| Summary | 第1-8页 |
| Ecological and ecophysiological traits | 第8-78页 |
| 1 Background | 第8-10页 |
| 2 The nature of elms | 第10-12页 |
| 3 Elm trees in North China | 第12-15页 |
| 4 Sparse-elm-grassland in Hunshandak Sandland | 第15-18页 |
| 5 Degradation and restoration of sparse-elm-grassland | 第18-29页 |
| 6 Impacts of human disturbance on the parse-elm-grassland | 第29-37页 |
| 7 Chlorophyll fluorescence characteristics of sparse-elms-grassland | 第37-46页 |
| 8 Comparison of ecophysiological responses to drought stress between native and exotic trees | 第46-57页 |
| 9 Gas exchange and water use efficiency of three native tree species | 第57-67页 |
| 10 Why elms distribute on the sandy dunes | 第67-78页 |
| Reference | 第78-88页 |
| Appendix | 第88-95页 |
| I: Resume | 第88-89页 |
| II: Publications | 第89-94页 |
| III: Research projects & Ministrant works | 第94-95页 |
| Acknowledgements | 第95-96页 |
| Resume (in Chinese) | 第96-97页 |
| Abstract (in Chinese) | 第97页 |
