关键词: 孵化率, 虎斑乌贼, 光周期, 光照强度

Abstract: This paper aims to offer theory on the spatial contraposition allocation and land-use structural adjustment in Lanlingxi watershed in Three Gorges area. With the data collected from forest inventory survey and obtained from Forest Ecological Station in Three Gorges area (Zigui) of Yangtze River, an indicator system including three level indicators (i.e. vegetation structure, ecological service and ecological environment) and 16 secondary indicators (i.e. forest age structure, canopy density, shrub layer coverage, etc.) were selected to assess forest ecosystem health level based on matterelement model and forest subcompartment scale. The numbers of subcompartments with the integrated assessment grades of “better”, “normal” and “poor” were 83, 115 and 59, accounting for 32.30%, 44.75% and 22.96% of total subcompartments, respectively. An extremely significant positive relationship existed between forest ecosystem health level and soil organic matter density, canopy density (P<0.01), and a significant correlation was found between forest ecosystem health level and bare rock rate, soil porosity. The forest ecosystem health level for the different vegetation types was in order of broadleaf forest, arbor and shrub forest > coniferous forest > economic forest. With extension transformation, the matterelement model can provide more information of every single index, therefore, it is suitable to assess the forest ecosystem health level.

Key words: Sepia pharaonis, light intensity, photoperiod, hatching rate.