关键词: 农户生计, 脆弱性, 集对分析, 障碍度, 海原县

Abstract: Artemia- plays an important role in the biological management of saltworks ecosystem. To approach the effects of the ecological environment of saltworks on the dynamics of Artemia population, six salt ponds with different salinity in Haixin Division of Chengkou saltworks, Shandong Province were chosen, and the related ecological factors were investigated by means of monthly sampling, onsite measuring, and laboratory analysis. It was observed that the brine temperature varied with seasons, and slightly increased with increasing salinity. The brine pH slightly decreased with increasing salinity. In general, the chlorophyll a content in the brine was lower (<0.3 ug·L^-1), as compared to that in normal seawater. The total nitrogen and phosphorous concentrations in the brine increased with increasing salinity, and the nitrogen was the restrictive element for phytoplankton growth in lower salinity ponds whilst the phosphorous became the limiting factor in higher salinity ponds. The density of Artemia population varied with the brine temperature and salinity, being higher at higher temperature (from June to August) and lower salinity (7-12 °Bé). The analysis of the sex ratio of female and male Artemia indicated that in the Chengkou saltworks, there existed mixed Artemia populations of both parthenogenetic and bisexual. The density of the populations was affected by salinity and temperature, i.e., parthenogenetic population was predominantly existed in lower salinity salt ponds and in spring and summer, whilst the bisexual population became majority in higher salinity salt ponds and in autumn.

Key words: agro-household livelihood, vulnerability, set pair analysis, obstacle degree, Haiyuan County.