Spatial differentiation of heritage trees in the rapidly-urbanizing city of Shenzhen, China

In China, heritage trees are actively surveyed and reported. Over 300 relevant published articles were reviewed to assess the contents, trends and geographical distributions of the investigations. The majority of the heritage trees studies in China were found in the eastern provinces and published within 2010-2014. Most studies reported surveys on all old trees. For studies focused on single species, Ginkgo (Ginkgo biloba) and Chinese Yew (Taxus chinensis) was most frequently reported. Unlike the champion tree registry in the US and other countries, the tree registry in China emphasized more on the tree age than the size. We then have studied the heritage trees in the rapidly-developed municipality of Shenzhen in South China in details. The species composition, diversity and spatial distribution were investigated using ecological indices and statistical techniques. Most trees were native with domination by Ficus microcarpa. Heritage-tree density was not correlated with land area, population density, green cover, or district development year. The oldest and youngest districts have relatively higher species diversity and tree density. It indicated the preservation of an old town plan and the creation of a new town plan conducive to accommodating pre-urbanization heritage trees. Village and forest habitats with rich tree endowments can be targeted for conservation in new urban areas. The importance of adopting a nature-friendly town plan, and the associated policies that can facilitate it, are instrumental in heritage-tree nurturing and protection. The findings can inform tree preservation and urban green infrastructure provision in fast developing cities in China and beyond.