Submitted on: 08 March 2001.
Revised on: 11 April 2001.
Accepted on: 05 May 2001.
URBAN ECOSYSTEMS---SPRINGER
http://reply.papertrans.cn/4/302/30192/30192-32.png
http://reply.papertrans.cn/4/302/30192/30192-33.png
Submitted on: 02 October 1999.
Revised on: 27 October 1999.
Accepted on: 16 November 1999.
URBAN ECOSYSTEMS---SPRINGER
http://reply.papertrans.cn/4/302/30192/30192-35.png
http://reply.papertrans.cn/4/302/30192/30192-36.png