Biology subjects

Henriques, J. F.

Publications and source records attributed to Henriques, J. F..

3 recordsLinked to original sources

bioRxiv2025

Herbivore pressure modulates soil multifunctionality in a Mediterranean landscape

Ongoing global environmental changes demand cost-effective strategies to restore ecosystem functioning. Within this context, the reintroduction of large mammalian herbivores has emerged as a promising approach to recover ecological processes and foster self-sustaining, biodiverse ecosystems. However, the impacts of such initiatives remain poorly understood, particularly regarding their effects on soil functions and ecological processes. We tested whether large herbivore densities (wild horses (Garrano breed) and cattle (Maronesa breed, an ancient lineage close to aurochs) modulates soil multifunctionality (the simultaneous provision of multiple ecosystem functions) across habitats (grasslands, shrublands, and forests) and seasons (fall and spring) in a Mediterranean landscape. Using composite multivariate indices describing soil functions related to biogeochemical cycles (i.e., enzymatic activities) and physicochemical properties (pH, conductivity, organic matter, and nutrient loads), we found that soil enzymatic activities varied seasonally, being higher in spring, and interacted with habitat and herbivore pressure gradients. Habitat and herbivore pressure explained the variation in soil multifunctionality during spring, while in fall it was mainly driven by herbivore pressure. Enzymatic stoichiometry, particularly C:P ratios, strongly predicted soil fertility and multifunctionality, showing positive relationships in forest habitats and under herbivore pressure. A mechanistic approach confirmed that herbivore impacts on soil functioning operated primarily through changes in soil properties and nutrient cycling rather than direct effects. Mediterranean landscapes are rapidly changing, and our results highlight herbivore management as a key tool to sustain soil ecological processes under the rewilding framework. Highlights- Large herbivores impacted soil functions and properties in different habitats - Large herbivores significantly impacted soil nutrient cycling and multifunctionality. - The magnitude of the effects was dependent on season and habitat - Large herbivores indirectly impact soil ecosystem multifunctionality through changes in soil properties.

ecology↗

bioRxiv2022

Trait-specific indirect effects underlie variation in the response of spiders to cannibalistic social partners

Organisms may respond in different ways to the risk posed by conspecifics, but the cause of such variation remains elusive. Here, we use a half-sib/full-sib design to evaluate the contribution of (indirect) genetic or environmental effects to the behavioral response of the cannibalistic wolf spider Lycosa fasciiventris (Dufour, 1835) towards conspecific cues. Spiders showed variation in relative occupancy time, activity, and velocity on patches with or without conspecific cues, but direct genetic variance was only found for occupancy time. These three traits were correlated and could be lumped in a principal component: spiders spending more time in patches with conspecific cues moved less and at a lower rate in those areas. Genetic and/or environmental components of carapace width and weight loss in the social partner were significantly correlated with the principal component of focal individuals. Variation in these traits may reflect the quality and/or quantity of cues produced by social partners, hence focal individuals were likely behaving along a continuum of strategies in response to the risk posed by social partners. Therefore, environmental and genetic trait variation in the social partners may be key to maintain trait diversity in focal individuals, even in the absence of direct genetic variation.

evolutionary biology↗

bioRxiv2019

Alcohol intake triggers aberrant synaptic pruning leading to synapse loss and anxiety-like behavior

Alcohol use adversely impacts the life of millions of people worldwide. Deficits in synaptic transmission and in microglial function are common findings in human alcohol users and in animal models of alcohol intoxication. Here, we show that alcohol intake over ten consecutive days resulted in substantial loss of excitatory synapse in the prefrontal cortex, a consequence of aberrant synaptic pruning, which led to increased anxiety-like behavior. Mechanistically, these effects of alcohol intake were mediated by a detrimental increase of microglia engulfment capacity via Src-dependent activation of NFkB and consequent TNF production. Accordingly, pharmacological blockade of Src activation or TNF production by microglia, genetic ablation of TNF, or diphtheria toxin-mediated conditional ablation of microglia attenuated aberrant synaptic pruning preventing excitatory synapse loss and anxiety-like behavior. Overall, our data suggest that aberrant pruning of excitatory synapses by microglia might disrupt synaptic transmission during alcohol use.

neuroscience↗