Functional characteristics rather than co‐occurrences determine the outcome of interactions between neighbouring plants in sub‐Antarctic ponds: Consequences for macrophyte community biomass

Abstract

1. Understanding of the mechanisms underlying species coexistence within plant communities is crucial to predict their fate given the current context of biodiversity loss. Freshwater ecosystems are among the most abiotically constrained habitats because they harbour clonal macrophyte communities. Strong habitat

How does trait variance partitioning help us to understand plant community assembly? The example of pond communities in the Kerguelen Islands

“…As abiotic variables are likely to vary within ponds, in each quadrat at the ramet collection points, we measured the mean water depth (based on three measurements) and mean dissolved oxygen (DO) concentration (based on measurements taken at three water depths). We also measured the pH and electrical conductivity (EC), since they are not related to the phytoplankton concentration in the studied systems (Douce et al., 2023b). These measurements were performed using a multiparameter HQ40D HACH sensor (EC ± 0.1 mS cm −1 , DO concentration ± 0.01 mg L −1 ).…”

“…From September 2020 onward, whole‐pond water temperatures were recorded every 30 min using loggers (Hobo MX2202) positioned in the middle of the water column. Water temperatures in November 2019–August 2020 were simulated using their relationship to air temperatures recorded by Meteo France (2020 records, Port‐aux‐Français; see Douce et al., 2023b). Each pond area (length × width) was measured in November 2019.…”

“…To characterize the abiotic conditions within ponds, the mean of daily (day and night) water temperatures from November 2019 to November 2020 was calculated for each pond (Douce et al., 2023b). Abiotic variables measured at the quadrat scale were averaged at the pond scale.…”

“…Water temperatures in November 2019-August 2020 were simulated using their relationship to air temperatures recorded by Meteo France (2020 records, Port-aux-Français; see Douce et al, 2023b).…”

Biotic and abiotic drivers of aquatic plant communities in shallow pools and wallows on the sub-Antarctic Iles Kerguelen

“…the growing season, than in winter, and was mostly attributed to the availability of nutrients in sediments (P bio , N tot ) and to the variance in daily water temperature within ponds, regardless of the sampling season and the year. In Kerguelen, water temperature appears independent from pond area and water depth (Douce et al, 2023). Ponds with higher variation in water temperature among days were preferentially inhabited by J. scheuchzerioides, suggesting that this aquatic species could be more tolerant than the five others to the instability of temperatures resulting from climate changes of Kerguelen, although this assertion remains to be tested.…”