manusia berupa pemanfaatan makroalga, konversi lahan, dan transportasi laut dapat menjadi penyebab penurunan biodiversitas makroalga. Tujuan penelitian ini adalah untuk menganalisis struktur dan distribusi makroalga pada ekosistem lamun di Kecamatan Tabukan Selatan, Kabupaten Kepulauan Sangihe, Sulawesi Utara. Lokasi penelitian di tiga stasiun penelitian yaitu Pantai Karurung - Desa Salurang, Pantai Palareng - Desa Palareng dan Pantai Galoghong – Desa Batuwingkung. Penelitian dilakukan pada November-Desember 2018 dengan pengambilan sampel menggunakan metode garis transek (line transect) dengan teknik pencuplikan kuadrat. Makroalga yang ditemukan sebanyak 36 spesies yang terdiri atas 25 spesies Divisi Chlorophyta, sembilan (9) spesies Divisi Rhodophyta dan dua (2) spesies Divisi Phaeophyta. Makroalga Bornetella nitida memiliki Indeks Nilai Penting 39, 24% mendominasi di lokasi penelitian. Keanekaragaman Shannon-Wiener (H’) spesies makroalga di Stasiun I (H’:3,02) tergolong tinggi sedangkan pada Stasiun II (H’:2,86)  dan Stasiun III (H’:2,63) tergolong sedang. Secara keseluruhan, keanekaragaman spesies makroalga di Kecamatan Tabukan Selatang tergolong tinggi (H’:3,00). Kata kunci:   struktur makroalga, Pantai Karurung, Pantai Palareng, Pantai Galoghong,Tabukan Selatan Abstract Marine macroalgae are marine plant-like organisms that has no true roots, stems, or leaves. The human ativities of macroalgae utilization, land conversion, and sea transportation can cause of macroalgae biodiversity decline. The purpose of this study was to analyze the structure and distribution of macroalgae in seagrass ecosystems at South Tabukan District, Sangihe Islands Regency, North Sulawesi. The research locations were at three research stations, i.e. Karurung Beach - Salurang Village, Palareng Beach - Palareng Village and Galoghong Beach - Batuwingkung Village. The study was conducted in November-December 2018 with line transect method sampling and quadrate sampling technique. Macroalgae were 36 species consists of 25 species of Chlorophyta Division, nine (9) species of Rhodophyta Division and two (2) species of Phaeophyta Division. Macroalga Bornetella nitida had Importance Value Index 39.24% that dominated research locations. The Shannon-Wiener biodiversity Index (H’) of macroalgae species at Station I (H': 3.02) was classified as high while Station II (H': 2.86) and Station III (H ': 2.63) were moderate. Overall, macroalgae species diversity at Tabukan Selatang District was high (H’: 3.00). Keywords: Macroalgae structure, Macroalgae distribution, Karurung Beach, Palareng Beach, Galoghong Beach, South Tabukan

scholarly journals Changes in Woody Vegetation over 31 Years in Farmed Parkland of the Central Plateau, Burkina Faso

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 470
Author(s):  
Koichi Takenaka ◽  
Kenta Ikazaki ◽  
Saïdou Simporé ◽  
François Kaboré ◽  
Natacha Thiombiano ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Eucalyptus Camaldulensis ◽  
Woody Vegetation ◽  
Importance Value Index ◽  
Importance Value ◽  
Central Plateau ◽  
West Region ◽  
Sapling Survival ◽  
Tree Composition ◽  
Insight Into

Farmed parklands of the Central Plateau, Burkina Faso, integrate native woody vegetation with managed cropland. However, sapling survival in the parklands is increasingly threatened. This study characterized woody vegetation abundance along a 2.7 km long transect in the Doulou Basin, Boulkiemdé Province, Central West Region, to assess changes in vegetation composition since 1984. In addition, a householder survey was conducted to gain insight into tree uses and preferences and residents’ knowledge of regulations. In total, 4999 individuals from 26 tree species were recorded, including 123 individuals (11 species) with stem DBH ≥ 5 cm, and 4876 individuals (21 species) with stem DBH < 5 cm. The three species with the highest importance value index provided fruit for sale or self-consumption. Tree abundance was associated with soil type and topography; highest abundance was on Lixisol soils along the lower transect. Soil degradation and preference changes among residents since 1984 may have influenced tree abundance. Certain beneficial species (e.g., Vitellaria paradoxa) have declined in abundance, and certain exotics (Azadirachta indica and Eucalyptus camaldulensis) have expanded in distribution. Respondents expressed strongest interest in three species, including V. paradoxa, that show high versatility. These results supported the recorded tree composition. The respondents generally understood forest conservation regulations. Dissemination of regreening technology and awareness promotion among residents is essential for sustainable tree use in farmed parklands.

Toward a predictive theoretical model for osmolality rise with non-humidified incubation: a randomized, multivariate response-surface study

2021 ◽  
Author(s):  
Steven F Mullen
Keyword(s):  
Mathematical Model ◽  
Response Surface ◽  
Surface Area ◽  
Embryo Culture ◽  
Culture Medium ◽  
Conflicts Of Interest ◽  
Volume Ratio ◽  
P Value ◽  
Cook Medical ◽  
Over Time

Abstract STUDY QUESTION What factors associated with embryo culture techniques contribute to the rate of medium osmolality change over time in an embryo culture incubator without added humidity? SUMMARY ANSWER The surface area-to-volume ratio of culture medium (surface area of the medium exposed to an oil overlay), as well as the density and height of the overlaying oil, all interact in a quantitative way to affect the osmolality rise over time. WHAT IS KNOWN ALREADY Factors such as medium volume, different oil types, and associated properties, individually, can affect osmolality change during non-humidified incubation. STUDY DESIGN, SIZE, DURATION Several experimental designs were used, including simple single-factor completely randomized designs, as well as a multi-factor response surface design. Randomization was performed at one or more levels for each experiment. Osmolality measurements were performed over 7 days, with up to 8 independent osmolality measurements performed per treatment group over that time. For the multi-factor study, 107 independent combinations of factor levels were assessed to develop the mathematical model. PARTICIPANTS/MATERIALS, SETTING, METHODS This study was conducted in a research laboratory setting. Commercially available embryo culture medium and oil was used. A MINC incubator without water for humidification was used for the incubation. Osmolality was measured with a vapor pressure osmometer after calibration. Viscometry and density were conducted using a rheometer, and volumetric flasks with an analytical balance, respectively. Data analyses were conducted with several commercially available software programs. MAIN RESULTS AND THE ROLE OF CHANCE Preliminary experiments showed that the surface area-to-volume ratio of the culture medium, oil density, and oil thickness above the medium all contributed significantly (P &lt; 0.05) to the rise in osmolality. A multi-factor experiment showed that a combination of these variables, in the form of a truncated cubic polynomial, was able to predict the rise in osmolality, with these three variables interacting in the model (P &lt; 0.05). Repeatability, as measured by the response of identical treatments performed independently, was high, with osmolality values being ± 2 of the average in most instances. In the final mathematical model, the terms of the equation were significant predictors of the outcome, with all P-values being significant, and only one P-value &gt; 0.0001. LIMITATIONS, REASONS FOR CAUTION Although the range of values for the variables were selected to encompass values that are expected to be encountered in usual embryo culture conditions, variables outside of the range used may not result in accurate model predictions. Although the use of a single incubator type and medium type is not expected to affect the conclusions, that remains an uncertainty. WIDER IMPLICATIONS OF THE FINDINGS Using this predictive model will help to determine if one should be cautious in using a specific system and will provide guidance on how a system may be modified to provide improved stability during embryo culture. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by Cook Medical. The author is a Team Lead and Senior Scientist at Cook Medical. The author has no other conflicts of interest to declare TRIAL REGISTRATION NUMBER N/A.

Spectral characterization of ciliary beating: variations of frequency with time

1985 ◽  
Vol 249 (1) ◽  
pp. C160-C165 ◽  
Author(s):  
D. Eshel ◽  
Y. Grossman ◽  
Z. Priel
Keyword(s):  
Mathematical Model ◽  
Power Spectra ◽  
Ciliary Beating ◽  
Isolated Lung ◽  
Ciliary Cell ◽  
The Mathematical Model ◽  
Beating Frequency ◽  
Over Time ◽  
Dominant Frequencies

Ciliary beating frequency in tissue culture from frog palate and isolated lung was optically examined using instrumentation that was adjusted to measure a fraction of the surface area of a single ciliary cell. Consecutive 1-s segments of the analogue signal were fast Fourier transformed (FFT) to obtain a power spectrum. At room temperature, these power spectra changed over time from 1 s to the next. Each spectrum contained several dominant frequencies of similar intensities. Cooling the preparation resulted in a single-peak spectrum that was constant over time. A mathematical model is proposed to simulate these findings. The results and the mathematical model support the hypothesis that ciliary beating frequency fluctuates over short periods of time.

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