Human and environmental factors shape tree species assemblages in West African tropical forests

•Aim: This study investigated how human activities and local environmental variables shape tree assemblages (species composition in a defined location), comparing their effects on edible and inedible tree species. Three hypotheses were tested: (1) Environmental filtering impacts spatial beta‐diversity more than dispersal limitation; (2) human activities significantly influence regional tree beta‐diversity; and (3) predictors of beta‐diversity differ between edible and inedible species. •Location: Tropical forest in Nigeria and Cameroon in West and Central Africa. •Methods: Tree data were collected between 2002 and 2019 from 66 forest plots. Species were categorised as edible and inedible by humans using interviews and online databases. Pairwise beta‐diversity (partitioned into total beta‐diversity and turnover) between plots was analysed using Generalised Dissimilarity Models (GDMs) with geographical distance, plot‐specific variables (forest composition, climate, elevation, stem density, human influence indicators), and human influence indicators (distance to closest human presence [DCHP], and nearest anthropogenic edges [DNAE]) as predictors. •Results: The dataset included 236 edible species (11,097 stems) and 472 inedible species (17,202 stems), with high species turnover (> 90%) dominating beta‐diversity patterns. Due to local plot‐level factors, environmental filtering (deviance explained for all species: 37.4%, edible: 18.9% and inedible: 31.4%) exerted greater influence on species assemblages than geographical distance alone. Beta‐diversity drivers differed between edible and inedible species: elevation strongly influenced turnover in inedible species, whereas forest composition significantly shaped the assemblage of edible species, reflecting patterns of human‐mediated species selection and species dominance. Human presence impacted the overall beta‐diversity of inedible species but only influenced the turnover component of edible species. •Main Conclusions: Tree assemblages in the Nigeria–Cameroon forest region were primarily structured by local environmental conditions and human activities rather than by dispersal limitation. Effective conservation should incorporate sustainable human activities and traditional ecological knowledge, with further research needed to explore the long‐term anthropogenic impacts on these forests

Citizen scientists as butterfly predators: using foraging theory to understand individual recorder behaviour

Citizen science is increasingly important in the collection of biological data. However, to understand the broader utility of the growing number of citizen-derived records, we need to understand exactly how recorder behaviour affects the geographic distribution of records made. Here, we apply an optimal foraging model to citizen science data from the UK to determine how likely a recorder (predator) is to visit any given kilometre square and record a butterfly (prey). By defining the square with the highest density of an individual’s records as their ‘origin’, we show that the probability of visiting a given site depends on its distance from the origin and the rarity-weighted species richness of the species thought to be present. This pattern of behaviour differs between recorders visiting more than or fewer than five squares, termed broad and narrow-range foragers. The model shows that recorder behaviour is driven, in part, by a simple trade-off between distance travelled and the rarity-weighted species richness. This collective behaviour helps explain over-recording by broad-ranging foragers in protected areas at distance and under-recording, by narrow-range foragers, in the wider countryside. It also implies that estimating parameters describing rare species’ distributions (e.g. mean occupancy) will be challenging, since sample inclusion depends on occupancy itself. Mapping rare species’ distributions should be simpler, since the sites at which they can be found tend to be well-sampled, but the same is unlikely to be true of common species, which also occupy areas that are unlikely to be sampled. More work is needed to understand how widely our results can be generalised beyond the UK and the dataset considered

Predicting the way forward for the Global Biodiversity Framework [Opinion]

In order to truly look ahead and address pressing biodiversity challenges, the GBF needs a new international program that coordinates biodiversity research and modeling. We label this initiative the World Biodiversity Research Programme

Modelling of the potential of floating photovoltaics for mitigating climate change impacts on reservoirs

Deployment of floating photovoltaics (FPVs) on water reservoirs is accelerating, and their lifetimes are expected to extend far into the 21 st century. One of their potential co-benefits is mitigation of climate change-induced impacts on water quality. However, there has been little investigation of this possibility. We used MyLake, a 1D (vertical) numerical model, to simulate water quality impacts in a UK reservoir of different FPV coverages under four future climate scenarios and a present-day baseline case. We tested hypotheses that increased FPV coverage would offset climate-induced reservoir warming, stratification duration lengthening, phytoplankton biomass increases and taxonomic dominance changes. FPV coverage's ability to offset climate warming varied between the four climate scenarios, and seasonally within them. It was able to fully offset changes in stratification duration and to entirely prevent thermal stratification in all four future scenarios. Climate-induced increases in phytoplankton biomass and taxonomic dominance patterns were also entirely offset if sufficient FPV coverage was applied in all future scenarios. According to these results, FPV coverage will be able to compensate partially or fully for thermal and phytoplanktic changes in reservoirs under future climates. However, the amount of coverage required varies seasonally and depends on future climate trajectories

Extreme Antarctic Sea Ice Loss Facilitated by Negative Shift of Southern Annular Mode

Antarctic sea ice area exhibited an abrupt decline in 2015–2016, transitioning from a near record maximum state to a then-record minimum state. The underlying drivers are still being studied, raising questions whether this marks the onset of a long-term decline, or an isolated internal climate variability event. We identify extreme events in CMIP6 pre-industrial control simulations that are comparable to the observed extreme event in 2015–2016 and explore their atmospheric and oceanic drivers. Results show these events are rare but possible. The most robust association we find is between a negative Southern Annular Mode transition and extreme Antarctic sea ice loss. Most models show sea ice recovery after extreme loss, differing from the persistent decline observed in recent years. This contrast suggests anthropogenic forcing may now be playing a role. Our results underscore the role of internal variability while improving understanding of extreme events and their relevance for future sea ice predictability

The genome sequence of the shy cosmet moth, Limnaecia phragmitella Stainton, 1851 (Lepidoptera: Cosmopterigidae)

We present a genome assembly from an individual male Limnaecia phragmitella (Shy Cosmet Moth; Arthropoda; Insecta; Lepidoptera; Cosmopterigidae). The assembly contains two haplotypes with total lengths of 539.22 megabases and 553.78 megabases. Most of haplotype 1 (98.9%) is scaffolded into 30 chromosomal pseudomolecules, including the Z sex chromosome. Haplotype 2 was assembled to scaffold level. The mitochondrial genome has also been assembled, with a length of 15.26 kilobases. This assembly was generated as part of the Darwin Tree of Life project, which produces reference genomes for eukaryotic species found in Britain and Ireland

A techno-societal framework for quantifying the risk of heavy rainfall events over Ramsar wetlands

Wetlands are often found in depressions or around rivers, lakes, and coastal seas, where they periodically flood. Hence, this study presents a new techno-societal framework for quantifying the risk of heavy rainfall events (HREs) on wetland ecosystems and surrounding communities in India. By integrating advanced technological approaches such as Bayesian analysis, fuzzy logic, and remote sensing with societal considerations, we provide a comprehensive assessment of wetland vulnerability to climate change impacts. An effort has been made to understand the non-stationarity of HREs, inundation patterns of wetlands, impact evaluation, and future precipitation trends (CMIP6). The overall assessment of the extreme precipitation indices indicated that return periods were highest for Thane Creek, followed by Bhoj Wetland. We also assessed the risk index based on the parameters of hazard, vulnerability, and exposure for all wetlands using the fuzzy logic approach. The overall risk index evaluation indicated that Bhoj Wetland, Thane Creek, Point Calimere, Deepor Beel, Sasthamkotta Lake, and Vembannur Wetland are at “very high” risk. The study also investigated inundation patterns of critical “very high” risk wetlands and conducted an impact evaluation for the Bhoj Wetland, highlighting the influence of HREs on infrastructures, human settlements, and ecosystems. Wetlands such as Point Calimere, Vembannur Wetland, Karikili Bird Sanctuary, Vendanthangal, and Vaduvur Bird Sanctuary showed a significantly increasing trend in precipitation for both historical and future SSP2-4.5 scenario. These findings are useful in decision-making for policymakers to adopt the best practices to manage the local wetlands wisely

Aspects of the Global Thermohaline Circulation in the Absence of Wind Forcing

The global ocean’s overturning circulation plays an important role in climate and climate variability through its transport of heat, freshwater and nutrients. As part of this three-dimensional overturning circulation, dense waters sink in narrow regions at high latitudes in the North Atlantic and along the Antarctic coast. To close this circulation, it is generally assumed that either intense interior mixing by winds and internal tides, or wind-driven upwelling is required to bring these water masses back to the surface. Nevertheless, more recent work questions this requirement for winds and tides, arguing that surface buoyancy forcing alone can drive such a circulation through a process known as rotating horizontal convection. In particular, it has been shown that the presence of a re-entrant channel, such as the Southern Ocean, is required for rotating horizontal convection to generate many features of the global ocean’s overturning circulation. Building on previous work in which rotating horizontal convection was forced by only thermal forcing, here we demonstrate, using an idealised eddying ocean model with both thermal and haline surface forcing, that rotating horizontal convection can produce many of the observed features of the global ocean’s overturning circulation. These results therefore suggest that a global “thermohaline circulation” can exist in the ocean in the absence of winds and in the limit of small vertical diffusion

Can a Major Geomagnetic and Auroral Disturbance Originate From a Solar Active Region Close to the Limb?

When forecasting major geomagnetic storms, it is commonly assumed that coronal eruptions near the solar limb are not of concern. We here discuss two sequences of events: the Fátima storms of January 1938 and the Halloween storms of October/November 2003. In both cases, a highly active sunspot group generated a major eruption when it reached the western solar limb. In the 2003 events, this generated no terrestrial disturbance, despite being estimated to be the most powerful flare on record. In contrast, the only known solar eruption that could have given the second Fátima storm, was the major flare on the western limb. The geomagnetic and Dcx indices in this storm exceeded disturbance levels that have been seen for less than, respectively, 0.0015% and 0.0091% of the time and caused aurora to be seen at geomagnetic latitudes down to (at Tataouine, Tunisia), making it the 13th most extensive auroral event known since the Maunder minimum. We investigate if this storm was caused by the limb eruption and conclude that it would be a possible but rare occurrence, although the historic data do not allow us to fully eliminate other scenarios. We show that the longitude distribution of low-latitude auroral sightings depends upon the Universal Time of the impact of the coronal mass ejection and the subsequent timing of substorm activity is consistent with the theory of how low-latitude red aurora is generated. We show how the Dcx and indices give understanding of the substorm behavior during historic events

Nature-based solutions (Nbs) for flood mitigation: recent UK case studies

Implementing Nature-based solutions (Nbs) can potentially reduce the flood risk in catchments and improve water and soil quality and biodiversity. Understanding the hydrological functioning of the Nbs interventions is important in determining their effectiveness in reducing flood risks. This study reports the findings from two UK projects namely the Littlestock Brook Natural Flood Management (NFM) pilot and LANDWISE (Land Management in Lowland Catchments for Integrated Flood Risk Reduction). The Littlestock Brook NFM study showed that the Nbs interventions successfully attenuated all storm event discharge peaks during the monitoring period (up to 55% reductions) and that over 40% of the total storage volume remained available throughout all events. The LANDWISE project demonstrated that whilst increased organic matter improves soil structure and porosity, innovative arable management practices (e.g., controlled traffic and min till) can also improve soil structure and porosity, increasing soil hydraulic conductivity and therefore NFM potential