Long-term supratidal rockpool invertebrate community, Discovery Bay, Jamaica.

The rockpool cluster offers unique characteristics making it a model system for general questions in ecology: (1) all rockpools share biotic history (any species can reach any rockpool); (2) they form a strong gradient of conditions from benign to harsh; (3) 1-day sampling across all rockpools ensures census consistency; (4) rockpools respond to changing conditions within a short (days) time frame; (5) they are easy to manipulate (note: the data are from an unmanipulated rockpool subset), and (6) they may act as a single metacommunity that exhibits consistent species distribution patterns on a broader scale (unpublished). Consequently, the rockpools continue generating insights, with the first publications in 1996. The data represent an intensive rockpool metacommunity monitoring project, making them of considerable value to our understanding of tropical coastal metacommunity dynamics and general ecological processes.

Examining the relative influence of dispersal and competition on co-occurrence and functional trait patterns in response to disturbance.

Disturbance gradients are particularly useful for understanding the relative influences of competition and dispersal. Shortly after disturbance, plant composition should be influenced more strongly by dispersal than competition; over time, this should reverse, with competition becoming more important. As such, we predicted that plant functional traits associated with high dispersal ability would be over-represented shortly after a disturbance event occurs, while those associated with high competitive ability would have increased representation as time progresses.

A comparative evaluation of five common pairwise tests of species association.

Researchers have long viewed patterns of species association as key to understanding the processes that structure communities. Community-level tests of species association have received the most attention; however, pairwise species associations may offer greater opportunity for linking patterns to specific mechanisms. Although several tests of pairwise association have been developed, there remain gaps in our understanding of their performance.

The Influence of Matrix Size on Statistical Properties of Co-Occurrence and Limiting Similarity Null Models.

Null models exploring species co-occurrence and trait-based limiting similarity are increasingly used to explore the influence of competition on community assembly; however, assessments of common models have not thoroughly explored the influence of variation in matrix size on error rates, in spite of the fact that studies have explored community matrices that vary considerably in size. To determine how smaller matrices, which are of greatest concern, perform statistically, we generated biologically realistic presence-absence matrices ranging in size from 3-50 species and sites, as well as associated trait matrices. We examined co-occurrence tests using the C-Score statistic and independent swap algorithm.

An unusual erysipelas-like presentation.

A 61-year-old man presented with erysipelas-like cutaneous leishmaniasis.