scholarly journals Distribution pattern and population structure of Calanus australis Brodsky, 1959 over the southern Patagonian Shelf off Argentina in summer

2000 ◽  
Vol 57 (6) ◽  
pp. 1856-1866 ◽  
Author(s):  
M Sabatini
Keyword(s):  
Population Structure ◽  
Distribution Pattern ◽  
Patagonian Shelf

scholarly journals POPULATION STRUCTURE AND SPATIAL DISTRIBUTION OF Bauhinia cheilantha (Bong.) Steud. IN TWO FRAGMENTS AT DIFFERENT REGENERATION STAGES IN THE CAATINGA, IN SERGIPE, BRAZIL

2015 ◽  
Vol 39 (3) ◽  
pp. 431-437 ◽  
Author(s):  
Ana Cecília da Cruz Silva ◽  
Diogo Gallo de Oliveira
Keyword(s):  
Population Structure ◽  
Spatial Distribution ◽  
Distribution Pattern ◽  
Spatial Distribution Pattern ◽  
Breast Height ◽  
Diameter Structure ◽  
Student’S T ◽  
Two Populations ◽  
Vegetation Regeneration ◽  
Student’S T Test

ABSTRACTThis study aimed to analyze the vertical and diameter structure and the spatial distribution pattern of Bauhinia cheilantha in two Caatinga fragments in Sergipe, Brazil, at different regeneration stages. Thirty plots were demarcated in area I (Canindé de São Francisco and Poço Redondo), which has vegetation regeneration, and 25 plots in area II (Porto da Folha) with preserved vegetation, both having 400 m2. All B. cheilanthaindividuals had their height and circumference (circumference at breast height > 6 cm) measured. Possible differences in height and diameter at breast height were tested in the two populations by using Student’s T-test. The distribution pattern of species was calculated through Payandeh’s index. We sampled 154 B. cheilantha individuals, equivalent to 33.3% of the plots in area I and in 1,027 individuals in area II, totaling 100% frequency. Height and the diameter of the two populations were statistically different, where AI achieved all values lower than AII. The spatial distribution pattern of B. cheilantha found in both areas was aggregate, with values of 11.85 and 9.00, respectively. Thus, it became clear that the population in AII is at a more advanced successional status than AI, due to its longer conservation time.

scholarly journals Distribution patterns and population structure of salagundi (Rhodoleia teysmanii) From North Tapanuli-North Sumatra

2021 ◽  
Vol 912 (1) ◽  
pp. 012078
Author(s):  
K S Hartini ◽  
A Susilowati ◽  
M Rizky
Keyword(s):  
Population Structure ◽  
Distribution Pattern ◽  
Distribution Patterns ◽  
Tree Level ◽  
Vegetation Analysis ◽  
Analysis Techniques ◽  
Home Construction ◽  
Excessive Consumption ◽  
Index Value ◽  
North Sumatra

Abstract North Sumatra known as bigger island with abundant of tropical tree species. Some of those were lesser known species. One of lesser-known and potential species from North Sumatera is Salagundi (Rhodoleia teysmanii). Despite being widely utilized by locals peoples, information on Salagundi’s population and other characteristics is very limited. The community in the surrounding area frequently uses wood for a variety of functions, such home construction. Excessive consumption potentially threatent the species’ existence in the habitat. Therefore, this study aims to determine the distribution pattern and population structure of Salagundi in Simorangkir Julu Village, Siatas Barita District, North Tapanuli Regency, North Sumatra Province. For those purpose, vegetation analysis techniques using a combination of plotted lines and lines were adopted. Result of this research showed that, distribution pattern of Salagundi at the seedling to tree level was clumped with the Morisita (Ip) index value of 0.51 -0.53. The population structure curve was the J-shaped reversed. This shows that the condition of the population is sustainable.

scholarly journals Population structure of Annona coriacea Mart. (Annonaceae) in different Cerrado phytophysiognomies

2020 ◽  
Vol 11 ◽  
pp. e3330
Author(s):  
Patrícia Oliveira da Silva ◽  
Jessica Barros Cabral Valente ◽  
Patricia Lacerda Silva ◽  
Carolina Ferreira Gomes ◽  
Gisele Cristina de Oliveira Menino
Keyword(s):  
Population Structure ◽  
Distribution Pattern ◽  
Basal Area ◽  
Sensu Stricto ◽  
T Test ◽  
Savanna Woodland ◽  
Establishment Success ◽  
Adult Age ◽  
Cerrado Biome ◽  
Absolute Density

Knowing the regeneration and structure of a species in different phytophysiognomies is extremely important to understand its pattern of occurrence. In spite of its importance, this type of study is still scarce in the Cerrado biome. In this perspective, this work aimed to compare the structure of the arboreal and regenerating strata of Annona coriacea in the cerrado sensu stricto and in the cerradão (savanna woodland). For that purpose, 13 plots of 400m² were installed in each physiognomy. All individuals of A. coriacea were sampled and had their diameter and height measured. The individuals were divided into regenerating and arboreal and were distributed in classes of height and diameter. Furthermore, the absolute density and the basal area of each extract were calculated in each physiognomy. The parameters were compared using the T-test. In total, 130 individuals of A. Coriacea were sampled, with 42 regenerating individuals in the cerrado sensu stricto and 49 in the cerradão. As for the arboreal individuals, 33 were sampled in the cerrado sensu stricto and 6 in the cerradão. All evaluated parameters revealed to be significantly different for the physiognomies. Based on these results, it is possible to affirm that A. coriacea did not present a distribution pattern in the two physiognomies, although it presents a better establishment success in the cerrado sensu stricto. In the cerradão, although the seeds can germinate, the seedlings fail to develop and reach the adult age.

scholarly journals Population structure and density of Attalea phalerata Mart. ex Spreng. (Arecaceae) in a semideciduous forest

2012 ◽  
Vol 36 (4) ◽  
pp. 637-645 ◽  
Author(s):  
Aelton Biasi Giroldo ◽  
André R. Terra Nascimento ◽  
Pedro Paulo Ferreira Silva ◽  
Gastão Viegas Pinho Júnior
Keyword(s):  
Population Structure ◽  
Distribution Pattern ◽  
Ecosystem Functioning ◽  
Natural Regeneration ◽  
Basal Area ◽  
Population Characteristics ◽  
Stable Population ◽  
Canopy Openness ◽  
Semideciduous Forest ◽  
Ontogenetic Stages

The structure of a population can be seen as the result of biotic and abiotic interacting forces. The studies of population characteristics are vital to improve the understanding of ecosystem functioning. In this study, we attempted to answer the two following questions: What are the population structure of Attalea phalerata? and Are there any influence of reproducers presence, canopy openness, declivity, basal area and soil coverage on recruitment of individuals in this population? We distinguished four ontogenetic stages in A. phalerata. Reproducers and virgins were sampled by using 25 plots (400 m²), juveniles and seedlings were sampled in sub-plots (100 m²). We found 2,328 Attalea phalerata individuals per hectare, first two ontogenetic stages accounted for 89.8% of the total, describing a relatively stable population. None of the analyzed factors were affecting the natural regeneration of Attalea phalerata in the fragment. The density and distribution pattern found for the population are probably signs of formation of oligarchic forests, moreover, the species seems to be able to colonize clearings and open areas.

scholarly journals Cattle influence on the population structure of yerba mate (Ilex paraguariensis) in Araucaria Forest

2019 ◽  
Vol 49 (11) ◽  
Author(s):  
Lilian Iara Bet Stedille ◽  
Edicléa Zulian Pires ◽  
Juliano Pereira Gomes ◽  
Newton Clóvis Freitas da Costa ◽  
Alison Paulo Bernardi ◽  
...  
Keyword(s):  
Population Structure ◽  
Spatial Distribution ◽  
Data Collection ◽  
Distribution Pattern ◽  
Spatial Distribution Pattern ◽  
Diameter Distribution ◽  
Ilex Paraguariensis ◽  
Random Pattern ◽  
Yerba Mate ◽  
Araucaria Forest

ABSTRACT: This study characterized the demography and spatial pattern of a yerba mate (Ilex paraguariensis A.St.-Hil) population covering areas with different use histories (Presence and Absence of Cattle) in a Araucaria Forest. Data collection was performed in three ha, half in each area. The frequency of individuals by height, spatial distribution pattern, diameter distribution (for reproductive individuals) and sexual ratio were evaluated. An inverted “J” pattern predominated, being exclusive to an area with Cattle Presence, a place which presented a lower density of individuals. The predominant spatial distribution pattern was aggregated, and the reproductive individuals have a preferentially random pattern at the shortest distances. Results indicated that cattle presence changes the density of I. paraguariensis individuals and the proportion of individuals in the evaluated demographic classes.

scholarly journals Population structure, distribution pattern and microhabitat characteristics of Aglaonema simplex in Pasatan Protected Forest, Jembrana, Bali, Indonesia

2017 ◽  
Vol 18 (4) ◽  
pp. 1663-1668
Author(s):  
DEWI LESTARI ◽  
NI PUTU SRI ASIH
Keyword(s):  
Population Structure ◽  
Distribution Pattern ◽  
Conservation Policy ◽  
Air Humidity ◽  
Low Light ◽  
Soil Humidity ◽  
Population Pattern ◽  
Pattern Distribution ◽  
Over Time ◽  
Morisita's Index

Lestari D, Asih NPS. 2017. Population structure, distribution pattern and microhabitat characteristics of Aglaonema simplex in Pasatan Protected Forest, Jembrana, Bali, Indonesia. Biodiversitas 18: 1663-1668. Aglaonema simplex Blume is one species of Aglaonema that is distributed in Bali, Indonesia. This species can be found in the forests of Jembrana, Karangasem, Tabanan, Buleleng and Bangli. There is no recent data for A. simplex’s population and microhabitat in Bali, while this data is needed to develop future conservation policy. By tracking populations over time, ecologists can see how these populations have changed and may be able to predict how they are likely to change in the future. Monitoring the size and structure of populations can also help ecologists to manage populations. This study was aimed to determine the current condition of A. simplex in the Pasatan forest and to find out the population structure, distribution, and its microhabitat characteristics. The study was conducted along two tracks at Pasatan Forest, Bali on June 9- 11, 2015. Data were collected using the purposive quadrant plot method and analyzed descriptively, tabulated in tables and graphs. The population pattern distribution was as defined by standardized Morisita's index and microhabitat differences in both tracks were determined by the Mann-Whitney test in SPSS 16. The total number of A. simplex was 114 individuals. Thirty-seven percent of plants were juveniles, while 36% were mature plants without fruit and 27% were mature plants with fruit. The population structure along the first track was dominated by a mature population of plants without fruit, while fruiting mature plants dominated the structure of the population along the second track. The distribution of the population along the first track was clustered, while distribution along the second track was uniform. A. simplex was found at an altitude of 367- 448 m asl., oil pH of 6.7-6.8, soil humidity of 73%-84%, air temperature 27°-28° C, air humidity at 80%-86%, with low light intensity of 170-225 lux.

scholarly journals Population structure of giant clams (tridacnidae) in Aceh Besar district waters

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
M Rizki Fazillah ◽  
Chitra Octavina ◽  
Muhammad Agustiar ◽  
Muhammad Akhyar
Keyword(s):  
Population Structure ◽  
Coral Reef ◽  
Distribution Pattern ◽  
Diversity Index ◽  
Similarity Index ◽  
Giant Clam ◽  
Giant Clams ◽  
Coral Reef Area ◽  
The Individual ◽  
Index Value

Giant clams have an essential ecological role in the coral reef ecosystem. Given the decreasing number of giant clams in nature, the status of giant clams as protected animals, and there is still little information about giant clams, data or information is needed to make policies regarding giant clam conservation management. This study aimed to determine the population structure of giant clams (Tridacnidae) in the coral reef area of Aceh Besar District. The research was conducted in May 2018, located in Aceh Besar Regency waters with six observation stations. Observation of giant clams is carried out using a visual census technique with the belt transect method. The observations showed that the giant clams found in Aceh Besar waters consisted of 2 species, namely Tridacna maxima and Tridacna crocea. Overall stations, the individual density of giant clams is 0.041 ind. m-2. The diversity index of giant clams shows a value ranging from 0–0.97, classified in the low diversity category. The similarity index value of giant clams is classified into the stressed to stable similarity category with values ranging from 0–0.97. The dominance index value of giant clams is classified in the medium to high dominance category with values ranging from 0.52 to 1. The distribution pattern of the two giant clam species found in the waters of Aceh Besar District has a uniform distribution pattern with values ranging from 0.20–0.29. The overall population structure of Tridacnidae is in unstable condition.

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