[{"command":"openDialog","selector":"#drupal-modal","settings":null,"data":"\u003Cdiv id=\u0022republish_modal_form\u0022\u003E\u003Cform class=\u0022modal-form-example-modal-form ecl-form\u0022 data-drupal-selector=\u0022modal-form-example-modal-form\u0022 action=\u0022\/en\/article\/modal\/9925\u0022 method=\u0022post\u0022 id=\u0022modal-form-example-modal-form\u0022 accept-charset=\u0022UTF-8\u0022\u003E\u003Cp\u003EHorizon articles can be republished for free under the Creative Commons Attribution 4.0 International (CC BY 4.0) licence.\u003C\/p\u003E\n \u003Cp\u003EYou must give appropriate credit. We ask you to do this by:\u003Cbr \/\u003E\n 1) Using the original journalist\u0027s byline\u003Cbr \/\u003E\n 2) Linking back to our original story\u003Cbr \/\u003E\n 3) Using the following text in the footer: This article was originally published in \u003Ca href=\u0027#\u0027\u003EHorizon, the EU Research and Innovation magazine\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003ESee our full republication guidelines \u003Ca href=\u0027\/horizon-magazine\/republish-our-stories\u0027\u003Ehere\u003C\/a\u003E\u003C\/p\u003E\n \u003Cp\u003EHTML for this article, including the attribution and page view counter, is below:\u003C\/p\u003E\u003Cdiv class=\u0022js-form-item form-item js-form-type-textarea form-item-body-content js-form-item-body-content ecl-form-group ecl-form-group--text-area form-no-label ecl-u-mv-m\u0022\u003E\n \n\u003Cdiv\u003E\n \u003Ctextarea data-drupal-selector=\u0022edit-body-content\u0022 aria-describedby=\u0022edit-body-content--description\u0022 id=\u0022edit-body-content\u0022 name=\u0022body_content\u0022 rows=\u00225\u0022 cols=\u002260\u0022 class=\u0022form-textarea ecl-text-area\u0022\u003E\u003Ch2\u003E Protecting forests on the front line of the climate-change battle\u003C\/h2\u003E\u003Cp\u003E\u003Cbr\u003EForests help counter global warming, but they are also threatened by it. Many tree species struggled this past summer as much of Europe was hit by heat waves and a severe drought - thought to be the worst in 500 years.\u003C\/p\u003E\u003Cp\u003EEven olive trees, known for their ability to resist dry conditions, have suffered. Spain is the world\u2019s leading producer of olive oil but many Spanish farmers expect their olive-oil harvests this year to decline by as much as 50%.\u003C\/p\u003E\u003Cp\u003EIn this context, Horizon researchers are racing to understand more about how trees respond to drought as part of the fight against climate change.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECarbon sinks\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EExisting forests already remove about a third of the greenhouse gas emissions caused by human activities. A worldwide afforestation programme could do the same for almost a third of the discharges that remain in the atmosphere.\u003C\/p\u003E\u003Cp\u003E\u0027If you look at the last 10 years or so, there have been a number of events where severe drought has caused large-scale death of trees in forests.\u0027 said Dr Jaideep Joshi, of the Plant-FATE project, which is studying plant traits to protect forests from climate change.\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EPlanting billions of trees is a relatively inexpensive way to tackle the climate crisis, according to a study about \u003Ca href=\u0022https:\/\/www.science.org\/doi\/full\/10.1126\/science.aax0848\u0022\u003Ethe potential for global forest cover to mitigate climate change\u003C\/a\u003E. \u0026nbsp;\u003C\/p\u003E\u003Cp\u003EBut as drought spreads, forests worldwide are at risk. In Europe, 500 000 hectares of forest were wiped out as a result of drought between 1987 and 2016.\u003C\/p\u003E\u003Cp\u003E\u003Cblockquote class=\u0022tw-text-center tw-text-blue tw-font-bold tw-text-2xl lg:tw-w-1\/2 tw-border-2 tw-border-blue tw-p-12 tw-my-8 lg:tw-m-12 lg:tw--ml-16 tw-float-left\u0022\u003E\n \u003Cspan class=\u0022tw-text-5xl tw-rotate-180\u0022\u003E\u201c\u003C\/span\u003E\n \u003Cp class=\u0022tw-font-serif tw-italic\u0022\u003EIf you look at the last 10 years or so, there have been a number of events where severe drought has caused large-scale death of trees in forests.\r\n\u003C\/p\u003E\n \u003Cfooter\u003E\n \u003Ccite class=\u0022tw-not-italic tw-font-normal tw-text-sm tw-text-black\u0022\u003EDr Jaideep Joshi, Plant-FATE \u003C\/cite\u003E\n \u003C\/footer\u003E\n\u003C\/blockquote\u003E\n\u003Cbr\u003E\u0026nbsp;\u003Cbr\u003EJoshi led the Horizon-funded \u003Ca href=\u0022https:\/\/cordis.europa.eu\/project\/id\/841283\u0022\u003EPlant-FATE project\u003C\/a\u003E, which broke new ground when it comes to predicting the impact of drought on trees of all kinds.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETree resilience\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EA major limitation of current models is that they rarely consider trees\u2019 ability to adapt to dry conditions and how resilience may differ between species. That leads to inconsistencies when projecting how forests will respond to future climate scenarios.\u003C\/p\u003E\u003Cp\u003E\u2018That is where the largest uncertainty currently lies,\u2019 said Dr Joshi. \u2018You have this whole ecosystem of mixed species - we have tried to bring this all together in a simple but comprehensive modelling framework.\u2019\u003C\/p\u003E\u003Cp\u003EA model acts as a tool for simulating outcomes and he believes his team\u2019s model will be particularly useful when it comes to planning tree-planting programmes. That\u2019s because it can signal the carbon capture and storage potential of different species over the next 50-100 years, when climate conditions will be different to what they are today.\u003C\/p\u003E\u003Cp\u003E\u2018It could help make the right choices of which species to plant or where to plant them,\u2019 said Dr Joshi. \u2018It\u2019s our model\u2019s most promising conservation application.\u2019\u003C\/p\u003E\u003Cp\u003EIn their model, the Plant-FATE researchers incorporated trees\u2019 ability to adjust to changing climate and looked at a range of timescales.\u003C\/p\u003E\u003Cp\u003EIn shorter timeframes of weeks to months, for example, trees exposed to drought may shed their leaves to conserve water (because water evaporates through pores on the surface of leaves) in what\u2019s known as a \u2018false autumn\u2019.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ENew wood\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EBut over longer timescales, trees can grow new wood with different properties better suited to dry conditions.\u003C\/p\u003E\u003Cp\u003EDr Joshi and his team also took scale into account. For example, some responses occur in specific parts of a tree as roots and leaves, while others take place at the level of an entire species.\u003C\/p\u003E\u003Cp\u003ETo test their full model, Dr Joshi and his colleagues used data from an Amazon rainforest site containing about 400 species in a 5 000 square-metre area. They found that their model\u2019s predictions closely matched what happened in real life at the site.\u003C\/p\u003E\u003Cp\u003E\u003Cblockquote class=\u0022tw-text-center tw-text-blue tw-font-bold tw-text-2xl lg:tw-w-1\/2 tw-border-2 tw-border-blue tw-p-12 tw-my-8 lg:tw-m-12 lg:tw--ml-16 tw-float-left\u0022\u003E\n \u003Cspan class=\u0022tw-text-5xl tw-rotate-180\u0022\u003E\u201c\u003C\/span\u003E\n \u003Cp class=\u0022tw-font-serif tw-italic\u0022\u003EIf it wasn\u2019t worth it to be tall, then trees wouldn\u2019t grow tall.\r\n\u003C\/p\u003E\n \u003Cfooter\u003E\n \u003Ccite class=\u0022tw-not-italic tw-font-normal tw-text-sm tw-text-black\u0022\u003EDr Laura Fern\u00e1ndez de U\u00f1a, DISTRESS \u003C\/cite\u003E\n \u003C\/footer\u003E\n\u003C\/blockquote\u003E\n\u003C\/p\u003E\u003Cp\u003EIt marks the first time that a vegetation model has performed realistically over different timescales while using very few parameters, according to Dr Joshi, a researcher at the International Institute for Applied Systems Analysis in Laxenburg, Austria.\u003C\/p\u003E\u003Cp\u003E\u2018It gives you the capacity to predict forest performance for unknown conditions,\u2019 he said. \u2018That makes it much more useful to predict the response of global forests to future climate scenarios.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ETall trees\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EWhile tall trees are often considered to be more vulnerable to dry conditions than shorter ones, much remains to be discovered about why and to what extent a tree\u2019s height affects its resistance to drought.\u003C\/p\u003E\u003Cp\u003EDr Laura Fern\u00e1ndez de U\u00f1a leads the Horizon-funded \u003Ca href=\u0022https:\/\/cordis.europa.eu\/project\/id\/844028\u0022\u003EDISTRESS project\u003C\/a\u003E, which is examining how a tree\u2019s ability to transport water changes with height and how that might influence drought responses.\u003C\/p\u003E\u003Cp\u003EShe and her colleagues stand to shake up some conventional wisdom in the field.\u0026nbsp; \u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u2018We see certain differences between individual trees and also between species types,\u2019 said Dr Fern\u00e1ndez de U\u00f1a, a post-doctoral fellow at public research centre CREAF in Barcelona, Spain.\u003C\/p\u003E\u003Cp\u003E\u003Cfigure role=\u0022group\u0022\u003E\n\u003Cimg alt=\u0022Tree mortality in a Western USA conifer forest. \u00a9 Laura Fern\u00e1ndez de U\u00f1a, 2020\u0022 data-entity-type=\u0022file\u0022 data-entity-uuid=\u002283bf94cf-0f9e-4ac3-88e8-e8021dab0832\u0022 src=\u0022\/sites\/default\/files\/hm\/IMCEUpload\/BODY%20Picture%20DISTRESS1a.jpg\u0022\u003E\n\u003Cfigcaption class=\u0022tw-italic tw-mb-4\u0022\u003ETree mortality in a Western USA conifer forest. \u00a9 Laura Fern\u00e1ndez de U\u00f1a, 2020\u003C\/figcaption\u003E\n\u003C\/figure\u003E\n\u003C\/p\u003E\u003Cp\u003EUnsurprisingly, research confirms that it\u2019s harder for water to reach the heights of taller trees. Even in normal conditions, gravity is a basic impediment.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAir bubbles\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDuring a drought, it is harder for trees to extract water from dry soil and draw it upwards. This increases the risk of water-transporting conduits sucking in air bubbles, which can block the flow (similar to embolisms in human blood vessels). If any bubbles occur, parts of a tree can be denied water and die.\u003C\/p\u003E\u003Cp\u003EFurthermore, tall trees in a forest are exposed to more heat and wind and less humidity. \u2018The canopy conditions themselves are drier than for a smaller tree in the understory,\u2019 said Dr Fern\u00e1ndez de U\u00f1a. \u2018All this is negative for tall trees during a drought.\u2019\u003C\/p\u003E\u003Cp\u003ENonetheless, past research indicates that tall trees can adapt to heat and water stress or even cope better than small trees. They are able to expand their water-conducting pipes, for example, to get more flow up their long trunks.\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EWell rooted\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EIn addition, larger trees have more roots that reach greater depths, allowing access to water even when levels in the upper ground are low.\u003C\/p\u003E\u003Cp\u003EThey also tend to have thicker trunks, which allow bigger trees to store more carbohydrates and water. \u0026nbsp;\u003C\/p\u003E\u003Cp\u003EFor Dr Fern\u00e1ndez de U\u00f1a, all this shows that \u2013 contrary to common assumptions \u2013 tall trees have a fighting chance when temperatures soar and water becomes scarce for prolonged periods.\u003C\/p\u003E\u003Cp\u003E\u2018They are able to adapt and overcome their limitations,\u2019 she said. \u2018We need to be more open-minded about how they may respond to drought. If it wasn\u2019t worth it to be tall, then trees wouldn\u2019t grow tall.\u2019\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EResearch in this article was funded via the EU\u2019s Marie Sk\u0142odowska-Curie Actions (MSCA). 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