DISTRIBUIÇÃO ESPACIAL E ESTRUTURA POPULACIONAL DE Parkia platycephala Benth

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.

Download Full-text

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

Revista Árvore ◽

10.1590/1806-90882017000400006 ◽

2018 ◽

Vol 41 (4) ◽

Author(s):

Adelson Rocha Dantas ◽

Luiz Carlos Marangon ◽

Marcelino Carneiro Guedes ◽

Ana Lícia Patriota Feliciano ◽

Ana Claudia Lira-Guedes

Keyword(s):

Spatial Distribution ◽

Population Density ◽

Basal Area ◽

Floodplain Forest ◽

Floodplain Forests ◽

Breast Height ◽

Management Plans ◽

Pentaclethra Macroloba ◽

Successful Establishment ◽

Diameter Classes

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.

Download Full-text

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.

Download Full-text

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

Revista Árvore ◽

10.1590/0100-67622015000300003 ◽

2015 ◽

Vol 39 (3) ◽

pp. 431-437 ◽

Cited By ~ 1

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.

Download Full-text

Growth and survival dynamics of partially cut northern hardwood stands as affected by precut competition and spatial distribution of residual trees

Forestry An International Journal of Forest Research ◽

10.1093/forestry/cpz051 ◽

2019 ◽

Cited By ~ 1

Author(s):

Guillaume Moreau ◽

Alexis Achim ◽

David Pothier

Keyword(s):

Spatial Distribution ◽

Spatial Pattern ◽

Basal Area ◽

Competitive Environment ◽

Marginal Effect ◽

Growth And Survival ◽

Permanent Sample Plots ◽

Northern Hardwood ◽

Partial Harvesting ◽

Individual Trees

Abstract Modelling growth and survival dynamics after partial harvesting must take account of the heterogeneous spatial pattern of residual trees that results from the presence of machinery trails. We used data from 23 permanent sample plots in northern hardwood stands to reconstruct the growing environment of individual trees before and after partial harvesting. We modelled harvest probability, growth response and survival probability using a complementary set of explanatory variables that was assembled to reflect the spatial distribution of trees and skid trails prior to and after harvest. Results showed that the distribution of harvested trees was concentrated in skid trails and in their close vicinity. However, this spatial pattern had no significant effect on either the post-cut basal area increment (BAI) or the survival of residual trees. BAI and survival of individual trees were both mostly related to the competitive environment prior to harvest, while post-cut changes in competitive environment had only a marginal effect on growth and survival dynamics. We conclude that selection cuts did not substantially increase the growth and survival of residual trees, likely because tree removal was mostly concentrated near skid trails, where the negative effects of machinery access were highest.

Download Full-text

Spatial patterns of a tropical tree species growing under an eucalyptus plantation in South-East Brazil

Brazilian Journal of Biology ◽

10.1590/s1519-69842010000200006 ◽

2010 ◽

Vol 70 (2) ◽

pp. 271-277 ◽

Cited By ~ 7

Author(s):

P. Higuchi ◽

AC Silva ◽

JNC Louzada ◽

ELM Machado

Keyword(s):

Spatial Distribution ◽

Spatial Pattern ◽

Basal Area ◽

Tree Height ◽

Distribution Patterns ◽

Eucalyptus Plantation ◽

Source Distance ◽

Se Brazil ◽

Population Competition ◽

Linear Regressions

The objectives of this study were to evaluate the influence of propagules source and the implication of tree size class on the spatial pattern of Xylopia brasiliensis Spreng. individuals growing under the canopy of an experimental plantation of eucalyptus. To this end, all individuals of Xylopia brasiliensis with diameter at soil height (dsh) > 1 cm were mapped in the understory of a 3.16 ha Eucalyptus spp. and Corymbia spp. plantation, located in the municipality of Lavras, SE Brazil. The largest nearby mature tree of X. brasiliensis was considered as the propagules source. Linear regressions were used to assess the influence of the distance of propagules source on the population parameters (density, basal area and height). The spatial pattern of trees was assessed through the Ripley K function. The overall pattern showed that the propagules source distance had strong influence over spatial distribution of trees, mainly the small ones, indicating that the closer the distance from the propagules source, the higher the tree density and the lower the mean tree height. The population showed different spatial distribution patterns according to the spatial scale and diameter class considered. While small trees tended to be aggregated up to around 80 m, the largest individuals were randomly distributed in the area. A plausible explanation for observed patterns might be limited seed rain and intra-population competition.

Download Full-text

ESTRUTURA E PADRÃO ESPACIAL DA VEGETAÇÃO EM UMA ÁREA DE CAATINGA

FLORESTA ◽

10.5380/rf.v43i1.27807 ◽

2013 ◽

Vol 43 (1) ◽

pp. 83 ◽

Cited By ~ 6

Author(s):

Gabriel Paes Marangon ◽

Rinaldo Luiz Caraciollo Ferreira ◽

José Antônio Aleixo Da Silva ◽

David Fagner de Souza e Lira ◽

Emanuel Araújo Silva ◽

...

Keyword(s):

Spatial Distribution ◽

Forest Management ◽

Spatial Pattern ◽

Spatial Patterns ◽

Tree Species ◽

Vegetation Structure ◽

Diversity Index ◽

Basal Area ◽

History Of ◽

Aggregated Distribution

A vegetação do Nordeste revela carência relacionada ao manejo florestal da Caatinga. Objetivou-se estudar o padrão espacial de espécies e estrutura da vegetação em área de Caatinga, localizada no município de Floresta, PE. Em uma área de aproximadamente 10 ha, com histórico de perturbação, foram instaladas 20 parcelas de 20 x 20 m, de forma sistemática. Todas as árvores com CAP a 1,30 m do solo ≥ 6 cm foram identificadas e tiveram suas circunferências e alturas mensuradas. Foram encontradas 18 espécies arbóreas, distribuídas em 15 gêneros, dentro de 6 famílias botânicas, com índice de diversidade de Shannon (H') de 2,11 nats.ind-1, e área basal total estimada de 4,53 m2.ha-1. Destacaram-se as famílias Fabaceae, com 48,93% dos indivíduos, e Euphorbiaceae, com 41,28%. As espécies Poincianella bracteosa (Tul.) L. P. Queiroz, Croton rhamnifolius Kunth, Manihot cartaginenses subsp. glaziovii (Muell. Arg.) Allem. e Mimosa ophtalmocentra Mart. ex Benth somaram 55% do total do valor de importância. A maioria das espécies apresentou distribuição agregada, exceto algumas, como Myracrodruon urundeuva Fr. Allem. para o índice de McGuinnes (IGA), Commiphora leptophloeos (Mart.) J. B. Gillett para McGuinnes (IGA) e Payandeh (Pi) e Manihot cartaginenses subsp. glaziovii (Muell. Arg.) Allem. para Fracker e Brischle (Ki), que obtiveram tendência ao agrupamento.Palavras-chave: Semiárido; Pernambuco; distribuição espacial.AbstractStructure and spatial pattern of vegetation in a caatinga area. Forest management deficiency in relation to Northeast vegetation, specifically caatinga, are remarkable. This research aims to analyze spatial patterns of species and vegetation structure in Caatinga area, located in the municipality of Floresta-PE. In an area of approximately 10 ha, and a history of disturbance, 20 plots (20 x 20 m) were installed in systematic way. All trees with CAP (at 1.30 m above the ground) ≥ 6 cm had been identified, and their circumferences and heights measured. 18 tree species were sampled, distributed in 15 genus, within 6 botanical families, with diversity index of Shannon (H ') of 2.11 nats / ind, and estimated total basal area of 4, 53 m2.ha-1. The highlighted families were Fabaceae, 48.93% of individuals, and Euphorbiaceae 41.28%. The species Poincianella bracteosa (Tul.) L.P.Queiroz, Croton rhamnifolius Kunth, Manihot cartaginenses Subsp. glaziovii (Muell. Arg.) Allem., and Mimosa ophtalmocentra Mart. ex Benth totalized 55% of the total value of importance. Most species revealed aggregated distribution, except some like Myracrodruon urundeuva Fr. Allem. for the McGuinness index (IGA), Commiphora leptophloeos (Mart.) J.B.Gillett for McGuinness (IGA) and Payandeh (Pi), and Manihot cartaginenses Subsp. glaziovii (Muell. Arg.) Allem. for Fracker and Brischle (Ki), which obtained grouping tendency.Keywords: Semiarid; Pernambuco; spatial distribution.

Download Full-text

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.

Download Full-text

Spatial Patterns of Urban Innovation and Their Evolution from Perspectives of Capacity and Structure: Taking Shenzhen as an Example

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi11010007 ◽

2021 ◽

Vol 11 (1) ◽

pp. 7

Author(s):

Erjie Hu ◽

Di Hu ◽

Handong He

Keyword(s):

Spatial Distribution ◽

Spatial Pattern ◽

Distribution Pattern ◽

Spatial Patterns ◽

Spillover Effect ◽

Tertiary Industry ◽

Innovation Capacity ◽

Structure Index ◽

Secondary Industry ◽

Spatial Spillover Effect

Innovation is a key factor for a country’s overall national strength and core competitiveness. The spatial pattern of innovation reflects the regional differences of innovation development, which can provide guidance for the regional allocation of innovation resources. Most studies on the spatial pattern of innovation are at urban and above spatial scale, but studies at urban internal scale are insufficient. The precision and index of the spatial pattern of innovation in the city needs to be improved. This study proposes to divide spatial units based on geographic coordinates of patents, designs the innovation capability and innovation structure index of a spatial unit and their calculation methods, and then reveals the spatial patterns of innovation and their evolutionary characteristics in Shenzhen during 2000–2018. The results show that: (1) The pattern of innovation capacity of secondary industry exhibited a pronounced spatial spillover effect with a positive spatial correlation. The innovation capacity and innovation structure index of the secondary industry evolved in a similar manner; i.e., they gradually extended from the southwest area to the north over time, forming a tree-like distribution pattern with the central part of the southwest area as the “root” and the northwest and northeast areas as the “canopy”. (2) The pattern of innovation capacity of tertiary industry also had a significant spatial spillover effect with a positive spatial correlation. There were differences between the evolutions of innovation capacity and innovation structure index of tertiary industry. Specifically, its innovation capacity presented a triangular spatial distribution pattern with three groups in the central and eastern parts of the southwest area and the south-eastern part of the northwest area as the vertices, while its innovative structure showed a radial spatial distribution pattern with the southwestern part of the southwest area as the source and a gradually sparse distribution toward the northeast. (3) There were differences between the evolution modes of secondary and tertiary industries. Areas with high innovation capacity in the secondary industry tended to be more balanced, while areas with high innovation capacity in the tertiary industry did not necessarily have a balanced innovation structure. Through the method designed in this paper, the spatial pattern of urban innovation can be more precise and comprehensive revealed, and provide useful references for the development of urban innovation.

Download Full-text

Occurrence of tuberculosis cases in Crato, Ceará, from 2002 to 2011: a spatial analisys of specific standards

Revista Brasileira de Epidemiologia ◽

10.1590/1980-5497201500020003 ◽

2015 ◽

Vol 18 (2) ◽

pp. 313-325 ◽

Cited By ~ 2

Author(s):

Mayrla Lima Pinto ◽

Talina Carla da Silva ◽

Lidiane Cristina Félix Gomes ◽

Maria Rita Bertolozzi ◽

Lourdes Milagros Mendoza Villavicencio ◽

...

Keyword(s):

Spatial Distribution ◽

Spatial Pattern ◽

Urban Area ◽

Temporal Trend ◽

Kernel Method ◽

Quantitative Approach ◽

Point Pattern ◽

Hybrid Design ◽

Population Densities ◽

Population Groups

OBJECTIVE: to analyze the spatial distribution of tuberculosis in Crato, Ceará, Brazil, from 2002 to 2011, aiming to check for a point pattern. METHODS: This is an ecological, temporal trend and hybrid design study, with a quantitative approach. A total of 261 cases of tuberculosis were geo-referenced and 20 (7.1%) were considered as losses due to the lack of address. The profile of patients in 10 years of study was in accordance with the following pattern: men aged between 20 and 59 years, with low schooling, affected by the pulmonary form of tuberculosis and who were cured from the disease. RESULTS: The analysis of the spatial distribution of tuberculosis points out that in the period of study, new cases of the disease were not distributed on a regular basis, indicating a clustered spatial pattern, confirmed by the L-function. The map with the density of new cases estimated by the Kernel method showed that the "hot" areas are more concentrated in the vicinity of the central urban area. CONCLUSION: The study allowed pointing out areas of higher and lower concentration of tuberculosis, identifying the spatial pattern, but it also recognized that the disease has not reached all of the population groups with the same intensity. Those who were most vulnerable were the ones who lived in regions with higher population densities, precarious living conditions, and with intense flow of people.

Download Full-text

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.

Download Full-text