Identifying drivers of forest resilience in long-term records from the Neotropics

Here we use 30 long-term, high-resolution palaeoecological records from
Mexico, Central and South America to address two hypotheses regarding
possible drivers of resilience in tropical forests as measured in terms of
recovery rates from previous disturbances. First, we hypothesise that
faster recovery rates are associated with regions of higher biodiversity,
as suggested by the insurance hypothesis. And second, that resilience is
due to intrinsic abiotic factors that are location specific, thus regions
presently displaying resilience in terms of persistence to current
climatic disturbances should also show higher recovery rates in the past.
To test these hypotheses, we applied a threshold approach to identify past
disturbances to forests within each sequence. We then compared the
recovery rates to these events with pollen richness before the event. We
also compared recovery rates of each site with a measure of present
resilience in the region as demonstrated by measuring global vegetation
persistence to climatic perturbations using satellite imagery. Preliminary
results indeed show a positive relationship between pre-disturbance
taxonomic diversity and faster recovery rates. However, there is less
evidence to support the concept that resilience is intrinsic to a region;
patterns of resilience apparent in ecosystems presently are not
necessarily conservative through time.