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

2010 ◽  
Vol 70 (2) ◽  
pp. 271-277 ◽  
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.

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

2019 ◽  
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.

scholarly journals Stand Structure, Regeneration Status and Distribution Patterns of Six Important Tree Species along Altitudinal Gradients at the Kilum-Ijim Forest Reserve, Cameroon

2020 ◽  
pp. 41-57
Author(s):  
Franklin Bantar Nworo ◽  
Njoh Roland Ndah ◽  
Egbe Enow Andrew
Keyword(s):  
Tree Species ◽  
Stand Structure ◽  
Anthropogenic Activities ◽  
Elevation Gradient ◽  
Basal Area ◽  
Tree Height ◽  
Distribution Patterns ◽  
Forest Reserve ◽  
Altitudinal Gradients ◽  
Regeneration Status

Tropical montane forests are considered to be one of the most species diverse ecosystems. These areas pose specific edaphic and environmental characteristics which enable these areas to harbour wide varieties of organisms. Some of these organisms are threatened and others are endemic to the area. The quest for food and other resources has resulted to indiscriminate exploitation of these montane forest. This study aimed to investigate the stand structure, distribution patterns and regeneration status of six tree species (Nuxia congesta, Pittosporum mannii, Podocarpu slatifolius, Prunus africana, Schefflera abyssinica and Syzygium guineense) along altitudinal gradients in the Kilum-Ijim Forest Reserve, Cameroon. A total of six study plots of one hectare (100 x100 m) each were laid across a 120 m elevation gradient. Two plots were established at each altitudinal gradient with elevations 2377 m, 2437 m and 2497 m. Measurements were taken for tree height, diameter at breast height (DBH 1.3 m) for the tree and poles. The digital Vernier callipers were used to measure collar diameters of seedlings and saplings. The highest tree density of 385 stems/ha was recorded for N. congesta at altitude 2497 m while the least was 20 stems/ha for S. abyssinica at altitude 2377m. The highest seedling density was 1563 stems/ha recorded for P. mannii at altitude 2377m and the least was noted for S. abyssinica at all the three altitudinal gradients.  Nuxia congesta had the highest basal area of 8809.23m2/ha at altitude 2437 m and the least of 74.82m2/ha for P. latifolius at altitude 2437 m.  The highest IVI occurred in N. congesta (131.91) was recorded at altitude 2377 m and the least (24.91) occurred in P. latifolius at altitude 2437 m. The spatial distributions of studied tree species were generally clumped and irregular. The regenerations of species were generally poor, though fair regenerations were noticed for N. congesta and P. mannii. The results showed that the six tree species were highly disturbed by anthropogenic activities. It is therefore imperative to develop and implement effective conservation measures to sustain the biodiversity of this reserve.

scholarly journals Spatial Distribution Patterns Analysis of Hotspot in Central Kalimantan using FIMRS MODIS Data

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Adisty Pratamasari ◽  
Ni Ketut Feny Permatasari ◽  
Tia Pramudiyasari ◽  
Masita Dwi Mandini Manessa ◽  
Supriatna Supriatna
Keyword(s):  
Remote Sensing ◽  
Spatial Distribution ◽  
Correlation Analysis ◽  
Spatial Pattern ◽  
Forest Fires ◽  
Nearest Neighbor ◽  
Kernel Density ◽  
Distribution Patterns ◽  
Central Kalimantan ◽  
Noaa Avhrr

<p><em>One of the ways to observe the </em><em>hotspot created by </em><em>forest fires in Indonesia </em><em>is </em><em>through </em><em>Remote sensing imagery, such as MODIS, NOAA AVHRR, etc</em><em>. </em><em>Central Kalimantan is one of the areas in Indonesia with the highest hotspot data. In this research, MODIS FIRMS hotspot data in Central Kalimantan collected from 2017 – 2019, covering 13 districts: South Barito, East Barito, North Barito, Mount Mas, Kapuas, Katingan, Palangkaraya City, West Kotawaringin, East Kotawaringin, Lamandau, Murung Raya, Pulang Pisau, Seruyan, and Sukamara. That is four aspects that this research evaluated: 1) evaluating the spatial pattern using the Nearest Neighbor Analysis (NNA); 2) evaluate the hotspot density appearance using Kernel Density; and 3) correlation analysis between rainfall data and MODIS FIRMS. As a result, the hotspot in Central Kalimantan shows a clustered pattern. While the natural breaks KDE algorithm shows the most relevant result to represent the hotspot distribution. Finally, the hotspot is low correlated with rainfall; however, is see that most of the hotspot (~90%) appeared in low rainfall month (less than 3000 mm/month).</em></p><p><strong><em>Keywords</em></strong><em>: Forest fire, Hotspot, NNA, Kernel density, Central Kalimantan</em></p>

scholarly journals Oceanic and climatic drivers of mangrove changes in the Gulf of Urabá, Colombian Caribbean

2017 ◽  
Vol 43 (5) ◽  
pp. 972-985
Author(s):  
July A. Suárez ◽  
Ligia E. Urrego ◽  
Andrés Osorio ◽  
Hiara Y. Ruiz
Keyword(s):  
Organic Matter ◽  
Spatial Pattern ◽  
Environmental Variables ◽  
Anthropogenic Disturbance ◽  
Basal Area ◽  
Tree Height ◽  
Avicennia Germinans ◽  
Water Salinity ◽  
Structural Development ◽  
Mangrove Species

The Gulf of Uraba is the largest estuary on the Caribbean coast of Colombia. The aim of this research was to analyse the oceanic, climatic and environmental variables that influence mangrove structure and composition in the gulf. Based on the availability of remote sensing, the study area was divided into western and eastern zones. The spatial pattern of environmental variables (water salinity, pH and percentage of organic matter, sand, silt and clay in the soils) and oceanic and climatic variables (winds, wave height and wave period) was analysed. The relationship of these variables with variables of vegetation structure (basal area, diameter at breast height, tree height, and abundance of seedlings of mangrove species in 1 m2 subplots) was analysed in 27 plots of 500 m2 containing fringe mangroves and 5 plots containing basin mangroves. Mangroves of the western zone showed a higher structural development and were dominated by Rhizophora mangle (red mangrove). This zone is supplied by fresh water and sediments, and the soils have a high content of organic matter and clay and a low degree of anthropogenic disturbance. The eastern zone was characterized by higher pore water salinity due to lower freshwater input from rivers. In this area there is a smaller impact of waves and winds, higher sedimentation rates, high anthropogenic disturbance and mangroves are dominated by Avicennia germinans (black mangrove). Although Laguncularia racemosa (white mangrove) did not show a particular spatial pattern, due to its tolerance to open canopy conditions it was commonly found in anthropogenically disturbed areas.

Construction of a New Spatial Pattern of Industries under the Industrial Transfer in Xi'an Metropolitan Area

2012 ◽  
Vol 174-177 ◽  
pp. 2243-2247
Author(s):  
Yong Pan ◽  
Xiao Jian Chen
Keyword(s):  
Spatial Distribution ◽  
Spatial Pattern ◽  
Metropolitan Area ◽  
Distribution Patterns ◽  
Analysis Method ◽  
Industrial Transfer ◽  
Main Component Analysis ◽  
Countermeasures And Suggestions ◽  
Surrounding Areas ◽  
Main Component

Under the development background of Xi’an international metropolitan area, the industries spatial distribution patterns facing with Xi’an and its surrounding areas change greatly. The authors explore the current industries distribution characters in Xi’an based on the industrial spatial transfer perspective and empirical analysis. Then the authors discuss the potential holding spaces for industrial transfer based on the main component analysis method. Finally, the new pattern and some countermeasures and suggestions are put forward.

scholarly journals ESTRUTURA E PADRÃO ESPACIAL DA VEGETAÇÃO EM UMA ÁREA DE CAATINGA

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 ◽  
...  
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. 

scholarly journals DISTRIBUIÇÃO ESPACIAL E ESTRUTURA POPULACIONAL DE Parkia platycephala Benth

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 ◽  
...  
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.

Modeling spatial distribution of the unionid mussels and the core-satellite hypothesis

1998 ◽  
Vol 38 (7) ◽  
pp. 73-79 ◽  
Author(s):  
Hooi-Ling Lee ◽  
Donald DeAngelis ◽  
Hock-Lye Koh
Keyword(s):  
Spatial Distribution ◽  
Life Cycle ◽  
Success Rate ◽  
Distribution Patterns ◽  
Fish Host ◽  
Limited Movement ◽  
Unionid Mussels ◽  
Species Characteristics ◽  
Major Factors ◽  
Fish Hosts

This paper discusses the spatial distribution patterns of the various species of the Unionid mussels as functions of their respective life-cycle characteristics. Computer simulations identify two life-cycle characteristics as major factors governing the abundance of a species, namely the movement range of their fish hosts and the success rate of the parasitic larval glochidia in finding fish hosts. Core mussels species have fish hosts with large movement range to disperse the parasitic larval glochidia to achieve high levels of abundance. Species associated with fish host of limited movement range require high success rate of finding fish host to achieve at least an intermediate level of abundance. Species with low success rate of finding fish hosts coupled with fish hosts having limited movement range exhibit satellite species characteristics, namely rare in numbers and sparse in distributions.

scholarly journals Deriving Tree Size Distributions of Tropical Forests from Lidar

2021 ◽  
Vol 13 (1) ◽  
pp. 131
Author(s):  
Franziska Taubert ◽  
Rico Fischer ◽  
Nikolai Knapp ◽  
Andreas Huth
Keyword(s):  
Size Distribution ◽  
Spatial Scales ◽  
Basal Area ◽  
Tree Height ◽  
Tree Size ◽  
Diameter Distribution ◽  
Forest Inventories ◽  
Allometric Relations ◽  
Lidar Measurements ◽  
Derived Data

Remote sensing is an important tool to monitor forests to rapidly detect changes due to global change and other threats. Here, we present a novel methodology to infer the tree size distribution from light detection and ranging (lidar) measurements. Our approach is based on a theoretical leaf–tree matrix derived from allometric relations of trees. Using the leaf–tree matrix, we compute the tree size distribution that fit to the observed leaf area density profile via lidar. To validate our approach, we analyzed the stem diameter distribution of a tropical forest in Panama and compared lidar-derived data with data from forest inventories at different spatial scales (0.04 ha to 50 ha). Our estimates had a high accuracy at scales above 1 ha (1 ha: root mean square error (RMSE) 67.6 trees ha−1/normalized RMSE 18.8%/R² 0.76; 50 ha: 22.8 trees ha−1/6.2%/0.89). Estimates for smaller scales (1-ha to 0.04-ha) were reliably for forests with low height, dense canopy or low tree height heterogeneity. Estimates for the basal area were accurate at the 1-ha scale (RMSE 4.7 tree ha−1, bias 0.8 m² ha−1) but less accurate at smaller scales. Our methodology, further tested at additional sites, provides a useful approach to determine the tree size distribution of forests by integrating information on tree allometries.

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