Environmental change can impact host–parasite interactions, but the effects of multiple stressors on parasites are rarely measured. Considering stressor interactions may allow parasitologists to evaluate how parasite burdens change in nature, where stressors rarely occur in isolation. This study aimed to understand how combined stressors such as warming, nutrients and pollution (i.e. metal concentrations) influence myxozoan prevalence and abundance in the Pearl River, Louisiana, USA. Fish were seined between 1963 and 2005 upstream and downstream of a pulp-mill outfall and were then preserved and accessioned into the Royal D. Suttkus Fish Collection of the Tulane University Biodiversity Research Institute. In 2024, we dissected 1188 fish individuals across 7 host species, and we identified myxozoans in 6 species. Six myxozoan genera were detected, including Chloromyxum, Henneguya, Myxidium, Myxobolus, Thelohanellus and Unicauda, with some novel host–parasite combinations. The abundance of Myxobolus infecting Carpiodes velifer gills declined by 86% over the study period, while the abundance of Myxobolus infecting Pimephales vigilax gills was significantly lower downstream of the pulp mill outfall. Among the drivers analyzed, temperature had a significant negative effect on this parasite’s abundance, metal concentrations had a positive effect, and these 2 drivers interacted. Our results highlight the differential susceptibility of wild fishes to myxozoan infections and the usefulness of museum collections for understanding historical change in myxozoan burdens in fish. Since stressor-driven changes in myxozoan abundance do not follow a single pattern across species, we expect a shift in freshwater myxozoan communities with progressing climate change and pollution.

The impacts of long-term warming on soil physical structure and soil organic carbon (SOC) pools are currently disputed and uncertain. We conducted an eleven-year warming experiment in wheatland field in Henan, China. We found that long-term warming significantly increased soil bulk density by 4.5%, and significantly decreased total porosity and non-capillary porosity by 3.4% and 5.0%, respectively. Besides, long-term warming decreased the >2 mm fraction proportion and increased <0.053 mm fraction proportion of dry and wet aggregates. The mean weight diameter value for dry and wet aggregates in long-term warming treatment was significantly decreased by 7.0% and 6.7%, respectively. Moreover, long-term warming significantly decreased the total SOC, very labile pool (F1) and labile pool (F2) content by 10.6%, 30.6%, and 43.6%, and significantly increased the less labile pool (F3) and non-labile pool (F4) content by 94.2% and 21.1%, respectively. Long-term warming increased the passive carbon pool percentage but decreased the active carbon pool (ACP) percentage. Our results suggest that long-term warming negatively affected the soil's physical structure and impaired soil ACP accumulation. The findings of this study help improve our understanding of the response of farmland soils in northern China to climate change and provide scientific basis for establishing carbon management measures in farmland.

The ecological ubiquity of parasites and their potential impacts on host behaviour have led to the suggestion that parasites can act as ecosystem engineers, structuring their environment and physical habitats. Potential modification of the relationship between parasites and their hosts by climate change has important implications for how hosts interact with both their biotic and abiotic environment. Here, we show that warming and parasitic infection independently increase rates of bioturbation by a key detritivore in aquatic ecosystems (Gammarus). These findings have important implications for ecosystem structure and functioning in a warming world, as alterations to rates of bioturbation could significantly modify oxygenation penetration and nutrient cycling in benthic sediments of rivers and lakes. Our results demonstrate a need for future ecosystem management strategies to account for parasitic infection when predicting the impacts of a warming climate.

Within the English Channel, the common cuttlefish Sepia officinalis is a semelparous species for which a 2-year life cycle was exclusively described in the 1980s. In the 1990s, new research indicated that whilst a 2-year life cycle was still evident for females and the large majority of males, a small proportion of males were actually maturing at only 1 year of age. Since 1980, the interest of French and UK fishers for this resource has increased and it is nowadays one of the most important demersal species of the area and is considered to be fully exploited. From the start of the 20th century, fishing effort and sea surface temperatures have increased in the English Channel and have probably impacted the life history traits of S. officinalis. A 2-year sampling programme was undertaken at French landing sites of the English Channel during the reproduction season in 2010 and 2011 to estimate if the proportion of 1-year-old mature animals has changed. Age determination was carried out by coupling polymodal decomposition and lipofuscin measurement. Size-at-maturity for each year and each sex was estimated by fitting a binomial error GLM. Results highlight that a variable percentage of males and females belonging to the first cohort are mature and that size-at-maturity was lower than that observed in the 1990s. Finally, different parameters, such as temperature and fishing pressure are explored to discuss changes in life history traits suggesting that cuttlefish could be an indicator of the temperature regime shift in the English Channel.

Assessing the sensitivity of ectotherms to variability in their environment is a key challenge, especially in the face of rapid warming of the Earth's surface. Comparing the upper temperature limits of species from different regions, at different rates of warming, has recently been developed as a method to estimate the long term sensitivity of shallow marine fauna. This paper presents the first preliminary data from four tropical Ascension Island, five temperate New Zealand and six Antarctic McMurdo Sound species. The slopes and intercepts of these three assemblages fitted within the overall pattern for previously measured assemblages from high temperature tolerance in tropical fauna and a shallow slope, to low temperature tolerance and a steep slope in Antarctic fauna. Despite the tropical oceanic Ascension Island being subject to upwelling events, the fit of the intercept and slope within the overall assemblage pattern suggests that the upwelling is sufficiently predictable for the fauna to have evolved the plasticity to respond. This contrasts with previously analysed species from the Peruvian upwelling region, which had a steeper slope than other temperate fauna. The speed and capacity of faunal assemblages to acclimatize their physiology is likely to determine the shape of the rates of warming relationship, and will be a key mechanism underpinning vulnerability to climate warming.

We have investigated how the microbially-driven processes of carbon (C) mineralization (respiration) and nitrogen (N) mineralization/immobilization in a soil from the northern Maritime Antarctic respond to differences in water availability (20% and 80% water-holding capacity) and temperature (5°C and 15°C) in the presence and absence of different organic substrates (2 mg C as either glucose, glycine or tryptone soy broth (TSB) powder (a complex microbial growth medium)) in a controlled laboratory experiment over 175 days. Soil respiration and N mineralization/immobilization in the presence of a C-rich substrate (glucose) increased with increases in water and temperature. These factors were influential individually and had an additive effect when applied together. For the N-rich substrates (glycine and TSB), microbial responses to increased water or temperature alone were weak or not significant, but these factors interacted to give significantly positive increases when applied together. These data indicate that under the expected changes in environmental conditions in the Maritime Antarctic, where temperature and the availability of water and organic substrates will probably increase, soil microbial activity will lead to more rapid C and N cycling and have a positive feedback on these biogeochemical processes, particularly where or when these factors increase concurrently.

To estimate the net effect of climate change on natural populations, we must take into account the positive and negative effects of temperature oscillations and climate variability. Warming because of climate change will likely exceed the physiological optima of tropical insects, which currently live very close to their thermal optima. Tropical insects will be negatively affected if their optima are exceeded otherwise warming may affect them positively. We evaluate the demographic responses of the cowpea aphid, Aphis craccivora, to summer warming in subtropical and tropical Taiwan, and examine the effects of diel temperature oscillation on these responses. Aphids were reared at four temperatures (current summer mean, +1.4, +3.9 and +6.4 °C), the latter three simulating different levels of warming. At each average temperature, aphids experienced constant or oscillating (from −2.9 to +3.6 °C of each mean temperature) regimes. As the simulated summer temperatures increased, so did the negative effects on life-history traits and demographic parameters. Compared with aphids reared in constant temperatures, aphids reared in oscillating temperatures developed more slowly and had a longer mean generation time, but their net reproductive rate was higher. These findings demonstrate that climate warming will affect demographic parameters and life-history traits differentially. Studies that use constant temperatures are unlikely to accurately predict biotic responses to climate change.

The aim of the present experiment was to investigate the effects of placing newborn piglets under the heat lamp or both drying and placing them under the heat lamp on piglet mortality. Sixty-seven healthy (Landrace × Yorkshire) sows were divided equally into three different experimental groups: a control group where the farrowings occurred without supervision from the farmer (C; n = 23 litters), another group where the piglets were placed under the heat lamp in the creep area immediately after birth (HL; n = 22 litters) and a third group where the piglets were dried with straw and paper towels followed by placing them under the heat lamp in the creep area immediately after birth (DHL; n = 22 litters). The sows were individually loose-housed in farrowing pens during farrowing and lactation. The piglets were not closed inside the creep area, but were free to move around in the pen. The routines in the experimental groups required the stock person to attend the farrowings from the onset of birth of the first piglet until the last piglet was born. All the dead piglets were weighed and subjected to a post mortem examination at the farm to ascertain the causes of death. Postnatal mortality (% of live born) was significantly lower in the HL and DHL groups than in the control group (P < 0.0001). This was significant concerning all causes of mortality. Compared to the control group, crushing occurred in significantly fewer litters when the piglets were both dried and placed under the heat lamp (P < 0.05). In the DHL treatment, crushing of one or more piglets by the sow occurred in only 13.6% of the litters, whereas this was increased to 34.8% in the HL and to 47.9% in the control group, respectively. All causes of death, except the proportion of stillborn piglets, increased significantly with increasing litter size. Because of the relatively large potential that these rather simple routines may have to improve piglet survival, different types of management or human interference around the time of farrowing should be compared on a larger scale, both experimentally and on commercial farms.