SPATIAL DISTRIBUTION OF A POPULATION OF Pentaclethra macroloba (Willd.) KUNTZE IN A FLOODPLAIN FOREST OF THE AMAZON ESTUARY1

ABSTRACT We analyzed the spatial distribution pattern of Pentaclethra macroloba to assist in the development of management plans and conservation of this species in estuarine floodplain forests. The study was conducted in an area of floodplain forest of 55.94 ha, in Mazagão, Amapá, Brazil. A census was performed and all individuals of ≥ 30 cm circumference at breast height (CBH), living and dead, were georeferenced. Ripley’s K function was used to analyze the spatial distribution of the population, including mortality and diameter classes. The relationships between distance to the edge of inundation and density and basal area of the population were analyzed using linear regression. We recorded 993 live individuals and 22 dead. The distribution of the population was found to vary with the topographic gradient associated with the distance to the edge of the inundation. Diameter classes 1 (≤ 13.2 cm) and 2 (≤ 18.6 cm) were spatially aggregated close to the water and randomly distributed far from the water. Classes 3 (≤ 24.0 cm) and 4 (≤ 29.5 cm) were aggregated at all distances, and classes 5 (≤ 34.9 cm), 6 (≤ 40.3 cm), 7 (≤ 45.7 cm) and 8 (≤ 51.2 cm), were randomly distributed at all distances. Mortality was randomly distributed. The population density was 18 trees h-1 with a basal area of 49 m2 h-1, and both density (r2=0.51; p=0.0195) and basal area (r2=0.67; p=0.0039) increased with the distance from the edge of the inundation. We conclude that the spatial distribution and successful establishment of this species in floodplain forest are related to the dynamics of flooding and the resultant impacts on dispersal processes.

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SPATIAL DISTRIBUTION AND STRUCTURAL VARIATION OF Copaifera arenicola IN A CAATINGA FRAGMENT

FLORESTA ◽

10.5380/rf.v50i3.65583 ◽

2020 ◽

Vol 50 (3) ◽

pp. 1660

Author(s):

Dráuzio Correia Gama ◽

Robério Anastácio Ferreira ◽

Janisson Batista de Jesus ◽

José Monteiro do Nascimento Júnior

Keyword(s):

Spatial Distribution ◽

Tree Species ◽

Structural Variation ◽

Basal Area ◽

Stable Population ◽

Distribution Analysis ◽

Expansion Phase ◽

Breast Height ◽

Absolute Density ◽

Univariate Function

The study of spatial distribution of tree populations has proven to be important for revealing how individuals are horizontally organized in the environment, facilitating the structural understanding and forms of colonization and dispersion of propagules. The present work aimed at studying the pattern of spatial distribution of tree species Copaiferaarenicola [(Ducke) J. Costa e L.P.Queiroz] and its structural relation with the altimetric profile in a Caatinga fragment in Ribeira do Pombal municipality, Bahia. Census of all individuals in the area with circumference at breast height (CBH) ≥ 6 cm was performed. The spatial distribution analysis was conducted for the whole population using Ripley K univariate function, with maximum search radius (h) of 128 m. 409 individuals were found, corresponding to absolute density of 89.49 ind. ha-1 and 0.681 m². ha-1 of basal area. The group of C. arenicola individuals corresponds to a stable population in expansion phase, presenting higher number of young and medium individuals. The pattern of spatial distribution of individuals in the area under study was the uniform arrangement. None of the altimetric classes of the area had a different influence on the structure and distribution of arboreal individuals.

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DISTRIBUIÇÃO ESPACIAL E ESTRUTURA POPULACIONAL DE Parkia platycephala Benth

Nativa ◽

10.31413/nativa.v7i6.7556 ◽

2019 ◽

Vol 7 (6) ◽

pp. 739

Author(s):

Leovandes Soares da Silva ◽

Cristiane Coelho de Moura ◽

Diego Dos Santos Vieira ◽

Tatiano Ribeiro dos Santos ◽

Evandro Luiz Mendonça Machado ◽

...

Keyword(s):

Spatial Distribution ◽

Spatial Pattern ◽

Basal Area ◽

Breast Height ◽

K Function ◽

Occurrence Pattern ◽

Distribution Class ◽

Aggregate Population ◽

Two Populations ◽

Do So

O objetivo conhecer o padrão espacial e a estrutura de duas populações de Parkia platycephala, em duas áreas no sul do Piauí. Realizou-se um censo de indivíduos que apresentaram pelo menos um fuste com diâmetro altura do peito (DAP) ≥ 5 cm. Para tanto, as duas áreas amostradas foram divididas em faixas contendo 20 metros de largura. Dentro destas faixas, foram coletadas as coordenadas cartesianas o diâmetro dos indivíduos. Para o cálculo da distribuição espacial, foi aplicado a função K de Ripley univariada. Para a distribuição diamétrica foi utilizada intervalos de classes com amplitudes crescentes. Na área I foram amostrados 101 indivíduos e área basal de 7,744 m2/ha, para a área II, 66 indivíduos e área basal de 4,654 m2/ha. Os indivíduos da P. platycephala apresentou padrão de ocorrência agregado em ambas as áreas. Os indivíduos menores ocorrem próximos dos indivíduos maiores, formando população agregada. Em relação ao padrão espacial dos indivíduos por classe diamétrica predominou-se o aleatório, diferindo em intensidades, à medida que aumenta os diâmetros. As classes de diâmetro e altura revelam possíveis dificuldades de recrutamento, isso porque a maioria dos indivíduos estão acima de 10cm de diâmetro e 6m de altura respectivamente.Palavras-chave: função K de Ripley; análise espacial; conservação. SPATIAL DISTRIBUTION AND POPULATION STRUCTURE OF Parkia platycephala Benth ABSTRACT: The objective was to know the spatial pattern and structure of two populations of Parkia platycephala, in two areas in the south of Piauí. A census was taken of individuals who had at least one bole with breast height diameter (DBH) ≥ 5 cm. To do so, the two areas sampled were divided into tracks containing 20 meters wide. Within these ranges, the Cartesian coordinates were the diameter of the individuals. To calculate the spatial distribution, the univariate Ripley K function was applied. For the diametrical distribution, class intervals with increasing amplitudes were used. In area I, 101 individuals and basal area of 7,744 m2 / ha were sampled, for area II, 66 individuals and basal area of 4,654 m2 / ha. The individuals of P. platycephala showed an aggregate occurrence pattern in both areas. Smaller individuals occur close to larger individuals, forming an aggregate population. In relation to the spatial pattern of the individuals by diametric class the random was predominant, differing in intensities, as the diameters increase. The diameter and height classes reveal possible recruitment difficulties, which is why most individuals are above 10cm in diameter and 6m in height, respectively.Keywords: Ripley's K function; spatial analysis; conservation.

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Spatial Distribution of Lichens in Metrosideros excelsa in Northern New Zealand Urban Forests

Diversity ◽

10.3390/d13040170 ◽

2021 ◽

Vol 13 (4) ◽

pp. 170

Author(s):

Gladys N. Benitez ◽

Glenn D. Aguilar ◽

Dan Blanchon

Keyword(s):

Spatial Distribution ◽

Species Richness ◽

New Zealand ◽

Lichen Species ◽

Positive Correlation ◽

Breast Height ◽

Lichen Community ◽

The North ◽

The City ◽

Lichen Flora

The spatial distribution of corticolous lichens on the iconic New Zealand pōhutukawa (Metrosideros excelsa) tree was investigated from a survey of urban parks and forests across the city of Auckland in the North Island of New Zealand. Lichens were identified from ten randomly selected trees at 20 sampling sites, with 10 sites classified as coastal and another 10 as inland sites. Lichen data were correlated with distance from sea, distance from major roads, distance from native forests, mean tree DBH (diameter at breast height) and the seven-year average of measured NO2 over the area. A total of 33 lichen species were found with coastal sites harboring significantly higher average lichen species per tree as well as higher site species richness. We found mild hotspots in two sites for average lichen species per tree and another two separate sites for species richness, with all hotspots at the coast. A positive correlation between lichen species richness and DBH was found. Sites in coastal locations were more similar to each other in terms of lichen community composition than they were to adjacent inland sites and some species were only found at coastal sites. The average number of lichen species per tree was negatively correlated with distance from the coast, suggesting that the characteristic lichen flora found on pōhutukawa may be reliant on coastal microclimates. There were no correlations with distance from major roads, and a slight positive correlation between NO2 levels and average lichen species per tree.

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A Quantitative Evaluation of the Multiple Narratives of the Recent Sahelian Regreening*

Weather Climate and Society ◽

10.1175/wcas-d-15-0012.1 ◽

2016 ◽

Vol 8 (1) ◽

pp. 67-83 ◽

Cited By ~ 6

Author(s):

Mimi Stith ◽

Alessandra Giannini ◽

John del Corral ◽

Susana Adamo ◽

Alex de Sherbinin

Keyword(s):

Spatial Distribution ◽

Population Density ◽

Environmental Change ◽

Burkina Faso ◽

Social Dimensions ◽

Adaptation To Climate Change ◽

Southern Central ◽

Second Category ◽

The Impact

Abstract A spatial analysis is presented that aims to synthesize the evidence for climate and social dimensions of the “regreening” of the Sahel. Using an independently constructed archival database of donor-funded interventions in Burkina Faso, Mali, Niger, and Senegal in response to the persistence of drought in the 1970s and 1980s, the spatial distribution of these interventions is examined in relation to population density and to trends in precipitation and in greenness. Three categories of environmental change are classified: 1) regions at the northern grassland/shrubland edge of the Sahel where NDVI varies interannually with precipitation, 2) densely populated cropland regions of the Sahel where significant trends in precipitation and NDVI decouple at interannual time scales, and 3) regions at the southern savanna edge of the Sahel where NDVI variation is independent of precipitation. Examination of the spatial distribution of environmental change, number of development projects, and population density brings to the fore the second category, covering the cropland areas where population density and regreening are higher than average. While few, regions in this category coincide with emerging hotspots of regreening in northern Burkina Faso and southern central Niger known from case study literature. In examining the impact of efforts to rejuvenate the Sahelian environment and livelihoods in the aftermath of the droughts of the 1970s and 1980s against the backdrop of a varying and uncertain climate, the transition from desertification to regreening discourses is framed in the context of adaptation to climate change.

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A New Index Representing Individual Tree Competitive Status

Canadian Journal of Forest Research ◽

10.1139/x73-073 ◽

1973 ◽

Vol 3 (4) ◽

pp. 495-500 ◽

Cited By ~ 46

Author(s):

James A. Moore ◽

Carl A. Budelsky ◽

Richard C. Schlesinger

Keyword(s):

Spatial Distribution ◽

Strong Correlation ◽

Basal Area ◽

Tree Size ◽

Competition Index ◽

Individual Tree ◽

Silvicultural Practices ◽

Basal Area Growth ◽

Hardwood Species ◽

Area Growth

A new competition index, modified Area Potentially Available (APA), was tested in a complex unevenaged stand composed of 19 different hardwood species. APA considers tree size, spatial distribution, and distance relationships in quantifying intertree competition and exhibits a strong correlation with individual tree basal area growth. The most important characteristic of APA is its potential for evaluating silvicultural practices.

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POPULATION ECOLOGY OF THE NORTHERN SLIMY SALAMANDER (PLETHODON GLUTINOSUS) IN EAST-CENTRAL ILLINOIS

Journal of North American Herpetology ◽

10.17161/jnah.vi1.11902 ◽

2015 ◽

pp. 17-21

Author(s):

John A. Crawford ◽

Andrew R. Kuhns ◽

Mathys J. Meyer

Keyword(s):

Population Density ◽

Population Ecology ◽

Demographic Data ◽

Ecosystem Integrity ◽

East Central ◽

Plethodon Glutinosus ◽

Capture Success ◽

Plethodontid Salamanders ◽

Management Plans ◽

Central Illinois

The importance of plethodontid salamanders in forested habitats has been recognized for decades and more recently plethodontids have been touted as a model taxon for monitoring ecosystem integrity and recovery. However, basic demographic data that are crucial to conservation and management plans are currently lacking for many species and regions. The objectives of our study were to characterize the population density, biomass, and capture success of a peripheral population of Plethodon glutinosus to provide a comparison for eastern populations and set a baseline for future monitoring of Midwestern populations. We estimated the population density of P. glutinosus at our site to be 0.41 salamanders/m2, with an estimated biomass of 0.70 g/m2. We did not find any evidence for temperature or precipitation affecting capture success. Our results showed that our density estimate falls within the range of other population ecology studies of Plethodon and sets a baseline for other peripheral Midwestern populations.

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Geospatial characterizing of Under-Five Mortality in Alexandria, Egypt

10.1101/2021.04.24.21255886 ◽

2021 ◽

Author(s):

Mahmoud Adel Hassan ◽

Ahmed Mohamed Ramadan ◽

Mohamed Mostafa Tahoun ◽

Abdelrahman Omran ◽

Shimaa Gad El-karim Ali ◽

...

Keyword(s):

Cardiac Arrest ◽

Spatial Distribution ◽

Cardiovascular Diseases ◽

Population Density ◽

Spatial Pattern ◽

Under Five ◽

Size Population ◽

Access To Water ◽

Alexandria City ◽

Low Incidence

This study aimed to identify geo-spatial pattern of under-five mortality (U5M) in Alexandria and its key determinants. We analyzed the geospatial distribution of 3064 deaths registered at 24 health offices reported from January 2018 to June 2019. The localities of Alexandria city were clustered into high and low incidence areas. Neonates represented 58.7% of U5M, while post-neonates and children were 31.1%, 10.2% respectively. Male deaths were significantly higher (P=0.036). The main leading causes of U5M were prematurity (28.32%), pneumonia (11.01%), cardiac arrest (10.57%), congenital malformation (9.95%), and childhood cardiovascular diseases (9.20%). Spatial distribution of U5M (including the most common three causes) tend to be clustered in western parts of Alexandria (El Hawaria, Bahig, Hamlis and Ketaa Maryiut). Another 9 clusters are at risk of being hotspots. Illiteracy, divorce, and poor locality characteristics (household size, population density, and access to water supply and sanitation), were statistically significant predictors of U5M.

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Niche differentiation and regeneration in the seasonally flooded Melaleuca forests of northern Australia

Journal of Tropical Ecology ◽

10.1017/s0266467407004130 ◽

2007 ◽

Vol 23 (4) ◽

pp. 457-467 ◽

Cited By ~ 17

Author(s):

Donald C. Franklin ◽

Peter S. Brocklehurst ◽

Dominique Lynch ◽

David M. J. S. Bowman

Keyword(s):

Basal Area ◽

Niche Differentiation ◽

Floodplain Forests ◽

Northern Australia ◽

Closely Related Species ◽

The North ◽

Wide Range ◽

Using Data ◽

Seasonally Flooded ◽

Burnt Areas

Gallery and floodplain forests in monsoonal northern Australia are mostly sclerophyllous and dominated by five closely related species of Melaleuca (Myrtaceae) amongst which niche differentiation is unclear. We present a floristic and environmental analysis of ‘the flooded forest’ using data from 340 plots distributed across 450 000 km2 of the Top End of the Northern Territory. Melaleuca argentea was confined to streams and occurred on sandier substrates, whereas M. cajuputi mostly occurred in the near-coastal lowlands on clay soils. The greater basal area of M. cajuputi suggests an association with productive sites. Melaleuca dealbata, M. viridiflora and M. leucadendra occurred on a wide range of soils. More deeply floodprone sites were occupied by M. argentea and M. leucadendra along streams and by M. leucadendra and M. cajuputi on floodplains and in swamps. A general deficiency but occasional abundance of Melaleuca seedlings suggests that regeneration is episodic. Seedlings were more frequent in recently burnt areas and especially where fires had been severe. We propose that Melaleuca forests occur where disturbance by fire and/or floodwater is too great for rain forest to persist, rendering them the wetland analogue to the eucalypts that dominate well-drained portions of the north Australian environment.

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Remarks on the spatial distribution of a reproducing population

Journal of Applied Probability ◽

10.1017/s002190020002581x ◽

1977 ◽

Vol 14 (03) ◽

pp. 577-583 ◽

Cited By ~ 6

Author(s):

J. F. C. Kingman

Keyword(s):

Spatial Distribution ◽

Population Density ◽

Poisson Process ◽

Limiting Distribution ◽

Statistical Equilibrium ◽

Spatially Distributed ◽

Simple Models

Several authors have noted that simple models for the evolution of a reproducing and spatially distributed population have no limiting distribution, although a Poisson process in statistical equilibrium has sometimes been implicitly assumed. It is shown that, even when a mechanism for restricting population density is postulated, a Poisson process is usually impossible to achieve, essentially because of an assumption of independent displacements. When this assumption is abandoned, a Poisson process is possible, at least for some highly idealised models.

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EFICIÊNCIA DE DUAS VARIAÇÕES ESTRUTURAIS DO MÉTODO DE AMOSTRAGEM DE ÁREA FIXA EM PLANTAÇÕES DE Pinus taeda

FLORESTA ◽

10.5380/rf.v43i4.29928 ◽

2013 ◽

Vol 43 (4) ◽

pp. 621

Author(s):

João Paulo Druszcz ◽

Nelson Yoshihiro Nakajima ◽

Sylvio Pellico Netto ◽

Sebastião do Amaral Machado ◽

Nelson Carlos Rosot ◽

...

Keyword(s):

Pinus Taeda ◽

Relative Efficiency ◽

Block Design ◽

Basal Area ◽

Average Diameter ◽

Breast Height ◽

Variable Diameter ◽

Randomized Block Design ◽

Fixed Area ◽

Pinus Taeda L

Este estudo foi conduzido em três diferentes condições de plantações de Pinus taeda L., sem desbastes, com 10, 9 e 7 anos de idade, 2.000 árvores por hectare e diferentes inclinações no terreno, localizados no Estado do Paraná. O objetivo foi avaliar a eficiência do inventário florestal, utilizando-se a amostragem de área fixa com a estrutura de parcela circular (PC) e conglomerado em cruz (CC), através da análise do comportamento quanto às precisões e eficiências relativas nas estimativas das seguintes variáveis: diâmetro médio (cm), número de árvores por ha, área basal (m2/ha) e volume total (m3/ha). Para isso, utilizou-se o delineamento em blocos casualizados com 40 unidades amostrais para a PC e 10 unidades para o CC, sendo este composto por 4 subunidades circulares. Concluiu-se que, para as variáveis diâmetro médio (cm), número de árvores (N/ha), área basal (m2/ha) e volume total (m3/ha), indica-se a utilização do método de área fixa com PC, tendo em vista a maior eficiência no levantamento dessas variáveis.Palavras-chave: Eficiência relativa; precisão; reflorestamento. AbstractStructural efficiency of two variations of method of sampling of fixed area in plantations of Pinus taeda. This study was carried out in three different stands of Pinus taeda L., unthinned and aged 10, 9 and 7 years. The stands have 2.000 trees per hectare and are located in Parana State. The aim was to evaluate the efficiency of inventories using circular plot (PC) and cross cluster (CC) by analyses of behavior towards accuracies and relative efficiencies for estimation of the following variables: average diameter at breast height, number of trees, basal area and total volume per hectare. For this study, it was taken a sample of 40 units to the PC structure and 10 units for the CC structure, which is composed of four circular subunits, and it was used the randomized block design. It was concluded that for the variable diameter (cm), number of trees (ha), basal area (m2/ha) and total volume (m3/ha) it is indicated the use of PC, since its greater efficiency in the survey of these variables.Keywords: Relative efficiency; accuracy; reforestation.

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