Clustering at multiple critical scales may be common for plants since many different factors and processes may cause clustering. This is especially true for tropical rain forests for which theories explaining species coexistence and community structure rest heavily on spatial patterns. We used point pattern analysis to analyze the spatial structure of Shorea congestiflora, a dominant species in a 25‐ha forest dynamics plot in a rain forest at Sinharaja World Heritage Site (Sri Lanka), which apparently shows clustering at several scales. We developed cluster processes incorporating two critical scales of clustering for exploring the spatial structure of S. congestiflora and interpret it in relation to factors such as competition, dispersal limitation, recruitment limitation, and Janzen‐Connell effects. All size classes showed consistent large‐scale clustering with a cluster radius of ∼25 m. Inside the larger clusters, small‐scale clusters with a radius of 8 m were evident for recruits and saplings, weak for intermediates, and disappeared for adults. The pattern of all trees could be divided into two independent patterns: a random pattern (nearest neighbor distance > 8 m) comprising ∼12% of the trees and a nested double‐cluster pattern. This finding suggests two independent recruitment and/or seed dispersal mechanisms. Saplings were several times as abundant as recruits and may accumulate several recruit generations. Recruits were only weakly associated with adults and occupied about half of the large‐scale clusters, but saplings almost all. This is consistent with recruitment limitation. For ∼70% (95%) of all juveniles the nearest adult was less than 26 m away (53 m), suggesting a dispersal limitation that may also be related to the critical large‐scale clustering. Our example illustrates the manner in which the use of a specific and complex null hypothesis of spatial structure in point pattern analysis can help us better understand the biology of a species and generate specific hypotheses to be further investigated in the field.

We propose a hypothesis to explain the temporal and spatial patterns of mass flowerings in dipterocarp tree species on the Malay Peninsula. The literature on these mass flowerings reveals that during 1980–2002 at least 11 flowerings occurred at irregular intervals of 1–6 yr in a lowland rain forest. Five of them were typical mass flowerings—a high density of flowering trees and the characteristic sequential flowering of Shorea species. The 11 flowerings were classified into two flowering times: spring and autumn. There is evidence that low temperature and drought triggered the flowerings. Therefore, the seasonality of mass flowerings is characterized by the annual patterns of rainfall and low temperature. In addition, changes in El Niño–Southern Oscillation (ENSO) may play important roles in determining the supra‐annual occurrence of mass flowerings. Flowering surveys on the Malay Peninsula implied that regions with spring or autumn mass flowerings corresponded geographically to those regions that had one cool season (December–February) or two (December–February and June–August), respectively. This finding anticipates the seasonal pattern and geographical distribution of mass flowerings on the Malay Peninsula.