PARENT SESSION
Poster Session 2: Forest Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Spatial patterns of seedling establishment at multiple scales: Do seedlings respond to all levels of patchiness?

Gómez-Aparicio, Lorena^{*,1, 2}, Gómez, Jose María¹, Zamora, Regino¹, ¹ University of Granada, Granada, Spain² Institute of Ecosystem Studies, Millbrook, New York, USA

ABSTRACT- Factors affecting seedling establishment vary in space at multiple scales. However, the scarcity of studies comparing the same process at more than one scale limits our knowledge concerning the scale at which recruitment patterns are most prominent and at which one they disappear. In this study, we analyse the spatio-temporal patterns of seedling emergence and survival of the small tree Acer opalus subsp. granatense, in order to understand how heterogeneity in Mediterranean mountain forests affects seedling establishment at multiple scales. For this, we used a hierarchical model of patch structure with three nested scales of patchiness: mountain ranges within the landscape (regional scale), populations within the mountain range (habitat or local scale), and microhabitats within the population (microhabitat scale). Seedlings did not respond to patchiness at the regional scale, but they did at the local and, especially, at the microhabitat scale. The microhabitat scale was not only the main scale of seedling response, but it was also the most sensitive to hierarchical and temporal effects, the suitability of a microhabitat for recruitment varying depending on both larger spatial scales (local scale) and the climatic conditions of the year. The present work shows that scaling effects are crucial for understanding plant recruitment. Moreover, the results suggest that in order to find the key scale of study of an ecological process, the first step is to look at the scaling behaviour of the factors that determine it.

Key words: Acer opalus subsp. granatense, hierarchical system, seedling emergence and survival, spatiotemporal heterogeneity