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Press Release: ArbNet accredits 500th arboretum

Tree Heritage Park in Ibadan, Nigeria accredited by ArbNet, the only accreditation program in the world specific to arboreta

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Lisle, Ill. (January 10, 2022) — The Tree Heritage Park in Ibadan, Nigeria, became the 500th arboretum to be accredited by ArbNet, the only accreditation program in the world specific to arboreta – or tree-focused botanical gardens.

The park earned level II accreditation status for standards pertaining to its tree collections, programs and operations. The Tree Heritage Park is located within and managed by the International Institute of Tropical Agriculture (IITA) in the Guinean Forests of West Africa, a biodiversity hotspot. The park hosts more than 100 species of native trees, about half of which are classified as threatened and/or endemic.

“It is a great honor for the Tree Heritage Park to be accredited, and it feels more special for it to be the 500th accredited arboretum in the ArbNet network,” said Hilde Koper-Limbourg, deputy director-general at the IITA. “I hope this will inspire others to see the value of growing indigenous trees for research, education and awareness creation.”

The Tree Heritage Park started in the early 1990s as an agroforestry arboretum incorporating both food and forest crops. In 2015, it was restored for the conservation of rare and endangered Nigerian trees. In addition to serving as a repository of genetic resources, it provides opportunities for environmental education.

“We will now be able to brainstorm with a pool of about 500 experts and institutions,” said Adewale Awoyemi, manager of the Forest Center at the IITA, about its involvement with ArbNet. “I am particularly keen on harnessing this synergy to raise greater awareness and funding opportunities for the conservation of threatened and rare West African trees and promote capacity building among our staff,” Awoyemi added.

Administered by The Morton Arboretum, near Chicago, Ill., USA, ArbNet has accredited arboreta in 37 countries. In addition to arboreta and botanical gardens, accreditation can be earned by other institutions with a focus on tree and woody plant collections and conservation, such as parks, historical sites, college campuses and nature preserves.

“ArbNet is focused on expanding and reaching arboreta in biodiversity hotspots to support their tree-focused purposes,” said Sue Paist, ArbNet’s coordinator. “Through resource sharing, connections with other arboreta and funding opportunities, we hope to expand this program to every corner of the world and further the global conservation of trees,” she added.

The accreditation program recognizes arboreta at various levels of development and capacity, based on an arboretum’s tree collections and curation, education and public programming, scientific research and conservation initiatives, governance and staff or volunteer support.

“Over the past decade, the ArbNet community has grown significantly in scale and impact,” said Gerard T. Donnelly, PhD, president and CEO of The Morton Arboretum. Donnelly led the establishment of ArbNet in 2011 with a vision to strengthen the arboretum community and enable collaboration to advance the planting, study and conservation of trees.

“By working together, arboreta throughout the world play a key role in preventing the extinction of tree species and protecting the many living organisms they support that are threatened as a result,” Donnelly said. According to the Global Tree Assessment released this year by Botanic Gardens Conservation International (BGCI) and its partners, one third of all trees on Earth are threatened with extinction.

In the future, the ArbNet network will continue to increase its reach and programs, focusing on new science and conservation opportunities. ArbNet supports all types of arboreta as they study and protect trees, and ultimately advance the professionalism and impact of their work.

A free-to-access whitepaper in Plants, People, Planet provides a detailed exploration of the past, present and future of ArbNet. Information about the global, interactive community of arboreta can be found at