Among invasive species, floating plants have a great impact on aquatic ecosystems, forming dense mats that cause a great alteration of the physical and chemical water features. We experimentally assessed the effect of Azolla filiculoides mats on Mediterranean temporary waters using mesocosms with sediments from an invaded marsh and amphibian larvae from surrounding wetlands. Azolla filiculoides formed a dense mat over the water surface in the experimental tanks, which decreased pH and oxygen concentration, and increased nutrients, nitrogen and phosphorus compounds in the water compared to mesocosms lacking the exotic fern. Macrophyte abundance and richness were reduced under the Azolla mat. Invaded mesocosms also had higher phytoplankton abundance and different zooplankton composition, which was mainly characterized by higher abundance of juvenile copepods. Regarding amphibian development, tadpoles requiring a long developmental period, the western spadefoot toad, Pelobates cultripes, had significantly lower survival in the presence of A. filiculoides (4.8% compared to 60% survival in fern-free mesocosms). For tadpoles of the Mediterranean tree frog, Hyla meridionalis, which develop faster, we did not detect effects on survival, but on body size and physical condition of metamorphs. The formation of A. filiculoides mats produced a deterioration of the trophic web, as it caused most sources to be depleted in ¹³C and ¹⁵N. Primary consumers, tadpoles and zooplankton, were also ¹³C depleted, although the diet of tadpoles from Azolla mesocosms was mainly composed of the invasive fern. We therefore conclude that A. filiculoides has a negative impact on physical and chemical water features, reduces the richness and biomass of the submerged macrophyte guild and reduces survival and body condition of tadpoles. Overall, A. filiculoides causes substantial deterioration of the food web of the aquatic ecosystem.

在外来入侵物种中，漂浮植物对水生生态系统有很大影响，形成致密的垫层，导致物理和化学水特征发生巨大变化。我们实验性地使用了侵略性沼泽地沉积物和周围湿地的两栖幼体的中观方法，对地中海临时水域的Azolla filiculoides垫进行了评估。与缺少外来蕨类植物的中观世界相比，满江红在实验水箱的水面上形成了一层致密的垫子，从而降低了pH和氧气的浓度，并增加了水中营养素，氮和磷的含量。在Azolla下，大型植物的丰富度和丰富度降低了垫。入侵的中生代也具有较高的浮游植物丰度和不同的浮游动物组成，其主要特征是幼小co足类的丰度较高。关于两栖动物发展，需要较长的发育期蝌蚪，西部锄足蟾，Pelobates cultripes，在存在有下显著生存A. filiculoides（4.8％相比，在自由蕨生物群落60％存活）。对于生长较快的地中海树蛙Hy（Hyla meridionalis）的,，我们未发现对存活率有影响，但对变体的体型和身体状况没有影响。丝状灰霉菌垫的形成导致营养网的恶化，因为它导致大多数来源的营养耗尽。¹³ C和^15N。主要消费者t和浮游动物也被消耗了¹³ C，尽管来自Azolla中观的of的饮食主要由侵入性蕨类组成。因此，我们得出结论，A。filiculoides对物理和化学水特征具有负面影响，降低了淹没大型植物行会的丰富度和生物量，并降低了survival的存活和身体状况。总体而言，丝状线虫会导致水生生态系统食物网的大量恶化。