High Level of Phenotypic Differentiation of Common Yew (Taxus baccata L.) Populations in the North-Western Part of the Balkan Peninsula

Jasnica Medak,Irena Šapić,Antonio Vidaković,Joso Vukelić,Igor Poljak,Zlatko Šatović,Marilena Idžojtić,Katarina Tumpa,Patricija Nikl,Zlatko Liber

doi:10.3390/f13010078

Jasnica Medak, Irena Šapić + Show 8 more

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https://doi.org/10.3390/f13010078

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Abstract

Common or English yew (Taxus baccata L., Taxaceae) is a conifer species, native to Europe, northern Africa, Asia Minor and Caucasus. It is a dioecious, wind-pollinated and animal-dispersed tree, known for its high-quality wood and medicinal properties, albeit poisonous. The species is rare and has been legally protected at the European and national levels. In addition, its low population density and disjunct character of distribution have reinforced the need for its protection as regeneration is mostly lacking. The aim of this study was to phenotypically characterise the north-western Balkan yew populations. Phenotypic diversity was examined for seven populations, using morphometric analysis of nine phenotypic traits of needles. Descriptive and multivariate statistical analyses were conducted to evaluate the inter- and intrapopulation variability. In addition, to test correlations between geographic, climatic and phenotypic data, Mantel test was used. We identified a geographic structure across studied populations that exhibited high levels of variability on intra- and interpopulation levels. Two groups of populations have been defined and are consistent with previously described genetic divergent lineages from separate refugia. In addition, a significant correlation between phenotypic and geographic data were revealed, i.e., isolation by distance (IBD). However, the Mantel test revealed no significant correlation between morphometric and environmental data. In conclusion, our data reveal that the historical events and persistent IBD acted in combination to produce the morphological patterns observed in common yew populations in the north-western part of the Balkan Peninsula. Finally, we suggested conservation measures to be implemented on a stand level, with habitat preservation as the main goal. In addition, ex situ conservation should be considered, both in the form of collections and urban planting, as both provide additional gene pool reserves.

Highlights

Data on the status of threatened species can be used as baseline information in the planning and management of protected areas [1]
Descriptive statistics and hierarchical analysis of variance were carried out using the STATISTICA
Distinction between the Dinaric (P01—Učka, P02—Senj and P03—Klek) and continental scriptive statistics and hierarchical analysis of variance were carried out using the S

Summary

Introduction

Data on the status of threatened species can be used as baseline information in the planning and management of protected areas [1]. Its distribution extends across much of temperate Europe, occurring in North Africa, Asia Minor and the Caucasus [2] It is a non-resinous, poisonous tree that grows up to 20 (−28) m, often with multiple trunks. It has thin, scaly, reddish-brown bark and glossy, dark green needles. Yew is a relatively tolerant species, growing in a wide variety of soils and light conditions, it prefers humic, well-drained soils and partial shade. It tolerates rainfall in the range of 500–1000 mm but truly thrives in a humid climate (>2000 mm). Yew grows across eleven plant associations in Europe [8], in two divergent gene pools as a result of two separated refugia during glacial periods [9]

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