Using spatial patterns of seeds and saplings to assess the prevalence of heterospecific replacements among cloud forest canopy tree species
Por:
Mejia-Dominguez, Nancy R., Meave, Jorge A., Diaz-Avalos, Carlos, Gomez-Aparicio, Lorena
Publicada:
1 sep 2021
Resumen:
Questions To gain insights into the role of species-by-species
replacements in cloud forest community structuring, we asked: (1) What
are the effects of the spatial distribution of standing individuals on
the seed rain, soil seed bank, and sapling density and survival in this
cloud forest?; and (2) What is the prevalence of conspecific vs
heterospecific replacements in the regeneration of this forest? Location
Santo Tomas Teipan, Oaxaca State, southern Mexico. Methods In a 1-ha
cloud forest plot, we assessed seed rain, seed bank, and sapling density
and survival of four canopy tree species (Chiranthodendron
pentadactylon, Cornus disciflora, Quercus laurina and Oreopanax
xalapensis). All standing individuals of these and other tree species
(diameter at breast height [DBH] >= 2.5 cm) were mapped. We used
neighbourhood models to examine the spatial patterns of the three life
cycle stages relative to the spatial distribution of adults. The
neighbourhood effect was assessed through the Neighbourhood Index, which
integrates information on size (DBH) and distance to adults. Data
analysis was based on maximum likelihood and model selection procedures.
Results We found large between-species differences regarding the spatial
patterns of seeds and saplings. Three species showed evidence for the
Janzen-Connell effect operating at the seed (Chiranthodendron
pentadactylon and Quercus laurina) or sapling (Oreopanax xalapensis)
stage. We also found support for a critical role of specific microsite
factors (i.e. niche differentiation) in the regeneration of two species
(Chiranthodendron pentadactylon and Cornus disciflora). Conclusions Seed
and sapling distribution patterns suggest the prevalence of
heterospecific replacements and that both Janzen-Connell and niche
differentiation effects contribute to this pattern. Our results largely
support the notion that the prevalence of heterospecific replacements
among canopy species promotes species co-existence in cloud forests.
Filiaciones:
Mejia-Dominguez, Nancy R.:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Coyoacan 04510, Ciudad De Mexic, Mexico
Univ Nacl Autonoma Mexico, Inst Invest Matemat Aplicadas & Sistemas, Dept Probabilidad & Estadist, Coyoacan, Ciudad De Mexic, Mexico
Meave, Jorge A.:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Coyoacan 04510, Ciudad De Mexic, Mexico
Diaz-Avalos, Carlos:
Univ Nacl Autonoma Mexico, Inst Invest Matemat Aplicadas & Sistemas, Dept Probabilidad & Estadist, Coyoacan, Ciudad De Mexic, Mexico
Gomez-Aparicio, Lorena:
CSIC, Inst Recursos Nat & Agrobiol Sevilla IRNAS, Seville, Spain
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