Biology subjects

Lemmens, P.

Publications and source records attributed to Lemmens, P..

3 recordsLinked to original sources

bioRxiv2026

Cladoceran diversity build-up in newly created pondscapes

This study aimed to identify the most important drivers of cladoceran species richness build-up and species accumulation patterns in newly created ponds that collectively form entirely new pondscapes (networks of closely situated ponds in a landscape). A total of 26 newly created ponds across two newly established pondscapes were surveyed repeatedly (n=11) for key environmental pond variables and cladoceran community characteristics during the first three years after the pondscapes creation. The study ponds vary in surface area and maximum depth and cover a wide range of hydroperiods, from permanent to temporary systems with only a short hydroperiod. In total, 16 cladoceran species colonized the newly created ponds within the first three years of the pondscapes existence. Consistent with previous research, Daphnia obtusa was the first species to colonize ponds in both pondscapes. Macrophyte establishment was the most important local factor influencing the accumulation of cladoceran species over time, with vegetated ponds leading to faster species accumulation, likely because of the close association of chydorid species, Simocephalus vetulus and Ceriodaphnia spp with macrophytes. Our observations highlight the role of the establishment of macrophytes for cladoceran species richness build-up during early pond succession and offer valuable insights for designing resilient pondscapes that support rapid cladoceran species accumulation. Statements and DeclarationsThe authors have no conflicts of interest to declare.

ecology↗

bioRxiv2025

Eco-evolutionary feedback of adaptive evolution to a pesticide worsens the impact of a pesticide switch in a pivotal freshwater non-target species

Pest management often requires the switches of insecticides, sequentially exposing non-target populations to different compounds. In a two-phased experiment, we assessed whether exposure to the pesticide chlorpyrifos induces rapid evolution in the non-target species Daphnia magna, and quantified the response of control and pre-exposed populations to a second exposure to the same pesticide, another pesticide with the same mode of action (malathion), or a pesticide with another mode of action (deltamethrin). Chlorpyrifos selection induced rapid shifts in genotype composition and reduced genotype richness, and strongly influenced population development following the second exposure. Chlorpyrifos-selected populations outperformed control populations when subsequently exposed to chlorpyrifos and malathion, but underperformed when exposed to deltamethrin. Our results highlight an eco-evolutionary feedback in which rapid adaptive responses to a pesticide worsens the response when exposed to a different type of pesticide in non-target species, increasing vulnerability to common agricultural practices.

ecology↗

bioRxiv2020

Disentangling metacommunity processes using multiple metrics in space and time

Metacommunity ecology has focused on using observational and analytical approaches to disentangle the role of critical assembly processes, such as dispersal limitation and environmental filtering. Many methods have been proposed for this purpose, most notably multivariate analyses of species abundance and its association with variation in spatial and environmental conditions. These approaches tend to focus on few emergent properties of metacommunities and have largely ignored temporal community dynamics. By doing so, these are limited in their ability to differentiate metacommunity dynamics. Here, we develop a Virtual ecologist approach to evaluate critical metacommunity assembly processes based on a number of summary statistics of community structure across space and time. Specifically, we first simulate metacommunities emphasizing three main processes that underlie metacommunity dynamics (density-independent responses to abiotic conditions, density-dependent biotic interactions, and dispersal). We then calculate a number of commonly used summary statistics of community structure in space and time, and use random forests to evaluate their utility for understanding the strength of these three processes. We found that: (i) time series are necessary to disentangle metacommunity processes, (ii) each of the three studied processes is distinguished with different descriptors, (iii) each summary statistic is differently sensitive to temporal and spatial sampling effort. Some of the most useful statistics include the coefficient of variation of abundances through time and metrics that incorporate variation in the relative abundances (evenness) of species. Surprisingly, we found that when we only used a single snapshot of community variation in space, the most commonly used approaches based on variation partitioning were largely uninformative regarding assembly processes, particularly, variation in dispersal. We conclude that a combination of methods and summary statistics will be necessary to understand the processes that underlie metacommunity assembly through space and time.

ecology↗