José A. González-Pérez

Spanish National Research Council | CSIC · Institute for Natural Resources and Agrobiology of Sevilla

Increasing intensity and frequency of droughts are leading to forest dieback, growth decline and tree mortality worldwide. Reducing tree-to-tree competition for water resources is a primary goal for adaptive climate silviculture strategies, particularly in reforested areas with high planting density. Yet, we need better insights into the role of st...

Compost amendments, apart from improving fertility and the general characteristics of agricultural soils, have known implications for global C cycling and sequestration in soils. Their effects are usually assessed via the quantification of soil organic carbon (SOC) pools, usually labile (fast) and recalcitrant (slow) pools, with varying intrinsic d...

Slash-and-burn of Amazon Forest (AF) for pasture establishment has increased the occurrence of AF wildfires. Recent studies emphasize soil organic matter (SOM) molecular composition as a principal driver of post-fire forest regrowth and restoration of AF anti-wildfire ambience. Nevertheless, SOM chemical shifts caused by AF fires and post-fire vege...

Changes in climatic and environmental conditions can affect both, plant chemical molecular and atomic composition. Therefore, biomass carbon isotope composition is frequently used to gain information about the environmental conditions at the time a plant thrives. In this field, most studies use isotope values obtained from bulk samples. However, th...

Fire-induced alterations to soil pH and organic matter play an important role in the post-fire microbial response. However, the magnitude of which each parameter affects this response is still unclear. The main objective of this work was to determine the magnitude in which soil pH and organic matter fire-induced alterations condition the response o...

Mediterranean savannahs (dehesas) are agro-sylvo-pastoral systems with a marked seasonality, with severe summer drought and favourable rainy spring and autumn. These conditions are forecasted to become more extreme due to the ongoing global climate change. Under such conditions, it is key to understand SOM (soil organic matter) dynamics at a molecu...

There is a need for tools to determine the origin of organic matter (OM) in Blue Carbon Ecosystems (BCE) and marine sediments to (1) facilitate the implementation of Blue Carbon strategies into carbon accounting and crediting schemes and (2) decipher changes in ecosystem condition over decadal to millennial time scales and thus to understand and pr...

The so-called humic substances are widely distributed in soil, water and fossil organic resources and represent the greatest reservoir of organic carbon on the surface of the Earth. They include complex mixtures of altered biosynthetic materials in addition to newly-formed macromolecules. Apart from ecologically assessing the spatial variability of...

The application of biochar as an organic amendment in polluted soils can facilitate their recovery by reducing the availability of contaminants. In the present work, the effect of biochar application to acid soils contaminated by heavy metal spillage is studied to assess its effect on the quantity and composition of soil organic matter (SOM), with...

Soil water repellency (SWR) is a physical property due to a complex interaction of factors (e.g., fire, soil organic matter, soil texture) that reduces the soil water infiltration capacity. Traditionally, SWR is attributed to the accumulation and redistribution of hydrophobic compounds within soil profile. To obtain further insight into chemical co...

This study aims to evaluate the effects of technosols made with different organic amendments to restore degraded soils in a semiarid limestone quarry. The effects on soil quality, functionality and organic matter dynamics of the technosols amended with waste of gardening, greenhouse horticultural, stabilized sewage sludge and two mixtures of sludge...

High severity wildfires consume or alter soil organic matter (OM), thereby causing a drastic alteration of the carbon cycle and usually are followed by strong runoff and erosion events (Shakesby, 2011). Post-fire straw mulching has been used to mitigate post-fire soil erosion (Fernandez and Vega, 2016), both at small and microcatchment scales (Prat...

Post-fire soil recovery strategies (e.g., tillage, tree logging and reforestation) may modify the quality of soil organic matter (SOM) at molecular level. The aim of this research was to assess the molecular alteration of SOM produced by anthropogenic post-fire restoration activities. The effect of fire and restoration on SOM was analysed in bulk s...

An innovative approach based on the combination of analytical pyrolysis coupled with gas chromatography-mass spectrometry (Py-GC/MS) with compound-specific isotope analysis (Py-CSIA) is used to study the composting process of maize biomass. This multidisciplinary approach aims to elucidate the decomposition rate of the main biogenic materials (lign...

High severity wildfires cause a drastic alteration of soil carbon cycling – both oxidising and thermally altering soil organic matter (SOM) - and usually are followed by strong runoff and erosion events. To restore wildfire-degraded soils, SOM needs to be rebuilt while soil erosion is prevented. Post-fire straw mulching has been shown to mitigate s...

Analytical pyrolysis is a tool widely used for investigating the nature of macromolecules. This technique has been applied with success for solving the chemical structure of geo- and biopolymers. However, with complex macromolecules, such as fungal melanins, analytical pyrolysis presents some drawbacks due to the fact that they rarely can be obtain...

In Castañar Cave (Cáceres, Spain), Mg-Si phases forming fibres and films occur associated with aragonite, magnesite, huntite and spheroidal dolomite in moonmilk, coatings and crust speleothems. A detailed study of bulk and carbonate-removed samples allowed us to identify the Mg-Si phases as kerolite (Mg3Si4O10(OH)2·nH2O) and sepiolite Mg4Si6O15(OH)...

Cylindrospermopsin (CYN) and Microcystin-LR (MC-LR) are biotoxins produced by cyanobacteria species that, due to climate change and water eutrophication, proliferate together with an increase of the associated cyanotoxins. Both toxins are usually found in the aquatic environment and filter feeding organisms such as mussels are particularly exposed...

Soil organic matter (SOM) is a major component of the biogeochemical cycle contributing to soil general properties and conservation. The progressive depletion of the SOM in Mediterranean ecosystems results in an increased advance of desertification. The SOM not only plays a crucial role in soil resilience, but also represents a repository of enviro...

Sedimentary organic matter (OM) origin and molecular composition provide useful information to understand carbon cycling in coastal wetlands. Core sediments from threors’ Contributionse transects along Ria Formosa lagoon intertidal zone were analysed using analytical pyrolysis (Py-GC/MS) to determine composition, distribution and origin of sediment...

This work studies carbon (C) and hydrogen (H) isotope composition of plant biomass and soil organic matter (SOM) in an attempt to assess both, changes exerted by fire and possible inputs of charred materials to the soil after a wildfire. Isotope composition of bulk soil, soil particle size fractions and biomass of the dominant standing vegetation i...

Anthropogenic impact can alter food web structure through changes in species interactions. In this study, we explored the food web of three Mediterranean stream reaches (two seasonal and one permanent) along an anthropogenic impact gradient to test the hypothesis that increasing impact simplifies food webs. To test this, we applied the isotopic (δ1...

The two most widely extended mountain grasslands in Europe (Nardus-mat grasslands and chalk grasslands) are distributed forming complex patterns. In the Ordesa and Monte Perdido National Park (Central Pyrenees, NE-Spain), they grow as secondary pastures within the treeline ecotone at the subalpine belt. This work aims to show the influence of soil...

Hydrothermal carbonization and dry pyrolysis transform sewage sludge (SS) into nitrogen‐ (N) and phosphorus‐ (P) rich hydrochars (Hyd) and pyrochars (Py), respectively, which may act as slow‐release fertilizers with carbon (C) sequestration potential. Whereas this has been mostly studied with short‐term experiments, this study focussed on the cycli...

The impact of wildfires and of restoration actions on soil organic matter (SOM) content and structure was studied in a soil under pine (Pinus pinea) from Doñana National Park (SW Spain). Samples were collected from burnt areas before (B) and after post-fire restoration (BR) and compared with an unburnt (UB) site. Analytical pyrolysis (Py-GC/MS) was...

Estuaries are dynamic interfaces between land, rivers and the ocean that play major roles in the global carbon cycle. These coastal wetlands store huge amounts of organic carbon (OC), commonly known as "blue carbon" and excellent places to study C cycling. The Guadiana river estuary is among the most important tidal salt marshes in the South-Iberia...

Estuaries are dynamic interfaces between land, rivers and the ocean that play major roles in the global carbon cycle. These coastal wetlands store huge amounts of organic carbon (OC), commonly known as “blue carbon” and excellent places to study C cycling. The Guadiana river estuary is among the most important tidal salt marshes in the South - Iber...

Natural preservatives are used in food packages to improve the shelf life of perishable products. Carvacrol and thymol, the main components of oregano essential oil (OEO), are used in active packaging due to their antimicrobial and antioxidant properties. Here, the effect of a bioactive polylactic acid (PLA)/polybutylene succinate (PBS) package in...

The determination of heavy metals in soils and organic amendments, such as compost, manure, biofertilizer, and sludge, generally involves the digestion of samples with aqua regia, and the determination of those in the solution using various techniques. Portable X-ray fluorescence (PXRF) has many advantages in relation to traditional analytical tech...

The presence of the toxin cylindrospermopsin is increasingly frequent in samples from different ecosystems and it is a serious problem both at environmental level and for animal and human health. To be able to prevent CYN exposure risk, it is important to have suitable analytical methods, but also quick and economical ones. Analytical pyrolysis cou...

The analysis of the hydrogen stable isotope composition (δ2H) of organic compounds provides information about its geographical origin. In this work, δ2H composition of specific compounds released by direct analytical pyrolysis (Py-CSIA) of extra virgin olive oils EVOOs was studied avoiding the use of any chemical and/or physical treatments, derivat...

Changes in climatic and environmental conditions can affect both, plant chemical and isotope composition. An isotopic characterization of individual biogeochemical compounds is desirable in order to differentiate the isotopic composition of the main plant components. Here, a particular analytical pyrolysis technique combining Py‐GC with a continuou...

The peat bog studied here may well be considered as relict and one of the last and more Meridional still in existence in the Northern hemisphere. The vertical molecular composition of a 85 cm peat bog from Ribetehilo lagoon (Doñana National Park; SW‐Spain 37° 7'30.81"N; 6°37'50.19"O) is studied using analytical pyrolysis (Py‐GC/MS) and ultra‐high r...

Mangrove vegetation covers extensive areas along Brazilian tropical coasts and accumulates large amounts of organic carbon in the intertidal sediments. We have investigated the molecular biomarker composition of mangrove sediments from the Potengi estuary North-East Brazil. To characterise sources and fate of sedimentary organic matter (OM), a dire...

Los biomarcadores de suelos son compuestos extraíbles, cuantificables y estables con un precursor biosintético específico conocido. La estructura química de estos compuestos proporciona valiosa información sobre aspectos diversos de la materia orgánica del suelo (MOS), como son su origen, estado de evolución, dinámica y otros procesos ambientales....

[ES] Los suelos son el mayor reservorio de carbono en la superficie de la Tierra y su estructura y composición responde a los cambios ambientales. Además, el suelo, también mantiene un registro que nos informa sobre características ambientales de interés y que están relacionadas con los principales ciclos biogeoquímicos (C, N, H, O). Una de las her...

Siliceous speleothems frequently reported in volcanic caves have been traditionally interpreted as resulting from basalt weathering combined with the activity of microbial communities. A characteristic feature in lava tubes from Hawaii, Azores and Canary Islands is the occurrence of black jelly-like speleothems. Here we describe the formation proce...

Biochar has been shown as a potential mean to enhance carbon sequestration in the soil. In Brazil, approximately 15% of the produced charcoal is discarded as charcoal fines, which are chemically similar to biochar. Therefore, we aimed to test charcoal fines as a strategy to increase soil carbon sequestration. Charcoal fines of hardwood Mimosa scabr...

The introduction of coniferous species in former deciduous forests may exert changes in soil organic matter, particularly in its molecular composition. In this work, pyrolysis-gas chromatography–mass spectrometry was used to study changes in SOM quality related to the centennial afforestation of Scots pine in an area formerly covered by European be...

In this work, we introduce the Py-CSIA technique in the field of cultural heritage as a novel technique for the direct determination of the isotopic composition of polymers and biopolymers. Case studies on the characterization of biopolymers using Py-CSIA are presented and the potential application in the field of cultural heritage conservation is...

Castañar cave (Cáceres, Spain) characteristically contains a series of Mg-Si phases forming fibres and films associated to aragonite, magnesite, huntite and spheroidal dolomite in moonmilk, which form coatings and crust speleothems. These Mg-Si phases consist of kerolite, sepiolite and its admixtures. Under scanning electron microscope kerolite app...

Given the artistic, social and economic value of cultural heritage, its conservation is of upmost importance for being preserved for future generations. Through accurate characterization of this material using pyrolysis-compound-specific isotope analysis (Py-CSIA), regarding alteration products and biopolymers used in the past as construction, supp...

Changes in climatic and environmental conditions can affect both, plant chemical and isotope composition. Therefore, biomass carbon isotope composition is frequently used to gain information about the environmental conditions at the time a plant was growing In this field, the majority of studies use isotope values obtained from bulk samples. Howeve...

Mulching has amply proven its effectiveness to mitigate post-fire soil erosion but its impacts on soil organic matter (SOM) quality and quantity continue poorly studied. The present study addressed this knowledge gap for a eucalypt plantation in central Portugal that had been burnt and, immediately after the wildfire, mulched with 13.6 Mg ha⁻¹ of e...

Microplastics (small particles of plastic <5 mm in size) have become a major threat to the environment due to their newly increased pollution levels. Detailed understanding of their chemical composition require the establishment of standardized analysis procedures. In this work, we present pyrolysis-gas chromatography coupled to mass spectrometry (...

Easily Extractable Glomalin (EEG) represents an organic fraction of the soil that contains mainly glomalin-related soil proteins (GRSP), a glycoprotein abundantly found in soils produced by arbuscular mycorrhizal fungi in the phylum Glomeromycota. The EEG fraction is confirmed to have multiple ecological functions in soils, including its contributi...

Microplastics (small particles of plastic <5 mm in size) have become a major threat to the environment due to their newly increased pollution levels. Detailed understanding of their chemical composition require the establishment of standardized analysis procedures. In this work, we present pyrolysis-gas chromatography coupled to mass spectrometry (...

Easily Extractable Glomalin (EEG) represents an organic fraction of the soil that contains mainly glomalin-related soil proteins (GRSP), a glycoprotein abundantly found in soils produced by arbuscular mycorrhizal fungi in the phylum Glomeromycota. The EEG fraction is confirmed to have multiple ecological functions in soils, including its contributi...

We studied the fire record and its environmental consequences during the Holocene in the Central Ebro Basin. This region is very sensitive to environmental changes due to its semiarid conditions, lithological features and a continuous human presence during the past 6000 years. The study area is a 6 m buried sequence of polycyclic soils developed ap...

Restoring humus in soil represents a key factor for improving soil quality. Digestates from anaerobic digestion (AD) can be successfully applied as soil amendments. Here, we investigated changes of the organic matter (OM) composition of digestates from solid-state anaerobic digestion (AD) of straw and pig slurry at different percolate recirculation...

Fire is one of the most important modulating factors of the environment and the forest inducing chemical and biological changes on the most reactive soil component, the soil organic matter (SOM). Assuming the complex composition of the SOM, we used an ultra-high resolution mass spectrometry analysis technique to assess the chemical composition and...

Although combustion ashes are usually used in soils, little attention is paid to the CO2 sequestration potential of this practice. The present study aims to quantify carbon sequestration as carbonate compounds in a tailored synthetic calcareous soil treated with biomass ash from a gasification power plant that uses olive cake. It is estimated that...

The replacement of native European beech forests (Fagus sylvatica) with Scots pine (Pinus sylvestris) afforestation may exert changes in soil properties, particularly with respect to soil organic matter (SOM). Stable isotope composition of light elements (δ13C, δ15N) in soils are known proxies for the characterisation of SOM genesis and dynamics. I...

Straw and pig slurry Solid-State Anaerobic Digestion (SS-AD) was carried out in a pilot-scale apparatus using percolate recirculation technology. The digestion experiments were performed using 1, 2 and 4 recirculations per day; an additional experiment without percolate recirculation was used as control. The initial mixture and the digestates were...

Wildfires are a recurrent disturbance in Mediterranean forests, triggered by high fuel load, high environmental temperature and low humidity. Although, human intervention is behind the initiation of most fire episodes, the situation is likely to worsen in the future due to the effects of climate change in the Mediterranean "hot-spot". Here we study...

Purpose Data management strategies of pyrolysis results and NMR acquisition modes were examined in humic acids (HAs) from control soils and fire-affected soils. The information supplied by dipolar dephasing (DD) ¹³C NMR spectroscopy and Curie-point pyrolysis were used to assess chemical structures hardly recognizable and measurable, or of unclear i...

Early-to late Holocene sedimentary infill of the Potengi-Jundiai Estuary (Brazil) was studied in a 31.5 m long sediment core. The borehole was drilled in a mangrove area within the central part of the flood tide delta. The sedimentary record, encompassing the last 10 kyr, was studied for sediment texture and for the n-alkanes composition of organic...

The following document presents the CARBOSOL Database that gathers data of physical and chemical properties of 6,609 georeferenced soil profiles in Spain associated to a related analytical dataset of 22,100 horizons compiled from 635 soil studies. The CARBOSOL Database provides a wealth of information on soil organic matter content, its distributio...

The SOM is a heterogeneous material composed of diverse chemical structures with variable functionality. The study of the changes exerted by fire requires a combination of complementary analytical techniques. Thermogravimetric analysis and differential scanning calorimetry are useful to quantitatively differentiate thermolabile from recalcitrant o...

The deposition of soot on building surfaces darkens their colour and leads to undesirable black crusts, which are one of the most serious problems on the conservation of built cultural heritage. As a preventive strategy, self-cleaning systems based on the use of titanium dioxide (TiO2) coatings have been employed on building materials for degrading...