There is a general agreement within the Scientific community that plant diversity is declining worldwide, and estimates suggest the around a third of all plant species are threatened with extinction. Some of the threats that are affecting biodiversity are habitat loss and climate change. Considering the importance of plant diversity in providing ecosystem services, there is an urgency to apply appropriate conservation actions to prevent species’ extinction. In this context, in situ conservation is the preferred option to prevent further loss of biodiversity. Among these practises, plant translocations can be used to boost wild populations or create new populations within the natural range of the species. The material for translocation can be sourced from seeds stored ex situ in seed banks, facilities that allow the conservation of seeds for many years. This study focuses on a translocation of the artic-alpine species Viscaria alpina (L.) G. Don on the summit of Monte Prado (2054 m a.s.l.), in the northern Apennines, at the southern edge of the species distributional range. Plants were grown from six different seed accessions collected over the last twenty years (2000, 2001, 2005, 2018, 2019, 2020) and stored in the Seed Bank of the University of Pavia. Accessions were divided in two groups by collection year: ancestors for the older seeds and descendants for the newer ones. The first aim was to test the effectiveness of ex situ conservation to provide suitable plants for translocation back to nature. The second aim was to use survival, vegetative and reproductive traits to determine if there were differences between plants produced from seeds stored for different lengths of time. Plants were moved to the translocation site in September 2021. Over the next two years we evaluated survival and measured the traits of flowering stem height and number of flowers produced. Seeds were collected after the first year at time of capsule maturity. The initial results indicate that the translocation has been successful. Plants had a high survival rate (97% at the end of the second year) and most produced flowers, although there was a significant reduction in flowering in the second year. There was no difference between ancestors and descendants in survival and flowering. However, there were differences in the height of the flowering stems which were significantly shorter in plants derived from newer accessions compared to older ones, implying plants have become smaller over the last 20 years. This reduction in size could be an adaptation to the more frequent drought conditions experienced at the site in the last two decades. Overall, the results are promising for the use of stored seeds for future translocation efforts of V. alpina and other alpine species. However, more recently collected seeds appear to produce plants that are better adapted to current and future climate conditions. Therefore, seed banks should increase the frequency of seed collection and use newer seeds for plant translocation. Further monitoring of the translocation in the coming years is needed to assess the long-term survival and fitness of the plants.
La comunità scientifica è concorde sul fatto che la diversità vegetale a livello globale sta diminuendo e le stime indicano che un terzo delle specie è minacciato d'estinzione. Tra le minacce che influiscono maggiormente sulla biodiversità si trovano perdita di habitat e cambiamenti climatici. Considerata l'importanza delle piante nel fornire servizi ecosistemici, è urgente trovate e applicare le giuste tecniche di conservazione per evitare l'estinzione delle specie vegetali. A tal scopo, la conservazione in situ è l'opzione più appropriata che permette di evitare ulteriori perdite di biodiversità. Tra queste pratiche, la traslocazione può essere usata per aumentare il numero di individui in popolazioni esistenti o crearne di nuove all'interno del range naturale della specie. Il materiale necessario per le traslocazioni può provenire da banche del germoplasma, strutture che permettono lo stoccaggio di semi ex situ per diversi anni. Questo studio è concentrato su un intervento di traslocazione della specie artico-alpina Viscaria alpina (L.) G. Don, sulla cima del Monte Prado (2054 m a.s.l.), che rappresenta il limite più a sud di distribuzione della specie. Le piante sono state fatte crescere a partire da sei diverse accessioni di semi raccolti nel corso di vent'anni (2000-2001-2005-2018-2019-2020) e conservati nella Banca del Germoplasma dell'Università di Pavia. Lo scopo primario dello studio è stato testare l’efficacia della conservazione ex situ nel fornire materiale per le traslocazioni in natura. In secondo luogo, determinare eventuali differenze nelle piante derivanti da accessioni di età diverse usando dati di sopravvivenza e tratti vegetativi e riproduttivi. Le piante sono state spostate nel sito di traslocazione a settembre 2021. Per i due anni successivi è stato osservato il tasso di sopravvivenza e misurati la lunghezza dello stelo e il numero di fiori prodotti. Dopo il primo anno, quando le capsule hanno raggiunto la maturità, sono stati raccolti i semi. I primi risultati dimostrano che la traslocazione ha avuto successo: le piante hanno avuto un alto tasso di sopravvivenza (97% dopo il secondo anno) e la maggior parte ha prodotto fiori. Non c’è differenza tra antenati e discendenti per sopravvivenza e fioritura. Tuttavia, abbiamo osservato che gli steli delle piante da accessioni più vecchie sono significativamente più lunghi rispetto alle più recenti. Le piante sono quindi rimpicciolite negli ultimi vent’anni. Questa riduzione di taglia potrebbe significare un adattamento alla scarsità d’acqua, considerato l’aumento della frequenza dei fenomeni di siccità nel sito negli ultimi due decenni. Nell'insieme i risultati sono promettenti per quanto riguarda l’uso di semi conservati ex situ per future traslocazioni di V. alpina. Tuttavia, semi più recenti sembrano produrre individui meglio adattati alle condizioni climatiche attuali. Pertanto, le banche del germoplasma dovrebbero aumentare la frequenza delle raccolte semi e dare priorità all’uso di materiale più recente per azioni di traslocazione. Il monitoraggio degli individui nel sito studio nei prossimi anni è necessario per valutare la sopravvivenza a lungo termine e la fitness delle piante traslocate.
Traslocazione di specie alpine [Viscaria alpina (L.) G. Don] utilizzando semi conservati in banche del germoplasma.
ORENGO, MICOL
2022/2023
Abstract
There is a general agreement within the Scientific community that plant diversity is declining worldwide, and estimates suggest the around a third of all plant species are threatened with extinction. Some of the threats that are affecting biodiversity are habitat loss and climate change. Considering the importance of plant diversity in providing ecosystem services, there is an urgency to apply appropriate conservation actions to prevent species’ extinction. In this context, in situ conservation is the preferred option to prevent further loss of biodiversity. Among these practises, plant translocations can be used to boost wild populations or create new populations within the natural range of the species. The material for translocation can be sourced from seeds stored ex situ in seed banks, facilities that allow the conservation of seeds for many years. This study focuses on a translocation of the artic-alpine species Viscaria alpina (L.) G. Don on the summit of Monte Prado (2054 m a.s.l.), in the northern Apennines, at the southern edge of the species distributional range. Plants were grown from six different seed accessions collected over the last twenty years (2000, 2001, 2005, 2018, 2019, 2020) and stored in the Seed Bank of the University of Pavia. Accessions were divided in two groups by collection year: ancestors for the older seeds and descendants for the newer ones. The first aim was to test the effectiveness of ex situ conservation to provide suitable plants for translocation back to nature. The second aim was to use survival, vegetative and reproductive traits to determine if there were differences between plants produced from seeds stored for different lengths of time. Plants were moved to the translocation site in September 2021. Over the next two years we evaluated survival and measured the traits of flowering stem height and number of flowers produced. Seeds were collected after the first year at time of capsule maturity. The initial results indicate that the translocation has been successful. Plants had a high survival rate (97% at the end of the second year) and most produced flowers, although there was a significant reduction in flowering in the second year. There was no difference between ancestors and descendants in survival and flowering. However, there were differences in the height of the flowering stems which were significantly shorter in plants derived from newer accessions compared to older ones, implying plants have become smaller over the last 20 years. This reduction in size could be an adaptation to the more frequent drought conditions experienced at the site in the last two decades. Overall, the results are promising for the use of stored seeds for future translocation efforts of V. alpina and other alpine species. However, more recently collected seeds appear to produce plants that are better adapted to current and future climate conditions. Therefore, seed banks should increase the frequency of seed collection and use newer seeds for plant translocation. Further monitoring of the translocation in the coming years is needed to assess the long-term survival and fitness of the plants.È consentito all'utente scaricare e condividere i documenti disponibili a testo pieno in UNITESI UNIPV nel rispetto della licenza Creative Commons del tipo CC BY NC ND.
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https://hdl.handle.net/20.500.14239/16765