Spatial Patterns and Associations between Species Belonging to Four Genera of the Lauraceae Family

Abstract

Spatial distribution pattern of biological related species present unique opportunities and challenges to explain species coexistence. In this study, we explored the spatial distributions and associations among congeneric species at both the species and genus levels to explain their coexistence through examining the similarities and differences at these two levels. We first used DNA and cluster analysis to confirmed the relative relationship of eight species within a 20 ha subtropical forest in southern China. We compared Diameter at breast height (DBH) classes, aggregation intensities and spatial patterns, associations, and distributions of four closely related species pairs to reveal similarities and differences at the species and genus levels. These comparisons provided insight into the mechanisms of coexistence of these congeners. O-ring statistics were used to measure spatial patterns of species. Ω 0–10, the mean conspecific density within 10 m of a tree, was used as a measure of the intensity of aggregation of a species, and g-function was used to analyze spatial associations. Our results suggested that spatial aggregations were common, but the differences between spatial patterns were reduced at the genus level. Aggregation intensity clearly reduced at the genus level. Negative association frequencies decreased at the genus level, such that independent association was commonplace among all four genera. Relationships between more closely related species appeared to be more competitive at both the species and genus levels. The importance of competition on interactions is most likely influenced by similarity in lifestyle, and the habitat diversity within the species’ distribution areas. Relatives with different lifestyles likely produce different distribution patterns through different interaction process. In order to fully understand the mechanisms generating spatial distributions of coexisting siblings, further research is required to determine the spatial patterns and associations at other classification levels.

Spatial distribution patterns of Symplocos congeners in a subtropical evergreen broad-leaf forest of southern China

“…The distribution patterns of tree species in space provide fundamental information for comprehending underlying ecological process and species coexistence mechanisms (Li et al 2014). Similar species occupying one ecological area theoretically repel sibling species because of the similarity between their strategies for resource use.…”

“…Previous comparative spatial pattern studies focused mostly on many species of different families/genera and occupying different habitats (He et al 1997;Lan et al 2012;Li et al 2014). Nonpartitioning between habitat heterogeneity and phylogenetic difference has led to confusion about the relative importance of abiotic versus biotic factors on species spatial patterns and has hindered development of theory relating abiotic/biotic factors with patterns of distribution and coexistence.…”

“…Research on congeners helps to exclude the ambiguous impact caused by phylogenetic differences (Bevill and Louda 1999;Lloyd et al 2002;Swenson et al 2006), and might elucidate factors that induce species distribution patterns such as weak scatter abilities (Cowling 2001;Simon and Hay 2003) or specialized habitat requirements (Queenborough et al 2007). Therefore, analysis of the distributions of congeneric pairs in space offers special opportunities to explain species coexistence in a more scientific and rigorous manner (Li et al 2014). Alternatively, there exists much fiercer interspecific competition among congeneric species since they have similar phenotypic and ecological characteristics and probably use resources in similar ways (Ackerly and Donoghue 1998;Mooney et al 2008), which, in principle, should discourage their coexistence (Webb et al 2002;Mooney et al 2008).…”

INTERAÇÕES ESPACIAIS INTRAESPECÍFICAS DE Ocotea odorifera NA FLORESTA NACIONAL DE IRATI

“…Para Jan zen (1970) e Connell (1971), as plântulas estabelecidas sob a área de influência do parental sofrem efeitos negativos da "sombra" de sua copa, têm seu crescimento suprimido e eventualmente são atacadas por predadores oriundos do próprio parental ou do solo abaixo dele. Indivíduos congêneres compartilham mu itas características fenotípicas e ecológicas semelhantes e tendem a utilizar u m conjunto de recursos de maneira semelhante, podendo apresentar concorrência intraespecífica (LI et al, 2014), inclusive co m a estratégia da autoalelopatia que pode ser exercida pela planta-mãe sobre os regenerantes mais pró ximos (CRAW LEY, 1986).…”

“…Foi possível verificar u ma tendência de as interações positivas diminuírem de intensidade (menos significativas) entre indivíduos maio res. Li et al (2014) estudaram quatro pares de espécies congêneres da família Lauraceae (Lindera, Machilus, Neolitsea e Cryptocarya), e os resultados apontaram que a intensidade de agregação também d iminuiu com o aumento do diâmet ro dos indivíduos , em nível tanto de espécie como de gênero. Para Zhang et al (2007), geralmente os indivíduos jovens de uma mes ma espécie tendem a se agregar, e indivíduos adultos acabam se distribuindo de forma aleatória ou uniformemente.…”