Innovative In Situ and Ex Situ Conservation Strategies of the Madonie Fir Abies nebrodensis

Abstract

Abies nebrodensis (Lojac.) Mattei is an endemic species of the north-west of Sicily located in an 84 ha area in the Madonie Regional park. The relic population is limited to 30 relic adult trees and a fluctuating number of juveniles of natural regeneration. The species is defined as “Critically Endangered” in the Italian list of threatened plants and is classified as CR-D in the 2000 IUCN Red List of Threatened Species. This article reports the key action undertaken by the LIFE4FIR project aimed at preserving A. nebrodensis, and the results obtained so far in three years of activity. OpenArrays SNPs genotyping revealed a high rate of inbreeding in the natural population and that the adult trees are genetically related. Controlled cross-pollination was consequently performed to increase the genetic variability of the progeny. Outbred offspring are currently being grown in the nursery. Reforestation has been planned by using 4000 selected outbred seedlings in 10 areas within Madonie Park to create re-diffusion cores. Support and protection of the relic population have been implemented through regular phytosanitary surveys, as well as new fencing and video surveillance systems against grazing and wild herbivores. A seedbank and cryobank for the long-term germplasm conservation have been established.

Long-Term Conservation for the Safeguard of Abies nebrodensis: An Endemic and Endangered Species of Sicily

“… Pollen grain morphology of A. nebrodensis observed under optical microscope (( a ); from Frascella et al [ 1 ]), stereomicroscope ( b ). …”

“…This species is subject to significant threats caused by genetic erosion, fragmentation, poor natural regeneration, and a high rate of empty seeds leading to low seed germination. The remaining natural population is alarmingly small, consisting of only 30 adult trees, underscoring the urgency for effective conservation strategies [1][2][3]. According to the International Union for Conservation of Nature (IUCN), A. nebrodensis is classified as CR-D in the Red List of Endangered Species (https://top50.iucn-mpsg.org/species/1; accessed on 12 March 2024).…”

“…The LIFE4FIR project (http://www.life4fir.com/it/), started in 2019, aims to develop an effective strategy to improve the conservation status of A. nebrodensis (Figure 1a) through a comprehensive approach that includes different actions: protecting the relic population, increasing genetic diversity by controlled cross-pollination, breeding selected outbred seedlings, and reforesting with selected seedlings to create new cores of the species within the Madonie Regional Park [1]. The project strategy is also based on ex situ conservation strategies, like establishing a seed bank and a cryobank for long-term germplasm conservation.…”

Genomic-guided conservation actions to restore the most endangered conifer in the Mediterranean Basin

“…Many in-situ and ex-situ conservation efforts have been implemented over the last two decades, encompassing breeding programs generating thousands of seedlings via natural pollination and the removal of non-native fir species from the vicinity of the population (Venturella et al 1997; Frascella et al 2022; Rogatis et al 2022). However, there is scarce genetic information available on both the natural occurring and the nursery-propagated seedlings, hindering the assessment of a viable long-term conservation plan.…”

“…Moreover, fir species show a pronounced tendency for hybridization (Klaehn & Winieski 1962;Balao et al 2020). The presumed hybridization between the Sicilian fir and the non-native silver and Greek firs (A. alba and A. cephalonica, respectively) from the surrounding areas of the natural population may adversely impact seed viability and species integrity (Conte & Cristofolini 2003;Scialabba et al 2005) Many in-situ and ex-situ conservation efforts have been implemented over the last two decades, encompassing breeding programs generating thousands of seedlings via natural pollination and the removal of non-native fir species from the vicinity of the population (Venturella et al 1997;Frascella et al 2022;Rogatis et al 2022). However, there is scarce genetic information available on both the natural occurring and the nursery-propagated seedlings, hindering the assessment of a viable long-term conservation plan.…”