Abstract - research idea:
Climate warming involves not only elevated mean temperatures, but also more pronounced heat waves, with temperature fluctuations of high amplitude. These could be another source of stress for freshwater ecosystems, where biodiversity is already affected by biological invasions. Non-native species are commonly characterized by greater tolerance to elevated temperatures, outcompeting natives in warmer environments. We investigated how elevated water temperature affects two freshwater amphipod crustacean species: the native Gammarus jazdzewskii and the invasive Pontogammarus robustoides. Changes in amphipod assemblages, due to their key roles in coarse particulate organic matter breakdown and as a primary prey for fish, can have cascading effects on freshwater ecosystems. We exposed independent gammarid groups for 14 days to constant (17, 20, 23°C) and fluctuating (17-23°C) temperature regimes to mimic conditions experienced in the wild. We measured leaf consumption, total oxidative status (TOS), growth and survival. Although gammarids showed no temperature-induced changes in TOS, the survival rate of both species decreased at 23°C, as well as under fluctuating temperature. Irrespective of temperature, P. robustoides grew faster than G. jazdzewskii, and small individuals of P. robustoides tended to consume more food. Our study suggests that short-time elevated temperature peaks may be as important for the functioning of aquatic organisms as long-term increases in mean values experienced in the pace of global warming. The invasive species was not more resistant to elevated temperatures than native, suggesting that its invasive potential is driven by other traits, such as faster growth and more intense foraging.
Deposit files:
File "Warming - gammarids.xlsx" contains all data gathered for the laboratory experiment investigating gammarids response to diferent thermal regimes related to global warming. Structure:
File "Warming - gammarids.R" contains Rscript to recreate all analyses performed with the data provided that support findings of the study.
File "README Warming - gammarids.txt" contains detailed description of datasets provided.
(2026-10-31)
