Results
As expected, drought severity negatively affected the time to population
extinction (Table 1, Fig. 3). The number of the patches affected by
drought, however, had no effect (Table 1). Corridor quality positively
affected the time of population extinction (Table 1), indicating that
populations persisted longer in habitats connected by good quality
corridors. There was no effect of any of the two-way interactions of
treatments on the time of population extinction (Table 1).
Time negatively affected the variability of patch abundance (Table 2),
suggesting an overall decrease in variability over time (Fig. 4). The
variability of patch abundance was negatively affected by corridor
quality, with higher variability found in landscapes connected with poor
quality corridors. However, this was not affected by drought severity
and number of drought patches (Table 2). There were significant
interactions between time and corridor quality, and between time and
drought severity (Table 2), suggesting that the effect of corridor
quality, as well as drought severity, was largely time dependent.
Interestingly, the different changes in variability over time between
good and poor corridor quality suggest a contrasting response of
populations to stressors due different levels of connectivity. In poor
corridor quality, the rate of decrease in variability of patch abundance
aggravated as drought continuedly stressed populations, whilst in good
corridor quality the rate of decrease in variability eased (Fig. 4).
There were no significant interactions between other two-way factors
(Table 2).
Corridor quality negatively affected the maximum rate of population
decline, with their declining rate being slower in good than poor
corridor quality treatment. Surprisingly, increased number of drought
patches negatively affected the rate of population decline, but drought
severity had no effect (Table 3, Fig. 5). Corridor quality positively
interacted with number of drought patches (Table 3). There were no
effects of other two-way interactions on the maximum rate of population
decline (Table 3).