Changes in herbaceous plants in an urban habitat garden in Kyoto city, Japan, 9 years after construction

To understand the characteristics and problems of artificial urban ecological environments, we investigated the changes in herbaceous plants in an urban habitat garden for 9 years after construction and compared the results with 15 remnant semi-natural green spaces in Kyoto city, Japan. The area of the habitat garden is 0.6 ha and it was constructed approximately 3 km from the nearest mountains in 1996. From 1996 to 2004, 301 unplanted species, including 218 native species and 83 alien species, were recorded. Most newly recorded species were recorded in 1998 and the timing of colonization was different from ferns. The species turnover rate per year decreased from 30.8% in 1998 to 18.5% in 2004. This indicates that established species in the habitat garden have been gradually determined. In the species recorded in the habitat garden in 2004, the percentage of high-temperature species, which were relatively departed from the nested pattern of species composition for the 15 green spaces, was significantly high. It was considered that herbaceous plant succession in the habitat garden was at an early stage, even though it was 9 years ago since construction. Buried seeds and various environments are likely to contribute to higher species richness in the habitat garden as compared to remnant green spaces of approximately the same area. On the other hand, the high percentage of alien species and the low percentages of forest and forest edge species in the habitat garden indicate the problems of a habitat garden constructed in the center of a city.