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A general rule on the organization of biodiversity in Earth’s biogeographical regions
Get PDFLife on Earth is a mosaic distributed across biogeographical regions. Their regional species pools have experienced distinct historical and eco-evolutionary pressures, leading to an expected context-dependent organization of biodiversity. Here we identify a general spatial organization within biogeographical regions of terrestrial and marine vertebrates, invertebrates and plants (more than 30,000 species). We detect seven types of areas in these biogeographical regions that reflect unique combinations of four fundamental aspects of biodiversity (species richness, range size, endemicity and biogeographical transitions). These areas form ordered layers from the core to the transition zones of the biogeographical regions, reflecting gradients in the biodiversity aspects, experiencing distinct environmental conditions, and exhibiting taxonomic dissimilarities due to nestedness. These findings suggest this ubiquitous organization is mainly driven by the action of two complementary environmental filters, one acting on species from regional hotspots and the other on species from permeable biogeographical boundaries. The influence of these regional filters extends across spatial scales and shapes global patterns of species richness. Regional biodiversity follows a universal core-to-transition organization governed by general forces operating across the tree of life and space
Disentangling How Climate and Dispersal Drive Temporal Trends in Synchronous Population Dynamics
Get PDFABSTRACTSpatially synchronised population dynamics are driven by a combination of shared environmental conditions among sites and the movements of individuals between sites. Untangling the drivers of population synchrony requires investigation of how populations are correlated across space and time in relation to climate and mobility‐related attributes. Here, we use species survey data from over four decades to investigate average levels and temporal trends in population synchrony for 58 British bird and butterfly species. We first show that population synchrony is significantly associated with synchrony in seasonal climatic variables. After accounting for spatiotemporal climatic patterns, we determine whether temporal trends in population synchrony are shaped by mobility‐related attributes. We test this through an interspecies comparison using three variables correlated with mobility: biotope specialism, estimated species mobility, and local abundance change, which is known to affect emigration rate. We find that temporal trends in population synchrony are most marked for generalist butterfly species, butterflies with high estimated mobility, and butterflies that had changed in their mean abundance. For birds, we find changes in population synchrony are associated with specialist bird species and those that increased in abundance over time. Our results reveal a widespread effect of mobility attributes and abundance patterns on population synchrony over time, suggesting that variation in dispersal is a key factor determining the extent to which population dynamics are synchronised
Thermal acclimation of stem respiration implies a weaker carbon-climate feedback
Get PDFThe efflux of carbon dioxide (CO 2 ) from woody stems, a proxy for stem respiration, is a critical carbon flux from ecosystems to the atmosphere, which increases with temperature on short timescales. However, plants acclimate their respiratory response to temperature on longer timescales, potentially weakening the carbon-climate feedback. The magnitude of this acclimation is uncertain despite its importance for predicting future climate change. We develop an optimality-based theory dynamically linking stem respiration with leaf water supply to predict its thermal acclimation. We show that the theory accurately reproduces observations of spatial and seasonal change. We estimate the global value for current annual stem CO 2 efflux as 27.4 ± 5.9 PgC. By 2100, incorporating thermal acclimation reduces projected stem respiration without considering acclimation by 24 to 46%, thus reducing land ecosystem carbon emissions
Two-step drying of soya bean seed germplasm often improves subsequent storage longevity
Get PDFIt is recommended that seeds for genebank storage are dried to low moisture content at 10-25°C, 10-15% RH, but in some crops, an initial warmer drying temperature may provide better longevity. Seeds of diverse accessions of soya bean (Glycine max (L.) Merr.) produced in three seasons and harvested shortly before or at harvest maturity were initially dried at 17, 30 or 40°C with 15% RH and subsequently at 17°C with 15% RH; seeds were fumigated either before or after initial drying. Seed longevity in hermetic storage at 45°C with approximately 9% moisture content was affected by the initial drying treatments, but effects varied among treatment combinations and accessions. Seeds harvested before harvest maturity, at 10-14% moisture content, tended to benefit from warmer temperature drying. Fumigation before initial drying resulted in shorter longevity than fumigation afterwards for about 70% of harvested seed lots. Most treatment combinations across all experiments showed seed longevity was improved, often considerably, by 4 days’ initial drying at 40°C compared to drying at 17°C throughout. Longevity was also improved in many treatment combinations (fewer than at 40°C) by initial drying at 30°C compared to 17°C. In a minority of treatment combinations, seed longevity was reduced by drying at 40 or 30°C compared to 17°C. The research shows a potential benefit to subsequent seed longevity from initially drying soya bean seeds at 40°C, rather than 10-25°C, for most accessions, particularly those harvested early; this benefit may have been due to greater post-harvest maturation in the warmest regime
Improvements to the Met Office's global ocean–sea ice forecasting system including model and data assimilation changes
Get PDFThe Forecast Ocean Assimilation Model (FOAM) is the Met Office's operational, coupled ocean–sea ice system, which produces analyses and short-range forecasts at global and regional scales each day for various stakeholders, including defence, marine navigation and science users. This paper describes and evaluates the impacts of recent model and data assimilation (DA) updates on global FOAM when compared to its current operational version. The model updates include the use of the TEOS10 formulation for the seawater equation of state, with improved ocean model settings in the Southern Ocean and the implementation of a new sea ice model. Updates to the DA include an increase in the number of DA minimisation iterations, an improved specification of observation errors for sea surface temperature and sea level anomaly (SLA), and optimisations of the DA computational efficiency. Large-scale DA corrections for temperature have also been removed to prevent an inconsistent projection of the SLA DA signal onto large-scale temperature at depth. For 1-year runs at 1/12° resolution, the new FOAM system shows a 40 % improvement in observation-minus-background (OmB) statistics for SLA and subsurface temperatures relative to the current system in eddy-rich regions, which result in a similar level of improvement for ocean currents. To evaluate potential impacts on the pre-Argo period, 1-year experiments at 1/4° resolution are run withholding profiles of temperature and salinity observations in both new and current FOAM systems. Limited to the assimilation of only surface data, OmB statistics for SLA, temperature and salinity in the new FOAM system can reach improvements up to 90 % in the Southern Hemisphere relative to the current system, resulting in more temporally consistent ocean transport and heat content results. Therefore, it is expected that the model and DA updates will lead to more potential for use of FOAM reanalyses in climate studies, particularly in the pre-Argo period, and will provide improved ocean–sea ice initial conditions to FOAM as well as to the Met Office short-range and seasonal coupled ocean–atmosphere–land–sea ice forecasting systems
The temporality of childhood and children’s rights
No full textThe temporality of international human rights law is strikingly clear in the context of children’s rights. International human rights documents are ‘living documents’ and, whilst the text of treaties remains constant, the work of treaty monitoring bodies and States Parties, leads to an adaptation of the understanding of the normative content and scope of the text. This process also occurs within a system of human rights that holds its own temporalities. In addition to the challenge of applying human rights to an ever-evolving context, there is an additional and unique temporality confronting children’s rights: childhood. The understanding of children and childhood is key to the application of children’s rights, yet these concepts vary in meaning both in time and space, and offer their own temporalities. This paper highlights the varying temporalities associated with childhood and children’s rights, identifying some of the challenges and opportunities they offer for the protection and fulfilment of children’s rights
Tracing transitions and connecting communities in the archaeology of Southwest Asia: papers in honour of Roger Matthews
No full textThis book features a collection of papers produced in honour of Roger Matthews, Professor of Near Eastern Archaeology at the University of Reading. Roger previously taught at UCL’s Institute of Archaeology (2001-2010), before which he served as the director of the British School of Archaeology in Iraq (BSAI, today BISI) in Baghdad and the British Institute at Ankara (BIA) in the 1980s and 1990s. The volume honours Roger’s legacy by assembling interdisciplinary research by his students, collaborators, and colleagues that maps challenges and new possibilities in the archaeology of Southwest Asia across the interrelated themes that have emerged from his work in Iran, Iraq, Syria and Türkiye
An analysis of the optimal research and development investment level of contractor using the panel threshold regression model
Get PDFThis study explores the threshold effect between R&D investment and firm performance in the construction industry, focusing on optimizing R&D spending in this capital-intensive sector. Unlike industries with shorter innovation cycles, construction requires long project durations, high costs, and regulatory compliance, making strategic R&D allocation essential. Using the panel threshold regression model (PTRM), the study analyses data from 136 Korean construction firms with over 100 employees and in-house R&D centres. Threshold values of 0.47% for R&D project cost and 2.25% for researcher ratio are identified, beyond which investment efficiency declines. PTRM is suitable for detecting nonlinear effects, though future studies should test alternative models for greater reliability. While firm-specific financial factors are controlled, external influences such as market dynamics and government policies are not considered. A five-year lag is assumed between R&D investment and outcomes, aligning with South Korea's planning norms, but alternative lags are recommended for further study. The findings offer practical insights for SMEs in managing R&D and financial constraints, with relevance extending beyond Korea to developing nations seeking to close technological gaps. Future research should refine sector-specific benchmarks and consider firm size variations for more applicable R&D strategies
The entrainment efficiency of persistent Arctic mixed-phase clouds as inferred from daily large-eddy simulations during the MOSAiC drift
Get PDFLow-level mixed-phase clouds occur frequently and persistently in the central Arctic, and thus play a key role in climate feedback mechanisms, air mass transformations, and sea ice melt. Turbulent entrainment at cloud top driven by radiative cooling modulates these clouds by affecting the boundary-layer heat budget. However, reliable measurements of this small-scale process are scarce. This study presents new insights into entrainment in radiatively-driven cloudy mixed-layers at high latitudes based on a library of daily large-eddy simulations covering the full MOSAiC drift. The simulations are based on measurements, cover a periodic and homogeneously-forced small domain representing conditions observed at the Polarstern Research Vessel, and resolve Arctic turbulence and clouds to a high degree. Approximately 1 out of 3 simulated days contain cloud mass in liquid phase. A drift-average heat budget analysis shows that the bulk cloud-topped mixed-layer is dominated by radiative cooling. Warming by top-entrainment partially counters this cooling, at efficiencies of about 21%. While this compensation is significant, such efficiencies are also much lower compared to previous findings for subtropical warm marine stratocumulus. Interestingly, a few outlying MOSAiC cases show similarly high efficiencies. Analysis of turbulence energetics and dedicated sensitivity experiments reveal that high entrainment efficiency can be achieved in two ways: surface coupling and strong local wind shear. The former explains the high efficiencies in the subtropics, while the latter drives the highest efficiencies encountered during MOSAiC. In general, these findings emphasize the important role played by wind shear in boosting entrainment efficiency
Remote sensing of lichens with drones for detecting dinosaur bones
Get PDFAdvances in palaeontology and evolutionary biology are often linked to the discovery of new fossil-bearing localities, yet these discoveries are typically serendipitous[1]. Here we report on modern organisms - lichens - that serve as biological indicators of vertebrate fossils in western North America and can be identified using remote sensing techniques. Lichens are symbioses between fungi and algae (and/or cyanobacteria) that play important ecological roles[2], and colonise many different substrates, including fossils[3]. Preferential colonisation of dinosaur bones by lichen (Figure 1A-B) has been anecdotally recognised for decades, with one palaeontologist speculating in 1980 that the vibrant orange pigmentation of lichens observed on densely colonised Centrosaurus fossils in Alberta, Canada, might be detectable using satellites (Darren H. Tanke, personal communication). Supporting the use of remote sensing for lichen detection, the spectral reflectance profiles of lichen pigments have previously been used as ecological indicator targets, for example to map caribou habitat[4]. Increasingly, remote sensing platforms are being used to study palaeontological sites[5], but our work is the first to document that a preferential association between modern lichens and ancient bones can be used to detect dinosaur fossils by remote sensing, for which we propose new spectral indices