TY - JOUR
T1 - Comparative Analysis of Stability-Genetic Diversity in Seagrass (Posidonia oceanica) Meadows Yields Unexpected Results
AU - Arnaud-Haond, S.
AU - Marba, N.
AU - Diaz-Almela, E.
AU - Serrao, E.A.
AU - Duarte, Carlos
PY - 2010
Y1 - 2010
N2 - The diversity-stability relationship is the subject of a long-standing debate in ecology, but the genetic component of diversity has seldom been explored. In this study, we analyzed the interplay between genetic diversity and demographic responses to environmental pressures. This analysis included 30 meadows formed by the Mediterranean endemic seagrass, Posidonia oceanica, showing a wide range of population dynamics ranging from a near equilibrium state to steep decline due to strong environmental pressures close to aquaculture installations. Our results show that sedimentation rates are much better predictors of mortality than clonal or genetic components. An unexpected positive trend was observed between genotypic diversity and mortality, along with a negative relationship between allelic richness and net population growth. Yet such trends disappeared when excluding the most extreme cases of disturbance and mortality, suggesting the occurrence of a threshold below which no relationship exists. These results contrast with the positive relationship between genotypic diversity and resistance or resilience observed in previous manipulative experiments on seagrass. We discuss the reasons for this discrepancy, including the difficulties in designing experiments reflecting the complexity of natural meadows.
AB - The diversity-stability relationship is the subject of a long-standing debate in ecology, but the genetic component of diversity has seldom been explored. In this study, we analyzed the interplay between genetic diversity and demographic responses to environmental pressures. This analysis included 30 meadows formed by the Mediterranean endemic seagrass, Posidonia oceanica, showing a wide range of population dynamics ranging from a near equilibrium state to steep decline due to strong environmental pressures close to aquaculture installations. Our results show that sedimentation rates are much better predictors of mortality than clonal or genetic components. An unexpected positive trend was observed between genotypic diversity and mortality, along with a negative relationship between allelic richness and net population growth. Yet such trends disappeared when excluding the most extreme cases of disturbance and mortality, suggesting the occurrence of a threshold below which no relationship exists. These results contrast with the positive relationship between genotypic diversity and resistance or resilience observed in previous manipulative experiments on seagrass. We discuss the reasons for this discrepancy, including the difficulties in designing experiments reflecting the complexity of natural meadows.
U2 - 10.1007/s12237-009-9238-9
DO - 10.1007/s12237-009-9238-9
M3 - Article
SN - 1559-2723
VL - 33
SP - 878
EP - 889
JO - Estuaries and Coasts
JF - Estuaries and Coasts
ER -