Strengthening the conservation value of ex situ tree collections

Abstract

With % of trees (. , species) threatened with extinction there is an urgent need for botanical gardens to protect threatened trees in dedicated conservation collections. Species conservation is mentioned in the mission statements of most major botanical gardens, yet the actual conservation value of existing ex situ tree collections is low. We conducted interviews with members of the botanical garden community and organized a symposium at the th Global Botanic Gardens Congress to identify challenges and collect recommendations to improve living ex situ tree collections. We summarize and evaluate this information to facilitate gardens becoming more effective agents for global tree conservation. Experts agree that gardens offer valuable strengths and assets for tree conservation. Some challenges exist, however, including a lack of strategic conservation focus, collection management limitations, gaps in fundamental biological information for trees, and a lack of global coordination. Solutions are offered to facilitate gardens and arboreta of all sizes to participate more effectively in tree conservation. Prioritizing genetically diverse tree collections, participating in conservation networks, developing tree-specific conservation models and guidelines, and strengthening tree science research efforts are a few examples. Most importantly, a more coordinated global effort is needed to fill knowledge gaps, share information, and build conservation capacity in biodiversity hotspots to prevent the loss of tree species.

Geographic analysis of Red List Rhododendron (Ericaceae) taxa by country of origin identifies priorities for ex situ conservation

“…Comparison among endemic taxa demonstrates that there is greater conservation urgency for some countries (e.g., endemic taxa from India and Vietnam) than for others (e.g., Myanmar and Bhutan). Prioritising endemic taxa is a recognised conservation approach (Powledge 2011, Cavendar et al 2015, with our analysis showing that a finer resolution is possible and comparisons can also be made among countries.…”

“…The key assumption of the present analysis is that the primary drivers for ex situ conservation are threat, endemism, Data Deficiency, and presence 'in cultivation' (Newton & Oldfield 2008, Powledge 2011, Sharrock et al 2014, Cavendar et al 2015.…”

“…This process appears to be sufficient for small genera comprised of similar life forms, but does not have a fine enough resolution for large genera of wide distribution and multiple life forms, where there may be hundreds of taxa in any one Red List category. In these genera additional factors such as taxonomic groupings, geographic representation, endemism and centres of diversity (Farnsworth et al 2006, Castaneda-Alvarez et al 2015, Cavendar et al 2015, can be used to identify key groups of taxa. Rhododendron L. (Ericaceae) is one such large genus (of about 1 215 taxa) in which Gibbs et al (2011) and Argent (2015) Red Listed 715 taxa .…”

Analysis of geographic and taxonomic groups informs conservation of Rhododendron subgenus Vireya (Ericaceae)

“…GSPC Target 2 calls for an assessment of the conservation status of all known plants (as far as possible), to guide conservation action, and thus providing an overview of the 'conservation problem' and indicating initial priorities (Heywood & Iriondo 2003, Newton & Oldfield 2008, Kozlowski et al 2012, Cavender et al 2015, while ex situ conservation action is further focused by Target 8, which has the goal of having 75 % of threatened plant taxa in ex situ collections by 2020 (IUCN 2011). Such collections are usually found in botanic gardens, whose role in ex situ conservation is well known (Heywood & Iriondo 2003, Maunder & Byers 2005, Oldfield 2009, Blackmore et al 2011, Pritchard et al 2011, and has been recognised for many years (Given 1987).…”

“…the 201 vireya taxa that were Red Listed 4 , or the 60 taxa assessed as Vulnerable. While the Red List categories create an initial hierarchy, other factors such as geographic hotspots, endemism and taxonomic distinctiveness have also been used to shape priorities (Farnsworth et al 2006, Kozlowski et al 2012, Castañeda-Álvarez et al 2015, Cavender et al 2015. Identifying taxonomic distinctiveness can be problematic in 'big genera' because of their complex taxonomic structures with many subgroups, large numbers of taxonomic queries, frequent hybridisation and active speciation (Crutwell 1988, Frodin 2004, Ennos et al 2005, Milne et al 2010, Argent 2015; a comprehensive taxonomy is required to underpin any conservation assessment that considers taxonomic groups.…”