Centenaro, G. | Search bioRxiv

bioRxiv2025

Urban crops demonstrate comparable potential for organic carbon storage as natural ecosystems.

Urban greenspaces, encompassing parks, golf courses, roundabouts, and urban crops, have potential to offset urban carbon footprints by storing soil organic carbon (SOC). This study analyzed particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) stocks in topsoil across 27 Iberian cities, comparing urban greenspaces with natural ecosystems under varying climatic and edaphic conditions. Results revealed that urban greenspaces store comparable SOC stocks to natural ecosystems, with MAOC stocks being more dominant and stable across land-use types. POC stocks showed variability, particularly lower in roundabouts and parks compared to natural ecosystems, but remained similar in golf courses and urban crops. SOC fractions correlated inversely with mean annual temperature (MAT), emphasizing the need for cooling strategies in urban areas to preserve stable carbon pools. While MAOC exhibited saturation at higher SOC levels, POC showed a linear increase. This study highlights the importance of tailored management practices to enhance carbon storage in urban soils for climate change mitigation.

biochemistry↗

bioRxiv2020

Search for top-down and bottom-up drivers of latitudinal trends in insect herbivory in oak trees in Europe

AimThe strength of species interactions is traditionally expected to become stronger toward the Equator. However, recent studies have reported opposite or inconsistent latitudinal trends in the bottom-up (plant quality) and top-down (natural enemies) forces driving insect herbivory, possibly because these forces have rarely been studied concomitantly. This makes previous attempts to understand the effect of large scale climatic gradients on insect herbivory unsuccessful. LocationEurope Time period2018-2019 Major taxa studiedQuercus robur MethodsWe used scholar-based citizen science to simultaneously test for latitudinal variation in plant-herbivore-natural enemy interactions. We further investigated the underlying climatic factors associated with variation in herbivory, leaf chemistry and attack rates in Quercus robur across its complete latitudinal range in Europe. We quantified insect herbivory and the occurrence of specialist herbivores as well as leaf chemistry and bird attack rates on dummy caterpillars on 261 oak trees. ResultsClimatic factors rather than latitude per se were the best predictors of the large-scale (geographical) variation in the incidence of gall-inducers and leaf-miners as well as of leaf nutritional quality. However, insect herbivory, plant chemical defences (leaf phenolics) and bird attack rates were not influenced by latitude or climatic factors. The incidence of leaf-miners increased with increasing concentrations of hydrolysable tannins and decreased with those of condensed tannins, whereas the incidence of gall-inducers increased with increasing leaf soluble sugar concentration and decreased with increasing leaf C:N ratios. However, neither other traits nor bird attack rates varied with insect herbivory. Main conclusionsThese findings help to refine our understanding of the bottom-up and top-down mechanisms driving geographical variation in plant-herbivore interactions, and urge for further examination of the drivers of insect herbivory on trees.

ecology↗