Search Results (6)

The understanding of coastal ecosystems regarding variability and resilience under climatic and anthropogenic forcing is reliant upon long-term ecological records. We examined the Helgoland Roads time series (1968–2017), which includes temperature, salinity, nutrients (nitrate, phosphate), and biological parameters (diatoms and Acartia spp.). We applied autocorrelation, multi-taper spectral analysis, and wavelet and cross-wavelet transforms to identify dominant temporal patterns and scale-dependent interactions. Sea surface temperature shows consistent long-term warming, and subdecadal (2–3-year) and decadal (7–8-year) oscillations reflect coherent patterns with the North Atlantic Oscillation and Arctic Oscillation. Salinity varied in anti-phase to Elbe River discharge at 6–7-year scales, reflecting control of seasonal, riverine freshwater, and salinity scenarios. Nutrients, as declining long-term trends (particularly phosphate), are associated with seasonal to multi-year variability linked to episodic discharge events. Biological parameters had strong annual periodicities reflective of bloom cycles but also variability above the annual limit. Diatoms responded to climatic, nutrient, and biological responses at the 3–5-year scale associated with this ecological context, particularly nitrate and phosphate; Acartia (spp.) respond to temperature, salinity, and resource availability (diatoms), reflecting climate/nutrient/trophic linkages. This study indicates that Helgoland Roads is represented as a multi-scale, non-stationary system, in which climate variability, riverine input, and ecological linkages are cascaded down to physical and chemical processes that structure biological communities. Spectral methods reveal scale-dependent synchrony and highlight the risks of trophic mismatch under climate change, emphasizing the importance of sustained high-frequency monitoring. Full article

Scorpions of the genus Tityus are a diverse and medically important group, but many aspects of their natural history, particularly feeding ecology, are poorly documented. A coherent understanding of their natural prey is crucial for interpreting the evolution of their potent venoms. During fieldwork in Quito, Ecuador, we recorded a predation event involving a specimen of Tityus pugilator Pocock, 1898, subduing a scolopendromorph centipede, Otostigmus sp. The centipede was still moving when found, indicating a recent envenomation. This observation adds to the limited knowledge of the genus’s feeding habits both locally and regionally, demonstrating that Tityus can prey on large and dangerous arthropods. This trophic relationship is worth noting as scorpions of this genus have evolved highly potent venoms. Further in-field observations are needed to fully explore this connection between diet and venom evolution in Tityus scorpions. Full article

Northern Thailand frequently suffers from severe PM2.5 air pollution, especially during the dry season, due to agricultural burning, local emissions, and transboundary haze. Understanding how pollution moves across regions and identifying source–receptor relationships are critical for effective air quality management. This study investigated the spatial and temporal dynamics of PM2.5 in northern Thailand. Specifically, it explored how pollution at one monitoring station influenced concentrations at others and revealed the seasonal structure of PM2.5 transmission using network-based analysis. We developed a Python-based framework to analyze daily PM2.5 data from 2022 to 2023, selecting nine representative stations across eight provinces based on spatial clustering and shape-based criteria. Delaunay triangulation was used to define spatial connections among stations, capturing the region’s irregular geography. Cross-correlation and Granger causality were applied to identify time-lagged relationships between stations for each season. Trophic coherence analysis was used to evaluate the hierarchical structure and seasonal stability of the resulting networks. The analysis revealed seasonal patterns of PM2.5 transmission, with certain stations, particularly in Chiang Mai and Lampang, consistently acting as source nodes. Provinces such as Phayao and Phrae were frequently identified as receptors, especially during the winter and rainy seasons. Trophic coherence varied by season, with the winter network showing the highest coherence, indicating a more hierarchical but less stable structure. The rainy season exhibited the lowest coherence, reflecting greater structural stability. PM2.5 spreads through structured, seasonal pathways in northern Thailand. Network patterns vary significantly across seasons, highlighting the need for adaptive air quality strategies. This framework can help identify influential monitoring stations for early warning and support more targeted, season-specific air quality management strategies in northern Thailand. Full article

Analysis of the nematode community has been considered a key indicator of soil health. In this study, the assessment of nematodes was performed two times during the third growing season in soil contaminated by chemical elements where Miscanthus × giganteus was cultivated in the years 2019–2022. A morphological approach was used to identify the nematode communities that showed sensitivity to the level of soil contamination. In contrast, the value of M × g dry biomass was a more conservative indicator and displayed only a small yield, which decreased (3.6%) at the highest level of soil contamination by lead to 290.5 ± 75.4 µg/g. Principal component analysis revealed four trends associated with the coherent variability of contamination in soil and various organs of M × g. The variability of elements was reflected by the first three principal components and did not affect the nematode community. The variability of lead concentration was associated with principal component 4, which was the largest driver of changes in the nematode community. The trophic structure of the nematode communities was the most sensitive to soil contamination by lead. A decrease in the Structural Index was the general indicator in the transformation of the nematode community structure due to increasing levels of soil contamination. Full article

The risk of a broad range of respiratory and heart diseases can be increased by widespread exposure to fine atmospheric particles on account of their capability to have a deep penetration into the blood streams and lung. Globally, studies conducted epidemiologically in Europe and elsewhere provided the evidence base indicating the major role of PM_2.5 leading to more than four million deaths annually. Conventional approaches to simulate atmospheric transportation of particles having high dimensionality from both transport and chemical reaction process make exhaustive causal inference difficult. Alternative model reduction methods were adopted, specifically a data-driven directed graph representation, to deduce causal directionality and spatial embeddedness. An undirected correlation and a directed Granger causality network were established through utilizing PM_2.5 concentrations in 14 United Kingdom cities for one year. To demonstrate both reduced-order cases, the United Kingdom was split up into two southern and northern connected city communities, with notable spatial embedding in summer and spring. It continued to reach stability to disturbances through the network trophic coherence parameter and by which winter was construed as the most considerable vulnerability. Thanks to our novel graph reduced modeling, we could represent high-dimensional knowledge in a causal inference and stability framework. Full article

In the present work, we attempt to test the applicability of common trophic state indices such as Carlson’s index (1977), probability distribution diagrams of Vollenweider (1982), and fixed boundary systems of the OECD (1982) and of Nurnberg (1996) for evaluating the risk of eutrophication in the Sejnane reservoir in North Tunisia. The environmental parameters considered include monthly values of nutrients, chlorophyll a, Secchi transparency, turbidity and dissolved oxygen over a decade of monitoring from November 2001 through October 2011. To compile data and to identify key aspects of water quality, a multivariate technique as Principal Component Analysis was performed. Results show that productivity is limited by sedimentary turbidity, which contributes to decreasing water clarity and promotes the adsorption of phosphorus to suspended matter that decreases, indirectly, the bioavailability of nutrients. The Nurnberg model provides an accurate assessment of eutrophication with a clear internal coherence between self-indicators, and appears to be the most suitable way to evaluate eutrophication risk in the reservoir. Full article