Scenarios study on returning farmland to wetlands for protecting red-crowned cranes in the Liaohe Delta
辽河三角洲湿地以丹顶鹤生境保护为核心的退耕预案研究

The Liaohe Delta is one of the most important wetlands for wild animals, especially for water birds, to inhabit and breed. It is the southern most site for the breeding of red-crowned cranes (Grus japonensis), and an important stopover site on their migration route. Therefore this delta plays an important role in the international conservation of cranes. But the area of suitable habitat had reduced and the quality of habitat was degraded in the last decades, mainly due to oil and agricultural exploitation. The objective of this research was to find an appropriate land use model to keep economic development and habitat conservation of the region.Based on the study of land use change between 1988 and 1998 in the Liaohe Delta, and supported by intensive field investigation, four land use planning scenarios of the Dawa sub-delta were designed with the scenarios approach and the evaluation idea of LEDESS Model (Landscape Ecological Decision and Evaluation Support System). The four scenarios, Year 1988 (No.1), Year 1998 (No.2), Reed belt (No.3) and Habitat restoration (No.4), were different in the aims of ecological and economic benefit. The main measures were returning paddy fields to reed fields and prawn-crab-ponds to restore the habitat of wild animals. The habitat suitability, the breeding carrying capacity and the economic benefit of different scenarios on the red-crowned crane's habitat were simulated and evaluated with different methods, in which spatial diversity index was adopted to analyze the habitat suitability. The result was that the habitat suitability, the breeding carrying capacity and the economic index were 0.575, 33 pairs and 10.56 respectively in Scenario No.1, 0.357, 22 pairs and 16.68 in Scenario No.2, 0.435, 32 pairs and 17.42 in Scenario No.3, and 0.535, 41 pairs and 17.74 in Scenario No.4. It was concluded that Scenario No.1 was unpractical because of the lowest economic benefit in the four scenarios; Scenario No.2 had high economic benefit but the least ecological benefit, which endangered the suitable habitats of the wild animals; and Scenarios No.3 and No.4 were effective to keep harmonious development between economy and environment, which could be actualized in steps as the short-term and long term planning goals. It was indicated that appropriate land use models and habitat restoration measures could not only keep economic development but also offer a steady habitat for wild animals. This study can serve as a reference to the coordination between economic development and ecological conservation in the Liaohe Delta, as well as other similar area.