Plantations on Forest Gaps and Edges Disturbs the Ecology of Threatened Understory Flora: A Case of Critically Endangered Gentiana Kurroo

Background: Within biodiversity hotspots, forest habitats have been disproportionately reduced and conservation efforts are insufficient, making restoration ventures extremely important. However, the impacts of restoration efforts on native threatened understory biodiversity residing in forest gaps and open edges have been seldom investigated. The current study attempts to fill this knowledge gap by investigating the ecology of a critically endangered understory plant namely Gentiana kurroo, across different successional stages of forest plantations including, open grassland (OG), 3-5-year-old plantation (YP), 5-15-year-old plantation (OP) and a mature forest (MF).Results: The highest population of the species was observed in OG, followed by YP, OP and MF. The regeneration was blocked by the plantation as evidenced by a ‘poor’ status in MF and OP, ‘fair’ at the YP and was ‘good’ only at OG. With an increase in canopy openness, the number of regenerating individuals increased, indicating the negative effect of the closed canopy on regeneration. The ordination projections show that the species density responds negatively with the stand basal area of the woody layer, litter depth, and tree density, but responds positively with soil organic carbon, available phosphorus, and reduction in the plantation. Conclusion: The present study suggests that plantations are more likely to benefit when established on degraded land rather than a replacement of the natural ecosystems, though those systems were initially forested or not. The results have significant implications in designing forest restoration programs, particularly on sites with a high diversity of threatened understory species. Thus, we propose that the forest restoration projects should be designed in a way that favours sensitive understory species without compromising the supply of timber and other non-timber forest products.