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.