SCIENCE & conservation

Global trees conservation - Current projects

Nicole and Wei Bang


Current projects at The Morton Arboretum leading and assisting efforts to prevent extinction and secure the world’s threatened tree species.








Building support for the Global Trees Campaign. The Global Trees Campaign (GTC) was launched in 1999 as a joint initiative between Fauna & Flora International (FFI) and Botanic Gardens Conservation International (BGCI) to conserve the world’s threatened tree species.  The GTC works by directly supporting tree conservation programs, building capacity for organizations to protect trees, engaging local communities with conservation-focused training, promoting tree conservation in arboretum collections and in the wild, and providing useful conservation resources.

The Morton Arboretum is working with BGCI, FFI, and arboreta throughout the United States and abroad to explore ways in which public gardens can play a more active role in the GTC network. One strategy is to encourage partnerships between ArbNet arboreta and GTC conservation initiatives in tree diversity hotspots. ArbNet arboreta can provide botanical expertise and maintain safeguarded collections of threatened tree species, which support complementary conservation efforts in the wild. Pairing ArbNet arboreta with GTC initiatives in this way supports the organizations and communities that protect some of the world’s most diverse and imperiled tree communities. Encouraging these partnerships increases conservation capacity and can bring attention and government support to efforts to save threatened tree species.

Growing the ArbNet community. ArbNet, the interactive community of arboreta, is a powerful tool for building conservation capacity and strengthening the global garden network. ArbNet is sponsored by The Morton Arboretum and administers the ArbNet Arboretum Accreditation Program, which fosters professionalism and recognizes standards of excellence in arboreta. The new ArbNet website provides helpful resources, tree-focused news and events, and a searchable database of the world’s arboreta – the Morton Register of Arboreta. ArbNet members can use the Morton Register and the online discussion forum to identify other arboreta with complementary collections and conservation programs for collaboration opportunities. The Morton Arboretum is working with BGCI to link ArbNet member gardens with international conservation initiatives supported by the Global Trees Campaign.

Participating in conservation networks. The Morton Arboretum is a member of the Center for Plant Conservation (CPC) and works with that network to protect threatened plants of North America through monitoring of wild populations, protection of native habitats, and propagation and reintroduction of individuals to increase population numbers. The Arboretum has been working with the CPC since 1985 on a variety of conservation projects.

The North American Plant Collections Consortium (NAPCC) is a network of botanical gardens and arboreta coordinating a continent-wide effort to preserve threatened plant germplasm and promote high standards of plant collections management. The Morton Arboretum was one of the first members of NAPCC and maintains five outstanding collections that have been recognized for their conservation value, high standard of curation, and institutional commitment to conservation. They are the oak (Quercus), elm (Ulmus), maple (Acer), magnolia (Magnolia), and crabapple (Malus) collections. The oak, maple, and magnolia collections also are a part of national multi-institution collections. The NAPCC is a program of the American Public Garden Association (APGA), another valuable network for driving plant conservation in North America.  The Morton Arboretum is a member of APGA and participates in many professional sections, including International Gardens and Plant Conservation.

Forging partnerships in China. The Morton Arboretum is developing close partnerships with botanical gardens around the world to collaborate on various tree conservation initiatives. One region of strategic importance is China. One of the world’s most valuable biodiversity hotspots, China is home to 30,000 vascular plant species—10 percent of all known plants—and some of the most majestic and endangered tree species, including gingko (Ginkgo biloba) and dawn redwood (Metasequoia glyptostroboides). China faces many challenges to its endemic tree diversity, such as rapid and extensive industrialization, population growth, intensive agriculture, overharvesting of timber, and climate change. Fortunately, the Chinese government has recently made huge investments of funds and political interest in plant science research, establishing public gardens, and preserving endemic biodiversity.

China and the US are unique in sharing a broad range of climatic zones and vast size, making them natural partners in tree conservation efforts. The Morton Arboretum has a long history of collections and collaborations with China. Some of our earliest and oldest living accessions are from China, including seeds obtained in 1922, the year the Arboretum was established by Joy Morton. The Arboretum is a founding member of the North America China Plant Exploration Consortium (NACPEC), and Arboretum staff members have participated in collecting trips to China for over 20 years. In support of our goal to be a world leader in tree science, conservation, and the arboretum community, The Morton Arboretum has established formal partnerships with four Chinese institutions: Shanghai Chenshan Botanical Garden, Beijing Botanical Garden, Hunan Forest Botanical Garden, and Kunming Botanical Garden/Kunming Institute of Botany. These partnerships have several areas of focus including strengthening tree conservation efforts in gardens and in the wild, assessing genetic diversity of threatened Chinese tree species, developing ArbNet in China, and supporting the Global Trees Campaign. The objective of these initiatives is to influence the direction of tree conservation in China and build a supportive global network of arboreta.



Achieving conservation targets for tree collections in public gardens. An important way to prevent the extinction of trees that are endangered or threatened in their native habitats is to maintain some of those trees safely in the collections of arboreta and public gardens. These ex situ or “off site” conservation collections act as a gene bank, preserving some of the wild genetic diversity of threatened tree species, and also allow arboretum scientists and horticulturists to learn how threatened species grow and develop, reproduce, resist pests and disease, and how they might adapt to climate change and assisted migration efforts. Target 8 of the Global Strategy for Plant Conservation is to have at least 75 percent of the world’s threatened plant species in ex situ collections, preferably in the country of origin, and at least 20 percent available for recovery and restoration programs. To help advance this initiative, The Morton Arboretum is actively involved in preserving the world’s endangered tree species in its living collections. The Arboretum has over 100 threatened and endangered taxa in its collections and encourages all arboreta to collect or receive plants that need protection to ensure their survival as species. The Arboretum is also exploring opportunities to support and collaborate with in situ (“on site”) conservation efforts, like habitat restoration, for threatened trees around the world.

Assessing the genetic diversity of ex situ tree collections. The key purpose of an ex situ conservation collection of trees is to act as an insurance policy against the loss of the species in the wild. If all of the naturally occurring populations of a species disappear, for example through overharvesting or habitat destruction, the trees in the ex situ conservation collections can be used as a seed source to reintroduce the species to the wild. However, for ex situ tree collections to be of any real conservation value, they must capture as much of the natural genetic diversity of the species as possible. The Morton Arboretum is conducting the conservation genetics research needed to develop models to predict how many individuals of a species are needed in an ex situ collection to capture a sufficient amount of the natural genetic diversity. Two endangered tree species, Quercus georgiana (Georgia oak) and Acer griseum (paperbark maple) are currently being investigated by Arboretum scientists, with collaborators at Chicago Botanic Garden and Morris Arboretum. For these two species, leaf samples are being collected from all known ex situ specimens and from strategically chosen individuals in the few remaining wild populations. Conservation genetics analysis will reveal the extent to which the ex situ collections capture natural genetic diversity and inform future collecting expeditions to ensure these two threatened species are adequately protected in the world’s botanical gardens and arboreta.

Protecting exceptional species. Another important reason for botanical gardens and arboreta to maintain ex situ conservation collections is to protect “exceptional species,” those species that cannot be preserved through conventional seed banking technologies. Exceptional species either do not produce seed naturally or have seeds that do not survive the cold temperatures and low humidity of standard seed banks. Examples of exceptional species groups include the oaks (Quercus spp.), magnolias (Magnolia spp.), and several species in the rose family (Rosaceae). In order to preserve these exceptional species, individuals must be grown in living conservation collections by experts with horticultural knowledge, which is why it is so important for public gardens to prioritize these taxa for their collections. The Morton Arboretum supports the efforts of the Exceptional Plant Species Advisory Group, a collaboration between BGCI and the Cincinnati Zoo and Botanical Garden’s Center for Conservation and Research of Endangered Wildlife. The Group is working to identify which tree species are exceptional, prioritize species for conservation collections, and promote research in propagation and cryopreservation of exceptional species.



Assessing threat levels for the world’s oak species. Oaks are keystone species of forest ecosystems worldwide. However, oak-dominated ecosystems all over the world are disappearing, and many species are threatened with extinction. Less than half of the world’s roughly 425 oak species have been evaluated for the IUCN Red List of Threatened Species, the most comprehensive and widely accepted process for evaluating the global threat status of plant and animal species. The Arboretum is taking the lead on completing threat assessments for the world’s oak species, which will provide gardens with the information needed to prioritize species for ex situ conservation collections and enable policymakers to protect threatened oaks.

Leading a global oak research initiative. The Center for Tree Science at The Morton Arboretum is launching a coordinated and integrated portfolio ofPDF iconoak-focused collaborative research projects centered on oaks. Through this research initiative, Arboretum scientists and their collaborators will address urgent questions about oak evolution, diversity, and ecology. One project already underway is using conservation genetics techniques to investigate the amount of wild genetic diversity that is being captured by arboreta and garden collections of oaks. The results of these studies will inform collecting strategies so that the most genetically diverse wild populations can be targeted for future collection efforts, ensuring the arboreta and garden collections of these  threatened species are preserving as broad a gene pool as possible.

Improving our oak collection. The Morton Arboretum is working to improve the conservation quality of its oak collection by verifying the identity of each specimen, removing undocumented specimens, and increasing the number of threatened oak species. In the future, Arboretum researchers and curators plan to establish large, genetically diverse conservation collections of key threatened North American oak species.

Hosting the world’s oak experts. It was at The Morton Arboretum in 1994 that the International Oak Society (IOS) was founded, and to the Arboretum the Society will return for its 20th anniversary meeting in October 2015. The conference will bring together over 100 oak experts and enthusiasts from around the world to present research results, exchange germplasm, explore the Arboretum’s oak collection, and participate in regional field trips. A concurrent meeting of the IUCN Global Tree Specialist Group will run alongside the IOS conference and will focus on evaluating threat levels for the world’s tree species, including oaks.



Vanishing Acts: Trees Under Threat exhibition. The Morton Arboretum is committed to providing education and inspiration in support of tree conservation. In partnership with Botanic Gardens Conservation International (BGCI), the Global Trees Campaign, and the Institute of Museum and Library Services, The Morton Arboretum developed a traveling exhibit and comprehensive educational package to share information about globally endangered trees. This unique learning experience takes a compelling look at threatened and endangered trees and the importance of taking action to save them. The exhibit emphasizes trees’ important role in sustaining livable communities, and empowers people around the world to act as champions of trees. With the cooperation of the Beijing Botanical Garden, the exhibit has been translated into Chinese, and is currently on display in several botanical gardens in China. Educational materials and display panel images are available for free from The Morton Arboretum. To expand the reach of these critical messages, new interactive and family-oriented messages are currently being developed.