| As a human activity inducing land use change, rural land consolidation is an important tool to facilitate agricultural production and improve eco-environment, and is a compulsory and short-term tool that would have dramatic impact on ecosystem and landscape pattern instantly. The present rural land consolidation projects aim at increasing arable land in China, with less attention on rural land use and eco-environmental problems. Emprical studies show that land consolidation projects bring out disturbance of rural landscape, loss of biodiversity, and a potential threat on cultivated land protection, food security and quality of agricultural products. Instead, the rural land consolidation should be an important strategic tool of adpatating to climate change, improving eco-environment, ensuring food security, and coordinationg the development of urban and rural development. Consequently, there are still many questions to answer, such as how to use the technological and engineering measures of land consoliation to meet with the above objectives, what impacts of land consolidation on eco-environment, especially on habitats stablity, landscape diversity, land productivity, ecological services and hydrological process. There is a need for better theoretical and practical knowledge or understanding on land consolidation.This paper selected five "entire-village advancement" projects of land consolidation as cases, which distributed at different locations of Chongqing, such as the core urbanized area, and the southwest and southeast area, called as "one round and two wings". First, based on theories of land use change, rural land consolidation and landscape ecology, this paper attempted to discover how engineering and technical measures reduced land fragmentation through land consolidation, from an aspect of "rural land consolidation-land use change-landscape pattern and ecological process" The second objective was to explore the relationship between land use, agricultural bio-diversity and land parcels heterogeneity, based on landscape ecology. That would help improve our understanding about technical requirement of rural landscape rehabilitation and engineering adaptability of land consolidation. Finally, technical policies and alternatives were suggested to improve rural landscape pattern through land consolidation, from theoretic and technical aspect. The main findings and conclusions are as follows: (1) Rural settlements consolidation and its landscape effects:First, according to the relevant national standards, rural settlements area per capita approached at the standard in the five villages, while the area per household was larger than the standard, which reflects extensive land use. The rural settlements distributed scatter in the mountains and compact in the hills for those villages. The number and area of rural settlements decreased with altitude increased. Second, rural settlements consolidation was a systematic engineering, because it incorporated agricultural industrial development, and speed the transformation from disorder and dispersed rural settlements to large-scale and well-planned ones, and accelerated the land use transformation and the ecological restoration in those villages. Third, the density of rural settlements decreased significantly, while their size increased and their distribution became simple in those villages, through rural settlements consolidation. Fourth, the landscape diversity declined after consolidation, as indicated by the decrease of average SHDI from0.9209to0.8829. Average LSI decreased from23.2451to21.3039, reflecting that the shape of rural settlements became simple. The rural settlements get a higher level of spatial aggregation, since average CONT increased from93.9518to94.8299. We can infer from it that rural settlements consolidation was good for rural areas to some extent, because it decreased the dispersed pattern of natural villages, and rehabilitated the rural landscape, as well as provided more opportunities for local people. Espcially, it improved the links among rural land use, agricultural biological diversity and land parcles heterogeneity.(2) Land leveling and its landscape effects:First, the major problem confronting by shallow or low hilly areas was scarce land for a large population, while that confronting by mountainous or valley areas was extensive land use due to topography constraints. In general, most of paddy fields located in the areas with a slope less than15degree, while78.28%of rainfed land located in the areas above15degree. As a result, the fragmentation of paddy field and rainfed land had different meanings. That is, the use of paddy fields was contrained by curved and land-consuming path throuth fields. In constrast, the use of rainfed land was contrained by the sloping terrians, which made agricultural production more inconvenient due to soil erosion and crop reduction. Second, it was workable to eliminate small parcels of paddy fields, strip and regulate paddy field pattern, while it was good to change sloping rainfed land to rainfed terraces for land leveling, for reducing land fragementation and improve land use effiency. Third, with land leveling, rural landscape including paddy fields and rainfed land changed since the shape became regular. Therefore, to reduce land fragmentation, a few measures were suggested, including eliminating small parcels of paddy fields, striping and regulating paddy field pattern, and changing sloping land into terraces.(3) Rural roads construction and its landscape effects:First, the constuction of rural roads enhanced carrying capacity of roads and decreased transportation land occupation, by improving the distribution and quality of them. Excluding YD-â…¡ village, the other villages had an increase about2%-11%of the ratio between major field roads and minor ones. The roads built by concrete increased and the width of them enlarged. The looping index of rural roads (a) increased from0.32-0.37to0.37-0.46, while the connectivity index of rural roads (y) increased from0.54-0.58to0.58-0.64. Second, rural roads construction fragemented rural landscape, while the demolishing of rural roads reduced landscape fragementation. However, there were no significant impacts of rural roads construction on the connectivity and diversity of landscape, due to relatively small change of rural roads. As for the landscape types level, it was found that rural roads construction optimized road network and the pattern of arable land, rural settlements and ecological land, thus rebuilding and optimizing rural landscape.(4) Farmland water conservancy and its landscape effects:First, the characteristics of quantity, quality and network became better after implementation of farmland water conservancy than before. The irrigated areas were enlarged through land consolidation in the five villages. The number of newly built tanks amounted at65in those villages, the total length of irrigation cannals increased from19.94km to27.25km, and the length of drainage ditches increased from80.60km to136.03km. As a result, the density of irrigation and drainage network (D) increased from10.98-22.94to16.73-50.60, and their looping index increased from0.16-0.25to0.20-0.28, and their connectivity index from0.45-0.50to0.47-0.52, respectively. Second, at the landscape level, the provision of farmland water conservancy fragemented rural landscape by separating land patches and increasing shape complexity, but it had no significant impacts on the diversity and connectivity of rural landscape. At landscape type level, the provision of farmland water conservancy significantly changed the spaital pattern of cultivated and ecological land and resulted in land use change, but it had little impacts on the pattern of rural settlements.(5) The overall land use change and its landscape ecological effects before and after land consolidation:First, after land consolidation, agricultural land significantly increased, ecological land significantly decreased, and rural facilities land decreased slightly. Second, cultivated land was disturbed and fragmentated by land consolidation, rural settlements was disturbed and regularized by land consolidation, and ecological land was disturbed and regularized slightly. At landscape level, the overall landscape fragmentation reduced, the largest patch area and patch aggregation increased, the corridor connectivity of patches increased, and the regularity of shape and landscape diversity reduced. Among different villages, there were a few differences of landscape change by land consoliation, due to the impacts of terrain such as hills, flat land or mountainous areas. Third, the total ecological value increased after land consoliation among those villages, but the change of ecological value varied with land use types. For example, the ecological value of agricultural land and facilities land generally increased, with an increment of10.25percent and9.94percent respectively in the village of YD-I. However, the value of ecological land varied with villages. Fourth, the adjustment of land use structure resulted in the change of landscape configuration, and the land use conversion led to the change of landscape function. Consequently, through land consolidation, landscape pattern evolved and landscape ecological effect changed. Rural residential land was converted to cultivated land, orchard and forest in hilly areas by land consolidation, which increased the connectivity of ecological land patches and the stability of landscape. Rural roads construction and farmland water conservancy increased the connectivity of landscape. After land consolidation, the cultivated soil was disturbed, which had a negative effect on soil fertility and biodiversity by interrupting the moisture and nutrient cycling in soil. The adjustment of land use structure should take biodiversity conservation and rural land use optimization into consider, based on land heterogeneity. The results indicated that land consolidation harmonized the relationship between man and nature, and it also increased landscape diversity.(6) It was suggested that landscape plan methods should be incoprated into the designs of land consolidation projects, for the purpose of biodiversity protection. For instance, we should took those methods into practices, such as the protection of core habitat, the establishment of buffer, the construction of corridor, the enhancement of landscape heterogeneity and the recovery of habitat.To sum up, this paper provided an analytical framework of "rural land consolidation-land use change-landscape pattern and ecological process", based on strategy of rural land consolidation and ecological landscape construction. The framework provided possible solutions at local scales to those problems resulted from land use and landscape change by land consolidation, and revealed the links among land use, agricultural biodiversity and land heterogeneity. The results would help better understand of the relationships between land consolidation and ecological effects, and provided better technological suggestions or strategies of how to consolidate rural landscape and conduct land consolidation, as well as how to adjust land consolidation to improve ecological landscape. The results would also help testify and further the theories and technical innovations of land consolidation, based on landscape construction.
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