Analysis of habitat pattern change of red-crowned cranes in the Liaohe Delta using Spatial Diversity Index

Habitat pattern change of red-crowned cranes (Grus japonensis) in the Liaohe Delta between 1988 and 1998 was analyzed with the help of Spatial Diversity Index based on remote sensing data and field investigation. The result showed that the influence from human activities on the wetland habitat of red-crowned cranes was prominent with the development of oil and agricultural exploitation, and the habitat pattern of red-crowned cranes had been obviously changed by the human disturbance during the ten years. The areas with high Spatial Diversity values (SD ≥ 0.65) and that with mid-high values (0.5 ≤ SD < 0.65), which constituted the main part of suitable habitat of red-crowned cranes, had reduced to 9142ha and 5576ha respectively, with the shrinking of natural land cover, such as reed and Suaeda community. The habitat pattern became more fragmented, which was caused by roads and wells during oil exploration. It was indicated that the suitability and quality of habitat for red-crowned cranes in the Liaohe Delta were degraded in the last decade. The results also showed that diversity index could reflect the habitat suitability of red-crowned cranes quantitatively and describe the spatial pattern of the habitat explicitly. This study will provide a scientific basis for habitat protection of red-crowned cranes and other rare species in wetlands.