Climate change

Seeds transfer their microbes to the next generation

By | Climate change, News, Plant Science

Scientists have been pondering if the microbiome of plants is due to nature or nurture. Research at Stockholm University, published in Environmental Microbiology, showed that oak acorns contain a large diversity of microbes, and that oak seedlings inherit their microbiome from these acorns.

“The idea that seeds can be the link between the microbes in the mother tree and its offspring has frequently been discussed, but this is the first time someone proves the transmission route from the seed to the leaves and roots of emerging plants”, says Ahmed Abdelfattah, researcher at the Department of Ecology Environment and Plant Sciences (DEEP) at Stockholm University.

The microorganisms found on the seed are often valuable for the plant, promoting its growth and protecting it against certain diseases. Each plant species harbours a distinct microbial community, with some of the microbes living on its surface and others inside the plant’s tissues.

The finding also means that since the microorganisms from the seed are there first, they can constitute a barrier which influences subsequent colonization by other microbes from the environment. The experiment was done in oaks, since it’s one of the most abundant tree species in the Swedish and European forests.

“The microorganisms from the seed are also expected to be very important for plant health and functioning”, says Ahmed Abdelfattah.

The fossil record indicates that plants have been associated with fungi and bacteria – constituting the microbiome – for more than 400 million years. Several species the scientists found on the oak seeds are already shown by other studies to be involved in the protection against several plant pathogens, growth-promotion, nitrogen-fixing, and the detoxification or biodegradation of toxic environmental pollutants.

Demonstrating inheritance under natural conditions is challenging since seeds are exposed to and dependent on their surrounding environment when they sprout, especially the soil, which is a microbially rich environment. Therefore, it’s nearly impossible to differentiate between which microorganism actually come from the seed or from the soil. The research team therefore used a novel culturing device, to grow oak seedlings in a microbe-free condition and keep the leaves separated from the roots. This allowed them to be certain that the microorganisms came from the seed, and that they could demonstrate that some seed microorganisms migrate to the roots, and some others to the leaves.

“Plant leaves and roots are already known to harbor distinct microbial communities, as shown by several recent studies. In this study however, we were surprised to see that it is also true at an early stage of the plant development, and that the seed could, at least partially, be responsible for these differences”, Says Ahmed Abdelfattah.

“Several breeding companies are taking into consideration the seed microbiome in their programs hoping to have super plants with better genes and better microbes. One technique used, is to treat seeds with beneficial microorganism with the aim that those microbes will eventually colonize the plant and exert their effects throughout the plant’s life”, says Ahmed Abdelfattah.

The next step for the research team is now to discern which is the major source of the of the microbiome – the environment or the seed.

Read the paper: Environmental Microbiology

Article source: Stockholm University

Author: Amanda Gonzalez Bengtsson 

Image credit: Ирина Ирина / Pixabay 

How plants compete for underground real estate affects climate change and food production

By | Agriculture, Climate change, News

You might have observed plants competing for sunlight — the way they stretch upwards and outwards to block each other’s access to the sun’s rays — but out of sight, another type of competition is happening underground. In the same way that you might change the way you forage for free snacks in the break room when your colleagues are present, plants change their use of underground resources when they’re planted alongside other plants.

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Restoration of degraded grassland can benefit climate change mitigation and key ecosystem services

By | Climate change, News, Plant Health, Plant Science

New research has demonstrated how, in contrast to encroachment by the invasive alien tree species Prosopis julifora (known as `Mathenge` in Kenya or `Promi` in Baringo), the restoration of grasslands in tropical semi-arid regions can both mitigate the impacts of climate change and restore key benefits usually provided by healthy grasslands for pastoralists and agro-pastoralist communities.

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Siberian prim­rose has not had time to ad­apt to cli­mate change

By | Climate change, News, Plant Science, Scandinavian Plant Physiology Society

Global warming already affects Siberian primrose, a plant species that is threatened in Finland and Norway. According to a recently completed study, individuals of Siberian primrose originating in the Finnish coast on the Bothnian Bay currently fare better in northern Norway than in their home area. The results indicate that the species may not be able to adapt to quickly progressing climate change, which could potentially lead to its extinction.

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New study: Forests are still underrated as allies to curb rural poverty

By | Climate change, Forestry, Future Directions, News

In the face of the Covid-19 pandemic and the mounting threat of climate change, forests and trees are vital for the rural poor in countries around the world. However, the poor are rarely able to capture the bulk of benefits from forests. A global science assessment analyses how forests can realize their potential to reduce poverty in a fair and lasting manner.

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Trade and climate change increase pest threat to Europe’s forests

By | Climate change, News, Plant Health

Europe’s forests face a growing threat from pests due to global trade and climate change, but scientists are developing techniques that can give an early warning of infestations to help combat damaging insects and diseases.

Pests are responsible for damaging 35 million hectares of forest around the world every year. In the Mediterranean region alone an area the size of Slovakia – five million hectares – is affected by pests annually, according to the UN Food and Agriculture Organization (FAO).

And the threat posed by insects and pathogens appears to be growing. Climate change is allowing some native pests to breed more frequently, while international trade is spreading exotic insects and pathogens more widely.

Only a tiny proportion of exotic pests that arrive in Europe end up damaging trees. ‘But these are very harmful, and there are more and more (of them),’ said Dr Hervé Jactel, director of research for forest entomology and biodiversity at the French National Research Institute for Agriculture, Food and Environment

On average, six new species of tree pests are being introduced to Europe every year, up from two a year in the 1950s, says Dr Jactel. They arrive in potted plants and wooden products or packaging.

Many of the emerging threats to Europe’s forests originate in Asia.

The emerald ash borer, for example, spread from Asia to the United States where it killed more than 150 million trees and may have cost more than $10 billion in the last decade. It is now knocking at Europe’s door.

‘We know it will kill all ash trees, or most of them,’ said Dr Jactel, who is the coordinator of the HOMED project which is developing new ways to detect such exotic pests early.

The polyphagous shot-hole borer is another major threat. It can attack virtually all deciduous tree species in Europe, says Dr Jactel.

‘It’s a very, very dangerous tiny beetle,’ he said. ‘This is probably the next big issue for Europe.’

This little insect originated in Asia, spread to Israel, California, and then South Africa where it has killed hundreds of thousands of trees. In April this year it was discovered for the first time in Italy, in a tropical garden. There is no sign yet that it has spread anywhere else in Europe.

Despite all of the countries affected by the beetle being on the alert for it, none were able to detect it until it had already caused damage, says Dr Jactel. The problem is spotting exotic pests and pathogens before they start attacking trees.

Hundreds of thousands of containers filled with goods arrive in Europe’s harbours and airports every day. Tiny insects or spores from fungal diseases can stow away in shipments containing wooden products, pallets or packaging, or live plants. The sheer number of shipments is overwhelming the resources of sanitary inspectors to detect insects and spores, says Dr Jactel.

‘It’s like finding a needle in a haystack.’


Once the containers are opened, pests can then easily escape to nearby trees. So increasing surveillance of trees growing around ports and airports is a good starting point, says Dr Jactel.

Finding solutions to these pests is vital. Forests cover 43% of the EU’s land area – 182 million hectares in total – and growing. The forestry sector accounts for approximately 1% of EU GDP, and provides jobs for some 2.6 million people. If allowed to run rampant – without the natural predators found in their native habitats and among trees that have not evolved defences against them – the pests could be devastating.

But new tools are also needed to alert inspectors to the presence of pests in containers before they can escape, he adds.

The HOMED team are developing generic traps to attract a wide variety of insects. These will be placed in shipping containers before they set off from their country of origin, and in airports, harbours and train stations where the imports arrive.

The teams are also developing traps for fungal spores, and DNA tools and databases of species to help identify whether a spore is local or imported.

The project is also planting ‘sentinel’ European trees in Asia, North America and elsewhere that can help scientists identify early which pests might pose a particular threat to European trees.

For pests that have already taken hold in Europe, one possible solution is to import that pest’s natural enemies from its country of origin, says Dr Jactel.

Scientists in France and Switzerland are investigating whether the natural enemies of the destructive box tree moth – which has spread from China across Europe –  can be imported and used to contain it. But releasing this parasitic wasp to target the moths might bring other problems.

‘We need to be very cautious to check the Chinese parasitoids won’t affect European species,’ said Dr Jactel.

Native pests

Many threats to Europe’s forests, however, are closer to home. A warming climate in many regions is helping some native pests to become more common.

The bark beetle is one of the most damaging pests currently attacking Europe’s forests, destroying spruce trees in Central Europe.

The Czech Republic has had to cull so many infected trees in recent years the price of wood has plummeted as the resulting timber has been sold off, says Dr Julia Yagüe, project manager of My Sustainable Forest (MSF), which monitors the health of Europe’s forests. Spruce trees take up to 140 years to fully grow, so the loss of so many trees will be felt for a long time.

This is largely because warming temperatures have allowed the beetles to breed more frequently.

‘Some 20 years ago, we’d have one breeding cycle per summer, but nowadays we have up to four breeding cycles of bark beetle in the Czech Republic and southern Germany,’ said Dr Yagüe.

Warmer, longer and drier summers also mean trees are more vulnerable to attack because the conditions leave them less able to cope with pests, she says.

Scientists are creating variations of native spruce trees, which they hope will be more resistant to higher temperatures and drought, and so better able to fight off attacks from pests.

But in the meantime, forests urgently need closer monitoring, says Dr Yagüe. Forest managers usually take an inventory once every five to ten years. 

‘Because climate change is pressuring so hard, we need to update our data on forests much more often,’ she said.

The most efficient way to monitor large forests is with satellite observations, which can help detect the early warning signs of trees that are under water or heat stress, and so are more susceptible to attack.

They can also allow forest managers to spot the first signs of an infestation, such as dryness, loss of foliage, or dieback.

‘With remote sensing from satellites we can spot this sickness before even the human eye can detect it,’ said Dr Yagüe, who is a remote sensing expert at the Spanish aerospace company GMV.

MSF’s job of gathering data became easier with the launch of Europe’s Copernicus satellites in 2014, and the development of technology able to process huge amounts of information.

MSF now receives snapshots of Europe’s forests every five days instead of every 15 to 30 days before Copernicus. ‘We get this information for free,’ said Dr Yagüe.

But there is another crucial element to improving the health of Europe’s forests which is much closer to home.  

Many of Europe’s forests have been abandoned. While they were once carefully managed landscapes, as people moved to cities, ‘the knowledge of living together with nature has been lost’, said Dr Yagüe. ‘Recovering this is super important.’

The research in this article was funded by the EU.

Article source: Horizon Magazine

Author: Alex Whiting

Image: The emerald ash borer has killed more than 150 million trees in the US in the last decade and is a potential threat to Europe’s forests. Credit: Pikist, public domain

Scientists Reconstruct Spring Hydroclimate on South-central Tibetan Plateau by Living and Dead Alpine Juniper Shrubs

By | Climate change, Forestry, News, Plant Science

Alpine regions on the Tibetan Plateau are sensitive to climate change, however, little is known about their long-term hydroclimate variability due to short instrumental records. A research team established a 537-year standard shrub-ring chronology by cross-dating living and dead Wilson juniper shrubs sampled nearby the Nam Co Lake, on the south-central Tibetan Plateau.

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