The Summer Villa estate was famous for its wildness, preservation of Nature, pleasant climate, and beautiful scenery in the Qing Dynasty when the natural ecosystems were strictly conserved by the Emperors Kangxi and Qianlong (1703–93). Plants on the estate played an important role in this embellishment, 28 out of the 72 noted scenic sites being named after plants or plant etc. materials. The estate has been seriously destroyed in the last 150 years by wars, fires, and natural disasters, before the foundation of the new China. The damage was especially serious in the Hill Area, comprising some 80% of the estate.The present vegetation in the Hill Area is the result of reafforestion in the 1950s. Seven different plant communities, composed of natural and artificial elements, are now found there, most extensive of which is the Pinus tabulaeformis artificial forest with Vitex chinensis dominating the shrub layer. Some of these communities are unsuitable for the scenic spots on which they stand, some are not adaptable to the habitats, some have problems such as consisting of single species — so resulting in susceptibility to pests and offering little possibility for birds to make their nests and mammals to colonize.The natural environment in the estate is becoming widely degraded, with serious SO2 and Pb pollution caused by tourism and urbanization. Plants — especially needleleaf trees — are sensitive to these pollutants.This paper discusses the process of designing for Nature in the Hill Area of the Summer Villa estate, much of the work being concerned with problems of the present vegetation and the best approach to deal with them. To create Nature for the City of Chengde and at the same time recover the natural beauty in the Summer Villa estate, much attention is paid to the natural characteristics of suitable plants — especially those ‘historical’ natural species which can adapt to the present habitats. Five subsidary landscape areas with different plant characteristics in different habitats have been designed. Maps of the ‘historical’ natural vegetation, the present vegetation, and designs for Nature in the Hill Area, have been drawn and are here reproduced for practical use.
Effects of Nitrogen Addition on Leaf Decomposition of Single-Species and Litter Mixture in Pinus tabulaeformis Forests