The secret plant communication – Las comunicaciones secretas de las plantas

The websites of disseminating scientific knowledge SINC (La Ciencia es Notica) and NCYT (Notícias de la Ciencia y la Tecnología) have published an article on The secret plant communication, that includes declarations of Prof Josep Penuelas about Volatile organic compounds and plants communication.

SINC read the full text in Spanish

NCYT read the full text Spanish

 

Weakening temperature control on the interannual variations of spring carbon uptake across northern lands

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For the past decade, boreal forests have been a net carbon sink; but a new study in the journal Nature Climate Change show that the relationship between spring temperature and carbon uptake has recently shifted. Photo by Pexels

 

Ongoing spring warming allows the growing season to begin earlier, enhancing carbon uptake in northern ecosystems; but the sink-or-source status of arctic tundra cannot be deduced from current observations.

In a new study in the journal Nature Climate Change researchers use 34 years of atmospheric CO2 concentration measurements at Barrow, Alaska (BRW, 71 N) to show that the interannual relationship between spring temperature and carbon uptake has recently shifted. They use two indicators: the spring zero-crossing date of atmospheric CO2 (SZC) and the magnitude ofCO2 drawdown between May and June (SCC).

The previously reported strong correlation between SZC, SCC and spring land temperature (ST) was found in the first 17 years of measurements, but disappeared in the last 17 years. As a result, the sensitivity of both SZC and SCC to warming decreased. Simulations done in the study with an atmospheric transport model coupled to a terrestrial ecosystem model suggest that the weakened interannual correlation of SZC and SCC with ST in the last 17 years is attributable to the declining temperature response of spring net primary productivity (NPP) rather than to changes in heterotrophic respiration or in atmospheric transport patterns.

“Several mechanisms could explain the apparent weakening response of NPP in spring to interannual temperature variations.  A first possible mechanism is that winter warming comes with a loss of chilling, other possible mechanisms are the possible limitations of shorter day lengths when the growing season progressively advances earlier into the spring, and increasing occurrence of extreme events. Further studies are needed to verify these potential mechanisms”, said Prof. Josep Penuelas from CREAF-CSIC Barcelona.

Prof Penuelas notes that their results show that the linkage between spring carbon uptake and temperature is not a stable property of northern ecosystems. However, because of the relatively short run of CO2 observations, it remains uncertain whether the observed decrease in interannual correlation of spring carbon uptake with temperature reflects decadal variability, or a long-term shift in the ecological response of boreal and arctic regions to warming.

This study received support from the European Research Council Synergy grant ERC-2013-SyG-610028.

Journal Reference: Piao, S., Liu, Z., Wang, T.,Peng, S., Ciais, P., Huang, M., Ahlstrom, A., Burkhart, J., Chevallier, F., Janssens, I., Jeong, S., Lin, X., Mao, J., Miller, J., Mohammat, A., Myneni, R., Penuelas, J., Shi, X., Stohl, A., Yao, Y., Zhu, Z., Tans, P. 2017. Weakening temperature control on the inter-annual variations of spring carbon uptake across northern lands. Nature Climate Change, doi: 10.1038/nclimate3277.

Pathways for balancing CO2 emissions and sinks

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Oil pumps and Industry emissions. Photo by Pexels

 

Carbon dioxide (CO2) and other greenhouse gases in the atmosphere can be reduced in two ways — by cutting our emissions, or by removing it from the atmosphere, for example through plants, the ocean, and soil.

In December 2015 in Paris, leaders committed to achieve global, net decarbonization of human activities before 2100. This achievement would halt and even reverse anthropogenic climate change through the net removal of carbon from the atmosphere. However, the Paris documents contain few specific prescriptions for emissions mitigation, leaving the timing and details of these efforts to individual countries.

In a new study in the journal Nature Communications researchers project energy and land use emissions mitigation pathways through 2100, subject to best-available parameterization of carbon-climate feedbacks and interdependencies. Researchers used a global model of the carbon system that accounts for carbon release and uptake through both natural and anthropogenic activities.

“The study shows that the combined energy and land-use system should deliver zero net anthropogenic emissions well before 2040 in order to assure the attainability of a 1.5°C target by 2100,” says IIASA Ecosystems Services and Management Program Director Michael Obersteiner.

“Fossil fuel consumption will likely need to be reduced below a quarter of primary energy supply by 2100, and the allowable consumption rate drops even further if negative emissions technologies remain technologically of economically unfeasible at global scale”, said Dr. Brian Walsh from International Institute for Applied Systems Analysis, Austria, now a World Bank consultant.

Researchers find that, barring unforeseen and transformative Technological advancement, anthropogenic emissions need to peak within the next ten years in order to maintain realistic pathways to meeting the COP21 emissions and warming targets. In this sense, according to the study, fossil fuel consumption would likely need to be reduced to less than 25% of the global energy supply by 2100, compared to 95% today. At the same time, land use change, such as deforestation, must be decreased. This would lead to a 42% decrease in cumulative emissions by the end of the century compared to a business as usual scenario.

“This study gives a broad accounting of the carbon dioxide in our atmosphere, where it comes from and where it goes. We take into account not just emissions from fossil fuels, but also agriculture, land use, food production, bioenergy, and carbon uptake by natural ecosystems”, said Michael Obersteiner.

The study compares four different scenarios for future energy development, with a range of mixtures of renewable and fossil energy. In a “high-renewable” scenario where wind, solar, and bioenergy increase by around 5% a year, net emissions could peak by 2022, the study shows. Yet without substantial negative emissions technologies, that pathway would still lead to a global average temperature rise of 2.5°C, missing the Paris Agreement target.

Walsh notes that the high-renewable energy scenario is ambitious, but not impossible — global production of renewable energy grew 2.6% between 2013 and 2014, according to the IEA. In contrast, the study finds that continued reliance on fossil fuels (with growth rates of renewables between 2% and 3% per year), would cause carbon emissions to peak only at the end of the century, causing an estimated 3.5°C global temperature rise by 2100.

“Our results show thus that the severe consequences of global warming on ecosystems and society can only be avoided by achieving the goal of strictly carbon-neutral societies as soon as possible.” said Prof. Josep Penuelas from CREAF-CSIC Barcelona.

 

A new model

The study is one of the first published results from the newly developed FeliX model, a system dynamics model of social, economic, and environmental earth systems and their interdependencies. The model is freely available for download and use at http://www.felixmodel.com/.

This study received support from the European Research Council Synergy grant ERC-2013-SyG-610028

Journal Reference: Walsh, B., Ciais, P., Janssens, I.A., Peñuelas, J., Riahi, K., Rydzak, F., van Vuuren, D., Obersteiner, M. 2017. Pathways for balancing CO2 emissions and sinks. Nature Communications.

Human population growth offsets climate-driven increase in woody vegetation in sub-Saharan Africa

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Woody cover has actually increased over the past 20 years in large parts of Africa, and in particular in drylands. Researchers attribute much of this increase to changes in rainfall and the growing concentration of CO2 in the atmosphere. Photo by Pixabay

 

The rapidly growing human population in sub-Saharan Africa generates increasing demand for agricultural land and forest products, which presumably leads to deforestation. Conversely, a greening of African drylands has been reported, but this has been difficult to associate with changes in woody vegetation. There is thus an incomplete understanding of how woody vegetation responds to socio-economic and environmental change.

Deforestation in Africa has been high on the environmental agenda for decades. In a new study published in Nature Ecology and Evolution, researchers used a passive microwave Earth observation data set to demonstrate that the realities are more complex.

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Ethnobotanical convergence, a new junction of tradition and modernity to promote research on plant biodiversity

 

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The ethnobotanical convergence is a concept presented in an article published on the cover ofTrends in Plant Science.
xx Tradition, traditional knowledge, and applied research on plant biodiversity are the references for the progress of knowledge on ethnobotany, a science that studies the relation between human populations and their plant environment. Grouping similar uses of plants of a same taxon and easing the identification of new applications of natural products are the focuses of ethnobotanical convergence, a concept presented in an article published on the cover of Trends in Plant Science, signed by the experts Joan Vallès, from the Faculty of Pharmacy and Food Sciences and the Biodiversity Research Institute of the UB (IRBio), Teresa Garnatje, from the Botanical Institute of Barcelona (IBB-CSIC-ICUB), and Josep Peñuelas, CSIC researcher at the Ecological and Forestry Applications Research Centre (CREAF).
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Ethnobotany studies the relation between human populations and their plant environment.

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This discipline refers to the profits and the human uses of plants.
Ethnobotany: the world natural and cultural heritage of plants
Ethnobotany is a discipline which has advanced with the progress of natural and social sciences. It is a defining behavior of the cultural heritage of social groups, both for its reference to its profits and the human uses of plants. Advances in ethnobotany have enabled the preservation of biodiversity from a natural perspective (genetics, taxonomy, ecosystem, etc.) as well as cultural, such as the preservation of popular knowledge on the world of plants, their management and relation of human societies with plants over the years.Knowing popular uses of plants is essential to discover new medicines and foods, and therefore improve the health and nutrition of many populations. According to Joan Vallès, coordinator of the study and professor of Botany at the University of Barcelona, “lots of drugs and nutraceutical, alimentary, cosmetic products -and others for people’s wellbeing- come from plants. An important amount of these products comes from lore and traditional uses that were maintained over generations of people”.At the moment, only 62 out of the 457 families of angiosperms (flowering plants) and gymnosperms (non-flowering plants) are usually used for their medicinal features. Paclitaxel, an isolated product from the Pacific’s yew (Taxus brevifolia) and also present in the European yew (Taxus baccata), is one of the most cited examples as natural product applied in cancer treatments. Star anise (Ilicium verum), an Asiatic plant known in traditional Chinese medicine, was the base for oseltamivir, the most promising medicine against the avian flu epidemic, identified in a campaign of enthnobotany and pharmacology prospection promoted by the World Health Organization (WHO). With the discovery of artemisinin –derived from the plant Artemisia annua– also used in popular Chinese medicine-, pharmacologist Tu Youyou was distinguished with the Nobel Prize in Medicine (2015).

Valles_et al_Trends Plant Sci_2017_Lavandula_stoechasKnowing popular uses of plants is essential to discover new medicines and foods (image: Lavandula stoechas)

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Coincidences in use and thus, in the plants’ traits, can be understood regarding the study of evolutionary and parenting relations (image: Arnica montana)

Omics revolution in ethnobotany

Omics are widening the lines of knowledge in biology, biomedicine and other related areas. New knowledge on molecular phylogeny, for instance, changed the scientific view of taxonomy classification of many living beings.According to Josep Peñuelas, (CSIC-CREAF), awardee of Ramon Margalef in Ecology 2016, “the continuous development of new techniques on metabolomics provides an essential tool to discover a new generation of natural products inspired in the application of the new concept of phylogenetic convergence and ethnobotanical studies”.In the context of ethnobotany, studies on molecular phylogeny enabled creating the concept of enthonotanical convergence, a clear step forward to improve the election of plants of interest. This together with the recent revolution of omics –in particular, genomics and metabolomics –will enable the identification of new potential applications of natural products from plants.“The uses of the same species or similar ones, by human groups belonging to different cultures and which didn’t have contact among them, shows that this knowledge has been acquired independently” says Teresa Garnatge, director of the Botanical Institute of Barcelona. “These plants –says the researcher- which show similar traits (evolutionary convergence), can be also used in a similar way (ethnobotanical convergence)”.

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Sequence of plant responses to droughts of different timescales: lessons from holm oak (Quercus ilex) forests

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Tree physiology, forest structure and site-specific factors interact to determine the response of forests to recurring annual droughts, however, the increasing frequency of extreme droughts is making Mediterranean forests vulnerable. Picture shows Quercus ilex forests standing on the slopes of the sacred Montserrat mountain. Photo by Lluís Comas

 

The functional traits of plants in regions of the world with a Mediterranean climate have been shaped to tolerate periods of water deficit. These species are adapted to summer droughts but may not be able to cope with future increases in drought intensity, duration, and/or frequency.

In a new study published in Plant Ecology & Diversity researchers review the mechanisms and traits of drought resistance and recovery of the holm oak (Quercus ilex), which they propose as a model species for Mediterranean-type ecosystems. The aim of the study was to understand the differences and links between the responses of Q. ilex to summer droughts, extreme droughts, and long-term drought experiments. A main goal was to provide an integral picture of drought responses across organizational and temporal scales for identifying the most relevant processes that are likely to contribute to determining the future of Mediterranean vegetation. Evidence from long-term drought experiments showed that acclimation processes from the molecular (e.g. epigenetic changes) to the ecosystem level (e.g. reductions in stand density) mitigate the effects of drought.

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El fòsfor ha passat de ser un nutrient a ser un contaminant global

Els ecosistemes aquàtics propers a zones densament poblades de tot el món presenten valors molt alts de fòsfor i descompensats entre nitrogen i fòsfor. Això altera el funcionament d’aquests ecosistemes, en dificulta la conservació i redueix la qualitat de l’aigua.

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El llac eutrofitzat Dianchi, a la Xina. L’estat de l’aigua la feia inservible per al consum i l’ús agrícola i industrial. Autor: Greenpeace China (CC BY 2.0)

 

La vida depèn, entre altres coses, de la proporció de nitrogen (N) i fòsfor (P) que hi ha al medi. Normalment hi ha molt més nitrogen disponible que fòsfor, i les espècies han evolucionat per viure en aquestes condicions. Però, si aquesta proporció s’altera, els organismes redueixen la seva capacitat de creixement i manteniment de les funcions vitals.

Un estudi publicat a la revista Ecology Letters, en el que han col·laborat Josep Peñuelas, investigador del CSIC al CREAF, i Jordi Sardans, investigador del CREAF, ha analitzat la proporció de nitrogen i fòsfor en diferents ecosistemes d’aigua dolça del món. Els investigadors han constatat que aquesta proporció s’està alterant en les conques fluvials on l’activitat humana és més intensa i on hi ha més població.

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Future climate change will affect plants and soil differently

 

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Changes of aboveground net primary production and soil respiration in response to drought indicated that wet systems had an overall risk of increased loss of C but drier systems did not. Photo by: Pixabay

 

In a new study published in the Nature journal Scientific Reports, researchers have found that soil carbon loss is more sensitive to climate change compared to carbon taken up by plants. In drier regions, soil carbon loss decreased but in wetter regions soil carbon loss increased. This could result in a positive feedback to the atmosphere leading to an additional increase of atmospheric CO2 levels.

Scientists analysed data from seven climate change experiments across Europe to show how European shrubland plant biomass and soil carbon loss is affected by summer drought and year-around warming.

The research was conducted by a group of European and American scientists including Marc Estiarte and Josep Peñuelas from CSIC-CREAF.

The authors showed that soil carbon loss is most responsive to change in soil water. Soil water plays a critical role in wet soils where water logging limits decomposition processes by soil biota resulting in a build-up of soil carbon as peat. Drying of the soil removes this limitation resulting in soil carbon loss. In contrast in drier soils, reduced rainfall reduces soil water below the optimum for soil biota resulting in a decrease in soil carbon loss.

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