Abstract Detail



Ericaceae: Systematics, Ecology and Evolution

Fagundez, Jaime [1].

Heathers and heaths in the old world. From genes to ecosystems.

The western European traditional landscapes share some common elements driven both by bioclimatic conditions and by cultural heritage. Heathlands are one of the most special systems, maintained by sustainable management practices that have remained for centuries almost unchanged. The diversity patterns observed in the wet heaths, show that light grazing mainly by wild ponies creates a heterogeneous structure that supports a species-rich environment with a high conservation value. The negative trend of the occurrence of these habitats, explored by means of spatial analyses of historic maps and toponyms, will have a deep impact in the rural landscape of Atlantic Europe. These oligotrophic shrub communities are dominated by heathers, about 25 species of the genera Calluna, Daboecia and Erica, systematically placed in the tribe Ericeae within the Ericoideae (Ericaceae). Although a poor representation of the over 850 species currently recognized in the Ericeae, the northern heathers are very relevant because they are at the base of the clade, because they have a prominent ecological role in important habitats, and because they provide for human uses such as horticulture, honey-making, manufacture of different items, coal extraction and many others. The large clade of the South African Erica species can be dated back to the Miocene. At that time, probably a high diversity of Ericeae taxa occurred in Europe, many of them now extinct, such as Maiella miocaenica. This new fossil genus and species has intermediate characters between Erica and Calluna, and other exclusive features which support its recognition as a new member of the Ericeae. Further search suggest it may be just the first of a highly diverse extinct ericaceous flora, which may change our view on the history of this unique plant group. Hybridisation and reticulate evolution is also behind the difficulties to establish well-supported phylogenetic trees of heathers, when it comes to compare with phenotypic characterisation of the species. For example, seed morphology and anatomy shows a high diversification, poorly explained by phylogenetic relationships. The putative hybrid origin of Erica lusitanica is the best example, but crossing may also be beyond the spectacular species radiation of the African heathers. Modern events of hybridisation are also taken place in the genus. In the British Isles, Erica tetralix and related species E. ciliaris and E. mackayana frequently hybridise, but much rarely in continental Spain. Isolation of the latter species is probably behind this phenomenon, which we are only starting to understand.


1 - University Of A Coruna, Biology, Faculty Of Science, Zapateira Campus, A Coruņa, C, 15071, Spain

Keywords:
phylogeny
hybridisation
fossils
Ericaceae
Erica
western Europe
grazing
Conservation.

Presentation Type: Colloquium Presentations
Number:
Abstract ID:206
Candidate for Awards:None


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