Modeling dormancy in natural seedbanks

BENECH-ARNOLD R.L. AND BATLLA D.

SALT Lake City, Utah (USA)

Conferencia; Seed Ecology III; 2010

The possibility of accurately predicting timing and extent of seedling emergence from natural seed soil banks has long been an objective of both ecologists and agriculturalists. However, as dormancy is a common attribute of many wild temperate seed populations, dormancy changes need to be predicted if seedling emergence is intended to be assessed in the field. In order to predict dormancy changes of buried seeds, a number of steps need to be followed: 1-to have a clear notion of how the different environmental factors affect the dormancy level of buried seeds, 2-to quantify the effects of those factors on the dormancy level of the seedbank population and 3-to include the developed quantitative relationships in a coherent modeling framework. In this paper, an attempt to conceptualize the effect of environmental factors on the dormancy level of natural seedbanks is presented, aiming to distinguish factors that usually modulate dormancy level (as for example temperature) from those that usually terminate dormancy (as for example light and alternating temperatures). Based on this conceptual framework, different approaches are shown that can be used to establish functional relationships between soil temperature and changes in the seedbank sensitivity to factors that terminate dormancy under field conditions. Finally, the importance of correctly interpreting temperature effects on germination, dormancy and seed aging for developing models to predict seed dormancy is discussed. Some examples are used to illustrate common errors that can arise when interpreting germination data sets.