Carolina Puerta-Piñero

Direct and indirect landscape effects on Quercus ilex regeneration in heterogeneous environments.

Understanding how plant–animal interactions shape plant regeneration is traditionally examined at local scales. In contrast, landscape ecologists working at regional scales often have to infer the mechanisms underlying vegetation patterns. In this study, we empirically explored how landscape attributes (patch connectivity, size, shape, irradiance, slope, and elevation) influence biotic interactions in 1- and 2-year seedlings and saplings of Quercus ilex. We combined field data and GIS-based information under a set of five connectivity scenarios, presuming low, intermediate, and long-distance seed dispersal. Our study emphasizes that landscape, apart from its direct effects on plants, plays a key, albeit indirect, role in plant demography through its effects on seed dispersers and predators. Moreover, the effects of landscape on recruitment differed between plant life stages. One-year seedlings and saplings appear to depend more on plant–animal interactions, while 2-year seedlings depend more on irradiance. Differences in patch connectivity resulted in direct and indirect effects on biotic interactions, which, in turn, produced contrasting positive and negative effects on regeneration at different stages of the life cycle. While jays and wild boars seem crucial to all life stages and most of the connectivity scenarios, rodents and herbivores affected only 1-year seedlings and saplings, respectively, and only a few of the connectivity scenarios. By simultaneously including an ensemble of explanatory factors, our study emphasizes that regeneration depends on a set of key drivers, both abiotic (i.e. irradiance) and biotic (i.e. jays and wild boars), whose effects are greatly modulated by landscape traits.

Shade and Herbivory Induce Fluctuating Asymmetry in a Mediterranean Oak

Fluctuating asymmetry (FA), random nondirectional deviations from perfect symmetry, has been proposed as a useful indicator of environmental stress. Nevertheless, FA acts as a nonspecific indicator of stress; thus, factorial designs are needed to disentangle which of the factors may induce FA. We used an experimental approach in which seedlings of Quercus pyrenaica were exposed to two levels of light, water, and simulated herbivory. To determine whether FA may operate as a stress indicator, leaf width and number of lobes were measured. Our predictions were (1) different levels of light, water, and herbivory can bring different levels of FA and (2) fluctuating asymmetry can act as an early stress indicator. As predicted, FA was higher in shade than in sun, both for leaf width and number of leaf lobes. By contrast, pruning affected FA only for number of lobes. FA was higher in pruned seedlings in the sun but lower in pruned seedlings in the shade. The two FA indices used ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Effectiveness of rodents as local seed dispersers of Holm oaks.

\vert L-R\vert

Differences between structural and functional environmental heterogeneity caused by seed dispersal

\end{document} and \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

History matters: Previous land use changes determine post-fire vegetation recovery in forested Mediterranean landscapes

\mathrm{Var}\,( L-R)

Management of burnt wood after fire affects post-dispersal acorn predation

\end{document} , where L and R represent the left and right leaf sides) gave similar results. Because leaf FA in Q. pyrenaica increased with low light radiation and simulated herbivory and both are important in the dynamics of Mediterranean communities, FA appears to be a possible tool as an indicator of environmental stress.