Biology subjects

Tartini, N.

Publications and source records attributed to Tartini, N..

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↗

bioRxiv2025

Tracking the phenology of riverine insect communities using environmental DNA

Aquatic insects are iconic and ecologically highly relevant inhabitants of riverine ecosystems. They are also often the target of monitoring programs to assess the ecological status of these lotic habitats. Environmental DNA (eDNA) techniques have been widely and successfully implemented to investigate freshwater insects and other macroinvertebrates. Commonly, such monitoring is conducted at one or two timepoints per year, despite the known strong seasonality and phenology of aquatic insects. Here, we assessed if and how eDNA can capture the temporal changes of the orders Ephemeroptera (mayflies), Plecoptera (stoneflies), Trichoptera (caddisflies) and Diptera (true flies). We carried out eDNA sampling at roughly monthly intervals from April to October at 25 sites across a whole river catchment in the northeastern part of Switzerland. We found pronounced, cyclic phenological trends in all orders but Trichoptera: the communities diverged from spring to summer and then in fall gradually returned closer to the spring state. The four orders exhibited different predominance in gains or losses of species detection throughout this time interval. Lastly, we found that field replicates, despite showing a relatively high local stochasticity, were able to provide a more complete assessment of aquatic communities and could thus be used as a proxy for the frequency of observation of a species through the seasons. In fact, this approach yielded comparable temporal patterns to the ones extracted from the Global Biodiversity Information Facility (GBIF). Overall, our findings demonstrate that eDNA techniques can be used to reveal intra-annual dynamics of aquatic insects. Given the current necessity to assess and monitor the biodiversity status of ecosystems, we therefore show that eDNA methods are a viable option to obtain a deeper understanding of the structuring of freshwater communities over time.

ecology↗