The extent to which competitive interactions and niche differentiation structure communities has been highly controversial. To quantify evidence for key features of plant community structure, I recharacterized published data from interaction experiments as networks of competitive and facilitative interactions. I measured the network structure of 31 woody and herbaceous communities, including the intensity, distribution, and diversity of interactions at the species-pair and community level to determine the generality of competition, winner-loser relationships, and unequal interaction allocation. I developed novel methodology using meta-analysis to incorporate interaction uncertainty into estimates of structural metrics among independent networks. Plant communities were competitive, but intraspecific interactions were sometimes more intense than interspecific interactions. On the whole, interactions were imbalanced and communities were transitive. However, facilitation, balanced interactions, and intransitivity were common in individual communities. Synthesizing network metrics using meta-analysis is an original approach with which to generalize community structure in a systematic way.

Meta-analysis database of plant interaction networks

Data file lists the studies from which the 31 networks were extracted; the authors, journal, and title of each study are provided. Characteristics of each study are listed, including the location (country, latitude/longitude) and the design (e.g., experimental setting, replicate number, duration). Characteristics of each plant community are also described, including the identities of each species and several of their characteristics (e.g., invasive/native, C3/C4), as well as the mean and standard error of the measured plant performance metric. Last, the networks themselves are listed as a matrix of relative interaction indices for each network. The README file describes each column in the data file in more detail.

Data_PlantInteractionNetworks.csv