Biology subjects

Lambers, H.

Publications and source records attributed to Lambers, H..

4 recordsLinked to original sources

bioRxiv2025

Nutrient niche differentiation among European herbaceous species reflects an extinction to invasion continuum

Threatened and invasive plant species may appear worlds apart; however, we propose that mechanisms underlying invasive success and extinction risk among European herbaceous species constitute a continuum from successful, well-dispersing, fast-growing species to threatened, slow-growing species. We provide empirical evidence for such an extinction-invasion continuum and show that threatened and naturalized invasive plant species occur at opposite ends. Threatened species persist in phosphorus-limited nutrient-poor habitats, while naturalized and invasive species more often occur in nitrogen-limited nutrient-rich habitats. These opposing niches suggest invasive species do not directly displace threatened species; instead, species replacement and extinction result from nutrient regime shifts. Mitigating and preventing nutrient enrichment, especially phosphorus, for nature conservation protects existing nutrient niches for threatened species and limits plant invasion.

ecology↗

bioRxiv2024

Activation mapping in multi-center rat sensory-evoked functional MRI datasets using a unified pipeline.

Functional Magnetic Resonance Imaging (fMRI) in rodents is pivotal for understanding the mechanisms underlying Blood Oxygen Level-Dependent (BOLD) signals and phenotyping animal models of disorders, amongst other applications. Despite its growing use, comparing rodent fMRI results across different research sites remains challenging due to variations in experimental protocols. Here, we aggregated and analyzed 22 sensory-evoked rat fMRI datasets from 12 imaging centers, totaling scans from 220 rats, to assess the consistency of results across diverse protocols. We applied a standardized preprocessing pipeline and evaluated the impact of different hemodynamic response function models on group and individual level activity patterns. Our analysis revealed inter-dataset variability attributed to differences in experimental design, anesthesia protocols, and imaging parameters. We identified robust activation clusters in all (22/22) datasets. The comparison between stock human models implemented in software and rat-specific models showed significant variations in the resulting statistical maps. Our findings emphasize the necessity for standardized protocols and collaborative efforts to improve the reproducibility and reliability of rodent fMRI studies. We provide open access to all datasets and analysis code to foster transparency and further research in the field.

neuroscience↗

bioRxiv2023

Coordination among leaf and fine root traits across a strong natural soil fertility gradient

Unravelling how fundamental axes of trait variation correlate among leaves and roots and relate to nutrient availability is crucial for understanding plant distribution. While the leaf trait variation axis is linked to nutrient availability gradients, the response of root trait variation to the same gradients yields inconsistent results. We studied leaf and root trait variation among 23 co-occurring plant species along a 2-million year soil chronosequence to assess how leaf and root traits coordinate and how this resulting joint axis of variation relates to soil fertility. Mycorrhizal association types primarily structured the axes of leaf and root trait variation. However, when considering species abundance, soil nutrient availability was an important driver of trait distribution. Leaves that support rapid growth in younger, fertile soils were associated with roots of larger diameter and arbuscular mycorrhizal colonization. In contrast, leaves that favour nutrient conservation in nutrient-impoverished soil were associated with greater root hair length and phosphorus-mobilizing root exudates. At the species level, the signals deviated from the community-wide results presented above, highlighting the challenge of generalizing a specific set of root trait values that consistently meet the requirements of leaves supporting either rapid growth or survival.

ecology↗

bioRxiv2021

Elevated concentration and nitrogen addition affects responses of foliar phosphorus fractions in invasive species to increased phosphorus supply

No studies have explored how the invasive species of Mikania micranatha and Chromolaena odoratan adjust leaf phosphorus (P) among inorganic P (Pi) and organic P fractions to adapt the low soil P availability, especially under elevated CO2 concentrations ([CO2]) and nitrogen (N) deposition. Here, we address this by measuring foliar total N and P concentrations as well as functional P fractions (i.e. Pi, metabolic P, lipid P, nucleic acids P, and residual P) of both invasive species and a native species (Paederia. scandens) growing under different P supplies, N, and N+P addition under both ambient and elevated [CO2]. Phosphorus addition greatly increased plant biomass and foliar P concentrations but did not significantly affect foliar N concentration and leaf mass per unit leaf area (LMA). In response to P addition, the concentration of metabolic P increased the most, followed by that of nucleic acid P, Pi, and lipid P, in all species by an average of 754%, 82%, 53%, and 38%, respectively. However, elevated [CO2] and N addition weakened this positive effect on concentrations of foliar P fractions in the invasive species. Our results indicate that elevated [CO2] and N addition allowed the invasive species to acclimate to a low soil P availability, supporting their successful invasion, through greatly reducing P allocation to non-metabolic foliar P fractions (phospholipids and nucleic acid P) to meet their demand for metabolic P and Pi for photosynthesis, rather than altering LMA.

plant biology↗