Resident biodiversity was affected unimodally by
disturbance, whereas density linearly
Resident biodiversity (Simpson’s index) showed the same unimodal pattern
across disturbance frequencies irrespective of invader type (SM invader:
F1,86=10.3, p=0.002, WS: F1,79=7.87,
p=0.006) with the least diverse communities at both high and low
disturbance (Fig. 3). Resource abundance also altered resident
biodiversity (SM invader: F2,86=3.84, p=0.025, WS:
F2,79=33.1, p<0.001), with diversity being
significantly lower in the low resource treatment than the medium when
invaded by SM (p=0.025) and lower than both the medium and high resource
treatments when invaded by WS (p=<0.001 for both).
Like biodiversity, resident density showed the same patterns
irrespective of invader type (Fig. 4), with an interaction between
disturbance frequency and resource abundance significantly affecting
density (SM invader: F2,85=49.4, p<0.001, WS:
F1,79=47.0, p<0.001; Fig. 4). Resident density
increased with disturbance under high resources, but disturbance
negatively impacted density at low and medium resources (Fig. 4).