Invasiveness of Ludwigia and Nelumbo in Shallow Temperate Fluvial Lakes

The relationship between invasive plant functional traits and their invasiveness is still the subject of scientific investigation, and the backgrounds of transition from non-native to invasive species in ecosystems are therefore poorly understood. Furthermore, our current knowledge on species invasiveness is heavily biased toward terrestrial species; we know much less about the influence of allochthonous plant traits on their invasiveness in aquatic ecosystems. We studied physiological and ecological traits of two introduced and three native macrophyte species in the Mantua lakes system (northern Italy). We compared their photophysiology, pigment content, leaf reflectance, and phenology in order to assess how the invasive Nelumbo nucifera and Ludwigia hexapetala perform compared to native species, Nuphar lutea, Nymphaea alba, and Trapa natans. We found L. hexapetala to have higher photosynthetic efficiency and able to tolerate higher light intensities than N. nucifera and the native species especially at extreme weather conditions (prolonged exposure to high light and higher temperatures). Chlorophyll a and b, and carotenoid contents of both allochthonous species was substantially higher than that of the native plants suggesting adaptive response to the ecosystem of Mantua lakes system. Higher variability of recorded data in invasive species also was observed. These observations suggest advanced photosynthetic efficiency of the invasive species, especially L. hexapetala, resulting in faster growth rates and higher productivity. This was supported by the evaluation of seasonal dynamics mapped from satellite remote sensing data. This study provides empirical evidence for the relationship between specific plant physiological traits and invasiveness of aquatic plant species, highlighting the importance of trait studies in predicting ecosystem-level impacts of invasive plant species.

Authors: Viktor R. Tóth, Paolo Villa, Monica Pinardi, Mariano Bresciani

Keywords: macrophytes, photophysiology, leaf reflectance, leaf pigments, phenologyty

Full Range Photodiode Array UV-Vis-NIR Spectroradiometer

Working with a spectroradiometer in the lab is necessary for many applications that require handling sensitive materials that cannot maintain their integrity outside of lab conditions, such as calibration transfer or testing solar simulators, and scanning materials that require sanitary conditions. Spectral Evolution offers a variety of spectroradiometers designed with these delicate tasks in mind.

Spectral Evolution’s SR-Series Laboratory spectroradiometers deliver high sensitivity with a high signal-to-noise ratio and an unmatched wide dynamic range. Our spectroradiometers are calibrated for solar radiance to generate a spectral match report for measuring class performance as per IEC60904-9/ASTM E927-05, making them especially useful for measuring continuous or pulse solar simulators.

Common Laboratory Applications:

• Radiometric calibration transfer
• LED, laser and light source metrology
• Solar radiance and irradiance measurements
• Solar simulator test and classification
• Art & heritage analysis
• Food & pharmaceuticals identification
• Plastics identification
• Remote sensing applications