IFES 2017, International Forestry & Environment Symposium, 7 - 10 November 2017, Trabzon, Turkey

Abstract

Marginal population and some experiment on assisted gene flow in oaks

Ducci F. 1*, Proietti R.1, de Dato G. 1, Monteverdi M. C. 1, Belletti P.2, Calvo E.3, Ayan S.4

Key words: Marginal populations, Quercus robur, pedunculate oak, assisted gene flow, Po valley

Pedunculate oak (Quercus robur L.) and sessile oak (Q. petraea (Matt.) Liebl.) are widely distributed in fertile valleys and floodplains in Europe.
They derive from a common ancestral taxon and are interfertile. Partially sympatric, they share similar habitats, but in different eco-pedological areas. Interfertility is typically unidirectional with pollination from sessile towards pedunculate oak. This explains the sympatrism of both species and the peculiar adaptive behavior of this complex to water availability.
In the Po valley oak forests have been progressively harvested since the Roman age and were sensibly reduced during the 19th century to recover soils for agricultural crops, factories and infrastructures in one of the most productive regions in Northern Italy.
As a consequence, gene flows in the huge oak primary forest area were severely reduced or interrupted with losses of fitness and genetic variation. Together with pollution, lowering of the water table and climate change, the remnant oak populations can be eligible for examples of marginality due to human impacts.
In the framework of a wide programme to partially re-establish several plain ecosystems in the region, a new secondary oak forest was planted (40.0 ha) in early 2000’s in a completely cleaned area, with the aim 1) to obtain a seed source where the remaining Po valley gene pool was collated, 2) to re-establish gene flow connections and 3) to start an experimental field test on assisted migration for future monitoring.
After genetic analyses demonstrating the recent interruption of past gene flows, seeds sampled from fifteen different natural oak populations were used to establish the experiment in Carpaneta (Lat. 45°11’0.96” Long. 10°53’42”, province of Mantua).
The objective of this paper is to show how the Carpaneta forest is structured and its meaning as an experiment on assisted migration in an area considered an ancient diversity hub for this species.

*Coordinator of the research programme developed with the financial support of ERSAF – Lombardia, project title “Le 10 grandi foreste di pianura” [Ten big plain forests of Lombardy].