水文与营养条件对大型浅水湖泊中藻类生物量响应复合型热浪和干旱事件的调节作用
作者:W. Zou, Z. Cao, X. Wang, Q. Huang, H. Xu, M. Zhu, et al.
1. Compound heatwave and drought (CHWD) events are becoming increasingly frequent, posing significant challenges to aquatic ecosystems. This study assesses the impact of the 2022 CHWD on chlorophyll-a (Chla) concentrations in 40 large shallow lakes (> 50 km(2)) in the Chinese Eastern Plains ecoregion. 2. The findings reveal that the impact of CHWD on algal biomass varies depending on hydrological and nutrient conditions in a lake. In rapidly flushing lakes, CHWD did not change Chla concentration from 32.9 +/- 3.8 mu g/L in the reference year to 34.1 +/- 4.3 mu g/L in the CHWD year (Z = -1.098, p = 0.272), but in long retention lakes Chla concentration decreased from 35.9 +/- 4.1 mu g/L to 33.7 +/- 4.8 mu g/L (Z = -3.552, p < 0.001). 3. Field-monitoring data suggest that the Chla decline in long retention lakes is primarily due to reduced external nutrient inputs from decreased rainfall. In rapid flushing lakes, Chla shows minimal sensitivity to variations in TN or TP. Consequently, the direct effect of climate warming on algal biomass in these lakes may be limited. 4. The effect of CHWD on long retention lakes is nutrient-dependent. For example, Lake Gehu, a long retention lake, experienced an overall increase in Chla, likely because its surplus nitrogen and phosphorus made it less susceptible to drought-induced reductions in external nutrient loads. 5. This study highlights the complex responses of lake ecosystems to climate extremes and provides insights for managing eutrophication in a changing climate.
(来源:Freshwater Biology 2025 Vol. 70 Issue 6 DOI: 10.1111/fwb.70061)