Biology subjects

Formenti, L.

Publications and source records attributed to Formenti, L..

4 recordsLinked to original sources

bioRxiv2026

Extreme drought disrupts the bottom-up regulation of ground-dwelling invertebrate diversity under climate warming

Extreme climate events are becoming more frequent, yet their consequences for the recovery of plant-invertebrate relationships under warming remain poorly understood. We investigated over two years of how ground-dwelling invertebrate communities recovered from a 40-days drought in outdoor grassland mesocosms exposed to ambient conditions, constant warming or periodic heatwaves, and both combined. We then examined how post-drought community shifts were associated with above-ground plant biomass, measured concurrently with invertebrate sampling. Drought had no detectable effect on total invertebrate abundance at either recovery time (one or four months after drought). By contrast, diversity showed warming-dependent responses one month after drought and a delayed drought legacy four months later, when diversity declined only under constant warming, with or without periodic heatwaves. At the four-month post-drought sampling, plant biomass-invertebrate diversity coupling was evident only in non-drought plots, with negative relationships under ambient and heatwave regimes but a positive relationship under constant warming alone. This pattern was largely associated with responses of herbivores, particularly Stylommatophora. Our results highlight lagged drought effects in invertebrate diversity that emerged months later and, under warming, extended to weakened plant biomass-invertebrate diversity coupling, pointing to disrupted bottom-up control with potential consequences for food-web functioning.

ecology↗

bioRxiv2026

Resource acquisition is more sensitive than carbon storage in soil microorganisms under climate extremes

O_LIDrought and warming can disrupt soil microbial processes and ecosystem functioning. Although soil microorganisms can exhibit physiological adjustments to drought, it remains unclear how they allocate resources between extracellular resource acquisition, potential oxidative metabolism, and carbon storage during drought and recovery, particularly under constant warming and/or heat waves. C_LIO_LIHere, we tested the effects of drought on microbial resource allocation strategies across warming regimes during the resistance and recovery phases. We performed a full-factorial outdoor mesocosm experiment combining drought with constant warming and periodic heat waves, applied individually and in combination. We measured the potential activities of extracellular enzymes as proxy for the acquisition of microbial resources, the activity of dehydrogenase as a proxy for the potential active oxidative metabolism, and microbial glycogen pools as a proxy for carbon storage. We also quantified drought legacy effects by measuring microbial functioning before the new drought treatments, capturing the influence of the drought imposed in the previous year. C_LIO_LIDuring the resistance phase, dehydrogenase activity and glycogen pools remained stable, despite reduced extracellular enzyme production, while enzyme allocation shifted towards oxidative enzymes associated with acquisition of recalcitrant C in warming regimes. One month after rewetting, all microbial proxies no longer differed from the control soil moisture conditions. Drought legacy effects were observed in extracellular enzymes, dehydrogenase activity, and glycogen pools, with glycogen exhibiting the strongest legacy effect. C_LIO_LIWe conclude that the asymmetrical responses of extracellular resource acquisition and internal C storage to drought and warming may function as strategies for microbial survival in increasingly variable climates. C_LI

ecology↗

bioRxiv2026

Convergent post-drought recovery of biomass and functional traits under constant and periodic warming in slow- and fast-growing plants

Extreme climate events such as droughts and heatwaves are intensifying under climate change, yet their combined effects on plant recovery remain unclear. In a two-year outdoor mesocosm experiment, we tested how grassland species with contrasting growth strategies recover from summer drought under four warming regimes: ambient, moderate warming (+2 {degrees}C), periodic heatwaves (+7 {degrees}C), and their combination. Experimental communities of native fast- and slow-growing species plus the invasive Solidago canadensis were assessed for above-ground biomass and leaf traits (SLA, LDMC, chlorophyll content, stomatal conductance) at one- and four-months post-drought. Biomass fully recovered within one month in both growth strategies, but leaf traits showed transient shifts, over-recovery in SLA and under-recovery in LDMC, likely reflecting production of new leaf tissues. These deviations generally returned to control levels by four months, regardless of warming treatments. Solidago canadensis exhibited high tolerance to heat and drought, with early biomass and trait recovery, indicating potential for dominance under climate extremes. Biomass recovery was similar across growth strategies, suggesting that growth-related differences play a minimal role in short-term recovery; however, early regrowth was characterised by contrasting trait shifts. Such lagged trait recovery, combined with rapid invasive recovery, suggests potential for longer-term shifts in grassland composition and function. We recommend that incorporating trait-based recovery dynamics is essential for predicting ecosystem stability under compound climate extremes.

ecology↗

bioRxiv2018

Variable Effects on Growth and Defence Traits for Plant Ecotypic Differentiation and Phenotypic Plasticity along Elevation Gradients

Along ecological gradients, ecotypes generally evolve as the result of local adaptation to a specific environment to maximize organisms fitness. Alongside ecotypic differentiation, phenotypic plasticity, as the ability of a single genotype to produce different phenotypes under different environmental conditions, can also evolve for favouring increased organisms performance in different environments. Currently, there is a lack in our understanding of how varying habitats may contribute to the differential contribution of ecotypic differentiation and plasticity in growth versus defence traits. Using reciprocal transplant-common gardens along steep elevation gradients, we evaluated patterns of ecotypic differentiation and phenotypic plasticity of two coexisting but unrelated plant species, Cardamine pratensis and Plantago major. For both species, we observed ecotypic differentiation accompanied by plasticity in growth related traits. Plants grew faster and produced more biomass when placed at low elevation. In contrast, we observed fixed ecotypic differentiation for defence and resistance traits. Generally, low elevation ecotypes produced higher chemical defences regardless of the growing elevation. Yet, some plasticity was observed for specific compounds, such as indole glucosinolates. We speculate that ecotypic differentiation in defence traits is maintained by costs of chemical defence production, while plasticity in growth traits is regulated by temperature driven growth response maximization.

ecology↗