Conservation of understory ferns in Araucaria angustifolia plantations compared with native forests in northeastern Misiones, Argentina

PÉREZ FLORES, M; RITTERM, LJ; ARTURI, M; MEDINA, M; YAÑEZ, A; MÁRQUEZ, A; CELLINI, JM; LENCINAS, MV

Conferencia; IUFRO Conference Adaptive management for forested landscapes in transformation; 2018

Worldwide subtropical forests have been intensively transformed, with high impacts on biodiversity. However, among transformed lands, forest plantations could hold threatened biodiversity depending on their structural and management characteristics.The aim of this study was to assess the effect of Araucaria plantations over native forest?s understory ferns in northeastern Misiones, Argentina. Fifteen plantations and adjacent native forests were surveyed (30 plots). Species cover was sampled by point intercept method in five 9 m-length transects per plot and forest structure was characterized in plantations. Araucaria density-AD, total density-TD, Araucaria basal area-ABA, and total basal area-TBA were analyzed in three categories: AD1=≤150 ind.ha-1, AD2=>150≤200 ind.ha-1 and AD3=>200 ind.ha-1; TD1=≤400 ind.ha-1, TD2=>400≤500 ind.ha-1 and TD3=>500 ind.ha-1; ABA1=≤25 m2.ha-1, ABA2=>25≤35 m2.ha-1 and ABA3=>35 m2.ha-1; TBA1=≤35 m2.ha-1, TBA2=>35≤45 m2.ha-1 and TBA3=>45 m2.ha-1. Canopy cover was also registered by hemispherical photographs (CC1≤85%; CC2>85%). Regarding management, plantations were differentiated by time since last thinning (T1≤10 years; R2>10 years). Species cover was compared between sectors (plantations vs. native forests), and among categories of forest structure, canopy cover and management in plantations, by one-way ANOVAs.26 fern species were found, being Ctenitis submarginalis (67%) the most frequent. Plantations (4) and native forests (8) presented exclusive species. Ferns cover significantly differed between sectors, with higher values in plantations than in native forest for Alsophila setosa, Ctenitis submarginalis, Dennstaedtia globulifera and Didymochlaena truncatula. Significant differences also were found according to forest structure, canopy cover and management. Pteris deflexa showed higher cover in CC2 and T1 than in CC1 and T2 respectively. Dennstaedtia globulifera presented higher cover in lower categories of AD and TBA, and the same trend with ABA. Megalastrum connexum higher covers were associated to AD2.Forest plantations could be managed to benefit the development and conservation of ferns in northeastern Misiones.