Recruitment patterns and potential mechanisms of community assembly in an Andean cloud forest

Question What are the conditions necessary for the establishment and development of seedlings and an early stage sapling community in an old-growth cloud forest? Cloud forests are one of the most threatened ecosystems in the world; however, recruitment patterns in these forests remain largely unknown.

Location Cloud Forest, Northern Peruvian Andes.

Methods We constructed a sapling community model through the unconstrained technique of non-metric multidimensional scaling. We related the distribution of saplings of each species to the distance from conspecific adult (potential parent) trees through a point pattern analysis. We also used zero-inflated Poisson models to investigate the relationship between sapling distributions and environmental conditions and forest structure.

Results We found that recruitment in woody plant species tends to be widely spread throughout the forest. The distribution of some sapling species was either positively or negatively related to the position of adult conspecific trees. Several species tended to occur within particular microhabitat conditions, with some differentiation between canopy and understorey species.

Conclusions Cloud forest species recruitment may require the cover provided by the forest canopy. Under closed canopy conditions, both dispersal assembly and niche assembly mechanisms appear to simultaneously influence sapling distribution. The different strategies of various species may result in a trade-off between the importance of microhabitat conditions and distance mechanisms, with one prevailing over the other, depending on species and forest structure conditions.