Rafael Villar

• PhD Ecology
• Professor (Full) at University of Córdoba

Understory vegetation represents a large part of forest biodiversity and plays an important role in forest structure and functioning. However, little is known about how it is shaped by environmental gradients and overstory biomass. In this study, we analyse the changes in the taxonomic and functional composition of the understory communities in Que...

Mediterranean oak forests (MOFs) present huge interest in southern regions in Europe due to its multifunctional nature, specifically in Andalusia (Spain) where MOFs occupy almost half of the surface. Climatic change effects impact this ecosystem reducing their health and productivity in the last decades. We investigate MOFs response and resilience...

El cambio climático (CC) plantea desafíos importantes para la seguridad alimentaria mundial, tanto a escala global como local. Los efectos del CC ya están afectando a las prácticas agrícolas, la producción y la calidad nutricional de los cultivos alimentarios, como el olivar, lo cual tiene fuertes repercusiones socioeconómicas. Mediante la aplicaci...

El cambio climático plantea desafíos importantes para la seguridad alimentaria mundial. Los cambios a largo plazo en la temperatura, la humedad, los patrones de lluvia y la frecuencia de los fenómenos meteorológicos extremos ya están afectando a las prácticas agrícolas, la producción de cultivos y la calidad nutricional de los cultivos alimentarios...

Verticillium wilt of olive (VWO), caused by the soil borne fungus Verticillium dahliae, is one of the most relevant diseases affecting this crop worldwide. One of the best VWO management strategies is the use of tolerant cultivars. Scarce information is available about physiological and structural responses in the leaves of olive cultivars displayi...

Verticillium wilt of olive (VWO), caused by the soil-borne vascular pathogen Verticillium dahliae, is one of the most devastating diseases affecting olive, the woody crop. One of the best VWO management measures is the use of tolerant cultivars. Yet, our knowledge about defense mechanisms that operate at the root level to explain tolerance to this...

Extensive research efforts are devoted to understand fine root trait variation and to confirm the existence of a belowground root economics spectrum (RES) from acquisitive to conservative root strategies that is analogous to the leaf economics spectrum (LES). The economics spectrum implies a trade-off between maximizing resource acquisition and pro...

Prosopis pallida (algarrobo) is a highly adapted species to extremely dry and wet conditions. Its geographic distribution at both sides of the Pacific Ocean is associated with its plastic response to El Niño event, an extreme climate event that changes precipitation regimes. In this review, we summarized the current knowledge of this versatile spec...

Verticillium wilt of olive (VWO), caused by the soil-borne pathogen Verticillium dahliae, is considered one of the most important diseases affecting this tree crop. One of the best VWO management measures is the use of tolerant cultivars. Remarkably, no information is available about olive functional traits and their potential relationship with tol...

Plant functional traits are highly plastic to changes in climatic factors and nutrient availability. However, the intraspecific plant response to abiotic factors and the overall effect on tree growth and productivity is still under debate. We studied forest productivity for 30 Quercus ilex subsp. ballota forests in Spain along a broad climatic grad...

Key message Soil pH, EC, and salinity explain the leaf nutrient concentrations of Prosopis pallida despite the high amount of soil nutrients near the trees. Abstract Dryland forests constantly face extreme abiotic conditions, and this affects plant growth and nutrition. We have determined the effects of soil chemical attributes and soil nutrients...

Many studies have quantified the functional variation of fine root traits to understand the overarching trade‐off between maximizing resource acquisition or conservation (root economics spectrum [RES]). However, we know remarkably less on how plant strategies along the RES are actually constrained by the amount of photosynthates required to constru...

Economic principles can be extended to biological organisms as they optimize the use of resources, but their use in biology has been limited. We applied concepts from traditional economics to the main production unit of plants, the leaf. We quantified the profitability (profit/cost of investment) of leaves from seven biomes worldwide and compared t...

Plant functional traits are highly adaptable to changes in climatic factors and nutrient availability. However, the intraspecific plant response to abiotic factors and the overall effect on plant growth and productivity is still under debate. We studied forest productivity for 30 Quercus ilex subsp ballota forests in Spain along a broad climatic gr...

Iberian oak forests and woodlands are vital providing a variety of ecosystem services. They provide raw materials like cork, wood and fuel, and fodder (acorns) for wild and domestic animals. Oak trees provide a climate regulating service by their capacity to sequester carbon and therefore to mitigate the effects of climatic change. There is an incr...

Quantifying the functional variation of fine root traits and their interactions with symbiotic organisms is an uprising research topic to understand the overarching trade-off between maximizing resource acquisition or conservation (root economics spectrum -RES-). The currency of root traits economy is based on the carbon required to construct them;...

AimsRoot functions are multiple and essential for the growth and survival of terrestrial plants. The aim of this work was to analyse the main trends in the variation of root traits, their coordination with leaf traits and their relationships with soil conditions.Methods We measured the variation of 27 fine root traits (five morphological, 20 chemic...

World olive production is based on the cultivation of different varieties that respond differently to abiotic factors. Climate change may affect the area of land suitable for olive cultivation and change production levels, thus causing serious damage to this economically-relevant and highly-productive olive grove agroecosystem. In Mediterranean reg...

Key message Significant changes in root biomass allocation, water transport and leaf structure allow P. pallida seedlings to overcome El Niño extreme events. Abstract The North Peruvian dryland forests face long droughts which promote adaptive mechanisms to cope with low water availability. However, the impact of the El Niño South Oscillation on t...

Aims To assess the fertility island effect of Prosopis pallida in the North Peruvian dry forests and analyze if it is influenced by tree size and structural and/or chemical leaf traits. Methods We measured the soil nutrient concentrations under and outside the tree canopy in five populations that differ in mean annual temperature and annual rainfa...

Biochar (BC) application to soil could increase soil C sequestration, soil fertility, and crop production, which makes it an interesting soil amendment for organic agriculture. However, studies to date show a great variability in their results, depending on the plant species studied. Our hypothesis is that the different root responses of the specie...

Background and aims Leaf litter decomposition is an important process controlling nutrient cycling in most terrestrial ecosystems. We evaluated the relationships among traits of green leaves and decomposition rates of leaf litter (k) at different environmental scales and organisational levels (species and community). We also assessed the relationsh...

Para la conservación de la biodiversidad es fundamental la implicación de las personas, y para ello es necesario realizar una tarea de sensibilización y concienciación. Con el objetivo de promover la participación directa de los alumnos en experiencias reales, en el Campus de Rabanales de la Universidad de Córdoba se han desarrollado diferentes exp...

Para la conservación de la biodiversidad es fundamental la implicación de las personas, y para ello es necesario realizar una tarea de sensibilización y concienciación. Con el objetivo de promover la participación directa de los alumnos en experiencias reales, en el Campus de Rabanales de la Universidad de Córdoba se han desarrollado diferentes exp...

Key message This study reinforces the existence of the leaf economics spectrum in Mediterranean woody species, and demonstrates the strong influence of phylogeny, leaf habit and environmental context as main drivers of variability in structural and nutrient traits of leaves. Abstract Leaf structural and nutrient traits are key attributes of plant...

Water availability is one of the most important factors determining species distribution, plant community structure and ecosystem functioning. We explore how the functional structure of Mediterranean woody plant communities varies along a regional gradient of aridity in the Andalusian region (south Spain). We question whether communities located in...

Background and aims Root traits play a critical role in plant resource-use strategies and ecosystem functioning, but there is great controversy regarding their identity and functionality in different dimensions of belowground functional variation. Here, we explored the level of covariation among a suite of key root traits (i.e. specific root length...

The effect of the phosphoric fertilization on the quality and composition of pastures was assessed in different farms of the dehesas network (bio-dehesa Life+project). Fertilization was carried out with superphosphate and with natural phosphate (organic farms). Fertilized pastures showed a higher concentration of CP and digestibility. Additionally,...

We studied intraspecific trait variability (ITV) in functional leaf traits of Prosopis pallida trees located in eight populations along a climatic gradient on the Peruvian coast. The objectives were (1) to determine the relative importance of ITV at different ecological scales; (2) to understand how functional leaf traits relate to each other, and...

Forests and shrublands occupy a large area in the world (c. 31% of the total continental area) and in Spain (c. 36% of the area), in which around 30% of forests are formed by Quercus species. Therefore, the ecosystem services provided by Quercus species are critical to human well-being. Thus, it is essential to understand how Quercus species grow a...

El proyecto de innovación docente que se presenta utiliza la herramienta de los vídeos para mejorar la comprensión de distintos aspectos de la Ecología. Este proyecto de innovación docente se ha realizado en el marco de la asignatura de Ecología de grado de Ciencias Ambientales (2º curso) en la Universidad de Córdoba durante el curso 2016-17. Se ha...

The geographic distribution of deciduous versus evergreen woody species has been intensively investigated, but the ecological significance of both leaf habits is still far from being fully understood. The purpose of this chapter is to review the factors that are related with the carbon gain of deciduous and evergreenoak species under Mediterranean...

Understanding how different factors mediate the resistance of communities to climatic variability is a question of considerable ecological interest that remains mostly unresolved. This is particularly remarkable to improve predictions about the impact of climate change on vegetation. Here, we used a trait‐based approach to analyse the sensitivity t...

Leaf size varies by over a 100,000-fold among species worldwide. Although 19th-century plant geographers noted that the wet tropics harbor plants with exceptionally large leaves, the latitudinal gradient of leaf size has not been well quantified nor the key climatic drivers convincingly identified. Here, we characterize worldwide patterns in leaf s...

Leaf size varies by over a 100,000-fold among species worldwide. Although 19th-century plant geographers noted that the wet tropics harbor plants with exceptionally large leaves, the latitudinal gradient of leaf size has not been well quantified nor the key climatic drivers convincingly identified. Here, we characterize worldwide patterns in leaf s...

According with niche theory the species are specialized in different ecological niches, being able to coexist as result of a differential use of resources. In this context, the biogeochemical niche hypothesis proposes that species have an optimal elemental composition which results from the link between the chemical and morphological traits for the...

In recent years, as the result of different ecological and anthropogenic factors, significant explosions of black fly populations have been recorded in different regions of the Iberian Peninsula. The medical and economic importance of these hematophagous Diptera is a current challenge that obligates institutions to establish and maintain the early...

We determined the economic profitability of leaves by estimating the internal rate of return (IRR). IRR is the percentage of investment in construction of the leaf obtained as surpluses and therefore it can be allocated to manufacture other leaves or other plant parts. Analogously, for companies, the economic profitability (profits/total assets) ex...

Leaf dry mass per unit leaf area (LMA) is a central trait in ecology, but its anatomical and compositional basis has been unclear. An explicit mathematical and physical framework for quantifying the cell and tissue determinants of LMA will enable tests of their influence on species, communities and ecosystems. We present an approach to explaining L...

Climate models predict a further drying of the Mediterranean summer. One way for plant species to persist during such climate changes is through acclimation. Here, we determine the extent to which trait plasticity in response to drought differs between species and between sites, and address the question whether there is a trade‐off between drought...

The study of ecology and abiotic factors affecting Simuliidae populations is essential to develop an accurate early warning system and control program. For this purpose, in March 2016, a monitoring plan for Simuliidae in the municipality of Cordoba (supported by the City Council of Córdoba) was launched. During the spring of 2016 a total of 96 repr...

In recent years there has been a high incidence of nuisance and damage caused by spring and early summer explosions of black fly (Simuliidae) in the urban area of Cordoba, along with a growing concern about its importance as a disease vector. After some trials of biological control in 2015, in March 2016 a plan for monitoring and controlling bloods...

Questions How are ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) traits related to other plant traits at the community level? Which abiotic factors drive the variability of these ECM and AM traits? What is the relative importance of plant species turnover and plant intraspecific differences on mycorrhizal trait variability among communities?...

Aims Extreme climatic events mayhave important consequences forplant community structure and composition. In 2005, a severe drought together with a cold winter promoted extensive damage and mortality in shrubland communities of southwest Spain (DoñanaNational Park). Here, we aim to identify the mechanisms underlying community stability (resistance...

Extreme climatic episodes, likely associated with climate change, often result in profound alterations of ecosystems and, particularly, in drastic events of vegetation die-off. Species attributes are expected to explain different biological responses to these environmental alterations. Here we explored how changes in plant cover and recruitment in...

Leaf mass per area (LMA) is a morphological trait widely used as a good indicator of plant functioning (i.e. photosynthetic and respiratory rates, chemical composition, resistance to herbivory, etc.). The LMA can be broken down into the leaf density (LD) and leaf volume to area ratio (LVA or thickness), which in turn are determined by anatomical ti...

Pearson correlation coefficients between leaf traits. (DOC)

Mean data of leaf traits and soil water content (SWC). (DOC)

Description of the calculation of the variance explained by the different sources (LVA and LD or anatomical tissues). (DOC)

Cross-section of the 34 species studied. (PDF)

Mean ± SD values of the leaf traits for deciduous and evergreen species. (DOC)

Location of the sampling sites. (DOC)

The phylogenetic tree of the 34 species studied. (DOC)

Species studied and areas where the samples were collected. (DOC)

Linear regressions between leaf density (LD) and anatomical tissues. (DOC)

Aims Biochar is a carbon-rich product obtained from the pyrolysis of organic materials. Its use, combined with fertilizers, can modify soil properties and affect root morphology and functioning. The main objective of this study was to evaluate the impact of biochar and fertilizer addition on root development and morphology. Methods Durum wheat was...

QuestionsIs there any evidence of coordination among leaf, stem and root traits, and thereby of the existence of a plant economics spectrum at the species and community level in Mediterranean forests? Are these traits related to plant size and seed mass?LocationMediterranean forests and shrublands, Sierra Morena mountains, Córdoba, southern Spain.M...

Production of biochar (the carbon (C)-rich solid formed by pyrolysis of biomass) and its storage in soils have been suggested as a means of abating climate change by sequestering carbon, while simultaneously providing energy and increasing crop yields. Our results show that biochar can improve soil structure and fertility.These improvements induce...

Green leaf traits are very important for plant functioning and can also influence litter traits and therefore litter decomposition and C nutrient cycling. Thus, the mechanism of carbon and nutrients resorption can affect litter quality and at the end, soil fertility. Green leaf traits (structural and chemical) can provide key information about the...

Understanding which factors and rules govern the process of assembly in communities constitutes one of the main challenges of plant community ecology. The presence of certain functional strategies along broad environmental gradients can help to understand the patterns observed in community assembly and the filtering mechanisms that take place. We u...

The effects of the addition of a slow pyrolysis biochar (produced from olive-tree prunings) to a vertisol were studied in a field experiment during one wheat (Triticum durum L.) growing season. The biochar addition did not significantly affect soil parameters such as pH, dissolved organic C and N, ammonium, nitrate or microbial biomass N. By contra...

Abstract Background and aims Plant litter has an important role in terrestrial ecosystems (Lambers et al. 2008). Our aim was to assess the short-term effect of litter from 21 woody species (deciduous and evergreens) on plant growth and root development. Methods We conducted a short-term experiment (10 weeks) under controlled conditions adding litte...

Rasgos funcionales en el género Quercus: estrategias adquisitivas frente a conservativas del uso de recursos. Las especies del género Quercus constituyen uno de los grupos más abundantes e importantes de plantas leñosas de la Península Ibérica, estando su distribución determinada por la disponibilidad de agua, el tipo de suelo y la historia del man...

Background and aims Water availability is often one of the most limiting factors for plants. Climate change predictions for many areas suggest an intensification of water limitation. The ability of a plant to modify its root characteristics can be an important mechanism for preventing drought stress. Methods We studied the drought response of seed...

Aims The extent to which the spatial and temporal patterns of soil microbial and available nutrient pools hold across different Mediterranean forest types is unclear impeding the generalization needed to consolidate our understanding on Mediterranean ecosystems functioning. Methods We explored the response of soil microbial, total, organic and inor...

The use of biochar as a soil amendment is gaining interest to mitigate climate change and improve soil fertility and crop productivity. However, studies to date show a great variability in the results depending on raw materials and pyrolysis conditions, soil characteristics, and plant species. In this study, we evaluated the effects of biochars pro...