Species distribution models have been used to predict the distribution of invasive species for conservation planning. Understanding spatial transferability of niche predictions is critical to promote ...species-habitat conservation and forecasting areas vulnerable to invasion. Grain size of predictor variables is an important factor affecting the accuracy and transferability of species distribution models. Choice of grain size is often dependent on the type of predictor variables used and the selection of predictors sometimes rely on data availability. This study employed the MAXENT species distribution model to investigate the effect of the grain size on model transferability for an invasive plant species. We modelled the distribution of Rhododendron ponticum in Wales, U.K. and tested model performance and transferability by varying grain size (50 m, 300 m, and 1 km). MAXENT-based models are sensitive to grain size and selection of variables. We found that over-reliance on the commonly used bioclimatic variables may lead to less accurate models as it often compromises the finer grain size of biophysical variables which may be more important determinants of species distribution at small spatial scales. Model accuracy is likely to increase with decreasing grain size. However, successful model transferability may require optimization of model grain size.
•Climate and land use change were used to model habitat suitability of Rhododendron.•Land use and climate change interaction may change the invasiveness of Rhododendron.•South-western and ...north-eastern Wales may experience R. ponticum invasion by 2030.•The study demonstrates the significance of using policy-driven land use projections.
Global change drivers such as land use and climate changes are known to interact in their effects on biodiversity. The impact of these drivers on global biodiversity is increasingly evident in many forms including the spread of invasive species. Climate and land use changes affect introduction, colonization and spread of invasive species by affecting niche availability and dispersal potential. We tested the combined effects of land use and climate changes on the current and future habitat suitability of Rhododendron ponticum in Wales using a MaxEnt-based ecological niche model. We used two policy-driven land use change projections for Wales, in combination with two General Circulation Models and two Representative Concentration Pathways to derive eight different land use and climate change scenarios. In seven out of eight scenarios, the habitat suitability for R. ponticum is likely to reduce by 2030. However, in the eighth scenario representing an extreme where land use change and greenhouse gas emissions both accelerate, the interaction of land use and climate change forces an increase of habitat suitability of R. ponticum. The study highlights the importance of considering the combined effect of land use and climate change and including regional policy-based land use change projections to test the potential of an invasive species to expand or retreat in future.
The aim of this study is to compare the C/N/P stoichiometry of deadwood among four tree species at different stages of decomposition. The way in which the relative concentrations of these elements in ...the soil are directly impacted by deadwood decomposition is also explored. First, hornbeam, alder, aspen and fir logs in different decomposition stages (III, IV and V) were selected and sampled. Second, the concentration and stoichiometry of carbon, nitrogen and phosphorous were established. Marked differences in C/N/P stoichiometry were observed between deadwood in an advanced decomposition stage and the soil immediately under the log. The average C/N/P ratio of soil under the influence of deadwood was narrower compared to the C/N/P ratio of deadwood. The C/N/P ratio of studied soils was similar to the expected C/N/P ratio of organic soils or humus. The results indicate that stage of decomposition and tree species have an impact on the elemental stoichiometry of the soil. Thus, C/N/P stoichiometry is a useful indicator of the intensity of nutrient flux from deadwood to the soil.
•C:N:P ratio reflects the intensity of nutrient flow in the deadwood - soil system.•N/P ratio could be applied as useful indicator of soil organic matter quality.•Decomposition stage and wood species shape the C:N:P ratio.
Plant-based mulch has been proposed as a sustainable way of maintaining soil fertility. However, the role of mulch diversity, quality, and size in decomposition dynamics, and their effect on crop ...yield, has not been fully explored. We investigated how mulch quality, proxied by the constituent plant species diversity, and residue size drive mulch decomposition, nutrient release, crop nutrition, and yield. A rhizotron experiment was set up with barley as a model crop, with the addition of mulch of two particle sizes (1.5 and 30 cm) and four different plant residue mixes of differing biodiversity (17, 12, 6, and 1 species) in a fully factorial design. Soil nutrient dynamics were measured at advanced decomposition stages, together with residue quality, arbuscular mycorrhizal fungal (AMF) root colonisation, and crop yield. Residue mass loss was significantly affected by its chemical composition. Initial NDF content was more restricted factor in C and N mineralisation than C:N or lignin. Long residues retained significantly higher C and N content, than short residues. Crop yield was not affected by residue type or size. Residue size significantly affected barley growth rate, influencing seed protein content. Soil available K was significantly increased by residues with a higher initial C:N ratio. Short residues resulted in higher soil Zn. Residues of higher diversity resulted inhigher AMF root colonisationof the barley plants. Generally, long residue mulches maintain higher fertilisation capacity at advanced stage of decomposition than short ones, without a deleterious effect on crop yield. Further investigation should evaluate the effect of continuous application of long residue mulches on soil fertility and microbial symbiosis.
Human-machine communication can be substantially enhanced by the inclusion of high-quality real-time recognition of spontaneous human emotional expressions. However, successful recognition of such ...expressions can be negatively impacted by factors such as sudden variations of lighting, or intentional obfuscation. Reliable recognition can be more substantively impeded due to the observation that the presentation and meaning of emotional expressions can vary significantly based on the culture of the expressor and the environment within which the emotions are expressed. As an example, an emotion recognition model trained on a regionally-specific database collected from North America might fail to recognize standard emotional expressions from another region, such as East Asia. To address the problem of regional and cultural bias in emotion recognition from facial expressions, we propose a meta-model that fuses multiple emotional cues and features. The proposed approach integrates image features, action level units, micro-expressions and macro-expressions into a multi-cues emotion model (MCAM). Each of the facial attributes incorporated into the model represents a specific category: fine-grained content-independent features, facial muscle movements, short-term facial expressions and high-level facial expressions. The results of the proposed meta-classifier (MCAM) approach show that a) the successful classification of regional facial expressions is based on non-sympathetic features b) learning the emotional facial expressions of some regional groups can confound the successful recognition of emotional expressions of other regional groups unless it is done from scratch and c) the identification of certain facial cues and features of the data-sets that serve to preclude the design of the perfect unbiased classifier. As a result of these observations we posit that to learn certain regional emotional expressions, other regional expressions first have to be "forgotten".
Abstract
Biodiversity not only responds to environmental change, but has been shown to be one of the key drivers of ecosystem function and service delivery. Forest soil biodiversity is also governed ...by these principles, the structure of soil biological communities is clearly determined by spatial, temporal and hierarchical factors. Global environmental change, together with land-use change and forest ecosystem management, impacts the aboveground structure and composition of European forests. Due to the close link between the above- and belowground parts of forest ecosystems, we know that soil biodiversity is also impacted. However, very little is known about the nature of these impacts; effects they have on the overall level of biodiversity, the functions it fulfills, and on the future stability of forests and forest soils. Even though much remains to be learned about the relationships between soil biodiversity and forest ecosystem functionality, it is clear that better effort needs to be made to preserve existing soil biodiversity and forest conservation strategies taking soils into account must be considered.
Humic substances (HSs) constitute a primary component of soil organic matter (SOM) and play a crucial role in soil formation and fertility. However, comprehensive information regarding quantitative ...and qualitative changes in HS following biochar’s application to soil still needs to be improved. This study reports on the impact of biochar application at rates of 0, 10, and 20 t ha−1 (B0, B10, B20), both with and without nitrogen fertilisation at varying levels (N0, N1, N2), on SOM and HS contents throughout the cropping seasons between 2014 and 2019. The findings reveal changes in SOM and HS contents due to biochar addition and fertilisation. Notably, the most substantial increase in soil organic carbon content was observed in the B20N1 and B10N1 treatments, in stark contrast with the reference B0N0 treatment. A decrease in humification of SOM was noted across all treatments involving biochar, whether alone or combined with different N fertilisation levels. An interesting positive change in HS contents was observed in B10N2, where an increase in humic acids and a decrease in fulvic acids enhanced HS stability and improved HS quality. These findings shed light on the intricate dynamics of SOM and HSs in response to biochar application and nitrogen fertilisation over multiple vegetation seasons of crops on loamy Haplic Luvisols in Central Europe.
Climate change is a major threat to global biodiversity, although projected changes show remarkable geographical and temporal variability. Understanding this variability allows for the identification ...of regions where the present-day conservation objectives may be at risk or where opportunities for biodiversity conservation emerge. We use a multi-model ensemble of regional climate models to identify areas with significantly high and low climate stability persistent throughout the twenty-first century in Europe. We then confront our predictions with the land coverage of three prominent biodiversity conservation initiatives at two scales. The continental-scale assessment shows that areas with the least stable future climate in Europe are likely to occur at low and high latitudes, with the Iberian Peninsula and the Boreal zones identified as prominent areas of low climatic stability. A follow-up regional scale investigation shows that robust climatic refugia exist even within the highly exposed southern and northern macro-regions. About 23-31% of assessed biodiversity conservation sites in Europe coincide with areas of high future climate stability, we contend that these sites should be prioritised in the formulation of future conservation priorities as the stability of future climate is one of the key factors determining their conservation prospects. Although such focus on climate refugia cannot halt the ongoing biodiversity loss, along with measures such as resilience-based stewardship, it may improve the effectiveness of biodiversity conservation under climate change.
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