: Ecology :2773760 ;13070600647Email:sglhit.student@sina.com

2002200019932000

Serious issues in the 21th century in the world Population Food supplies Environment Energy sources Diseases

Agricultural land expansion

1 35~38Cyanophyta 1000 2 3

2 CO2O2 4 CO2 O2

3 DDT 50 DDT, DDT

2020

2020

EcologyHaeckel, 1869. Elton1927 Andrewartha, 1954Krebs, 1972

2 Braun-Blaquet, 1932E.P.Odum19561980--E.P.Odum1997Haeckel 1869

60

1962RachelCarson

19704221970422

1973ArneNaess

1992, 1983()2001

[M]20002~3.

1

2

3

4

1

DNA DNA1000

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3

Observation and description Hypotheses and Experimentation (Model and Simulation)

1 2 X 3

1 2 3

4 Gilbert (1991)Nature

categorical framework;.,,2002.

1

9,21 . 382.

DNA20021023

2020

1 2 3 3