Abstract:

 Karstic geological and ecological systems are the important components of the Earths surface system, and their changes will give impacts on other areas and even the Earth system. Biogeochemical cycling is the key subject of studies of global as well as local changes, since there is a strong linkage between change of an ecological system and biogeochemical cycling of water and nutrients. Accordingly, it is important to study the changes of karstic ecological system and its response to or impact on global change, based on a better understanding of biogeochemical cycling in a whole karstic ecological system. It is the base of further studies on plant adaptabilities and optimization of assemblage of plant species of an ecological system. Based on the previous studies, this review introduces our researches on biogeochemical processes and nutrient cycling occurring mainly at rock/soil and soil/plant interfaces in karstic ecological system by using chemical balance theory, stoichiometry and multiple isotope tracers (e.g., δ13C, δ15N, δ34S, 87Sr/86Sr). The achieved important understandings are that the biogeochemical cycling of nutrients in karstic ecological system is active, coupled to each other and closely related to ecoenvironmental change, that human activities are clearly impacting natural biogeochemical cycling in catchments and result in related ecological and environmental problems, and that the studies on areal change are important for studying global change. These findings or recognitions will be the main directions leading our further studies of biogeochemical cycling nutrients in karstic and other ecological systems.

Key words:  karstic ecological system; biogeochemical cycling; global change; areal response; ecological adaptability; research trends