Some edaphic properties in Dicranopteris linearis dominated landscape:A perspective for restoration success

Abstract

Land degradation is a global challenge leading to loss of biodiversity and ecosystem services. The ever-increasing population and developmental activities make it hard to confine; thus, restoration of highly degraded habitats is the only solution to lessen its impacts. Despite many restoration efforts to bring back the original glory to highly degraded habitats, majority of them are ended up in futility due to direct and/or indirect causes. Dicranopteris linearis is identified as a noxious weed prevalent in highly disturbed sites. Though the physical removal of the fern is known as a way to assist natural succession, the attempts to restore these fern-dominated landscapes in other parts of the tropics showed limited achievements. International Union for Conservation of Nature (IUCN) in Sri Lanka carried out a pilot project in order to revert these fernlands back to forests by transplanting native species following strip cutting. However, transplanted seedlings show rather poor growth with no apparent sign of successful finale. The lack of edaphic resources is considered as a major limiting factor behind landscape recovery following disturbances. The present study evaluated some edaphic resources (soil nutrients and arbuscular mycorrhizal fungi, AMF) in D. linearis dominated landscape to examine their implications for restoration success. Accordingly, a soil analysis was carried out in a fernland located in the buffer zone of the Kanneliya Forest Reserve (KFR) in Sri Lanka to quantify some chemical, physical, and biotic parameters. The results were compared with two reference sites nearby, a lowland tropical rainforest (LR) and a shrub-dominated land use (SD). The results revealed that despite few significant changes between the three land use types, their soils are generally of low fertility status. The fernlands (DD) also showed conspicuously a lower abundance, richness, and diversity of AMF community in comparison to the other two study sites. Therefore, the lack of soil chemical and biotic resources converts these fernlands into habitats with poor potential for revival on their own. Therefore, carefully selected interventions are needed (i. e., addition of an initial dosage of chemical, organic and/or bio-fertilizers) to enrich the edaphic environment prior to introducing native seedlings to convert these highly degraded fernlands into some form of vegetated landscape.