Genetic diversity of Lithuanian populations of Juniperus communis L. in relation to abiotic and biotic factors

Abstract

Juniperus communis L. is increasingly threatened in many parts of Europe, including the Baltic region. Our present study was aimed at evaluation of genetic diversity of J. communis populations of Lithuania. Fourteen selected populations differed in geography and habitats (coastal brown dunes covered with natural Scots pine forests, further referred as B; J. communis shrubs, F; transition mires and quaking bogs, D; subcontinental moss Scots pine forests, G; xero-thermophile fringes, E). Molecular variance was analyzed among populations (140 individuals, in total), employing 14 Inter Simple Sequence Repeat (ISSR) markers. Percentage of polymorphic loci differed between populations belonging to the different habitat type, being the highest for population representing habitat F (68.2%) and the lowest for populations D (42.9%). The data demonstrate the possibility to underestimate or overestimate this parameter if some habitat populations are bypassed. Means per population of Nei's gene diversity and Shannon's information indexes, were 0.158 and 0.239, respectively. Significant correlation between genetic and geographic distance of populations of J. communis was documented by Mantel test. Bayesian analysis of ISSR data has separated populations of Southern Lithuania from Northern part. Juniperus communis populations representing different habitats showed moderate interpopulation variance at ISSR loci. In ISSR-based dendrograms, individuals were correctly allocated to populations, even in case of populations growing in 0.5 km vicinity (habitats D and G). Among all populations the most distinct one was representing habitat of J. communis shrubs (F) protected by EUNIS. Principal coordinate analysis of weighted averages of Ellenberg's indicator values (EIV) for herbaceous species, separated populations according to habitat type, while the same type analysis of ISSR data allowed distinguishing E habitat populations from populations of all other habitat type but G. Our study shows that on the local (Lithuanian) scale, molecular variance between populations of J. communis at ISSR loci might be related to habitat type. For evaluation and preservation of diversity of J. communis, different assessment methods should be included and management strategies should be directed in the way to retain variety of habitats encompassing both widely spread and less common ones.

Using genetic evaluation to guide conservation of remnant Juniperus communis (Cupressaceae) populations

“…It is dioecious and wind‐pollinated. Its dark fleshy fruits are dispersed by birds (García 2001; Thomas et al 2007; Ward 2007; Vilcinskas et al 2016). This species has a circumpolar distribution, reflecting its wide distribution during the Holocene and the last glaciation.…”

“…For such species, genetic diversity loss due to a reduction in population size may not be apparent for several generations, a phenomenon termed ‘diversity debt’ (Bowles et al 2015). Wind‐pollinated coniferous tree species that exhibit obligate outcrossing due to dioecy are assumed to have high levels of intra‐population genetic diversity and low levels of genetic differentiation among populations, even if populations are declining as a result of habitat fragmentation (García et al 1999; Thomas et al 2007; Provan et al 2008; Vranckx et al 2012; Vilcinskas et al 2016). Optimal restoration measures for such species may thus differ from what is usually recommended for insect‐pollinated herbaceous species.…”

“…Common juniper, Juniperus communis L., is a wind‐pollinated and bird‐dispersed tree widely distributed but strongly declining in North Atlantic and Central European countries (Thomas et al 2007; Ward 2007; Vanden Broeck et al 2011; Vilcinskas et al 2016) due to poor regeneration by seeds, even after habitat restoration (Oostermeijer & De Knegt 2004; Vanden Broeck et al 2011). Assisted gene flow interventions may therefore be necessary to rescue remnant juniper populations.…”

“…These data may be particularly important given that junipers span diverse ecological contexts ( e.g . wet acidic moors versus dry calcareous grasslands) and therefore may express differential adaptation to different climate and soil conditions (Provan et al 2008; Vanden Broeck et al 2011; Vilcinskas et al 2016). Information on how genetic diversity is partitioned among the remnant populations may thus be helpful for designing recovery programmes.…”

Juniperus communis L.: A review of volatile organic compounds of wild and cultivated common juniper in Lithuania

“…A wide ecological range is typical of J. communis. Several recent studies have focused on the research of biotic and abiotic environmental conditions and genetic diversity of Lithuanian populations of common juniper [2][3][4][5]. The plants grow mostly in dry pinewoods, mixed forests, on river slopes, in maritime conditions, being light demanding, but also shade tolerant [6].…”