Population Structure, Dispersion and Microhabitat Regeneration of Carapa guianensis in Northeastern Brazil

Henriques, Raimundo Paulo Barros; Sousa, Erivanessa C.

doi:10.2307/2388644

Cited by 26 publications

(20 citation statements)

References 12 publications

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“…Clumped distribution and relatively short distances among adults were also found in populations of several of the most common species in a dry forest in Costa Rica (Hubbell 1979(Hubbell , 1980, and this was the prevalent pattern found in a study of a Caribbean semi-evergreen forest (Forman & Hahn 1980). Other studies of tree species, at least two in Neotropical forests (Henriques & Sousa 1989, Oliveira Filho et al 1996 and two in Asia (He et al 1997, Bunyavejchewin et al 2003 have also reported decreasing aggregation and increasing randomness from smaller to larger size classes.…”

Section: Discussionmentioning

confidence: 71%

Population structure of Eschweilera coriacea (DC.) S. A. Mori in forest fragments in eastern Brazilian Amazonia

Lopes¹

2007

Rev. bras. Bot.

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-(Population structure of Eschweilera coriacea (DC.) S. A. Mori in forest fragments in eastern Brazilian Amazonia). The population structure of a common canopy tree was examined in three sites to investigate the possible effects of forest fragmentation in eastern Amazonia. Evidence for the escape hypothesis of differential seed/seedling survival was evaluated. Two 1 ha plots were established at each site and all individuals of Eschweilera coriacea (DC.) S. A. Mori over 1 m tall were tagged, measured and mapped. Smaller individuals were recorded in the same way within subplots. Mature individuals were abundant at all sites with densities of 32-52 ha -1 . The species exhibited substantial regeneration, although total population density varied fourfold among sites (1,256-4,805 individuals ha -1 ). Overall, juveniles were clumped while adults were randomly distributed. The difference between the dispersion pattern of adults and juveniles supported the escape hypothesis. However, no difference in population structure among sites could be related to the forest fragmentation.

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Section: Discussionmentioning

confidence: 71%

Population structure of Eschweilera coriacea (DC.) S. A. Mori in forest fragments in eastern Brazilian Amazonia

Lopes¹

2007

Rev. bras. Bot.

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“…A diminuição de agregação ou mudança para padrões regulares ou aleatórios com o aumento da classe de tamanho ou estádio é um padrão comumente encontrado e interpretado como resultado da atuação de mortalidade dependente de densidade em espécies lenhosas de vários tipos de vegetação (Sterner 1986;Henriques & Souza 1989;Dovciak et al 2001;Gratzer & Rai 2004), inclusive em savanas (San José et al1991;Skarpe 1991;Barot et al 1999) e cerrados (Oliveira et al 1989;Souza & Silva 2006).…”

Section: Discussionunclassified

“…A descrição dos padrões de classes ou estádios permite identifi car fatores de mortalidade que modifi cam os padrões espaciais ao longo da ontogenia. Os fatores dependentes de densidade são muito comumente citados como responsáveis por tais mudanças (Sterner 1986;Henriques & Souza 1989;San José et al1991;Skarpe 1991;Barot et al 1999;Gratzer & Rai 2004), embora variações espaço temporais nos locais adequados para o recrutamento em diferentes estádios também modifi quem os padrões espaciais ao longo da ontogenia (Dovciak et al 2001). A combinação das duas abordagens permite um entendimento de como a dinâmica de populações de plantas varia em função de fatores como heterogeneidade ambiental (Getzin et al 2008), estratégias sucessionais das espécies (Franklin & Rey 2007) ou interações de competição e facilitação (Lingua et al 2008).…”

Section: Introductionunclassified

Padrões espaciais de Qualea grandiflora Mart. em fragmentos de cerrado no estado de São Paulo

Costa

Santos

2011

Acta Bot. Bras.

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Padrões espaciais de Qualea grandifl ora Mart. em fragmentos de cerrado no estado de São Paulo RESUMO (Padrões espaciais de Qualea grandiflora em fragmentos de cerrado no estado de São Paulo). A descrição dos padrões espaciais é importante para se elaborar hipóteses sobre a dinâmica de populações vegetais. Nosso objetivo foi verificar diferenças nos padrões espaciais de classes de tamanho de Q. grandiflora dentro e entre fragmentos com diferentes fisionomias de cerrado. Para isso descrevemos e comparamos os padrões espaciais do número de plantas por subparcela (5 x 5 m) em seis parcelas de 0,5 ha em quatro fragmentos. Descrevemos os padrões para duas classes de tamanho utilizando correlogramas com o índice I de Moran e testamos associações espaciais entre classes pelo teste de Mantel parcial. A abundância variou de 18 a 319 plantas 0,5 ha -1 . Plantas maiores (altura > 1,5 m) tiveram padrões agregados em todos os casos, com números e tamanhos das escalas de agregação variando independentemente da fisionomia. Somente em três parcelas foi possível descrever os padrões espaciais de plantas menores, onde foram aleatórios. Nesses casos, houve duas associações significativas positivas entre classes e uma não significativa. As diferenças de abundância e padrão espacial entre parcelas foram tão grandes no mesmo fragmento quanto entre fragmentos, indicando que a estrutura espacial de Q. grandiflora é imprevisível com base na fisionomia. A transição aleatório-agregado e a associação espacial entre classes indicam que mortalidade dependente de densidade não parece ser importante na dinâmica de Q. grandiflora, sendo a estrutura espacial dos locais adequados ao recrutamento para maturidade um possível fator mais importante. Palavras ABSTRACT(Spatial patterns of Qualea grandifl ora in cerrado fragments in São Paulo state). Th e study of spatial patterns is a helpful approach to formulating hypotheses about plant population dynamics. Our aim was to search for variation in spatial patterns of Q. grandifl ora height classes at diff erent scales within and among fragments of diff erent cerrado physiognomies. Spatial patterns of the number of plants in subplots (5 x 5 m) were described and compared among six 0.5-ha plots placed in four fragments. We performed Moran's I correlogram analysis to describe spatial patterns and tested spatial correlations of height classes by partial Mantel tests. We found 18 to 319 plants 0.5 ha -1. Larger plants (height >1.5 m) had a clumped pattern in all plots, varying in numbers and magnitudes of scales independently of the physiognomy. Correlogram analysis for smaller plants was possible in only three plots, where patterns were random. In two of these cases there was signifi cant positive correlation of size classes but in the third it was not signifi cant. Abundance and spatial patterns were as diff erent within the same fragment as in diff erent ones. Th ese results show that Q. grandifl ora spatial patterns cannot be predicted based on overall characteristics of cerrado physiognomy. Th e rando...

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“…A comparison of crowding levels among the three populations based on this index was problematic because interpretation of the values themselves is not clear except in a relative sense. (25,50,75, and 100 m) is used to readily identify the m-value at which clustering is at a maximum. Note that the peak of each curve associated to the degree of clustering is relative to the quadrat size.…”

Section: Mrmentioning

confidence: 99%

A New Approach for Interpreting the Morisita Index of Aggregation through Quadrat Size

Hayes

Castillo

2017

IJGI

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Abstract:Spatial point pattern analysis is commonly used in ecology to examine the spatial distribution of individual organisms or events, which may shed light on the operation of underlying ecological processes driving the development of a spatial pattern. Commonly used quadrat-based methods of measuring spatial clustering or dispersion tend to be strongly influenced by the choice of quadrat size and population density. Using valley oak (Quercus lobata) stands at multiple sites, we show that values of the Morisita Index are sensitive to the choice of quadrat size, and that the comparative interpretation of the index for multiple sites or populations is problematic due to differences in scale and clustering intensity from site to site, which may call for different quadrat sizes for each site. We present a new method for analyzing the Morisita Index to estimate the appropriate quadrat size for a given site and to aid interpretation of the clustering index across multiple sites with local differences. By plotting the maximum clustering intensity (Imr) found across a range of quadrat sizes, we were able to describe how a spatial pattern changes when quadrat size varies and to identify scales of clustering and quadrat sizes for analysis of spatial patterns under different local conditions. Computing and plotting the instantaneous rate of change (first derivative of rMax), we were able to evaluate clustering across multiple sites on a standardized scale. The magnitude of the rMax first derivative is a useful tool to quantify the degree of crowding, dispersion, or random spatial distribution as a function of quadrat size.

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Population Structure, Dispersion and Microhabitat Regeneration of Carapa guianensis in Northeastern Brazil

Cited by 26 publications

References 12 publications

Population structure of Eschweilera coriacea (DC.) S. A. Mori in forest fragments in eastern Brazilian Amazonia

Population structure of Eschweilera coriacea (DC.) S. A. Mori in forest fragments in eastern Brazilian Amazonia

Padrões espaciais de Qualea grandiflora Mart. em fragmentos de cerrado no estado de São Paulo

A New Approach for Interpreting the Morisita Index of Aggregation through Quadrat Size

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