Conservation gap analysis for Erica (Ericaceae)

Abstract

The flowering plant genus Erica (Ericaceae) includes well over 800 species and numerous formally described subspecies and varieties. Many of these are threatened in the wild. The Global Conservation Consortium (GCC) for Erica was established under Botanic Gardens Conservation International (BGCI) in order to collaboratively prevent species extinctions. To target this work, we need fundamental information on species distributions, conservation status in the wild, and representation in ex situ collections. In large, complex groups like Erica , such data are not necessarily available or easily accessible. Here, we document the current state of ex situ and in situ conservation of threatened Erica species, identify knowledge and resource gaps, and set out priorities for future work. We further developed and consolidated the large body of data on Erica nomenclature, taxonomy, and diversity now openly accessible as a result of collaborative efforts, in particular through the World Flora Online (WFO), the e-Flora of South Africa, and contributors to the Global Biodiversity Information Facility (GBIF). We obtained accessions data for living plant collections from BGCI’s PlantSearch and from botanic gardens directly, and wild distribution data from GBIF. We linked and summarised data in an updated version (4.03) of the openly available Erica Identification Aid to assist in prioritising work. Through discussions in thematic working groups of GCC Erica we identified further priorities for conservation action. The volume of openly available, georeferenced records for species has increased dramatically in recent years. Although fewer than half of threatened Erica taxa are in ex situ conservation collections, many more botanic gardens hold African/Cape species and could contribute to distributed meta-collections. The most urgent research gaps include undescribed and poorly understood diversity (particularly in South Africa and Madagascar) and shortfalls in up-to-date threat assessments. Between ex situ sites we need to establish accession-level comparisons of data and sharing of conservation grade material. We must improve knowledge of seed longevity and techniques for effective cultivation. We should secure species and collect data through collaboration with landowners and the public. Priority action in situ should include clearance of invasive alien plants as well as habitat restoration and reintroduction. Key statistics for Erica species: 1) Total: 830 species (excluding hybrids; plus 364 subspecies and varieties). South Africa: 747 species; Madagascar/Mascarenes: 41; Tropical Africa: 25; Europe/Mediterranean: 21. 2) 45% species revised taxonomically since 1965. 3) 77% species recorded on GBIF in the last 10 years. 4) 90% species threat assessed (38% in the last 10 years). 5) 46 Critically Endangered (CR), 48 Endangered (EN), 95 Vulnerable (VU) (23% threatened). 6) 47% of threatened species in ex situ collections.