Data from: Episodic bamboo die-off, neighbourhood interactions, and tree seedling performance in a Patagonian mixed forest

1. Episodic mass flowering and subsequent die-off of bamboo understories
may generate rare opportunities for tree regeneration by altering
consumer-seedling interactions as much as by increasing light availability
to seedlings. We hypothesized that bamboo dieback interacts with canopy
neighbourhood composition in creating recruitment microsites for tree
seedling species with varied shade tolerance and susceptibility to
herbivory. 2. We conducted a 2-year experiment in a Patagonian mixed
forest altered by extensive, but patchy dieback of the bamboo Chusquea
culeou. Newly emerged seedlings of Nothofagus alpina (more shade-tolerant)
and N. dombeyi (less shade-tolerant) were planted in conspecific and
heterospecific canopy neighbourhoods, with either a flowered (dead) or
nonflowered (live) bamboo understorey. Seedlings were placed inside and
outside mesh cages to assess mortality from vertebrate or invertebrate
consumers. 3. Vertebrate exclusion increased seedling survival regardless
of bamboo condition. Seedling loss to invertebrates decreased with bamboo
die-off, resulting in higher survival of N. alpina in dead than in live
patches. In contrast, bamboo die-off increased N. dombeyi mortality by
wilting, which counteracted the benefits of seedling release from
consumers. Bamboo die-off increased light availability and enhanced
seedling growth for both species. 4. N. alpina seedlings were less damaged
or killed by invertebrates under heterospecific canopies than under
conspecifics (associational resistance), whereas N. dombeyi performance
was unaffected by neighbourhood composition. Bamboo die-off did not change
seedling performance patterns observed across canopy neighbourhoods with
live bamboo understories. 5. Synthesis. Gaps created by bamboo die-off can
exert both positive and negative, species-specific effects on the
likelihood of tree seedling establishment. We conclude that infrequent
understorey disturbances coupled with canopy neighbourhood effects
mediated by seedling herbivores may drive gap-phase succession within
old-growth forests.