678 logical problems such as decreasing land fertility, soil erosion, and deforestation. The combination of ecological stress and high rates of rural-to-urban labor migration makes Chongqing an important study area for assessing the effects of rural migration on the rural environment. The study communities were selected through a two-stage process. First, based on the official ecological zoning of Chongqing (Luo et al. 2006), five major ecological sub- regions were identified: the metropolitan core zone, the western hilly agricultural zone, the middle parallel-valley agricultural and forest zone, the Three Gorges Reservoir ecological zone, and the southeastern evergreen broad- leaved forest zone.3 In addition, the 40 districts and counties under Chongqing’s jurisdiction display significant variability in social and economic conditions. In Chongqing’s 10th and 11th Five-Year Plans, the municipality is divided into three economic sub-regions according to geographic character- istics and socioeconomic development levels: the more- developed metropolitan area, the western economic corridor, and the Three Gorges Reservoir economic zone. By overlaying the five ecological zones with these three economic subareas, the study area was divided into four sub-regions in terms of social, economic, and ecological characteristics: the metropolitan eco-economic core area, the western-middle eco-economic corridor, the Three Gorges Reservoir eco-economic zone, and the southeastern eco- economic district (Fig. 2). In the second stage, one village from each eco-economic sub-region was purposively selected according to two criteria: (1) high magnitude of rural-to-urban labor migra- tion; and (2) abundance of natural resources such as farmland and forests. These two criteria magnify the connection between rural labor out-migration and the rural environment, and thus can facilitate understanding how rural-to-urban labor migration affects rural natural resource conservation. In sum, this two-stage selection procedure ensures heterogeneity among the final set of study communities, and helps capture the social, economic, and biophysical diversity across rural Chongqing. Four rural communities were thus selected for this study: Bailin Village (Beibei District) in the metropolitan eco-economic core area, Banliao Village (Wansheng District) in the western-middle eco-economic corridor, Dacao Village (Kaixian County) in the Three Gorges Reservoir eco- economic zone, and Tuanjie Village (Qianjiang District) in the southeastern eco-economic district (Fig. 2). Basic characteristics of these four study villages are summarized in Table 1, which shows community variations in labor 3 Luo et al. (2006) described seven ecological sub-regions of Chongqing. For ease of classification, the soil-erosion sensitive Three Gorges Reservoir zone, the Three Gorges Reservoir man-made wetland zone, and the northeastern evergreen broad-leaved forest zone are merged into the Three Gorges Reservoir ecological zone. Hum Ecol (2010) 38:675–690 migration rates, income levels, and natural resource endow- ments. Together these communities provide a representative sample of all rural areas in Chongqing. Data Collection The complexity of population-environment relationships necessitates the combination of multiple research methods. This study uses a mixed-methods approach to combine quantitative and qualitative methods (Tashakkori and Teddlie 1998). Analysis of secondary socioeconomic and biophysical data from statistic bureaus, environment protection agencies, and forestry administrations at different levels of government in Chongqing provided a structural context. Key informant interviews, conducted both before and along with rural household surveys, elicited detailed information about rural livelihood experiences for the survey questionnaire develop- ment, and provided a contextualized backdrop for the analysis of survey data. A total of 41 key informant interviews were conducted using a multiple-group and modified snowball sampling procedure (Luloff 1999). To represent the broad interests and perspectives in study communities, key inform- ants were selected from a range of categories: village leaders, school administrators or teachers, senior residents, natural resource management staff, and agricultural extension work- ers. All in-depth interviews were taped, transcribed, and qualitatively analyzed to identify common themes (Dunn 2000). Key findings are included in the discussion section below to facilitate interpretation of survey results. To empirically evaluate the efficacy of the rural migration–household livelihoods–rural environment con- ceptual model, a household survey was conducted to collect information about rural livelihood activities. The sample households were obtained using a stratified random sampling procedure (Singleton and Straits 2005). In each study community, a list of all households was compiled based on registration records. With the assistance of village leaders, these households were then subdivided into two groups according to their labor migration status. House- holds with at least one member working in an urban area for most of the time during the recent two years of survey were classified as labor-migrant households, while those with all members present for the period were classified as non-labor-migrant households. Finally, 45 households were randomly chosen from each category for survey sampling. Requests to participate in the survey were made in person, and all households contacted agreed to complete the survey. Whenever possible, households that could not be reached after repeated attempts were replaced by other randomly selected households from the same group. A total of 345 households (179 labor-migrant households and 166 non- labor-migrant households) from the four study villages were surveyed using face-to-face questionnaire interviews.