Soil phosphorus mediates trade-offs between constitutive and induced defences in young pine trees.

Nutrient availability, namely soil phosphorus, modulates trade-offs between constitutive and induced defences in maritime pine, with high phosphorus weakening these trade-offs and shaping plant allocation to different defensive strategies. Abiotic factors modulate trade-offs between plant functions, but their influence on trade-offs between constitutive and induced defences remains poorly understood. We tested for such trade-offs in maritime pine (Pinus pinaster) and examined whether soil phosphorus availability affected these defensive correlations.

Soil water-holding capacity does not mediate aridity effects on plant functional traits in Iberian dune ecosystems.

Background And Aims: Aridity drives plant adaptations such as reduced stature, sclerophyllous leaves, and increased phenolic production. While these patterns are well documented, the role of soil properties in modulating aridity's impact remains understudied. Trait responses may also vary-converging, diverging, or uncorrelated-across intraspecific and community levels, adding complexity to predictions of ecological responses to arid conditions.

Soil salinity effects on inter-plant signalling in wild cotton are contingent on herbivore load and differentially shape direct and indirect defences.

Inter-plant signalling effects on cotton defences are shaped by the joint effects of emitter herbivore load and soil salinity stress, with latter strengthening such effects on direct defences but weakening those on indirect defences. Volatile-mediated plant-to-plant signalling in response to herbivory is well documented, but its contingency on abiotic factors and variation in herbivore load is poorly understood. To address this gap, we investigated how soil salinity levels and herbivore load may influence signalling effects on plant defences and resistance in wild cotton (Gossypium hirsutum), using the specialist herbivore Alabama argillacea (cotton leafworm).

The impact of serpentine soils on plant traits and plant-herbivore interactions.

Serpentine soils, known for high heavy metal content and low nutrients, create harsh conditions for plants and herbivores. Although previous research has explored how serpentine soils affect herbivory, most studies have been restricted to a specific region, and the mechanisms involved remain unclear. Here, we conducted a large-scale study across 78 plant species from California, Spain, and Sweden, comparing insect herbivory and leaf traits (chemical, nutritional, and physical) in serpentine and non-serpentine habitats within each region.

The complex dynamics of ant-plant mutualisms: exploring the roles of plant-provided resources and bird predation on ants in shaping plant performance.

Background And Aims: Protection mutualisms involve plants receiving defence against herbivores from predators such as ants and insectivorous birds in exchange for food resources. Ants can reduce herbivory by actively patrolling plants with extrafloral nectaries (EFNs) or by tending trophobiotic insects that provide them with food rewards. Insectivorous birds also contribute to herbivore suppression but may simultaneously reduce ant activity through predation.

Effects of climate on leaf phenolics, insect herbivory, and their relationship in pedunculate oak (Quercus robur) across its geographic range in Europe.

An increase in biotic interactions towards lower latitudes is one of the most consistent patterns in ecology. Higher temperatures and more stable climatic conditions at low latitudes are thought to enhance biotic interactions, accelerating biological evolution and leading to stronger anti-herbivore defences in plants. However, some studies report contradictory findings, highlighting the need for further investigation into the underlying mechanisms.

Biotic and abiotic factors associated with genome size evolution in oaks.

The evolutionary processes that underlie variation in plant genome size have been much debated. Abiotic factors are thought to have played an important role, with negative and positive correlations between genome size and seasonal or stressful climatic conditions being reported in several systems. In turn, variation in genome size may influence plant traits which affect interactions with other organisms, such as herbivores.

Variation in insect herbivory across an urbanization gradient: The role of abiotic factors and leaf secondary metabolites.

Urbanization impacts plant-herbivore interactions, which are crucial for ecosystem functions such as carbon sequestration and nutrient cycling. While some studies have reported reductions in insect herbivory in urban areas (relative to rural or natural forests), this trend is not consistent and the underlying causes for such variation remain unclear. We conducted a continental-scale study on insect herbivory along urbanization gradients for three European tree species: Quercus robur, Tilia cordata, and Fraxinus excelsior, and further investigated their biotic and abiotic correlates to get at mechanisms.

Testing the joint effects of arbuscular mycorrhizal fungi and ants on insect herbivory on potato plants.

Ants, but not mycorrhizae, significantly affected insect leaf-chewing herbivory on potato plants. However, there was no evidence of mutualistic interactive effects on herbivory. Plants associate with both aboveground and belowground mutualists, two prominent examples being ants and arbuscular mycorrhizal fungi (AMF), respectively.

Effects of phytochemical diversity on multitrophic interactions.

The ecological effects of plant diversity have been well studied, but the extent to which they are driven by variation in specialized metabolites is not well understood. Here, we provide theoretical background on phytochemical diversity effects on herbivory and its expanded consequences for higher trophic levels. We then review empirical evidence for effects on predation and parasitism by focusing on a handful of studies that have undertaken manipulative approaches and link back their results to theory on mechanisms.

Test of Specificity in Signalling between Potato Plants in Response to Infection by Fusarium Solani and Phytophthora Infestans.

Plant-plant signalling via volatile organic compounds (VOCs) in response to insect herbivory has been widely studied, but its occurrence and specificity in response to pathogen attack has received much less attention. To fill this gap, we carried out a greenhouse experiment using two fungal pathogens (Fusarium solani and Phytophthora infestans) to test for specificity in VOC induction and signalling between potato plants (Solanum tuberosum). We paired potato plants in plastic cages, one acting as VOC emitter and the other as receiver, and subjected emitters to one of the following treatments: no infection (control), infected by F.

Volatile-Mediated Signalling Between Potato Plants in Response to Insect Herbivory is not Contingent on Soil Nutrients.

Plant-plant signalling via volatile organic compounds (VOCs) has been studied intensively, but its contingency on abiotic conditions (e.g., soil nutrients, drought, warming) is poorly understood.

Variation in the Outcome of Plant-Mediated Pathogen Interactions in Potato: Effects of Initial Infections on Conspecific vs. Heterospecific Subsequent Infections.

Plants are often attacked sequentially by multiple enemies. Pathogen sequential co-infections can lead to indirect interactions mediated by plant induced responses whose outcome is contingent on differences in the magnitude and type of plant induced defences elicited by different species or guilds. To date, however, most studies have tested unidirectional effects of one pathogen on another, not discerning between conspecific vs.

Soil physicochemical properties associated with the yield and phytochemical composition of the edible halophyte Crithmum maritimum.

There is growing interest in the consumption of halophytes due to their excellent nutritional profile and antioxidant properties, and their cultivation offers viable alternatives in the face of irreversible global salinization of soils. Nevertheless, abiotic factors strongly influence their phytochemical composition, and little is known about how growing conditions can produce plants with the best nutritional and functional properties. Crithmum maritimum is an edible halophyte with antioxidant properties and considerable potential for sustainable agriculture in marginal environments.

Effect of herbivore load on VOC-mediated plant communication in potato.

VOC emissions increased with herbivore load, but this did not result in concomitant increases in resistance in neighbouring plants, suggesting that communication occurred independently of herbivore load in emitter plants. Herbivore-damaged plants emit volatile organic compounds (VOCs) that can alert neighbours and boost their resistance. While VOC-mediated plant communication has been shown to be herbivore-specific, we know little about its contingency on variation in herbivore load.

Changes in the foliar fungal community between oak leaf flushes along a latitudinal gradient in Europe.

Aim: Leaves support a large diversity of fungi, which are known to cause plant diseases, induce plant defences or influence leaf senescence and decomposition. To advance our understanding of how foliar fungal communities are structured and assembled, we assessed to what extent leaf flush and latitude can explain the within- and among-tree variation in foliar fungal communities.

Location: A latitudinal gradient spanning .

Plant genetic relatedness and volatile-mediated signalling between Solanum tuberosum plants in response to herbivory by Spodoptera exigua.

It has been proposed that plant-plant signalling via herbivore-induced volatile organic compounds (VOCs) should be stronger between closely related than unrelated plants. However, empirical tests remain limited and few studies have provided detailed assessments of induced changes in VOCs emissions across plant genotypes to explain genetic relatedness effects. In this study, we tested whether airborne signalling in response to herbivory between Solanum tuberosum (potato) plants was contingent on plant genetic relatedness, and further investigated genotypic variation in VOCs potentially underlying signalling and its contingency on relatedness.

Linking herbivory and ecosystem services in urban forests.

Urban forests provide important benefits for humans. Species interactions, in particular herbivory, can alter their function and ultimately threaten their ecosystem service provisioning. We call for research that identifies herbivory drivers in urban forests and tests for links between herbivory and forest services.

Photosynthetic and defensive responses of two Mediterranean oaks to insect leaf herbivory.

Insect herbivory is a dominant interaction across virtually all ecosystems globally and has dramatic effects on plant function such as reduced photosynthesis activity and increased levels of defenses. However, most previous work assessing the link between insect herbivory, photosynthesis and plant defenses has been performed on cultivated model plant species, neglecting a full understanding of patterns in natural systems. In this study, we performed a field experiment to investigate the effects of herbivory by a generalist foliar feeding insect (Lymantria dispar) and leaf mechanical damage on multiple leaf traits associated with defense against herbivory and photosynthesis activity on two sympatric oak species with contrasting leaf habit (the evergreen Quercus coccifera L.

The co-existence of multiple oak leaf flushes contributes to the large within-tree variation in chemistry, insect attack and pathogen infection.

Many plant species produce multiple leaf flushes during the growing season, which might have major consequences for within-plant variation in chemistry and species interactions. Yet, we lack a theoretical or empirical framework for how differences among leaf flushes might shape variation in damage by insects and diseases. We assessed the impact of leaf flush identity on leaf chemistry, insect attack and pathogen infection on the pedunculate oak Quercus robur by sampling leaves from each leaf flush in 20 populations across seven European countries during an entire growing season.