LENCINAS Maria Vanessa
Conservation value of timber quality versus associated non-timber quality stands for understory diversity in Nothofagus forests
LENCINAS MV; MARTINEZ PASTUR G; RIVERO P; BUSSO C
BIODIVERSITY AND CONSERVATION
Lugar: Amsterdam; Año: 2008 p. 2579 - 2597
Conservation strategies of forested landscapes must consider biodiversity of the included forest types, i.e. timber-quality forests and associated non-timber-quality stands. The objectives were to characterize forest overstory structure in timber-quality versus associated non-timber-quality stands; and to compare their understory communities. Six forest types were sampled in Nothofagus forests of Tierra del Fuego (Argentina): two timber-quality N. pumilio forests, and four associated non-timber-quality stands (edge, N. antarctica, wetlands and streamside forests). Overstory structure and understory vegetation (species richness, frequencies, cover and biomass) were characterized during spring and summer seasons. Analysis of variance and multivariate were carried out. Overstory structure differed across the forest types, with higher tree size, canopy closure and tree volume in timber-quality stands. Fifty-one understory plant species were observed, but understory variables varied with forest types, especially wetlands (highest native and exotic richness, cover and biomass, and 25% of exclusive species). Forest types were grouped in three: N. antarctica stands, streamside stands and the other N. pumilio forests according to multivariate analysis. 43% of plants were distributed in all site types, and all timber-quality forest understory species were present in some associated non-timber-quality stands. Timber-quality N. pumilio forests have a marginal value for understory conservation compared to associated non-timber-quality stands, because these last included all the plants observed in timber-quality forests and also possessed many exclusive species. Therefore, protection of associated non-timber-quality stands during forest management planning could increase understory conservation at landscape level, and could be better reserves of understory diversity than retentions of timber-quality stands.