The journal Science publishes on Friday 21th a perspective article by CREAF researchersJosep Peñuelas and Jordi Sardans on the imbalance of nutrients on Earth, its effects on life and possible solutions.

Human action is altering the balance of nirogen and phosphorus, two elements essential for life on earth. Image: chemistryworld.com

The text ‘The global nitrogen-phosphorus imbalance‘ is based on recent research data from both specialists, and sets out the state of the issue and its scope for the international scientific community. They also propose alternatives and solutions aimed at political decision-makers.

According to Peñuelas and Sardans, ecosystems and species are at risk due to the global nutrient imbalance caused by the different ratio of nitrogen and phosphorus in land and water. These two elements are essential for life, and their ratio is being altered by human action. Both nitrogen and phosphorus affect the growth rate of micro-organisms, plants and animals. Plant species need CO2 for photosynthesis and nutrients to build their structures, of which the ratio of nitrogen to phosphorus is key. In addition, for optimal growth, adequate amounts and ratios of nitrogen and phosphorus are required. In recent decades, however, humans have enriched the biosphere with nitrogen through over-fertilisation and thus changed its relationship with phosphorus.

“International environmental bodies should address the risk to the biosphere posed by the nitrogen-phosphorus imbalance in a coordinated global policy.”

JOSEP PEÑUELAS, researcher at CREAF & CSIC.

Alternatives to imbalance

Among the possible alternatives, experts recommend increasing the efficiency of nitrogen and phosphorus use and cycling through precision farming, which avoids disproportionate fertiliser application. They also advocate applying methods, both management and innovative biotechnology, that enhance the efficiency of plants in capturing nutrients and benefiting from phosphorus sources. Other necessary policies that Peñuelas and Sardans point to include stimulating phosphorus recycling through national and regional regulations, subsidies or legislation, as well as reducing livestock production. Such solutions are in the early stages of implementation.

Too much nitrogen

Humans are over-fertilising the biosphere with nitrogen through nitrogen oxides emitted from burning fossil fuels, planting nitrogen-fixing crops, and using enriched fertilisers that leach into waterways. Although human activities have also increased the amount of phosphorus in soils and waters – for example, applying phosphorus-rich fertilisers and detergents – the overall increase in phosphorus in the soil is still less than that of nitrogen.

In fact, these are two synergistic problems. On the one hand, the presence of nutrients in the soil has increased disproportionately, and on the other hand, the balance between nitrogen and phosphorus has been disturbed. When there are too many nutrients in the environment, it becomes eutrophic: the increase of nutrients in freshwater causes algae and phytoplankton to grow out of control, until the ecosystem collapses. As a result, some countries have developed water treatment strategies to reduce the concentration of both chemicals. However, the technology used by water treatment plants retains more phosphorus than nitrogen, which encourages even more imbalance between the two nutrients.

Stability in doubtThe global imbalance between nitrogen and phosphorus may be even greater at the local and regional level, as nitrogen and phosphorus inputs are not evenly distributed around the world.

The global imbalance between nitrogen and phosphorus may be even greater at local and regional scales, as the inputs of both compounds are not evenly distributed around the world. Phosphorus, for example, is less soluble in water and does not volatilise, often adsorbs and precipitates in soil in mineral form, and remains buried in sediments. It therefore tends to remain close to its source of emission. In contrast, nitrogen is much more water-soluble and much more volatile, which makes it easier for it to disperse over a larger radius from its emission source.

The biological impacts of the increasing imbalance between the two nutrients have been observed in inland water bodies, on the structure and function of soil living communities, as well as on the species composition of plant communities. The lack of stability will have an increasing impact as the imbalance continues to shift in the same direction.

Phosphorus human crisis

Food security and agricultural production are the main victims of this imbalance, which has a direct impact on natural ecosystems and people. Nitrogen-containing fertilisers have an unlimited source – the atmosphere – from which this nutrient can be extracted through the Haber-Bösh reaction. This innovation has allowed its production to increase steadily, as well as its use as a fertiliser since the 1950s. However, sources of phosphorus have been largely limited to mines and are concentrated in very few countries, such as Morocco.Phosphorus may become economically inaccessible to low-income and food-deficit countries as it becomes depleted or unavailable for geopolitical and economic reasons.

In this sense, phosphorus could become economically inaccessible to low-income and food-deficit countries as these sources are depleted or become unavailable due to geopolitical and economic issues. In the future, phosphorus-producing countries are likely to manage their reserves to maximise the profits of their domestic mining and agricultural industries, making phosphorus-based fertilisers increasingly unaffordable for farmers in poorer countries and further exacerbating the imbalance between the two nutrients in regions where the problem is most acute. It would be a crisis that would further aggravate the economic gap between rich and poor countries.

Phosphorus and nitrogen lack

The lack of balance between these two elements in the soil changes the chemical composition of crops and can affect the health of people who consume products grown on these soils, thus creating a public health problem. For example, in regions where there is excessive use of inorganic and organic phosphorus fertilisers, phosphorus accumulates in soils and water bodies. Food produced in these environments can cause the local population to consume excess phosphorus, which can have negative implications for their health. Nutrient imbalance is also known to affect infectious and non-infectious human diseases that are strongly associated with diet, such as coeliac disease. CREAF researchers already warned in 2021 that excessive nitrogen fertilisation of wheat crops could explain the high prevalence of coeliac disease.

As if that were not enough, CREAF researchers point out that when the relationship between nitrogen and phosphorus is destabilised, human activities also generate imbalances between other elements. For example, changes have been observed in the relationship between carbon and nitrogen, in relation to iron, zinc, calcium and potassium, among others, in plant tissues. This indirectly leads to the fact that organisms, communities and ecosystems on planet earth are having their entire elementome, their elemental composition, modified.

Source: Blog CREAF

Nitrogen enrichment buffers phosphorus limitation by mobilizing mineral-bound soil phosphorus in grasslands. Phosphorus (P) limitation is expected to increase due to nitrogen (N)-induced terrestrial eutrophication, although most soils contain large P pools immobilized in minerals (Pi) and organic matter (Po).

In a new study published in the journal Ecology authors assessed whether transformations of these P pools can increase plant available pools alleviating P limitation under enhanced N availability.

The mechanisms underlying these possible transformations were explored by combining results from a 10-year field N-addition experiment and a 3700-km transect covering wide ranges in soil pH, soil N, aridity, leaching, and weathering that can affect soil P status in grasslands.

“Nitrogen addition promoted dissolution of immobile Pi (mainly Ca-bound recalcitrant P) to more available forms of Pi (including Al- and Fe-bound P fractions and Olsen P) by decreasing soil pH from 7.6 to 4.7, but did not affect Po”, explain Dr. Wang from State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China.

According to this study, soil total P declined by 10% from 385±6.8 to 346±9.5 mg kg-1, while available-P increased by 546% from 3.5±0.3 to 22.6±2.4 mg kg-1 after 10-year N addition experiment, associated with an increase in Pi mobilization, plant uptake, and leaching. Similar to the N-addition experiment, the drop in soil pH from 7.5 to 5.6 and increase in soil N concentration along the grassland transect were associated with an increased ratio between relatively mobile Pi and immobile Pi.

These results provide a new mechanistic understanding of the important role of soil Pi mobilization in maintaining plant P supply and accelerating biogeochemical P cycles under anthropogenic N enrichment. This mobilization process temporarily buffers ecosystem P-limitation or even causes P eutrophication but will extensively deplete soil P pools in the long run

“Our results also suggest that ecosystem P cycling model predictions should incorporate the interactions of N and P cycles by considering N enrichment effects on accelerating soil P cycling rates, that models can be further refined via delineating the dependence of Pi transformation on precipitation, and the ubiquitous role of soil pH in driving the biogeochemical pathways of Pi transformation”, concludes Prof. Josep Penuelas from CREAF-CSIC Barcelona.

Reference: Wang, R., Yang, J., Liu, H., Sardans, J., Zhang, Y., Wang, X., Wei, C., Lü, X., Dijkstra, F.A., Jiang, Y., Han, X., Peñuelas, J. 2021. Nitrogen enrichment buffers phosphorus limitation by mobilizing mineral-bound soil phosphorus in grasslands. Ecology, doi: 10.1002/ecy.3616

Summary:

An international research team succeeded in identifying global factors that explain the diversity of form and function in plants. Led by the University of Zurich, the Max Planck Institute for Biogeochemistry in Jena and the University of Leipzig, the researchers collected and analyzed plant data from around the world. For the first time, they showed for characteristics such as plant size, structure, and life span how strongly these are determined by climate and soil properties. Insights derived from this could be crucial to improving Earth system models with regard to the role of plant diversity.

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At first glance, the diversity of plant form and function seems difficult to comprehend. However, it can be described in terms of morphological, physiological, and biochemical characteristics. It has been shown previously that traits across species fall into two main categories within which each plant must maintain a balance: first, size and second, economy of metabolism. In a recent study in Nature Ecology and Evolution, a team of researchers has now confirmed for the first time, using a greatly enlarged global dataset for 17 different plant traits, that these two main categories apply to all plants studied worldwide. In the size category, plants balance height, leaf size, and seed size, among other traits. These traits are also influenced by hydraulic components of water transport in plants. The economics category describes how quickly and effectively the plant gains energy and biomass through photosynthesis, balanced against how long it survives. This category is determined by measurable characteristics such as the structure and composition of the leaves in terms of leaf area, as well as their elemental composition (nitrogen, phosphorus and carbon). The team showed that life strategies of the plant species collected worldwide in the TRY database are well explained by these two main categories.

Plant traits are influenced by a wide variety of external factors, such as climate, soil conditions, and human intervention. It has not yet been possible to determine which factors are decisive at the global level. To answer this question, the research team, led by Julia Joswig at the University of Zurich and the Max Planck Institute for Biogeochemistry in Jena, analyzed the characteristics of over 20,000 species. Information on climate and soil conditions at the location of each plant was included in the analysis.

“Our study clearly demonstrates that plant traits worldwide can be explained by joint effects of climate and soil,” Joswig said, adding, “This suggests that aspects of climate change and soil erosion, both of which occur as a result of land use change, for example, should be researched together.”

Many of the relationships described here were already known from small-scale, local studies. “But the fact that these processes could now be shown globally and their significance quantified is an important milestone,” adds Prof. Miguel Mahecha of the University of Leipzig. “Studies of this kind can guide global Earth system models to represent the complex interaction of climate, soil and biodiversity, which is an important prerequisite for future predictions,” Mahecha adds.

As expected, the study shows how the height of plant species changes along latitudes, due to differences in climate. However, the economic traits of plants do not show this gradient. Similarly, soil quality is only partially affected by climate, so there is a latitude-independent component in information about soil. Joswig and her colleagues show that this soil information is also relevant for the economic traits. Besides climate, soil-forming factors include organisms living in the soil, geology and topography, and of course time. Global change affects climate, organisms, and to some extent topography. Therefore, the study suggests that global risks to plant life should be explored especially in relation to climate change and soil erosion.

“In conclusion, our study contribute to the advance of our understanding of broad scale plant functional patterns. In particular, we highlight the combination of independent and particularly joint effects of climate and soil on trait variation, an interaction which has to date been neglected because few studies include both in a single analysis, at the global scale as we have done here”, concludes Prof. Josep Peñuelas from CREAF-CSIC.

Acknowledgments: This study used plant trait data from a collection of datasets made available in the TRY database at MPI-BGC.

Original publication:

Climatic and soil factors explain the two-dimensional spectrum of global plant trait variation

Julia S. Joswig, Christian Wirth, Meredith C. Schuman, Jens Kattge, Björn Reu, Ian J. Wright, Sebastian D. Sippel, Nadja Rüger, Ronny Richter, Michael E. Schaepman, Peter M. van Bodegom, J. H. C. Cornelissen, Sandra Díaz, Wesley N. Hattingh, Koen Kramer, Frederic Lens, Ülo Niinemets, Peter B. Reich, Markus Reichstein, Christine Römermann, Franziska Schrodt, Madhur Anand, Michael Bahn, Chaeho Byun, Giandiego Campetella, Bruno E. L. Cerabolini, Joseph M. Craine, Andres Gonzalez-Melo, Alvaro G. Gutierrez, Tianhua He, Pedro Higuchi, Herve Jactel, Nathan J. B. Kraft, Vanessa Minden, Vladimir Onipchenko, Josep Penuelas, Valerio D. Pillar, Enio Sosinski, Nadejda A. Soudzilovskaia, Evan Weiher, Miguel D. Mahecha. Nature Ecology and Evolution (2021) DOI 10.1038/s41559-021-01616-8

Press release based on

Ecosystems provide multiple services for humans. However, these services depend on basic ecosystem functions which are shaped both by natural conditions like climate and species and human interventions. in an article published in  Nature, a large international research team, led by Max Planck Institute for Biogeochemistry, has identified three key groups of functions that fully summarize ecosystem behaviour. The first function is the capacity to maximize primary productivity, the second is water-use efficiency, and third carbon-use efficiency. The sole monitoring of these key factors will make it possible to describe ecosystem behaviour and to understand the responsiveness to climatic and environmental changes.

Ecosystems on Earth’s land surface support multiple functions and services that are critical for society, such as biomass production, vegetation’s efficiency of using sunlight and water, water retention and climate regulation, and ultimately food security. Climate and environmental changes as well as anthropogenic impacts continuously threaten the provision of these functions. To understand how terrestrial ecosystems will respond to this threat, it is crucial to know which functions are essential to obtain a good representation of the ecosystems’ overall well-being and behaviour. This is particularly difficult since ecosystems are rather complex regarding their structure and their responses to environmental changes.

Scientists from several research centers including CSIC-CREAF Barcelona contributed to a large international network of researchers, led by Dr. Mirco Migliavacca at Max Planck Institute for Biogeochemistry in Jena, Germany, to tackle this question by combining multiple data streams and methods. The scientists used environmental data from global networks of ecosystem stations, combined with satellite observations, mathematical models, and statistical and causal discovery methods.  The result is strikingly simple: “We were able to identify three key dimensions that make it possible to summarise how ecosystems behave: the maximum realized productivity, the efficiency of using water, and the efficiency of using carbon” says Dr. Migliavacca, first author of the recent publication in Nature. “Using only these three major factors, we can explain 71.8% of the variability within ecosystem functions”, he adds.

The researchers particularly inspected the exchange rates of carbon dioxide, water vapour, and energy at 203 world-wide monitoring stations that cover a large variety of climate zones and vegetation types. For each site they calculated a set of the ecosystems’ functional properties, and further included calculations on average climate and soil water variables as well as vegetation characteristics and satellite data on vegetation biomass.

The three identified function groups critically depend on the structure of vegetation, e.g. on vegetation greenness, and nitrogen content of leaves as well as vegetation height and biomass. This also underlines the importance of ecosystem structure, that can be shaped by disturbances and forest management in controlling ecosystem behaviour. At the same time, the water and carbon use efficiency also critically depend on climate and partly on aridity, which points to the critical role of climate change for future ecosystem functioning. “Our exploratory analysis serves as a first step towards developing indicators of the whole ecosystem behaviour” says Max Planck director Prof. Markus Reichstein, “this will facilitate a more comprehensive assessment of the overall ecosystem response to climate and environmental changes.”

“The concept of the key axes of ecosystem functions could be used as a backdrop for the development of land surface models, which might help to improve the predictability of the terrestrial carbon and water cycle in response to future changing climatic and environmental conditions”, conclude Prof. Josep Penuelas from CREAF-CSIC-UAB.

Source: https://www.inrae.fr/en/news/behaviour-terrestrial-ecosystems-governed-only-three-main-factors

Reference: Migliavacca, M., Musavi, T., Mahecha, M.D., Nelson, J.A., Knauer, J., Baldocchi, D.D., Perez-Priego, O., Christiansen, R., Peters, J., Anderson, K., Bahn, M., Black, T.A., Blanken, P.D., Bonal, D., Buchmann, N., Caldararu, S., Carrara, A., Carvalhais, N., Cescatti, A., Chen, J., Cleverly, J., Cremonese, E., Desai, A.R., El-Madany, T.S., Farella, M.M., Fernández-Martínez, M., Filippa, G., Forkel, M., Galvagno, M., Gomarasca, U., Gough, C.M., Göckede, M., Ibrom, A., Ikawa, H., Janssens, I.A., Jung, M., Kattge, J., Keenan, T.F., Knohl, A., Kobayashi, H., Kraemer, G., Law, B.E., Liddell, M.J., Ma, X., Mammarella, I., Martini, D., Macfarlane, C., Matteucci, G., Montagnani, L., Pabon-Moreno, D.E., Panigada, C., Papale, D., Pendall, E., Penuelas, J., Phillips, R.P., Reich, P.B., Rossini, M., Rotenberg, E., Scott, R.L., Stahl, C., Weber, U., Wohlfahrt, G. Wolf, S., Wright, I.J., Yakir, D., Zaehle, S., Reichstein, M. 2021. The three major axes of terrestrial ecosystem function. Nature (2021). https://doi.org/10.1038/s41586-021-03939-9

Un model basat en tècniques de “machine learning” permet predir, a partir de dades de satèl·lits, si la reducció de l’activitat econòmica redueix els contagis. Desenvolupat amb participació del CSIC i de l’CREAF, el model permetrà afinar millor el temps i el grau de les mesures de confinament.

Un treball internacional amb participació dels científics Josep Peñuelas i Jordi Sardans, del CSIC i del CREAF, ha desenvolupat un model per predir, a partir de dades satel·litals de contaminació per diòxid de nitrogen, l’eficàcia del confinament per frenar epidèmies com la COVID-19. El model desenvolupat és capaç de predir com s’acceleren els contagis quan s’aixequen les mesures de confinament. Per tant, la informació permet optimitzar el temps i la intensitat de la implementació d’intervencions no farmacèutiques, i millorar l’efectivitat de control de la COVID-19 i en general de les pandèmies.

El Prof. Josep Peñuelas, investigador del CSIC i del CREAF explica que “el model millora significativament les prediccions fins ara usades per l’OMS i altres organitzacions governamentals i no governamentals”.

“Tal com hem vist en el treball, en l’hivern 2020-2021, prop d’un milió de casos diaris de COVID-19 es podrien haver evitat si s’haguessin optimitzat el temps i els nivells de restricció del confinament”, comenta Rong Wang, científic de la Universitat de Fudan (Xina) i coordinador d’aquesta investigació, que ha comptat amb finançament del programa PANDÈMIES 2020 de l’AGAUR.

La investigació es publica a la prestigiosa revista PNAS i ha comptat amb la participació d’una vintena de centres de recerca internacionals. Es tracta d’un treball interdisciplinari, amb especialistes en contaminació atmosfèrica, economia, epidemiologia, anàlisi de dades i intel·ligència artificial.

Els científics han aplicat tècniques d’aprenentatge automàtic que permeten seguir com es redueix l’activitat econòmica monitoritzant en temps gairebé real els nivells de diòxid de nitrogen (NO2) a l’atmosfera.

NO2, un indicador de l’activitat socioeconòmica

Per entrenar el model, s’han introduït i comparat els nivells de NO2 observats pels satèl·lits en les setmanes de confinament després del brot de COVID el 2020, amb els de les mateixes àrees en els anys 2016-2019.

Les observacions cobreixen 211 àrees geogràfiques, de les quals 31 són províncies a la Xina, 51 són estats dels EUA i 129 països d’Europa, Àsia, Est, Àfrica i Amèrica Llatina. Aquestes dades s’han correlacionat amb el nombre de contagis en cadascuna d’aquestes àrees en les setmanes de confinament i les posteriors, en què es van aixecar les mesures.

A més, els càlculs s’han ajustat per tenir en compte variables meteorològiques, ambientals i socials que poden influir tant en els nivells de NO2 com en la dispersió dels contagis, i que no estan relacionats amb l’activitat econòmica.

El model resultant pot predir la desacceleració en els contagis en les 211 àrees a partir de les observacions de NO2 i els 10 indicadors ambientals i socioeconòmics més determinants. En aquest sentit, el model també permet veure altres possibles resultats en funció de les mesures implementades.

“Sabíem que mesures no farmacològiques com el confinament són efectives per contenir les epidèmies com la de la COVID-19, però encara ens faltava una avaluació quantitativa de l’efectivitat i el moment adequat d’aplicació d’aquestes intervencions en diferents regions del món”, conclou Jordi Sardans, des del CREAF.

Article de referència: Xiaofan Xing et al. 2021. Predicting the effect of confinement on the COVID-19 spread using machine learning enriched with satellite air pollution observations. PNAS. DOI: 10.1073/pnas.2109098118 

Font: https://delegacion.catalunya.csic.es/monitorar-el-dioxid-de-nitrogen-en-latmosfera-permet-predir-si-el-confinament-sera-eficac-per-frenar-epidemies-com-la-covid19/?lang=ca

Un modelo basado en técnicas de “machine learning” permite predecir, a partir de datos satelitales, si la reducción de la actividad económica reduce los contagios. Desarrollado con participación del CSIC y del CREAF, el modelo permitirá afinar mejor los tiempos y el grado de las medidas de confinamiento.

Un trabajo internacional con participación de los científicos Josep Peñuelas y Jordi Sardans, del CSIC y del CREAF, ha desarrollado un modelo para predecir, a partir de datos satelitales de contaminación por dióxido de nitrógeno, la eficacia del confinamiento para frenar epidemias como la COVID-19. El modelo desarrollado es capaz de predecir cómo se aceleran los contagios cuando se levantan las medidas de confinamiento. Por lo tanto, la información permite optimizar el tiempo y la intensidad de la implementación de intervenciones no farmacéuticas, y mejorar la efectividad de control de la COVID-19 y en general de las pandemias.

El Prof. Josep Peñuelas, investigador del CSIC y del CREAF explica que “el modelo mejora significativamente las predicciones hasta ahora usadas por la OMS y otras organizaciones gubernamentales y no gubernamentales”.

“Tal como hemos visto en el trabajo, en el invierno 2020-2021, cerca de un millón de casos diarios de COVID-19 se podrían haber evitado si se hubieran optimizado los tiempos y los niveles de restricción del confinamiento”, comenta Rong Wang, científico de la Universidad de Fudan (China) y coordinador de esta investigación, que ha contado con financiación del programa PANDÈMIES 2020 de la AGAUR.

La investigación se publica en la prestigiosa revista PNAS, y ha contado con la participación de una veintena de centros de investigación internacionales. Se trata de un trabajo interdisciplinar, con especialistas en contaminación atmosférica, economía, epidemiología, análisis de datos e inteligencia artificial.

Los científicos han aplicado técnicas de aprendizaje automático que permiten seguir como se reduce la actividad económica monitorizando en tiempo casi real los niveles de dióxido de nitrógeno (NO2) en la atmosfera.

NO2, un indicador de la actividad socioeconómica

Para entrenar el modelo, se han introducido y comparado los niveles de NO2 observados por los satélites en las semanas de confinamiento tras el brote de COVID en 2020, con los de las mismas áreas en los años 2016-2019.

Las observaciones cubren 211 áreas geográficas, de las cuales 31 son provincias en China, 51 son estados de los EE.UU. y 129 países de Europa, Asia, Medio Este, África y Latinoamérica. Esos datos se han correlacionado con los números de contagios en cada una de esas áreas en las semanas de confinamiento y las posteriores, en las que se levantaron las medidas.

Además, los cálculos se han ajustado para tener en cuenta variables meteorológicas, ambientales y sociales que pueden influir tanto en los niveles de NO2 como en la dispersión de los contagios, y que no están relacionados con la actividad económica. 

El modelo resultante puede predecir la desaceleración en los contagios en las 211 áreas a partir de las observaciones de NO2 y los 10 indicadores ambientales y socioeconómicos más determinantes. En ese sentido, el modelo también permite ver otros posibles resultados en función de las medidas implementadas.

“Sabíamos que medidas no farmacológicas como el confinamiento son efectivas para contener las epidemias como la de la COVID-19, pero aún nos faltaba una evaluación cuantitativa de la efectividad y el momento adecuado de aplicación de estas intervenciones en diferentes regiones del mundo”, concluye Jordi Sardans desde el CREAF.

Artículo de referencia: Xiaofan Xing et al. 2021. Predicting the effect of confinement on the COVID-19 spread using machine learning enriched with satellite air pollution observations. PNAS. DOI: 10.1073/pnas.2109098118

Un trabajo internacional con participación de los científicos Josep Peñuelas y Jordi Sardans, del CSIC y del CREAF, ha desarrollado un modelo para predecir, a partir de datos satelitales de contaminación por dióxido de nitrógeno, la eficacia del confinamiento para frenar epidemias como la COVID-19. El modelo desarrollado es capaz de predecir cómo se aceleran los contagios cuando se levantan las medidas de confinamiento. Por lo tanto, la información permite optimizar el tiempo y la intensidad de la implementación de intervenciones no farmacéuticas, y mejorar la efectividad de control de la COVID-19 y en general de las pandemias.

El Prof. Josep Peñuelas, investigador del CSIC y del CREAF explica que “el modelo mejora significativamente las predicciones hasta ahora usadas por la OMS y otras organizaciones gubernamentales y no gubernamentales”.

“Tal como hemos visto en el trabajo, en el invierno 2020-2021, cerca de un millón de casos diarios de COVID-19 se podrían haber evitado si se hubieran optimizado los tiempos y los niveles de restricción del confinamiento”, comenta Rong Wang, científico de la Universidad de Fudan (China) y coordinador de esta investigación, que ha contado con financiación del programa PANDÈMIES 2020 de la AGAUR.

La investigación se publica en la prestigiosa revista PNAS, y ha contado con la participación de una veintena de centros de investigación internacionales. Se trata de un trabajo interdisciplinar, con especialistas en contaminación atmosférica, economía, epidemiología, análisis de datos e inteligencia artificial.

Los científicos han aplicado técnicas de aprendizaje automático que permiten seguir como se reduce la actividad económica monitorizando en tiempo casi real los niveles de dióxido de nitrógeno (NO2) en la atmosfera.

NO2, un indicador de la actividad socioeconómica

Para entrenar el modelo, se han introducido y comparado los niveles de NO2 observados por los satélites en las semanas de confinamiento tras el brote de COVID en 2020, con los de las mismas áreas en los años 2016-2019.

Las observaciones cubren 211 áreas geográficas, de las cuales 31 son provincias en China, 51 son estados de los EE.UU. y 129 países de Europa, Asia, Medio Este, África y Latinoamérica. Esos datos se han correlacionado con los números de contagios en cada una de esas áreas en las semanas de confinamiento y las posteriores, en las que se levantaron las medidas.

Además, los cálculos se han ajustado para tener en cuenta variables meteorológicas, ambientales y sociales que pueden influir tanto en los niveles de NO2 como en la dispersión de los contagios, y que no están relacionados con la actividad económica. 

El modelo resultante puede predecir la desaceleración en los contagios en las 211 áreas a partir de las observaciones de NO2 y los 10 indicadores ambientales y socioeconómicos más determinantes. En ese sentido, el modelo también permite ver otros posibles resultados en función de las medidas implementadas.

“Sabíamos que medidas no farmacológicas como el confinamiento son efectivas para contener las epidemias como la de la COVID-19, pero aún nos faltaba una evaluación cuantitativa de la efectividad y el momento adecuado de aplicación de estas intervenciones en diferentes regiones del mundo”, concluye Jordi Sardans desde el CREAF.

Artículo de referencia: Xiaofan Xing et al. 2021. Predicting the effect of confinement on the COVID-19 spread using machine learning enriched with satellite air pollution observations. PNAS. DOI: 10.1073/pnas.2109098118

Fuente: https://delegacion.catalunya.csic.es/monitorizar-el-dioxido-de-nitrogeno-en-la-atmosfera-permite-predecir-si-el-confinamiento-sera-eficaz-para-frenar-epidemias-como-la-covid19/

The importance of forests in the global carbon cycle that sustains life on Earth is undisputable. The multifunctional roles of forests extend to many aspects such as moderating air temperature and supporting a vast array of biodiversity on Earth. Forests also provide economic (e.g. timber, food, and fiber) and social benefits (e.g. subsistence for local populations and cultures. However, global climate change and human activities such as farming, mining, infrastructure expansion, are causing deforestation and subsequent degradation of soil properties and functions.

Afforestation, act or process of establishing a forest especially on land not previously forested, is an effective method to restore degraded land. Afforestation methods vary in their effects on ecosystem multifunctionality, but their effects on soil biodiversity have been largely overlooked.

In a new study published in the journal Global Change Biology authors studied the linkages between different afforestation practices and soil biodiversity in a tropical coastal forest in South China. The afforestation practices were initiated in the 1960s with no afforestation practices (bare land) and Eucalyptus exserta rotation monoculture. Later, in 1974, some Eucalyptus forests were clear-cut and reforested with native tree species. The study tested whether afforestation with native tree mixtures would restore the community composition, diversity, and abundance of diverse soil biota to levels of undisturbed native forests, while authors expected these effects to be less in Eucalyptus rotation monoculture forests. Furthermore, they also tested if afforestation with native tree mixtures would increase functional characteristics of soil biota more than afforestation with Eucalyptus rotation monocultures.

Sixty years after afforestation from bare land, plant species richness and the abundance of plant litter (398 ± 85 g m−2) and plant biomass (179 ± 3.7 t ha−1) in native tree species mixtures were restored to the level of native forests (287 ± 21 g m−2 and 243.0 ± 33 t ha−1, respectively), while Eucalyptus monoculture only successfully restored the litter mass (388 ± 43 g m−2) to the level of native forests. Soil fertility in Eucalyptus monoculture and species mixtures was increased but remained lower than in native forests.

Authors give the example of soil nitrogen and phosphorus concentrations in species mixtures (1.2 ± 0.2 g kg−1 and 408 ± 49 mg kg−1, respectively; p < 0.05) were lower than in native forests (1.8 ± 0.2 g kg−1 and 523 ± 24 mg kg−1, respectively; p < 0.05). Soil biodiversity, abundance (except for nematodes), and community composition in species mixtures were similar or greater than those in native forests. In contrast, restoration with Eucalyptus monoculture only enhanced the diversity of microbes and mites to the level of native forests, but not for other soil biota.

According with this study, afforestation with native species mixtures can end up restoring vegetation and most aspects of the taxonomic and functional biodiversity in soil whereas monoculture using fast-growing non-native species cannot. “Native species mixtures show a greater potential to reach completely similar levels of soil biodiversity in local natural forests if they received some more decades of afforestation. Multifunctionality of soil biotic community should be considered to accelerate such processes in future restoration practices”, highlights Dr. Wenjia Wu from the Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems & CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones, China.

“Although sixty years afforestation with native species did not reach the full level of soil fertility, abundance, and functional characteristics of belowground community of the more than 200-year-old native forest, certain traits of diversity of soil biota reached similar levels. This indicates that the overall habitat restoration may take several decades, with likely consequences for ecosystem functioning. However, the afforestation with native species can end up reaching similar levels of diversity than native forests whereas plantations using fast-growing non-native species cannot”, summarizes Prof. Josep Penuelas from CREAF-CSIC Barcelona.

Reference: Wu, W., Kuang, L., Li, Y., He, L., Mou, Z., Wang, F., Zhang, J., Wang, J., Li, Z., Lambers, H., Sardans, J., Peñuelas, J., Geisen, S., Liu, Z. 2021. Faster recovery of soil biodiversity in native species mixture than in Eucalyptus monoculture after 60 years afforestation in tropical degraded coastal terraces. Global Change Biology. doi: 1 0.1111/gcb.15774, in press..

Prof. Josep Peñuelas research professor of the CSIC and CREAF and director of the Global Ecology Unit CREAF-CSIC-UB-UAB had been ranked among the first 100 researchers in Spain and Spaniards abroad according to their Google Scholar Citations public profiles.

The list published by Webometrics and the National Research Council of Spain (CSIC) reaches the 16^th Edition. The list consists of the Top 91 000 profiles ranked first by h-index in decreasing order and then by the total number of citations. In the near future Webometrics and CSIC will intend to add rankings by discipline, genre or academic age.

Other distinguished members of the Global Ecology Unit as Prof. Jordi Sardans (among the first 1000 researchers), Prof. Iolanda Filella (among the first 1100), Prof. Marc Estiarte (among the first 1250) and Prof. Joan Llusià (among the first 1500) are also ranked in the list.

Link: https://www.webometrics.info/en/GoogleScholar/Spain

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El mundo avanza hacia una modelización climática más precisa, una formulación de políticas más equitativa y una producción de alimentos más sostenible, gracias a Imbalance-P, con Josep Peñuelas, Michael Obersteiner, Ivan Janssens and Philippe Ciais.

Josep Peñuelas, Michael Obersteiner, Ivan Janssens y Philippe Ciais, los investigadores europeos a cargo del proyecto Imbalance-P. Imagen: European Research Council

Este proyecto interdisciplinario European Research Council (ERC) Synergy Synergy ha permitido el trabajo conjunto entre cuatro científicos especializados en diversidad de ecosistemas, biogeoquímica, modelización de la Tierra y economía de los recursos: Josep Peñuelas, del CREAF y del CSIC, Ivan Janssens de la Universidad de Ambetes; Philippe Ciais, del Laboratoire des Sciences du Climat et de l’Environnement , y Michael Obersteiner, del International Institute for Applied Systems Analysis.

Gracias a Imbalance-P, el desequilibrio de nutrientes está ahora firmemente incluido en la agenda mundial y sus resultados ya influyen en la comunidad científica y política mundial. Los frutos de una intensa y sinérgica colaboración entre los cuatro destacados investigadores europeos son los impresionantes resultados: se han publicado más de 500 artículos, muchos de ellos en Science y Nature.Gracias a Imbalance-P, el desequilibrio de nutrientes está ahora firmemente incluido en la agenda mundial y sus resultados ya influyen en la comunidad científica y política mundial.

En su trabajo, los cuatro científicos se concentran en el impacto sobre el cambio climático, la biodiversidad, la seguridad alimentaria e incluso sobre la geopolítica que provoca el desequilibrio entre la disponibilidad de fosforo, carbono y nitrógeno. Entre estos elementos esenciales para la vida, la disponibilidad de carbono y de nitrógeno aumenta rápidamente en la mayor parte del mundo, pero la del fósforo no lo hace y es, por tanto, un recurso finito.

Frenar la pérdida de biodiversidad

Uno de los resultados más evidentes del proyecto Imbalance-P es que se han demostrado vías viables para frenar la pérdida de biodiversidad. Para ello, se han incluido datos sobre el ciclo de los nutrientes en relación con el funcionamiento de los ecosistemas en 9 modelos de biodiversidad. “La inclusión de la dimensión de los nutrientes en los modelos climáticos es especialmente importante para los países con mucha vegetación, como Rusia o Brasil”, según explica Obersteiner, “y hemos demostrado que es factible hacerlo”. Asimismo, se han mejorado y desarrollado modelos del sistema terrestre con más detalle que nunca, parametrizando los componentes de los ciclos de los tres nutrientes, a partir de datos de diferentes ecosistemas en Europa, América, Groenlandia, África y Asia.

Los nuevos Modelos del Sistema Tierra desarrollados permiten ahora evaluar en profundidad las posibilidades de producción biofísica optimizada para alimentar a una sociedad humana global cada vez más numerosa y exigente. Además, estos modelos permiten computar miles de nuevos escenarios globales del sistema Tierra que contemplan diferentes estrategias de gestión global, lo que potencialmente informará el desarrollo de un nuevo conjunto de objetivos del sistema Tierra basados en la ciencia.

“Este trabajo ERC Synergy nos ha permitido aprender mucho unos de otros. Así es como se consigue una ciencia de vanguardiaa”.

JOSEP PEÑUELAS, investigador del CREAF y del CSIC.

A lo largo de los dos últimos años, los cuatro científicos han combinado sus conocimientos y han despertado a la comunidad científica sobre lo que los desequilibrios de nutrientes pueden significar para nuestro planeta y para nuestra especie. “Este trabajo ERC Synergy nos ha permitido aprender mucho unos de otros. Así es como se consigue una ciencia de vanguardia”, afirma Josep Peñuelas.

Peñuelas, Ciais, Janssens y Obersteiner han cerrado de forma global el ciclo del fósforo y han generado un nuevo conocimiento integrado de los impactos de los desequilibrios de carbono, nitrógeno y fósforo en la diversidad y la función de los ecosistemas naturales, el clima, la agricultura y la sociedad. Las respuestas de la vida, la sociedad y el sistema de la Tierra están estrechamente interconectadas, pero hasta ahora se han considerado en su mayor parte en una investigación monodisciplinar fragmentada.

Fuente: Blog CREAF

The world is leading towards more accurate climate modelling, more equitable policymaking, and more sustainable food production thanks to the Imbalance-P project, with Josep Peñuelas, Michael Obersteiner, Ivan Janssens and Philippe Ciais.

Josep Peñuelas, Michael Obersteiner, Ivan Janssens and Philippe Ciais, the European researchers in charge of the Imbalance-P project. Image: European Research Council

The interdisciplinary European Research Council (ERC) Synergy project brought together four leading researchers specialising in ecosystem diversity, biogeochemistry, Earth modelling and resource economics: CREAF and CSIC researcher Josep Peñuelas, Ivan Janssens from University of Antwerpen; Philippe Ciais from Laboratoire des Sciences du Climat et de l’Environnement , and Michael Obersteiner from the International Institute for Applied Systems Analysis.

Thanks to Imbalance-P, the issue of nutrient imbalance is now firmly on the global agenda and its results are already influencing the global scientific and policy community. The fruits of an intense, synergistic collaboration among the four highlighted scientists are the impressive results: more than 500 papers have been published, most of them in top-tier journals such as Science and Nature.Thanks to Imbalance-P, the issue of nutrient imbalance is now firmly on the global agenda and its results are already influencing the global scientific and policy community.

In their work, the four scientists focus on the impact on climate change, biodiversity, food security and even geopolitics caused by the imbalance in the availability of phosphorus, carbon and nitrogen. Among these elements essential for life, the availability of carbon and nitrogen is increasing rapidly in most parts of the world, but the availability of phosphorus is not, and is therefore a finite resource.

Halting biodiversity loss

One of the results with the greatest impact of the Imbalance-P project is that it has demonstrated viable pathways towards curbing biodiversity loss. For this purpose, data on on nutrient cycling have been included, as it relates to ecosystem functioning in 9 biodiversity models. “The inclusion of the nutrient dimension in climate modelling is especially important for countries with a lot of vegetation, like Russia or Brazil”, according to Michael Obersteiner, “and we have demonstrated that this is feasible to do”. Earth system models have also been improved and developed in more detail than ever before, parameterising the components of the three nutrient cycles, based on data from different ecosystems in Europe, America, Greenland, Africa and Asia.

The new developed Earth System Models now allow in-depth assessments of optimized biophysical production possibilitislaes to feed an ever increasing and more demanding global human society. Moreover, these models make it possible to compute thousands of new global scenarios of the Earth system looking at different global management strategies, which will potentially inform the development of a new set of science-based Earth system targets.

“This Synergy grant enabled us to learn a lot from each other. This is how breakthrough science is achieved”.

JOSEP PEÑUELAS, researcher at CREAF and at CSIC.

Over the last two years the four of them combined their expertise and awoken the scientific community to what nutrient imbalances could mean for our planet, and for our species. “This Synergy grant enabled us to learn a lot from each other. This is how breakthrough science is achieved”, says Josep Peñuelas.

Peñuelas, Ciais, Janssens and Obersteiner have comprehensively closed the phosphorus cycle and generated new integrated knowledge of the impacts of carbon, nitrogen and phosphorus imbalances on the diversity and function of natural ecosystems, climate, agriculture and society. The responses of life, society and the Earth system are closely interconnected, but have so far been largely considered in fragmented monodisciplinary research.

Source: CREAF Blog