Quaternary disappearance of tree taxa from Southern Europe: timing and trends

Botanic gardens and arboreta, particularly in regions where iconic relict trees naturally occur, play a vital role in the conservation of these species. Maintaining well- managed living ex situ collections of rare and threatened relict tree species provides an immediate insurance policy for the future species conservation. The aim of this research was to investigate the origin, representativeness and genetic diversity of relict trees kept in botanic gardens and arboreta. We used as a model two ecologically and biogeographically distinct members of the prominent relict genus Zelkova (Ulmaceae), which survived the last glaciation in disjunct and isolated refugial regions: Z. carpinifolia in Transcaucasia and Z. abelicea endemic to Crete (Greece) in the Mediterranean. Our study revealed substantial differences in the genetic diversity and the origin of living ex situ collections of the two

/pdf/do-living-ex-situ-collections-capture-the-genetic-variation-1r4ka3o4tp.pdf

Do living ex situ collections capture the genetic variation of wild populations? A molecular analysis of two relict tree species, Zelkova abelica and Zelkova carpinifolia

Aim

To elucidate the phylogeographical patterns in three Cenozoic relict species: Zelkova sicula, Z. abelicea and Z. carpinifolia (Ulmaceae).



Location

Sicily, Crete and Transcaucasia.



Methods

Two chloroplast loci (trnH–psbA and trnL) and the nuclear ribosomal markers ITS1 and ITS2 were sequenced for 154 samples collected from 14 populations of Z. abelicea, 16 populations of Z. carpinifolia, and the two known populations of Z. sicula. We obtained georeferenced data, calculated median joining networks and carried out diversity analyses. A few ex situ samples collected from botanical gardens, of the East Asian species Zelkova serrata, Z. schneideriana and Z. sinica, were also analysed for comparative purposes.



Results

High levels of variability were found in the chloroplast markers within Z. carpinifolia (15 haplotypes) and Z. abelicea (33 haplotypes), in association with strong phylogeographical structure. Conversely, Z. sicula was characterized by low diversity, with each population exhibiting a single haplotype. Lower variability was found for ITS1 and ITS2 within Z. carpinifolia and Z. abelicea (13 and 7 ribotypes per species, respectively), with Z. carpinifolia showing a high proportion of populations with no intragenomic polymorphism. In the triploid and clonal Z. sicula, all individuals displayed intragenomic polymorphism and seven ribotypes were identified.



Main conclusions

The chloroplast diversity of Z. abelicea and Z. carpinifolia suggests a very ancient history of diversification and structuring, with footprints of past expansions and more recent bottlenecks. Zelkova sicula has had a history of severe isolation and is likely to be of hybrid origin.

/pdf/footprints-of-past-intensive-diversification-and-structuring-35umuq0rxj.pdf

Footprints of past intensive diversification and structuring in the genus Zelkova (Ulmaceae) in south-western Eurasia

https://doc.rero.ch/record/326718/files/koz_pcc.pdf

Predicting climate change impacts on the threatened Quercus arbutifolia in montane cloud forests in southern China and Vietnam: Conservation implications

Aim To elucidate the phylogeographical patterns in three Cenozoic relict species: Zelkova sicula, Z. abelicea and Z. carpinifolia (Ulmaceae). Location Sicily, Crete and Transcaucasia. Methods Two chloroplast loci (trnH–psbA and trnL) and the nuclear ribosomal markers ITS1 and ITS2 were sequenced for 154 samples collected from 14 populations of Z. abelicea, 16 populations of Z. carpinifolia, and the two known populations of Z. sicula. We obtained georeferenced data, calculated median joining networks and carried out diversity analyses. A few ex situ samples collected from botanical gardens, of the East Asian species Zelkova serrata, Z. schneideriana and Z. sinica, were also analysed for comparative purposes. Results High levels of variability were found in the chloroplast markers within Z. carpinifolia (15 haplotypes) and Z. abelicea (33 haplotypes), in association with strong phylogeographical structure. Conversely, Z. sicula was characterized by low diversity, with each population exhibiting a single haplotype. Lower variability was found for ITS1 and ITS2 within Z. carpinifolia and Z. abelicea (13 and 7 ribotypes per species, respectively), with Z. carpinifolia showing a high proportion of populations with no intragenomic polymorphism. In the triploid and clonal Z. sicula, all individuals displayed intragenomic polymorphism and seven ribotypes were identified. Main conclusions The chloroplast diversity of Z. abelicea and Z. carpinifolia suggests a very ancient history of diversification and structuring, with footprints of past expansions and more recent bottlenecks. Zelkova sicula has had a history of severe isolation and is likely to be of hybrid origin.

diversification and structuring in the genus Zelkova (Ulmaceae) in south-western Eurasia

Relict species provide a unique opportunity to understand past and recent biogeographical and evolutionary processes. Zelkova abelicea (Ulmaceae), which is endemic to the island of Crete (Greece), is one of the most prominent Tertiary relict trees of the Mediterranean region. We collected distribution, threat and population structure data by reviewing literature and herbaria and through field surveys at 14 study plots throughout the range of the species. The present distribution of Z. abelicea is extremely fragmented. Although the total estimated number of individuals is relatively high, the populations are dominated by dwarf, severely browsed, non-flowering individuals. The population structure is asymmetric. At most, 5% of a plot's trees are large and fruit-bearing. The asymmetric structure is particularly pronounced in isolated and small populations. Based on its limited geographical range, the fragmented spatial pattern, and data on distribution and population structure, our study confirms that Z. abelicea is a threatened species (IUCN category Endangered). Our research aim is to promote the development of new approaches for the improvement of conservation strategies for Tertiary relict trees characterized by major local disjunctions.

/pdf/the-tertiary-relict-tree-zelkova-abelicea-ulmaceae-2mpi0y35qe.pdf

The Tertiary relict tree Zelkova abelicea (Ulmaceae): distribution, population structure and conservation status on Crete

Relict species provide a unique opportunity to understand past and recent biogeographical and evolution- ary processes. Zelkova abelicea (Ulmaceae), which is endemic to the island of Crete (Greece), is one of the most prominent Tertiary relict trees of the Mediterranean region. We collected distribution, threat and population structure data by reviewing literature and herbaria and through field surveys at 14 study plots throughout the range of the species. The present distribution of Z. abelicea is extremelyfragmented. Althoughthetotalestimatednumber of individuals is relatively high, the populations are dominated by dwarf, severely browsed, non-flowering individuals. The population structure is asymmetric. At most, 5% of a plot's trees are large and fruit-bearing. The asymmetric structure is particularly pronounced in isolated and small populations. Based on its limited geographical range, the fragmented spatial pattern, and data on distribution and population structure, our study confirms that Z. abelicea is a threatened species (IUCN category Endangered). Our research aim is to promote the develop- ment of new approaches for the improvement of conserva- tionstrategiesforTertiaryrelicttreescharacterized bymajor local disjunctions.

The Tertiary relict tree Zelkova abelicea (Ulmaceae): distribution, population structure and conservation status on Crete G REGOR K OZLOWSKI ,D AVID F REY ,L AURENCE F AZAN ,B ERNHARD E GLI S ÉBASTIEN B ÉTRISEY ,J OACHIM G RATZFELD ,G IUSEPPE G ARFÌ and S TERGIOS P IRINTSOS

Bernhard Egli

Papers

The Tertiary relict tree Zelkova abelicea (Ulmaceae): distribution, population structure and conservation status on Crete

The Tertiary relict tree Zelkova abelicea (Ulmaceae): distribution, population structure and conservation status on Crete G REGOR K OZLOWSKI ,D AVID F REY ,L AURENCE F AZAN ,B ERNHARD E GLI S ÉBASTIEN B ÉTRISEY ,J OACHIM G RATZFELD ,G IUSEPPE G ARFÌ and S TERGIOS P IRINTSOS

The red list of Zelkova