Email : ivan.scotti(at)inrae.fr
Tél : +33 (0)4 32 72 29 56
Fax : +33 (0)4 32 72 29 02
INRAE
URFM - UR629
Site Agroparc
Domaine Saint Paul
F-84914 AVIGNON Cedex 9

https://www.researchgate.net/profile/Ivan_Scotti2

See my publications (all kinds) here

Visit my weblog : The Forest Genetics Campsite

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Directeur de Recherche à l'Unité de Recherche Écologie des Forêts Méditerranéennes rattachée au Département Écologie et biodiversité des milieux forestiers, prairiaux et aquatiques (ECODIV).

Research goals

I am a population biologist interested in the mechanisms underlying local adaptation, and in particular microgeographic adaptation, that is, adaptation to environmental variations occurring within populations – or to make it more formal, occurring over distances comparable to dispersal distances. Such processes are theoretically related to the maintenance of diversity within populations and to a selection-dispersal balance, and can occur when the environment is patchy or changes abruptly over short distances. I contend that such conditions are encountered frequently by plant populations, e. g. in soil composition and fertility, light and water availability, competition, occurrence of predators.

In parallel, I am also interested into how such adaptive processes (or lack thereof) can affect the viability and resilience of populations at the species range level, with the goal of using such information to support the management and conservation of forest genetic diversity, and biodiversity in general. In a way, this is a reversal of the environmentalist movement slogan: here, I think locally and act globally.

My background and my biological models

My background is in molecular biology and molecular population genetics, and has evolved to include quantitative genetics, statistical population genetics and genomics.
I like to work cooperatively with people from other fields, in a truly multidisciplinary approach to tackle the question of microgeographic adaptation. I collaborate (mostly) with ecologists, ecophysiologists and statisticians, locally and in other research centres, to build a comprehensive view of adaptation, covering all of its aspects (Darwinian selection, demography, plasticity, …).

My biological models are forest trees. I have worked on Alpine / nordic species (spruce), then on tropical trees (the Amazon and Guiana shield) and now I focus on Mediterranean and continental species (pines, beech). I consider trees an excellent study system to investigate microgeographic adaptation, thanks to their large, perennial populations, high fecundity and genetic diversity. I am a lover of trees and forests, and I consider it very important to contribute to the study of adaptation in the prospect of climate change, as this may help preserving forests worldwide from the threats associated to global warming.

Recent research news (most recent first)

Aleppo pine serotiny and adaptation to fire

We looked at whether one of the characters linked to adaptation to fire, serotiny, is under genetic control and shows signs of local adaptation to differences in fire frequency. 

We found that serotiny levels have an intriguing bimodal distribution, with some trees showing no sign of serotiny at all, and other showing quantitative variation. We therefore hypothesised that serotiny may be under a double genetic control, with both a threshold effect (presence/absence of serotiny) and a quantitative control. While we did not find strong evidence of gene-character association, there are suggestive signals pointing to genes involved in the control of floral development and wax metabolism being associated to serotiny. We also found a trend towards pine stands more frequently exposed to fire having higher incidence of serotiny, after controlling for environmental factors.

Selection at microgeographic scales can be strong

In a multi-species article, we have evaluated the strength of selection taking place at microgeographic scales, and shown that, while it probably affects only a small portion of the genome, it can have very strong effects at some loci. The large population sizes of the tree stands we've studied probably facilitates the action of selection (we express selection strength as N_es, the product of effective population size times selection coefficient, or "scaled selection coefficient"). This is interesting because we checked the pattern in species with very different ecological preferences (from Mediterranean pines to high-elevation cedars from dry and cold areas, to cool and moist climate-adapted fir), and retrieved similar selection signals, even though, as expected, the genetic regions affects are different.
It will be interesting to check whether this also applies in smaller, marginal populations.

Selective effect interact across hierarchical population structure levels in silico

We have tested such hypotheses theoretically in this paper, and shown that not only gene flow does not prevent the establishment of adaptive divergence, but also that, when adaptive processes take place at two nested geographical scales (that is, both within continuous populations and among disjunct populations), the patterns of adaptive divergence at each organisational level are influenced by the strength of selection at the other level.

Selection in nested population structures in natura affects non-overlapping genetic regions at different hierarchical levels

We have also verified experimentally that adaptation can occur at nested levels, with non-overlapping genomic regions being affected by adaptive divergence at each level, for example in this paper.

Ongoing research programs and grants

I currently am the coordinator of a large continental consortium, the aim of which is to characterise the genetic, functional, and ecological diversity of European Forest Genetic Resources. This consortium is supported by the European Commission's Horizon Europe program within the FORGENIUS project. 

Public outreach

I am also active in science popularisation. I am involved in the presentation of evolutionary theory and ideas to the general public of all ages, and I do not hesitate to argue for proven scientific facts of evolution when they come under attack by anti-science groups. I am in favour of public, independent research and I favour a publication system that values quality of science above publisher industrial goals.
In addition to this, I also contribute, though the research programs I lead / am involved in, to the transfer of scientific knowledge to public and private players in biological conservation and forestry policy making.