INSTYTUT DENDROLOGII

Federico Vessella, Antonello Salis, Mattia Scirè, Gianluca Piovesan, Bartolomeo Schirone
Natural regeneration and gender-specific spatial pattern of Taxus baccata in an old-growth population in Foresta Umbra (Italy)

Dendrobiology 2015, vol. 73: 75-90

http://dx.doi.org/10.12657/denbio.073.008

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Abstract: English yew is rare and endangered dioecious species. Research on regeneration processes of endangered taxa is important to understand the mechanisms allowing a species to survive under several ecological scenarios, to predict future distribution shifts, to achieve best management practices and conser­vation policies. Our investigation was focusing on one of the oldest yew population in Europe, in Foresta Umbra in Italy. The main aim of this study was to understand spatial regeneration processes and dynamics related with parent trees’ sex distribution.

Geostatistical analysis showed that seedlings occur in patches avoiding direct competition with adult yews. Negative relationship between regeneration and yew density and basal area was found.

A general model for the reproductive ecology is proposed: females are less competitive and more envi­ronmentally demanding than males, because of their reproductive effort. Indeed, male and female fitness responds differently across environmental gradients, thus favouring spatial segregation of seedlings. Un­derstanding the yew’s adaptive effectiveness is essential to ensure the conservation of existing populations, and encourage the species’ resilience into areas where yew is endangered.

Additional key words: Mediterranean environment, regeneration dynamics, endangered species, dioecy