Black truffle, Tuber melanosporum Vittad., production is increasing due to an improvement in cultivation management and to the demand for this highly appreciated fungus. However, this intensification of truffle cultivation has led to the appearance of problems related to pest incidence. Specifically, the truffle beetle, Leiodes cinnamomeus (Panzer, 1793) (Coleoptera: Leiodidae), causes significant losses in black truffle marketability. However, its biology is still poorly known, and no effective agro-ecological methods exist to mitigate its damage to the truffles. This study aimed at assessing the population dynamics of L. cinnamomeus over four seasons (2019-2023) in an orchard located in NE Spain and relating these dynamics to weather variables and damage to truffle fruit bodies. Moreover, we described the diversity of arthropods captured in the traps in search of potential natural enemies of this beetle. The maximum population peak was observed in November, except for a single season in which it occurred in December. Moreover, the sex ratio was balanced (0.54 on average), but it varied over the growing season and among years. Significant and positive relationships of the population density of truffle beetles with air temperature and relative humidity were observed. The number of beetles per trap and day was strongly linked to heat accumulation. Finally, the Carabid Percus (Pseudopercus) patruelis (L. Daufour, 1820) was identified as a natural enemy of L. cinnamomeus. These results could be used in the future for monitoring and predicting truffle beetle populations.
With the widespread use of biochar, the cascading effects of biochar exposure on soil fauna urgently require deeper understanding. A meta-analysis quantified hierarchical changes in functional traits and community diversity of soil fauna under biochar exposure. Antioxidant enzymes (24.1 %) did not fully mitigate the impact of MDA (13.5 %), leading to excessive DNA damage in soil fauna (21.2 %). Concurrently, reproduction, growth, and survival rates decreased by 20.2 %, 8.5 %, and 21.2 %, respectively. Due to a 39.7 % increase in avoidance behavior of soil fauna towards biochar, species richness ultimately increased by 80.2 %. Compared to other feeding habits, biochar posed a greater threat to the survival of herbivores. Additionally, macrofauna were the most sensitive to biochar. The response of soil fauna also depended on the type, size, concentration, and duration of biochar exposure. It should be emphasized that as exposure concentration increased, the damage to soil fauna became more severe. Furthermore, the smaller the biochar sizes, the greater the damage to soil fauna. To mitigate the adverse effects on soil fauna, this study recommens applying biochar at appropriate times and selecting large sizes in low to medium concentrations. These findings confirm the threat of biochar to soil health from the perspective of soil fauna.
The decomposition of returned straw is increasing facing the negative impacts by metal nanoparticles (NPs), however, which may be modulated by soil fauna and this modulation effect is unclear. Here, the interactive effects of ZnO NPs with soil fauna on wheat straw decomposition were investigated in a potted rice cropping system. The results showed that ZnO NP below middle concentrations did not significantly influence straw decomposition, and mass loss was mainly driven by microfauna and microbes. High concentrations of ZnO NPs significantly impeded decomposition, mainly by reducing the complexity of fungal communities. This negative effect was ascribed to the promotion of Zn solubilization by bacterial taxa such as unclassified Acidobacteria, Bacteroidetes and Gemmatimonadetes. ZnO NPs had a greater impact on soil microorganisms than on fauna, reduced microbial activity, promoted the released straw nutrients entering into the soil by damaging nutrient transferring microorganisms and dominated the effects on soil stoichiometry. However, soil fauna significantly increased the activities of C- and N-releasing enzymes, decreased the activity of P-releasing enzymes, regardless of ZnO NP concentration, and promoted straw C decomposition. ZnO NPs altered soil microbial community composition, but these changes were modulated by soil fauna. Nonetheless, nutrient transport by fungi such as Ascomycota and Zygomycota and grazing by fauna were the predominant modulators on straw stoichiometry. The results of this study revealed that rational control of soil fauna will be helpful for promoting straw decomposition and efficient recycling of straw nutrients by crops under ZnO NP contamination. High ZnO NP concentrations inhibit straw decomposition mainly by reducing diversity of fungal community.The negative effects of ZnO NPs are ascribed to Zn solubilization by bacterial taxa such as unclassified Acidobacteria, Bacteroidetes and Gemmatimonadetes.ZnO NPs have greater impact on soil microorganisms than on fauna, reduce microbial activity, promote the released nutrients into soil and dominate the effects on soil stoichiometry.Fungal transport (e.g., Ascomycota and Zygomycota) and fauna grazing are the predominant modulators on straw stoichiometry.
1. The relationship between biodiversity and multitrophic ecosystem functions (BEF) remains poorly studied in forests. There have been inconsistent reports regarding the significance of tree diversity effects on ecosystem functions, which may be better understood by considering critical biotic interactions of trees. 2. This study investigates the role of tree-mycorrhizal associations that may shape forest BEF relationships across multiple ecosystem functions. We used a field experiment (MyDiv) that comprises 10 deciduous tree species associated with either arbuscular mycorrhizal (AM) or ectomycorrhizal (EcM) fungi to create gradients in species richness (1, 2, 4 species) and different mycorrhizal communities (only AM-species [AM fungi associated tree species] or EcM-species [EcM fungi associated tree species], or a combination of both). We investigated the effects of tree species richness and mycorrhizal types on crucial multitrophic ecosystem functions (foliage damage, predation [using artificial caterpillars] and soil fauna feeding activity [similar to 0-10 cm]) and assessed how these effects were mediated by stand characteristics. 3. Overall, we found that tree species richness and mycorrhizal types strongly affected multitrophic ecosystem functions. Compared to monocultures, 4-species mixtures with both mycorrhizal types experienced significantly lower foliage damage. The mixtures of EcM-species supported significantly higher predation (i.e. a greater proportion of artificial caterpillars being attacked), and this effect strengthened with tree species richness. The effects of tree species richness on soil fauna feeding activity were negative across all mycorrhizal types in the lower soil layer. Moreover, we showed that tree diversity effects were mediated by above-ground tree biomass, vertical structural complexity and leaf quality, with the dominating mechanisms largely depending on the mycorrhizal types. 4. Synthesis. Tree species richness affected multitrophic ecosystem functioning by (1) directly decreasing the proportion of foliage damage in the communities with both mycorrhizal types, where AM-species benefited from mixing with EcM-species, and (2) increasing predation rates via changes in the vertical structural complexity in mixtures of EcM-species. Our results highlight the importance of considering mycorrhizal types for managing well-functioning mixed-species forests and contribute to broadening the mechanistic understanding of the context-dependent BEF relationships in forests.
Wetlands play a crucial role in oxygen production, air purification, and quality maintenance. Thus, conservation of wetland is essential in response to natural and anthropogenic damaging activities. Restored farmland, utilized to repair the southern buffer zone of Jiangsu Yancheng Wetland National Nature Reserve for Rare Birds, was used to investigate and analyze the diversity of migratory birds and soil fauna. In this study, five different crops, colza oil, mustard, Chinese cabbage, wheat, and barley, were planted in the restored plots, which were foraged by overwintering migratory birds, resulting in low crop yield. The soil fauna biodiversity and biomass in the wheat, Chinese cabbage, and colza oil plots during winter were relatively rich, which attracted many migratory birds to roost and feed. The variability and population of migratory birds significantly improved (18 species and 164231 migratory birds), which was owed to soil fauna and planted crops. Therefore, based on the results of our study, farmland restoration could significantly enrich the biodiversity of soil fauna and migratory birds, improve the ecological environment of wetlands, and attract more migratory birds as inhabitants.
Climate change is occurring globally, with wide ranging impacts on organisms and ecosystems alike. While most studies focus on increases in mean temperatures and changes in precipitation, there is growing evidence that an increase in extreme events may be particularly important to altering ecosystem structure and function. During extreme events organisms encounter environmental conditions well beyond the range normally experienced. Such conditions may cause rapid changes in community composition and ecosystem states. We present the impact of an extreme pulse event ( a flood) on soil communities in an Antarctic polar desert. Taylor Valley, McMurdo Dry Valleys, is dominated by large expanses of dry, saline soils. During the austral summer, melting of glaciers, snow patches and subsurface ice supplies water to ephemeral streams and wetlands. We show how the activation of a non-annual ephemeral stream, Wormherder Creek, and the associated wetland during an exceptional high-flow event alters soil properties and communities. The flow of water increased soil water availability and decreased salinity within the wetted zone compared with the surrounding dry soils. We propose that periodic leaching of salts from flooding reduces soil osmotic stress to levels that are more favorable for soil organisms, improving the habitat suitability, which has a strong positive effect on soil animal abundance and diversity. Moreover, we found that communities differentiated along a soil moisture gradient and that overland water flow created greater connectivity within the landscape, and is expected to promote soil faunal dispersal. Thus, floods can 'precondition' soils to support belowground communities by creating conditions below or above key environmental thresholds. We conclude that pulse events can have significant long-term impacts on soil habitat suitability, and knowledge of pulse events is essential for understanding the present distribution and functioning of communities in soil ecosystems.
Climatic changes resulting from anthropogenic activities over the passed century are repeatedly reported to alter the functioning of pristine ecosystems worldwide, and especially those in cold biomes. Available literature on the process of plant leaf litter decomposition in the temperate Alpine zone is reviewed here, with emphasis on both direct and indirect effects of climate change phenomena on rates of litter decay. Weighing the impact of biotic and abiotic processes governing litter mass loss, it appears that an immediate intensification of decomposition rates due to temperature rise can be retarded by decreased soil moisture, insufficient snow cover insulation, and shrub expansion in the Alpine zone. This tentative conclusion, remains speculative unless empirically tested, but it has profound implications for understanding the biogeochemical cycling in the Alpine vegetation belt, and its potential role as a buffering mechanism to climate change.