Spatial distributions of woody plants in tropical forests – Alicia Ledo, University of Aberdeen
Speaker: Alicia Ledo ( University of Aberdeen)
The cloud forest is a special type of forest ecosystem that depends on suitable conditions of humidity and temperature to exist; hence, it is a very fragile ecosystem. The cloud forest is also one of the richest ecosystems in terms of species diversity and rate of endemism. However, today, it is one of the most threatened ecosystems in the world.
Little is known about tree species distribution and coexistence among cloud forest trees. For this study, an analysis of woody plant species distribution at a small scale in a north-Peruvian Andean cloud forest was performed, and some of the factors implicated in the observed patterns were identified. Different factors were investigated: (i) intra-specific arrangements, (ii) heterospecific spatial relationships and (iii) relationships with external environmental factors. To do so, a point pattern analysis approach was mainly used, along with some multivariate statistical analysis. These analyses were conducted first on standing woody plants and then on seedlings.
The woody plants were found to be clumped in the forest. However, each species presented a specific pattern and specific spatial relationship among different-age individuals. Dispersal mode, growth form and shade tolerance played roles in the final distribution of the species. Spatial associations among species, either positive or negative, were observed. These associations were more numerous when considering individuals of the interacting species at different developmental stages. Some species appear to prefer certain habitat conditions and avoid other habitats. Seedling distribution was also associated with habitat conditions. The position of conspecific adult individuals also affected seedling distribution. The results from this thesis suggest that different species can coexist within a given space, forming a “puzzle” of species as a result of the intra- and interspecific spatial relationships along with niche preferences and adaptations that operate at different scales. These factors not only affect each species in a different way, but specific preferences also vary throughout species’ lifespans.