New Progress in the Field of Urban Forestry

Editor's Note

Recently, Professor Zhang Hongmao's research team, and Associate Professor Niu Hongyu's research team, both from the School of Life Science in CCNU, published the latest research findings on maintenance mechanism of woody plant diversity in urban forest in Landscape and Urban Planning, a top journal in the field of urban research, with Associate Professor Niu Hongyu as the first and corresponding author, Professor Zhang Hongmao the corresponding author,  master students Zhiwen Chen, Xingcheng Yue and Hengyue Zhao, Dr. Xiaorong Wang of Hubei Academy of Forestry, Dr. Finn Rehling, Dr. Dana G. Schabo and Professor Nina Farwig of the University of Marburg the co-authors.

The diversity of woody plants in fragmented urban forests tallied with the theory of island biogeography, and was affected by forest patch area and isolation, community structure and fragmentation of naturally regenerated woody plants, plant seed dispersal modes and early afforestation strategies.

In the process of urbanization, the original forest is often isolated by roads or construction, becoming a "green island" in the urban landscapes, and performing ecological functions such as biodiversity maintenance, climate regulation and ecological health care for the urban ecosystem. Understanding the natural regeneration status of existing woody plants and influencing factors can contribute insight into the structure and function maintenance mechanism of urban forests, and provide the rationale for urban forestry planning and management.

Among the 28 forest patches in Wuhan (Figure 1), the researchers recorded a total of 7231 mature trees, 7273 young trees and 8905 woody plant seedlings, among which the proportion of individual plant relying on animals to spread seeds in the mature, young and seedling stages increased by 49.1%, 65.1% and 80.7%, respectively.

Figure 1: The 28 Forest Patches in Wuhan

The results indicated that woody plant species diversity in urban forest patches in Wuhan is correlated with patch area, isolation degree, plant seed dispersal mode and plant growth stage. Different tree species were selected in different administrative districts of Wuhan during afforestation, resulting in similar community structures in forest patches in the same administration, but different ones among different  administrative districts. This difference was maintained from the tree stage to the seedling and young tree stage, showing that afforestation strategies had long-term effects on forest plant communities. However, plant communities that rely on animal to disperse seeds are consistent among forest patches with smaller patches or greater isolation, further demonstrating that animal-dispersed plants have higher renewal potential in fragmented urban forests.

Over time, relying on animals to disperse seeds will dominate urban forests. Therefore, in the long run, in order to maintain woody plant diversity, multiple replanting is required to promote the renewal of non-animal-dispersed plants in urban forests.

This research was supported by the National Natural Science Foundation of China, the China Scholarship Council, and the State Key Laboratory of Pests and Rodents in Agriculture, Institute of Zoology and Chinese Academy of Sciences.

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Editor: Lydia(trainee)

Revisor: Luyu

Designer: Crystal