Soil seed banks in three restored wildlife corridors; implications for linear habitats in tropical environments

Restoring habitat corridors between fragments and continuous forests can potentially counter the effects of isolation, especially in tropical forests where species sensitivity to fragmentation is high. The ability of restored linear habitats to absorb natural disturbance in inimical surroundings potentially reflects resilience, an important aim of ecological restoration practice. Soil seed banks (SSBs) are reservoirs of plant life that can respond to disturbance and contribute to site recovery and resilience. Using seedling emergence, we compared SSB floristics in three restored wildlife corridors aged 10–26 years and their adjoining reference forest and adjacent pastures in tropical northern Australia. A total of 1427 seedlings from 69 species and 27 families were counted and identified from 131 samples. SSBs in restored corridors, while containing higher numbers of exotic species, were more similar in composition to reference forests than pastures, which are dominated by exotic species. Small, vertebrate‐dispersed seeds of gap trees dominated reference forest SSBs and were also conspicuous in corridors. Exotic herbs and grasses occurred in all corridors, were most abundant in pastures, but rarely emerged in forest samples. Both distance from forest ( z ‐value = −2.641, p < 0.01) and year of planting ( z ‐value = −4.213, p < 0.001) had significant effects on the proportion of native species. Almost all of the exotic species recorded in corridors are benign. Few have a demonstrated ability to block or arrest native species regeneration, suggesting SSBs in linear restored habitats can make a significant contribution to resilience and recovery.