Abstract:

Plant functional types can be defined as sets of plants exhibiting similar responses to environmental variations and having similar effects on the dominant processes in ecosystems. In the present paper, 23 plant functional types were identified from five zonal woody plant communities occurred in Gansu province, NW of China. This paper has made some explorations on the relationship between the patterns of zonal woody plant functional types and the hydrothermic factors to which they subjected. Some conclusions are as follows: Environments with warm humid combinations would result in well developed plant communities characterized by arbor, big shrubs, lianas and parasites as the dominant life forms and key fruit, nut, drupe, follicle, caryopsis as the dominant fruit types, while dry cold habitats are always correspond to those with shrubs, small shrubs and deciduous trees as well as capsule as the dominant life forms and fruit types. The trade off of species relative richness between dry fruit and sarcocarp in a given plant community may be strongly influenced by the humidity level in plant's growing seasons. In addition, plants of cone fruit types are specially favored by wet cold habitats. A precipitation gradient is one of the decisive factors shaping the patterns of both species richness and richness of plant function types (in terms of plant stature and fruit types) among these five zonal woody plant communities in the study area, while environments with optimal hydrothermic combinations would lead to the highest diversity of fruits types.

Key words: Plant functional types, Zonal woody plant community, Hydrothermic factors