Home gardens contribute to conservation of the critically endangered Wollemi Pine: Evaluation of a botanic garden‐led horticultural release programme

Abstract

Societal Impact StatementBotanic gardens play a leading role in conserving plant species worldwide. Wollemi Pine, a critically endangered species described as new to science in 1994, has been the subject of botanic garden‐led conservation efforts, including widespread horticultural cultivation. An online survey found that gardeners hold a wealth of knowledge on the response of Wollemi Pine to local environmental conditions and horticultural regimes and a high level of awareness of the importance of plant conservation. This information could increase the success of future ex situ conservation efforts, such as the development of a genetically diverse, globally dispersed metacollection of Wollemi Pines.Summary The Wollemi Pine (Wollemia nobilis; Araucariaceae) is a critically endangered conifer and the source of public and horticultural fascination since its identification in 1994. An ex situ population of Wollemi Pine was initially established in a botanic garden for conservation purposes. Subsequently, a commercial propagation programme was developed to satisfy the demand for this tree as a garden plant, with the release of plants internationally in 2005. We sought to understand how well the original aim of the Wollemi Pine horticultural release programme (to safeguard the species in the wild by promoting its widespread use in horticulture and thereby reduce the risk of illegal and harmful collection) has been met and the factors correlated with Wollemi Pine presence and growth in gardens. We developed an online community science survey to gather data on the location and growth characteristics of Wollemi Pines in garden environments globally. We received 1510 individual responses from 31 countries on five continents. The key factors correlated with the presence of Wollemi Pine were: a temperate climate with mean monthly minimum and maximum temperatures between 3.2 and 25.4°C, respectively, and above‐average rainfall. Plants in the ground were favoured by loamy soil. Wollemi Pines are established in gardens in many parts of the world and are amenable to a variety of horticultural situations. The results of this survey inform future conservation horticulture of this species, such as the development of genetically diverse metacollections, by ensuring the selection of participating botanic gardens and arboreta in environmentally appropriate locations.