Data from: Initial colonization, community assembly, and ecosystem function: fungal colonist traits and litter biochemistry mediate decay rate

Priority effects are an important ecological force shaping biotic communities and ecosystem processes, in which the establishment of early colonists alters the colonization success of later-arriving organisms via competitive exclusion and habitat modification. However, we do not understand which biotic and abiotic conditions lead to strong priority effects and lasting historical contingencies. Using saprotrophic fungi in a model leaf decomposition system, we investigated whether compositional and functional consequences of initial colonization were dependent on initial colonizer traits, resource availability or a combination thereof. To test these ideas, we factorially manipulated leaf litter biochemistry and initial fungal colonist identity, quantifying subsequent community composition, using neutral genetic markers, and community functional characteristics, including enzyme potential and leaf decay rates. During the first 3 months, initial colonist respiration rate and physiological capacity to degrade plant detritus were significant determinants of fungal community composition and leaf decay, indicating that rapid growth and lignolytic potential of early colonists contributed to altered trajectories of community assembly. Further, initial colonization on oak leaves generated increasingly divergent trajectories of fungal community composition and enzyme potential, indicating stronger initial colonizer effects on energy-poor substrates. Together, these observations provide evidence that initial colonization effects, and subsequent consequences on litter decay, are dependent upon substrate biochemistry and physiological traits within a regional species pool. Because microbial decay of plant detritus is important to global C storage, our results demonstrate that understanding the mechanisms by which initial conditions alter priority effects during community assembly may be key to understanding the drivers of ecosystem-level processes.28S Sequence Alignment28S Sequence Alignments, one .fasta file for each harvest date28S_sequence_alignment.zip28S Tree File28S tree files, one file for each harvest data28S_tree_file.zip28S OTU tables28S OTUs tables, one file for each harvestCommunity Enzyme Dataenzyme_AH_all_harvests.txtCommunity Respiration AccumulationRespiration data was added weekly for the first 14 weeks of the experiment, and used for curve fittingAH_resp_accumulation_forcurvefitting.txtCommunity Ash-free massash_free_mass_AH_all_harvests.tx