Functional diversity estimates increasingly inform ecological research, yet how methodological choices such as trait number and coding affect common metrics remains poorly quantified. Here, we systematically evaluate the effects of trait number and coding strategy on functional diversity metrics using benthic macroinvertebrate traits. Across 14 functional diversity indices representing functional richness, evenness, dispersion, and redundancy, we showed that metric responses to trait number are highly facet-dependent. Functional richness and evenness indices were particularly sensitive to trait number, whereas dispersion and redundancy metrics were comparatively stable. Estimation uncertainty was minimized at intermediate trait number, indicating a potential balance between functional space resolution and statistical robustness. Despite broad consistency between binary and fuzzy coding approaches for several metrics, redundancy metrics showed substantial divergence between coding schemes. These results demonstrate that hidden methodological decisions can substantially influence functional diversity indices. Our study provides a quantitative framework for evaluating metric robustness and reveals that widely used indices differ fundamentally in their response to dimensionality—a mathematical behaviour that must be understood before ecological interpretation. We recommend reporting trait number alongside functional diversity values and exercising caution when comparing communities assessed with different trait sets, particularly for richness and evenness metrics.
Fine-scale habitat heterogeneity can generate marked short-distance variation in alpine-stream benthic macroinvertebrate assemblages, yet routine surveys often characterize a site using five Surber-net replicates collected within an approximately 100 m reach. We analyzed 99 quantitative samples collected at 10 m intervals along a 1 km reach of Qingbixi Stream on Cangshan Mountain, Dali, Yunnan, China, to relate taxonomic and functional diversity patterns to within-site sampling design. The samples contained 69 taxa and 15,034 individuals. Across 20 consecutive 50 m sections, turnover accounted for 70.9% of mean total pairwise taxonomic beta diversity, whereas nestedness accounted for 96.3% of mean total functional trait-state beta diversity. Taxonomic dissimilarity increased weakly but significantly with longitudinal distance. In ten simulated nominal 100 m sampling units, five spatial replicates detected an average of 82.9% of the locally observed taxon pool; completeness increased to 87.4% with six replicates and 94.6% with eight. These results support five replicates as a practical baseline for routine community characterization, while more intensive or microhabitat-stratified sampling is preferable when near-complete taxon detection or fine-scale beta-diversity assessment is required.
Groundwater represents one of the most important freshwater resources in Nigeria and serves as a major source of water for domestic, agricultural, and industrial activities. This scoping review synthesizes existing knowledge on groundwater systems, aquifer characterization, hydrogeophysical investigations, groundwater quality, and sustainability challenges across different hydrogeological environments in Nigeria. The review adopted the PRISMA-ScR framework and analyzed peer-reviewed studies published between 2000 and 2026, retrieved from Scopus, Web of Science, Google Scholar, ScienceDirect, and SpringerLink databases. The findings revealed substantial hydrogeological variability associated with the Basement Complex terrains, sedimentary basins, Coastal Plain Sands, and alluvial aquifer systems. Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT), hydrochemical analysis, GIS integration, and remote sensing emerged as the dominant groundwater investigation techniques. The review further identified increasing groundwater quality deterioration resulting from salinity intrusion, industrial pollution, oil spill contamination, excessive groundwater abstraction, and climate variability. Coastal aquifers within the Niger Delta, Lagos, and Akwa Ibom regions were found to be particularly vulnerable to seawater intrusion and hydrocarbon contamination. Despite increasing groundwater studies, major gaps remain in long-term monitoring, integrated hydrogeophysical investigations, and national groundwater database development. The study emphasizes the need for integrated groundwater management, sustainable policy frameworks, climate-resilient groundwater assessment approaches, and interdisciplinary research strategies to support long-term groundwater sustainability and water security in Nigeria.
In late May 2026, the Euphrates River experienced a significant flooding event, with water levels rising approximately four meters in some locations. Water flows increased from normal levels of approximately 300–500 m3/s to peak releases of 1800 m3/s. The flood resulted from a confluence of extreme meteorological conditions—record rainfall across Syria and Türkiye, combined with rapid snowmelt in the Turkish highlands—and dam operations, including the first opening of the Atatürk Dam spillway gates in seven years and the first opening of the Euphrates Dam floodgates in approximately four decades. While the 2026 event was moderate by historical standards (smaller than the 1969 flood and the 1988 flood of 2760 m3/s at Husaybah), the opening of the Euphrates Dam floodgates after approximately 40 years was unprecedented in the post-dam era. This paper synthesizes available data on the event’s causes, impacts, and implications for transboundary water management, drawing on official statements from Syrian, Turkish, and Iraqi authorities as well as hydrological literature and multiple language sources. The analysis places the 2026 event within the broader context of the Euphrates River’s hydrological history, examining both historical flooding events and the multi-decadal drought patterns that have characterized the basin over the past century. The paper also identifies institutional instability in Syria’s water sector following the 2024 political transition as a potential contributing factor deserving investigation, while acknowledging that direct causal evidence remains limited. Based on these findings, the paper recommends improved transboundary coordination, infrastructure upgrades, and—subject to further investigation of the institutional hypothesis—reconstitution of Syria’s water management technical capacity to ensure future hydrological resilience.
