References
- Saunders , D.A. , Hobbs , R.J. and Margules , C.R. 1991 . Biological consequences of ecosystem fragmentation: a review . Conservation Biology , 5 (1) : 18 – 32 .
- Diamond , J. 1989 . “ Overview of recent extinctions ” . In Conservation for the Twenty-first Century , Edited by: Western , D. New York : Oxford University Press .
- Hallam , T.G. , Clark , C.E. and Lassiter , R.R. 1983 . Effects of toxicant on populations: a qualitative approach. I. Equilibrium environmental exposure . Ecol. Modelling , 18 : 291 – 304 .
- Hallam , T.G. , Clark , C.E. and Jordan , O.S. 1983 . Effects of toxicant on populations: a qualitative approach. II. First order kinetics . J. Math. Biol. , 18 : 25 – 37 .
- Hallam , T.G. and Zhien , Ma . 1986 . Persistence in population models with demographic fluctuations . J. Math. Biol., IA , : 327 – 339 .
- Zhien , Ma , Baojun , Song and Hallam , T.G. 1989 . The threshold of survival for systems in a fluctuating environment . Bull. Math. Biol. , 51 (3) : 311 – 323 .
- Zhien , Ma , Guirong , Cui and Wendi , Wang . 1990 . Persistence and extinction of a population in a polluted environment . Math. BioscL , 101 : 75 – 97 .
- Huaping , Liu and Zhien , Ma . 1981 . The threshold of survival for system of two species in a polluted environment . J. Math. Biol. , 30 : 49 – 61 .
- Zhien , Ma , Wengang , Zong and Zhixue , Luo . 1997 . The threshold of survival for an ç-dimensional food chain model in a polluted environment . J. Math. Anal. Appl. , 210 : 440 – 458 .
- Yucun , C. 1994 . The urgent problems in reproduction of giant pandas . Chinese Wildlife , : 3 – 5 .
- Xiao , Y.N. 1999 . Permanence and periodic solution of nonautonomous delay Lotka-Volterra diffusion system . System Science and Mathematical Science , 12 (4) : 344 – 349 .
- Beretta , E. and Takeuchi , Y. 1987 . Global stability of single-species diffusion volterra models with continuous time . Bull. Math. Biol. , 49 : 431 – 448 .
- Hale , J.K. 1977 . Theory of Functional Differential Equations , New York : Springer-Verlag .
- Institute of Botany . 1978 . Environment Pollution and Plant , Beijing : Science Press .