Releasing Rain Forest Succession: A Case Study in the Dicranopteris linearis Fernlands of Sri Lanka

Abstract

Throughout tropical moist climates, Dicranopteris linearis fernlands can develop as a result of rain forest clearance followed by frequent burning. In Sri Lanka, D. linearis fern‐lands are capable of suppressing the regeneration of rain forest. Field experiments were conducted at Sinharaja Man and Biosphere Reserve, a rain forest where fernlands occupy substantial areas of the reserve boundary. The experiment's objective was to identify methods for initiating forest regeneration in fernlands dominated by D. linearis Three disturbance treatments were used to initiate seedling regeneration: clean weed, root removal, and till. We hypothesized that increasing the severity of the soil disturbance would establish vegetation with higher species richness and diversity, greater above‐ground dry biomass, and higher percentage cover and seedling density. Results indicate only partial support for this hypothesis. Dry biomass was greatest in till treatments, the most severe soil disturbance. By comparison, species richness and diversity, seedling density, and percentage cover were greatest in root‐removal treatments, though in many instances the differences were not significant. The study clearly demonstrated that any kind of soil disturbance can facilitate the establishment of herbs, shrubs, and trees in a fernland dominated by D. linearis. Results showed that herbs, sedges, grasses, and pioneer shrubs represented greater proportions of seedling recruits than did pioneer trees. Seedlings of primary‐forest tree species were nearly nonexistent. In general, results showed that soil disturbance can play an important role in site preparation for the purpose of initiating non‐fern vegetation in fernlands dominated by D. linearis.

Natural regeneration in abandoned fields following intensive agricultural land use in an Atlantic Forest Island, Brazil

“…Also, possible allelopathic effects of Gleicheniaceae species cannot be ruled out (SOARES; VIEIRA, 2000). The results demonstrated a low capacity of natural regeneration in the fern thickets, confirming the already observed inhibitory effects of ferns on woody recruitment as well as the need of human intervention by restoration techniques to their forest recovery (COHEN et al, 1995;SLOCUM et al, 2004).…”

Floral and environmental gradients on a Late Cretaceous landscape

“…Fern thickets dominated by Gleicheniaceae are common in wet, particularly upland, tropical regions, where species of Gleichenia, Dicranopteris, Sticherus and other genera can sometimes make up 75% of cover over areas of .1 ha (Walker 1994, Cohen et al 1995, Walker and Boneta 1995, Russell and Vitousek 1997, Russell et al 1998, Ohl and Bussmann 2004, Amatangelo and Vitousek 2009. Typically, these gleicheniaceous fern thickets occur on highly leached, nutrient-poor soils, or are associated with recent (and often frequent) disturbance.…”

Slow recovery of a secondary tropical forest in Southeast Asia

“…For example, thickets of the fern D. linearis, which is known to deter seed establishment (Cohen et al, 1995;Russell et al, 1998), was distributed in areas of the secondary forest plot farthest away from the primary forest. In addition, increasing soil moisture and decreasing radiation from top to bottom of the slope could potentially create abiotic gradients in the two plots.…”