The influence of canopy-layer composition on understory plant diversity in southern temperate forests

MESTRE, LUCIANA; TORO-MANRÍQUEZ, MÓNICA; SOLER, ROSINA; HUERTAS-HERRERA, ALEJANDRO; MARTÍNEZ-PASTUR, GUILLERMO; LENCINAS, MARÍA VANESSA

Forest Ecosystems

Springer

Lugar: Amsterdam; Año: 2017 vol. 4 p. 6 - 6

Background: Understory plants represents the largest component of biodiversity in most forest ecosystems andplays a key role in forest functioning. Despite their importance, the influence of overstory-layer composition onunderstory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed forests.The aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversityin three forest types (monospecific deciduous Nothofagus pumilio (Np), monospecific evergreen Nothofagusbetuloides (Nb), and mixed N. pumilio-N. betuloides (M) forests), comparing also between two geographical locations(coast and mountain) to estimate differences at landscape level.Results: We recorded 46 plant species: 4 ferns, 12 monocots, and 30 dicots. Canopy-layer composition influencesthe herb-layer structure and diversity in two different ways: while mixed forests have greater similarity to evergreenforests in the understory structural features, deciduous and mixed were similar in terms of the specific compositionof plant assemblage. Deciduous pure stands were the most diverse, meanwhile evergreen stands were least diverse.Lack of exclusive species of mixed forest could represent a transition where evergreen and deciduous communitiesmeet and integrate. Moreover, landscape has a major influence on the structure, diversity and richness ofunderstory vegetation of pure and mixed forests likely associated to the magnitude and frequency of naturaldisturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive species.Conclusions: Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous andpure evergreen understory plant species and different assemblages in coastal and mountain sites. Maintaining themixture of canopy patch types within mixed stands will be important for conserving the natural patterns ofunderstory plant composition in southern beech mixed forests.