关键词: 最大熵模型, 东洞庭湖, 沉水植物, 苦草属, 生境修复

Abstract: To clarify the key habitat factors affecting the growth and suitable habitats of submerged plants in East Dongting Lake, a habitat suitability model of Vallisneria in East Dongting Lake was established based on the maximum entropy model, taking the typical submerged plant Vallisneria as the indicator species and combining the geographical distribution, climate and hydrological environmental variables of Vallisneria. The habitat of Vallisneria was evaluated. The results showed that the AUC of the training data was 0.893, and the maximum entropy model had good prediction effect. The range of annual mean temperature, precipitation of the wettest month, water depth, precipitation of warmest quarter, temperature seasonality and mean diurnal range were the key habitat factors of Vallisneria in East Dongting Lake. Taking the threshold of maximum training sensitivity and specificity of 0.503 and the threshold of balanced training omission rate, predicted area and threshold of 0.063 as the dividing thresholds for suitable and sub-suitable habitats, the habitat of Vallisneria in East Dongting Lake could be divided into three categories, namely suitable, sub-suitable, and unsuitable. The suitable habitat area was 227.62 km², accounting for 17.14% of the total wetland area in the lake. The results reveal the habitat factors and the characteristics of suitable areas that affect the growth of submerged plant Vallisneria in East Dongting Lake, providing reference for ecological restoration of the lake.

Key words: Maxent model, East Dongting Lake, submerged plant, Vallisnerria, habitat restoration