Patrones de distribución de especies arbustivas respecto a arbóreas a lo largo de un gradiente ambiental atlántico-mediterráneo: una aproximación a partir de datos del tercer Inventario Forestal Nacional

Olthoff, A. E., Martinez-Ruiz, C., Alday, J. G. 2016. Distribution patterns of shrub vs. tree species along an Atlantic-Mediterranean environmental gradient: an approach from the third Spanish National Forest Inventory data. Ecosistemas 25(3): 22-34. Doi.: 10.7818/ECOS.2016.25-3.03 National forest inventories are a data source of great theoretical and management interest. However, its use as a tool for niche characterization of tree and shrub species has been limited. In this study, data from the third Spanish National Forest Inventory (3SNFI) in the Palencia province are used to describe the distribution patterns and the realized niche properties of main forest species (trees and shrubs), along the Atlantic-Mediterranean environmental gradient typical of northern Spain. The main community gradient (i.e. coenocline) is related to the north-south climatic differences, while the second shows a turnover in the floristic composition of forests in relation to the slope. Unimodal response curves dominate along the gradient, with species optima at different points, providing evidence of a sufficient amount of compositional turnover. Niche location of trait-related species is closely located. Species occupying environments with sharp contrast or transitional environments have broadest niches, whereas those species occupying localized habitats showed the narrowest niches. The methodology used provides an objective assessment of the shape of species’ responses along complex ecological gradients, using datasets from national forest inventories.