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

FLORESTA ◽  
2020 ◽  
Vol 50 (3) ◽  
pp. 1660
Author(s):  
Dráuzio Correia Gama ◽  
Robério Anastácio Ferreira ◽  
Janisson Batista de Jesus ◽  
José Monteiro do Nascimento Júnior

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.

2018 ◽  
Vol 41 (4) ◽  
Author(s):  
Adelson Rocha Dantas ◽  
Luiz Carlos Marangon ◽  
Marcelino Carneiro Guedes ◽  
Ana Lícia Patriota Feliciano ◽  
Ana Claudia Lira-Guedes

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.


2012 ◽  
Vol 88 (1) ◽  
pp. 60-73 ◽  
Author(s):  
Baburam Rijal ◽  
Aaron R. Weiskittel ◽  
John A. Kershaw

Height to live crown base (HCB) is an important input variable for several growth and yield models. Since HCB is rarely measured in the field, it is often predicted using static models. Instead of predicting HCB, the Forest Vegetation Simulator Northeastern Variant (FVS-NE) uses an equation that predicts crown ratio (CR), which has not been well validated. The main goal of the present study was to construct a regional HCB model for thirteen selected tree species of the Acadian Region of North America. The specific objectives were to: 1) evaluate FVS-NE model predictions, 2) compare suitable model forms, and 3) assess influence of various covariates to improve predictions. We evaluated three model forms, namely Holdaway (1986), logistic, and exponential. The findings indicated that FVS-NE models were significantly biased for all species as the overall mean bias and root mean square error (RMSE) were 0.11 m and 1.80 m, respectively. A logistic equation with size (diameter at breast height [DBH], total height [HT] and ratio of DBH to HT), and competition (crown competition factor [CCF] and basal area larger than subject tree [BAL]) gave the best predictions for all species in this analysis. This model had an overall mean bias <0.01 m and an RMSE of 1.59 m, which represents a significant improvement in predictions compared to FVS-NE. Despite the range of species and observed variation in the data, the equations worked well and can be easily calibrated to new stands with a few local observations.


2020 ◽  
Vol 24 (11) ◽  
pp. 1861-1865
Author(s):  
DM Taiwo ◽  
OR Olatidoye ◽  
OR Jeminiwa ◽  
TO Oyebola ◽  
C Omonu

Total enumeration of tree species was carried out fire experimental plot of Olokemeji forest reserve for relative importance value (RIV) mean heights, mean diameter at breast height and mean basal area. Three investigative plot (Plot A, B and C) were established. Plot A which represents Early Burn is burnt annually during the dry season while Plot B was burnt annually during the rainy season when the trees are still wet and Plot C serves as the protected area. Gmelina arborea had the highest relative importance value (28.31), this is followed by Dalbergia sissoo which had RIV of 10.94. Plot C recorded the highest frequency of trees with the highest tree heights, this is closely followed by Plot A and Plot B being the plot with the lowest mean height. Plot C has the highest mean diameter at breast height (DBH) of trees and it is followed by Plot B and Plot A with very close mean DBH. The highest mean basal area was also recorded in Plot C, the highest total basal area and tree volume was also recorded at Plot C as 32.2 m2 ha-1 and 188.8 m3. The size distribution of tree species depicts that Plot C has been protected just as expected Keywords: Forest, Structure, Flora, Dynamics, Fire


FLORESTA ◽  
2013 ◽  
Vol 43 (1) ◽  
pp. 83 ◽  
Author(s):  
Gabriel Paes Marangon ◽  
Rinaldo Luiz Caraciollo Ferreira ◽  
José Antônio Aleixo Da Silva ◽  
David Fagner de Souza e Lira ◽  
Emanuel Araújo Silva ◽  
...  

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. 


Nativa ◽  
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 ◽  
...  

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.


2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Faezah Pardi

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


1996 ◽  
Vol 112 (13) ◽  
pp. 907-914 ◽  
Author(s):  
Katsuaki KOIKE ◽  
Yoshifumi NOGUCHI ◽  
Hiroshi IWASAKI ◽  
Katsuhiko KANEKO

2019 ◽  
Vol 53 (5) ◽  
pp. 417-422
Author(s):  
P. De los Ríos ◽  
E. Ibáñez Arancibia

Abstract The coastal marine ecosystems in Easter Island have been poorly studied, and the main studies were isolated species records based on scientific expeditions. The aim of the present study is to apply a spatial distribution analysis and niche sharing null model in published data on intertidal marine gastropods and decapods in rocky shore in Easter Island based in field works in 2010, and published information from CIMAR cruiser in 2004. The field data revealed the presence of decapods Planes minutus (Linnaeus, 1758) and Leptograpsus variegatus (Fabricius, 1793), whereas it was observed the gastropods Nodilittorina pyramidalis pascua Rosewater, 1970 and Nerita morio (G. B. Sowerby I., 1833). The available information revealed the presence of more species in data collected in 2004 in comparison to data collected in 2010, with one species markedly dominant in comparison to the other species. The spatial distribution of species reported in field works revealed that P. minutus and N. morio have aggregated pattern and negative binomial distribution, L. variegatus had uniform pattern with binomial distribution, and finally N. pyramidalis pascua, in spite of aggregated distribution pattern, had not negative binomial distribution. Finally, the results of null model revealed that the species reported did not share ecological niche due to competition absence. The results would agree with other similar information about littoral and sub-littoral fauna for Easter Island.


Author(s):  
Barry T. Wilson ◽  
Andrew J. Lister ◽  
Rachel I. Riemann ◽  
Douglas M. Griffith

1970 ◽  
Vol 20 ◽  
Author(s):  
R. Goossens

Contribution to the automation of the calculations involving  the forest inventory with the aid of an office computer - In this contribution an attempt was made to perform the  calculations involving the forest inventory by means of an office computer  Olivetti P203.     The general program (flowchart 1), identical for all tree species except  for the values of the different parameters, occupies the tracks A and B of a  magnetic card used with this computer. For each tree species one magnetic  card is required, while some supplementary cards are used for the  subroutines. The first subroutine (flowchart 1) enables us to preserve  temporarily the subtotals between two tree species (mixed stands) and so  called special or stand cards (SC). After the last tree species the totals  per ha are calculated and printed on the former, the average trees occuring  on the line below. Appendix 1 gives an example of a similar form resulting  from calculations involving a sampling in a mixed stand consisting of Oak  (code 11), Red oak (code 12), Japanese larch (code 24) and Beech (code 13).  On this form we find from the left to the right: the diameter class (m), the  number of trees per ha, the basal area (m2/ha), the current annual increment  of the basal area (m2/year/ha), current annual volume increment (m3/year/ha),  the volume (m3/ha) and the money value of the standing trees (Bfr/ha). On the  line before the last, the totals of the quantities mentioned above and of all  the tree species together are to be found. The last line gives a survey of  the average values dg, g, ig, ig, v and w.     Besides this form each stand or plot has a so-called 'stand card SC' on  wich the totals cited above as well as the area of the stand or the plot and  its code are stored. Similar 'stand card' may replace in many cases  completely the classical index cards; moreover they have the advantage that  the data can be entered directly into the computer so that further  calculations, classifications or tabling can be carried out by means of an  appropriate program or subroutine. The subroutine 2 (flowchart 2) illustrates  the use of similar cards for a series of stands or eventually a complete  forest, the real values of the different quantities above are calculated and  tabled (taking into account the area). At the same time the general totals  and the general mean values per ha, as well as the average trees are  calculated and printed. Appendix 2 represents a form resulting from such  calculations by means of subroutine 2.


Sign in / Sign up

Export Citation Format

Share Document