Effect of rapid urbanization on plant species diversity in municipal parks, in a new Chinese city: Shenzhen

Shenzhen was a famous typical rapid-urbanization city in China, and this study compares plant species diversity in urban parks from the start of urbanization through 2011. Results show that the plant species biodiversity increased rapidly: the rate changed from 140% to 980% and the average increasing rate was 406.90%, but only 12.59% of plants spread into the park naturally. Shrubs had the highest rate; with change increasing from 20.70% to 43.54%, they replaced trees to become the dominant type. The biodiversity of native plants also increased, but their proportion relative to all species had declined. The homogenization of plant species in the parks increased; more than half of the plant species (62.24%) are located in 5–7 parks at once now, compared with 65.52% of species located in only 2–3 parks at the start of the study. The increase of species was faster than the increase of families; many new species planted belong to a few specific families. The ratio of species to families declined from 0.40 to 0.32. Results indicate that the rapid increase of plant species diversity as well as their homogenization happened in the initial stage of urbanization, and so rapid urbanization might be the major factor in the changes in plant species diversity in municipal parks. Rapid urbanization was an important cause of change in plant species diversity.