Acaena exigua NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.

ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.

FWS Digital Media Library -- The U.S.<a href="https://www.earth.com/news/ocean-surface-slicks-create-superhighway-for-fish/"> Fish</a> and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video. Acaena exigua is an extinct species of flowering plant in the rose family known by the common name liliwai. It was endemic to Hawaii, where it was known from Kauaʻi and west Maui. It had not been seen or collected since 1957 and was feared extinct until 1997, when one plant was discovered in a remote montane bog on <a href="https://www.bing.com/search?q=maui&amp;cvid=11f593b142284a109c4b71b63cd85874&amp;FORM=ANAB01&amp;PC=HCTS">Maui</a>. The plant died in 2000, and the species is now considered extinct.Acaena exigua A. Gray var. subtusstrigulosa Bitter: Classification. Click on a scientific name below to expand it in the PLANTS Classification Report. Rank Scientific Name and Common Name; Kingdom: Plantae – Plants Subkingdom: Tracheobionta

Acaena exigua

Acaena exigua NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation...

Zanthoxylum hawaiiense NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and <a href="https://www.earth.com/image/the-fall-rhapsody-in-ottawa/">Canada.</a> NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.Competition from alien plants; habitat destruction by cattle, goats, and sheep; limited numbers. Zanthoxylum hawaiiense (a'e) is a thornless tree usually 10-26 ft (3-7.9 m) tall with a trunk up to 10 in (25.4 cm) in diameter.

ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of <a href="https://www.bing.com/search?q=north+america&amp;cvid=e0fcbab5d0f1438ba258565e3a86d394&amp;aqs=edge.0.69i59j69i57j0l5.1719j0j9&amp;FORM=ANAB01&amp;PC=HCTS">North America</a> and the world.

FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.Zanthoxylum hawaiiense, commonly known aʻe or Hawaiʻi pricklyash, is a species of flowering plant in the family Rutaceae, that is endemic to Hawaii. It can be found at elevations of 550–1,740 m in dry forests, where it grows on lava flows, and mixed mesic forests on the Island of Hawaiʻi, Maui, Molokaʻi, and Lānaʻi. It is threatened by habitat loss.

Zanthoxylum hawaiiense

Zanthoxylum hawaiiense NatureServe Explorer Species Reports -- NatureServe Explorer is...

Zanthoxylum oahuense NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and <a href="https://www.earth.com/image/mistastin-lake-in-labrador-canada/">Canada</a>. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.

ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of <a href="https://www.bing.com/search?q=north+america&amp;cvid=84f1e8e9658b4caea7e69e7c7dff2555&amp;aqs=edge.0.69i59j69i57j69i59j0j69i60l3.1774j0j9&amp;FORM=ANAB01&amp;PC=HCTS">North America</a> and the world. North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be described as the northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. Because it is on the North American Tectonic Plate, Greenland is included as part of North America geographically. North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), about 16.5% of the Earth's land area and about 4.8% of its total surface. North America is the third-largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 579 million people in 23 independent states, or about 7.5% of the world's population

FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.

Zanthoxylum oahuense

Zanthoxylum oahuense NatureServe Explorer Species Reports -- NatureServe Explorer is...

NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.

Zanthoxylum thomasianum

NatureServe Explorer Species Reports -- NatureServe Explorer is a source...

Zizania texana NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and <a href="https://www.earth.com/image/lake-st-clair-of-the-u-s-and-canada/">Canada.</a> NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.

ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.

FWS Digital Media Library -- The U.S. <a href="https://www.bing.com/search?q=fish&amp;cvid=91f938cbd77c449aa5aeecec4dfa9db9&amp;aqs=edge.0.69i59j0l6.773j0j1&amp;pglt=43&amp;FORM=ANNTA1&amp;PC=HCTS">Fish</a> and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video. Zizania texana is a rare species of grass known by the common name Texas wild rice.

It is endemic to Texas, where it is found only on the upper San Marcos River in Hays County. It is threatened by the loss and degradation of its habitat. It is a federally listed endangered species of the United States. Texas wildrice Subordinate Taxa. This plant has no children Legal Status. Threatened and Endangered Information: This plant is listed by the U.S. federal government or a state. Common names are from state and federal lists. Click on a place name to get a complete protected plant list for that location.a rare and endangered species of aquatic grass, exists in the spring-fed headwaters of the San Marcos River within the city limits of San Marcos, Hays County, Texas. This unique plant is endemic to Texas and occurs, in the United States, naturally only in this location.

Zizania texana

Zizania texana NatureServe Explorer Species Reports -- NatureServe Explorer is...

Seasonal changes in leaf cover have a big impact on the local climate in forested <a href="https://www.earth.com/news/are-animals-bigger-on-the-rainy-side-of-the-mountain/">mountain</a> regions, according to a new study from the <a href="https://www.tsukuba.ac.jp/en/">University of Tsukuba</a>.



"Nocturnal temperature inversion (NTI) is an important factor characterizing the local climate in mountainous areas. In central Japan, most of the mountain slopes are covered by forests, but the effects of their leaf expansion/fall on the NTI variations in basins have not been clarified," wrote the study authors.&nbsp;



Since the forest canopy shields the forest floor from sunlight and reduces temperature variations throughout the day, the effects may also alter the surrounding climate at night.



"However, previous studies have not fully considered the contribution of mountain forests to the nocturnal local climate in downstream areas," said study senior author Professor Kenichi Ueno. "This is what we set out to investigate."



In particular, the researchers wanted to examine how leaf expansion may influence nocturnal temperature inversion (NTI) in mountain basins. Leaf expansion refers to the stage in deciduous plants when leaves expand from buds to mature leaves.



The researchers conducted a three-year study of leaf area index (LAI) on a forested mountain slope site in a small basin. The team observed sudden shifts in the development of the nighttime cold-air pool over the basin that were related to leaf expansion and leaf fall.&nbsp;



"Our results indicated that changeability in daytime forest heat storage can offset nighttime radiative cooling from the forest canopy," explained Professor Ueno. "In short, our research has revealed that the cycle of tree leaf growth and leaf shedding in mountain forests has an observable effect on the local climate."



"The estimated timings of leaf expansion/fall at the catchment scale based on the effective cumulative temperature almost coincided with the NTI changes," wrote the researchers. "Micrometeorology observations showed that NTI at the forest floor and downslope winds at the adjacent grassland strengthened during the dormant (leafless) season in the nighttime when the radiative cooling is strong."



The study is published in the <a href="https://www.jstage.jst.go.jp/browse/jmsj">Journal of the Meteorological Society of Japan</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Leaf cover affects the climate in mountain forests

Seasonal changes in leaf cover have a big impact on...

During war, factories often retool to support the needs of the combatants. For instance, assembly lines change course from producing car parts to machine guns, or from building washing machines to aircraft engines. According to a new study led by <a href="https://duke.edu/">Duke University</a>, <a href="https://www.earth.com/news/plants-have-a-memory-of-drought/">plants</a> are capable of shifting from peacetime to wartime production too.



Plants are frequently under attack from viruses, bacteria, and other pathogens. Each year, over 15 percent of crop yields are lost to bacterial and fungal diseases, costing the global economy about $220 billion. However, when a plant senses an imminent microbial invasion, it makes radical changes in the composition of its proteins to help them fight the invaders.



Since, unlike animals, plants do not have specialized immune cells which can travel through the bloodstream to the site of the infection, each plant cell needs to be able to stand and fight for itself, quickly shifting into battle mode. When microorganism attack, cell plants rapidly change their priorities from growth to defense, by starting to synthesize new proteins while suppressing the production of others.



To build a new protein, genetic instructions in the DNA packed inside a cell’s nucleus are translated into mRNA, which then travels to the cytoplasm, where ribosomes “read” the message and translate it into a protein. The scientists found that, when plants are infected, certain mRNA molecules are translated into proteins faster than others. These proteins have in common a region at the front end of the RNA strand with recurring letters in its genetic code, where the nucleotide bases adenine and guanine repeat themselves. This region works with other structures within the cell to activate “wartime” protein production.



Thus, when plants detect a pathogen attack, the molecular signposts responsible for signaling the usual starting point for ribosomes to land on and read the mRNA are removed, stopping the cells from making their typical “peacetime” proteins, and use instead the region of recuring adenine and guanine nucleotides for docking. “They basically take a shortcut,” explained study senior author Xinnian Dong, a distinguished professor of Biology at Duke.



These processes turn fighting infection into a balancing act for plants. When they allocate more resources for defense, less will be available for photosynthesis and other activities, which can often lead to collateral damage, causing plants with over-active immune systems to suffer stunted growth.



Further research is needed to clarify how plants strike this delicate balance in order for scientists to find new ways to engineer disease-resistant crops without compromising yields.&nbsp;



The study is published in the journal <a href="http://dx.doi.org/10.1016/j.cell.2022.06.037">Cell</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Plants reprogram their cells to fight pathogens

During war, factories often retool to support the needs of...

Lightning may influence the composition of tropical forests, according to a new study led by Steve Yanoviak of the <a href="https://stri.si.edu/">Smithsonian Tropical Research Institute</a>. The results of the study suggest that the tropical trees which are most likely to be struck are also the most resilient to <a href="https://www.earth.com/news/lightning-strikes-set-to-increase-by-100-percent-in-the-arctic/">lightning</a> strikes.&nbsp;



Over the course of several years, a team of lightning scientists and tropical field biologists analyzed the effects of lightning strikes on the Panama Canal forests of the Barro Colorado Nature Monument.



The researchers estimate that lightning strikes tropical trees millions of times a year. Considering that lightning is expected to become more frequent in the coming years, the experts set out to investigate how susceptibility to lightning may vary across tree species.



The study revealed that some types of trees were more resilient to lightning strikes than others. For example, palm trees were the most likely to die from lightning damage. Interestingly, the trees that were struck the most often were also the most likely to recover.&nbsp;



“The tree species that were most frequently damaged by lightning tended to be the same species that were most capable of surviving lightning strikes,” said study co-author Evan Gora. “This suggests that lightning is an important selective force with implications for the ecology and evolution of tropical forests.”



According to the researchers, the most lightning-resistant tree species had a few things in common including denser wood, larger vessels for transporting water, and leaves that were richer in nitrogen.



“Trees with denser wood tend to live longer and store more carbon, so finding this trait correlated with lightning tolerance implies an interesting compensatory mechanism where greater lightning frequency could actually favor species that are better at storing carbon,” explained study co-author Jeannine Richards.



The fact that tree species with a greater capacity for removing carbon dioxide from the atmosphere also seem to more capable of surviving lightning damage comes as a welcome discovery as greenhouse gas emissions continue to rise.&nbsp;



“The results of this study are especially interesting because they suggest that changes in lightning strike frequency can influence the composition of tropical forests over the long term,” said Yanoviak.



The study is published in the journal <a href="https://www.nature.com/nplants/">Nature Plants</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

In tropical forests, lightning strikes the most resilient trees

Lightning may influence the composition of tropical forests, according to...

Thousands of <a href="https://www.earth.com/news/plants-use-their-roots-to-sense-manganese-deficiency/">plants</a> and animals are classified as being "data deficient" by the International Union for Conservation of Nature (IUCN). Data deficiency means that there is not adequate information to assess the extinction risk of these species. Now, a new study has revealed that more than half of all lesser-known species may be threatened with extinction.



“We looked at species that are relatively poorly known, but where at least the geographical distribution is known. These species tend to be threatened with extinction more often than ones that we know more about,” explained study co-author Professor Francesca Verones from the <a href="https://www.ntnu.edu/">Norwegian University of Science and Technology</a> (NTNU).



Overall, the IUCN has listed 20,469 species as being data deficient. The research team used machine learning to calculate the risk of extinction for 7,699 of the little-known species, explained study co-author Jan Borgelt.



Compared with individual cases that the researchers analyzed manually, the computer model-created probabilities were extremely accurate.



“We found that as many as 85 percent of the amphibians that we have limited knowledge of are in danger of becoming extinct. For other groups, like mammals and reptiles, this applies to around half of the species,” said Borgelt.



Even though species unknown to us often face an uphill battle, the consolation is that new knowledge can be of great use if used correctly, said Borgelt. “More areas could become worthy of protective measures if we take species that we have little data on into account."



Borgelt also emphasized that the intention behind using the models is not to replace the work conducted by researchers, but to provide a first estimate of the risk of species becoming extinct in cases where there is not yet enough data.



"The Red List assesses extinction risks and reports Red List categorization for more than 140,000 species based on a set of quantitative criteria10 relying for instance on extent of occurrence, area of occupancy, population trends, or population size," explained the study authors.&nbsp;



"However, the sheer amount of known and unknown species globally, the dynamic nature of threats and trends, and limited human resources for undertaking such Red List assessments turn this critical endeavour into a Sisyphean task."



"Consequently, only a small proportion of known species have been assessed for their conservation priority so far, unevenly distributed across space, time and taxa."



The study is published in the journal <a href="http://dx.doi.org/10.1038/s42003-022-03638-9">Communications Biology</a>.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Data deficient species are often the most threatened

Thousands of plants and animals are classified as being "data...

A new project led by <a href="https://www.staffs.ac.uk/">Staffordshire University</a> and funded by <a href="https://research-and-innovation.ec.europa.eu/funding/funding-opportunities/funding-programmes-and-open-calls/horizon-europe_en">Horizon Europe</a> aims to contribute forensic intelligence to help protecting endangered species such as wolf, bear, lynx, or sturgeon from remote parts of Europe. Over the next three years, the NATURE FIRST project will bring together 12 global partners to safeguard <a href="https://www.earth.com/news/global-biodiversity-crisis-is-actually-worse-than-we-thought/">biodiversity</a> and protect the habitats of many animal species that are currently threatened by human activities, by developing proactive and preventive capabilities for nature conservation and law enforcement through a combination of forensic intelligence and remote sensing technologies.



Spanning Romania, Ukraine, Bulgaria, Serbia and Spain, this project will focus on regions such as the Carpathian Mountains, the Danube Delta, the Stara Planina Mountains, the Os Ancares and the O Courel, by drawing upon real-time data from satellites, drones, cameras, and other technological devices to closely monitor these locations.



“The overall aim is to halt and reverse the decline of biodiversity in Europe. We want to improve natural habitats where certain species are an incredibly important part of the ecosystem. To achieve this, we need a better understanding of why and where biodiversity is declining and what the key triggers are,” explained Claire Gwinnett, a professor of Forensic and Environmental Science at Staffordshire.



“As most of the threats and pressures on biodiversity are man-induced, this project will combine ecology and forensic science. This novel approach will use remote sensing technologies, machine learning and wildlife forensic methods to detect and recognize traces of human activities that negatively affect the environment.”



The regions that the scientists will investigate cover vast land masses that can’t be easily monitored from the ground. Thus, the use of advanced technologies to detect biodiversity threats - such as poaching of flora and fauna, trafficking and trading of rare animals and plants, or setting fires to forests and other natural areas for agricultural and commercial purposes – is essential for preserving biodiversity.



“The aim of the EU Biodiversity Strategy for 2030 is to ensure that ecosystems are healthy, resilient to climate change and rich in biodiversity so that they can keep delivering the range of services essential to the prosperity and well-being of all of us. We are excited to be taking positive steps to help achieve this by working with such a fantastic group of global partners,” Gwinnett concluded.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Forensics could be used to safeguard biodiversity

A new project led by Staffordshire University and funded by...

As we face the consequences of climate change there is renewed impetus to restore <a href="https://www.earth.com/news/forests-in-protected-indigenous-lands-are-healthy-and-resilient/">forests</a> so that they can once again provide ecosystem services, such as protecting species, sequestering carbon and securing livelihoods. But planting trees in areas that have been disturbed or denuded is costly, as is the maintenance of the new saplings after planting. This makes it especially important to understand the best conditions for successful reforestation.&nbsp;



A new study by a large international team of scientists has reviewed the success of reforesting programs at 176 sites in tropical and sub-tropical Asia. The researchers scoured the literature for published records of tree survival and growth data in areas where forest restoration has been attempted. They synthesized the evidence of forest recovery and the efficacy of tree planting as an intervention for ecosystem restoration.&nbsp;



In particular, the researchers used data on planted tree survival, planted tree size and/or growth, and area-based metrics of forest structure and diversity in planted and unplanted adjacent plots. They also collected data on other variables, such as location, duration of monitoring, disturbance history, site condition prior to planting, restoration methods, diversity of trees planted, planting density, and height of trees at planting. This was to identify the factors most closely correlated with the success of the replanting initiatives.&nbsp;



Overall, the researchers compiled data from 221,199 planted trees at sites across South and Southeast Asia. Of these trees, 207&nbsp;224 were monitored in terms of survival, while data on growth was collected for 102&nbsp;412 trees. In total, 625 tree species (252 genera; 81 families) were planted but species richness of plantings at individual sites was typically low (median of only three species planted per site). Although the maximum study duration was 33 years, only 49 (28 percent) sites conducted surveys at 5 years or more after planting, and the median study length was only two years.



The results of their analysis, published in the&nbsp;<a href="http://dx.doi.org/10.1098/rstb.2021.0090">Philosophical Transactions of the Royal Society B: Biological Sciences</a>, make for sobering reading. They found that, on average, 18 percent of planted saplings died within the first year, and that this mortality rose to 44 percent after five years. However, survival rates varied greatly between sites and species, with some sites seeing over 80 percent of trees still alive after five years, while at others a similar percentage had died.



Policy makers are aware that forest restoration is a powerful tool to tackle biodiversity loss and climate change, as growing trees lock away carbon and support important habitats. Reforestation projects are also used widely for carbon offsetting. While the main measurement used to gauge success is often the number of trees initially planted, this research shows that many of these trees are not surviving long-term. In addition, the ultimate goal of restoration is the structural and compositional recovery of the whole plant community and broader ecosystem, and monitoring often ceases before this can be assessed fully.&nbsp;



The analysis was not able to identify exactly what was responsible for different success rates at the various sites. Tree survival was not significantly correlated with climatic variables, soil type, species planted, or planting densities, but was highly dependent on the particular site of the reforestation project. This indicates that there are environmental, methodological and social factors that operate and affect whole sites, making restoration outcomes context specific.&nbsp;



“The large variability in survival we found across sites could be for a number of reasons, including planting densities, the choice of species, the site conditions, extreme weather events or differences in management and maintenance. Local socio-economic factors may also be important," said Dr Lindsay Banin, co-lead author based at the <a href="https://www.ceh.ac.uk/">U.K. Centre for Ecology and Hydrology</a>.



“What’s clear is that success is very site-dependent – we need to understand what works and why, and share that information, so we can bring all sites up to the level of the most successful and harness the full potential for restoration. There’s likely no one-size-fits-all approach and restoration action should be tailored to local conditions. This will help ensure the scarce resources and land available to restoration are used to best effect,” she added.



The researchers found that planting taller saplings did give better survival rates, and that reforestation efforts were more successful in areas where some established trees remained than in areas that had been fully deforested. Saplings planted in areas with existing mature trees had roughly a 20 percent higher chance of survival. Furthermore, there was evidence that active restoration provides faster results than simply letting nature take its course. Sites that included tree planting activities gained forest cover more quickly than sites that were left to regenerate naturally.



“The sites where active restoration is most needed – those that have already been cleared of trees – are also those where restoration is most risky and prone to higher numbers of trees dying," said study co-author Professor David Burslem. "We need to understand better how to improve the survival chances of saplings on these sites, to ensure restoration has positive outcomes. But the study also provides a warning, to protect our remaining forests as much as possible, both because restoration outcomes are uncertain and to provide the diverse seed sources needed for restoration activities.”



“Replanting is only going to be an answer to excess carbon dioxide in the atmosphere if we can guarantee that carbon is being successfully drawn out of the atmosphere and locked away – and be able to quantify the amounts and timescales involved," said study co-author Professor Robin Chazdon. "This is why assessing restoration outcomes over the long-term, and gathering information that helps to maximize success rates, are so important. We need the focus to shift away from simply planting trees toward growing them and helping our forests thrive.”



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer



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Half of plants used in reforestation projects do not survive

As we face the consequences of climate change there is...

Invasive plant species can have devastating effects on local ecosystems, comparable to those wrought by climate change. However, scientists do not yet know how many of such <a href="https://www.earth.com/news/managing-invasive-species-can-improve-climate-resilience/">invasive species</a> there are in the world. A new study led by the <a href="https://www.umass.edu/">University of Massachusetts Amherst</a> is the first to comprehensively pinpoint the various unknowns which should be addressed in order to effectively manage invasive plant species around the globe.



According to the experts, the most cost-effective method of stopping invasive species is to put a halt on their introduction. However, in order for this to happen, managers need to know exactly which plants are invasive. While lists of invasive plants worldwide include species reported by scientists, currently unreported species still pose a significant risk.&nbsp;



“Trade and climate change have facilitated the widespread movement of species around the globe,” said&nbsp;study lead author Brittany Laginhas, a doctoral student in Geospatial Analytics at the <a href="https://www.ncsu.edu/">North Carolina State University</a> who completed this research during her graduate studies at UMass Amherst. “In some cases, these species will establish and spread in their new environment, causing devastating ecological and economic damages. Basic information on invasive species, including which species are invasive, where they have invaded, and their timing of invasion, is critical for developing strategies to prevent their spread and subsequent damages.”



Together with her colleagues, Laginhas mined a database of 5,893 studies dating back to 1959 that reported 3,008 invasive species. However, statistical modelling suggests that there should be in fact 4,721 species, although the identity of the remaining 1,713 remains a mystery.



According to the researchers, so many invasive species are currently missing from scientific accounts mostly due to a systemic and geographically uneven undercount. For instance, while North America has been relatively well studied, Central and South America and Oceania have not been given similar attention. “There are vast differences in the studies conducted across different continents,” said study co-author Matthew Fertakos, a graduate student in Organismic and Evolutionary Biology at UMass Amherst. “We have statistical methods that can help tell us how many species there&nbsp;should&nbsp;be, but real data is always better than an estimation.”



Unfortunately, a comprehensive map of the world’s invasive species cannot be generated in the laboratory alone. “We need floristic surveys, where researchers actually go out into the field, especially in the places that have been understudied, like Africa, Southeast Asia, and South America, and identify the exact species causing problems,” concluded senior author Bethany Bradley, a professor of Environmental Conservation at the same university.



The study is published in the journal <a href="http://dx.doi.org/10.1002/eap.2776">Ecological Applications</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

How many invasive plant species are in the world?

Invasive plant species can have devastating effects on local ecosystems,...

The Devonian Period that occurred between 419 and 358 million years ago, prior to the evolution of terrestrial life, is well-known for mass extinction events during which an estimated 70 percent of life on Earth was decimated. Now, a team of scientists from <a href="https://www.iupui.edu/">Indiana University Purdue University-Indianapolis</a> has argued that the evolution of tree <a href="https://www.earth.com/news/deeper-plant-roots-could-boost-soil-carbon-storage/">roots</a> may have triggered this series of catastrophic extinctions which rocked the Earth’s oceans during this period.



“Our analysis shows that the evolution of tree roots likely flooded past oceans with excess nutrients, causing massive algae growth,” said study co-author Gabriel Filippelli, a biogeochemist at IU. “These rapid and destructive algae blooms would have depleted most of the oceans’ oxygen, triggering catastrophic mass extinction events.”



The process described by the scientists – known as “eutrophication” – is remarkably similar to the modern, albeit smaller-scale phenomena currently fueling “dead zones” in the Great Lakes and the Gulf of Mexico, as excess nutrients from fertilizers and other agricultural runoff trigger massive algal blooms which consume most of the water’s oxygen. However, the past events were likely caused by tree roots instead, which pulled large amounts of nutrients during times of growth, and abruptly dumped them into water during times of decay.



By chemically analyzing stone deposits from ancient lake beds, the scientists confirmed previously identified cycles of higher and lower amounts of phosphorous (a chemical element found in all life on Earth), as well as wet and dry cycles based upon signs of “weathering” - or soil formation - caused by root growth, with greater weathering indicating wet cycles with more roots and less weathering dry ones with fewer roots. Most importantly, the researchers found that the dry cycles coincided with higher levels of phosphorous, suggesting that dying tree roots released their nutrients into the Earth’s waters during those periods. Thus, the decay of tree roots seems to be the main suspect behind the Devonian mass extinctions.



Fortunately, modern trees don’t cause similar destruction, since nature has evolved better mechanisms to balance out the impact of rotting wood, and the depth of contemporary soils can retain more nutrients than the thin layer of dirt which covered ancient Earth. However, current pollution from fertilizers, manure, and other organic waste, has now placed the Earth’s oceans once more on the edge of anoxia – a complete lack of oxygen that could have disastrous consequences for marine life.



“These new insights into the catastrophic results of natural events in the ancient world may serve as a warning about the consequences of similar conditions arising from human activity today,” Fillipelli concluded.&nbsp;&nbsp;



The study is published in the journal <a href="http://dx.doi.org/10.1130/GSAB.S.XXXX">Geological Society of America Bulletin</a>.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Tree roots may have driven mass extinctions

The Devonian Period that occurred between 419 and 358 million...

<a href="https://www.earth.com/news/genetic-research-tomatoes-production/">Tomatoes</a> account for 22 percent of vegetables intake in Western diets. Previous research has linked consumption of tomatoes with reduced risk of developing various health conditions, such as cardiovascular diseases and certain cancers. However, tomatoes’ impact on the gut microbiome – the community of microorganisms living in the intestinal tract – has not yet been assessed.&nbsp;



Now, a research group led by the <a href="https://www.osu.edu/">Ohio State University</a> (OSU) has found that two weeks of eating a diet heavy in tomatoes increased the diversity of gut microbes and altered gut bacteria toward a more favorable profile in young pigs. These findings could be tested in humans too, in order to identify health-related links between tomato consumption and changes to the human gut microbiome.



“It’s possible that tomatoes impart benefits through their modulation of the gut microbiome,”&nbsp;said study senior author Jessica Cooperstone, an assistant professor of Horticulture and Crop Science at OSU. “Overall dietary patterns have been associated with differences in microbiome composition, but food-specific effects haven’t been studied very much. Ultimately, we’d like to identify in humans what the role is of these particular microorganisms and how they might be contributing to potential health outcomes.”



The scientists fed ten recently weaned piglets with a standard diet, and other ten with the standard diet fine-tuned so that ten percent of the food consisted of a freeze-dried tomato powder - with the amount of fiber, sugar, protein, fat, and calories identical in both diets.&nbsp;



The control and study pig populations were kept separately, and the researchers minimized the time spent with the pigs in order to ensure that any microbiome changes could be attributed solely to the chemical compounds in the tomatoes. Microbial communities were collected from fecal samples both before the study and seven and 14 days after the diet was introduced.



By using a method called “shotgun metagenomics,” the scientists sequenced all microbial DNA from the samples. The analysis revealed two main changes in the microbiomes of pigs fed the tomato-heavy diet: the diversity of microbes in their guts increased, and the concentration of two types of bacteria common in the mammal microbiome shifted to a more favorable profile. More specifically, the higher ratio of the phyla Bacteroidota compared to Bacillota has been found to be linked with more positive health outcomes.



“This was our first investigation as to how tomato consumption might affect the microbiome, and we’ve characterized which microbes are present, and how their relative abundance has changed with this tomato intervention,” Cooperstone said.



“To really understand the mechanisms, we need to do more of this kind of work in the long term in humans. We also want to understand the complex interplay – how does consuming these foods change the composition of what microbes are present, and functionally, what does that do? A better understanding could lead to more evidence-based dietary recommendations for long-term health,” she concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1128/spectrum.02506-22">Microbiology Spectrum</a>.



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.



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By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Tomatoes improve the health of the gut microbiome

Tomatoes account for 22 percent of vegetables intake in Western...

Plants reduce their pollen development under mild heat conditions in anticipation of potential <a href="https://www.earth.com/news/human-activities-are-fueling-more-extreme-heatwaves/">heatwaves</a>, according to a new thesis paper by Stuart Jansma, a PhD candidate at Radboud University. This response to warm weather can have a negative impact on fruit and seed production, and may have serious consequences as heatwaves become more common due to climate change.&nbsp;



Heat can damage pollen, prevent fertilization, and ultimately halt the production of fruits and seeds. While previous studies focused on heat shock by exposing plants to extreme heat for several hours at a time, Jansma wanted to study the effect of mild heat on a longer timescale.



For a few days, tomato plants were placed in an environment of 30°C to 34°C, which is six degrees higher than the ideal temperature for a tomato plant. Jansma studied how the plants responded on a molecular level. The results showed that mild heat triggers a different response in plants than heat shock.



“Plants react slightly less strongly when exposed to mild temperatures. The interesting thing is that this reaction to mild heat is not really necessary for the plant’s survival. You could say that the plant is ‘overreacting’; it’s anticipating a scenario with even hotter days to follow,” explained Jansma.



The experiment revealed that longer periods of mild heat affected the production of plant hormones, the conversion of sugars, and the folding of proteins. The combination of these changes led to reduced pollen development.&nbsp;



“The plant no longer focuses on reproduction, but arms itself against external stress factors," explained Jansma. “In principle, you don’t need that much pollen to fertilise a plant, but when the percentage of living pollen is low, the dead pollen block access to the pistil, thus preventing fertilization.”



“Every day that a plant ‘expects’ the warm weather to last for another week, it won’t produce any fruit. With climate change, warm days are growing in number, which only exacerbates the problem. To counter this effect, we could switch off the plants’ active reaction using genetic modification. However, this would require adjusting current European legislation.”



Jansma will present his PhD thesis at Radboud University on September 15.



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Plants overreact to warmer weather and stop producing fruit

Plants reduce their pollen development under mild heat conditions in...

Mountain landscapes across the world are threatened by <a href="https://www.earth.com/news/beaver-dams-mitigate-the-effects-of-climate-change-on-rivers/">climate</a> change. The evolution of these landscapes could lead to hazards and environmental risks affecting nearby communities.



On the eve of COP27, a scientist from the <a href="https://www.wits.ac.za/">University of the Witwatersrand</a> in Johannesburg highlights the sensitivity of mountains to global climate change in a <a href="https://peerj.com/articles/14253/">new study</a>. Professor Jasper Knight describes how complex mountain systems respond in different and unexpected ways to climate change. The study also reveals how these responses can affect mountain landscapes and communities.&nbsp;



Mountain glaciers across the world are retreating due to global warming, impacting mountain landforms and the ecosystems and people that rely on them. These impacts, however, are highly variable.&nbsp;



“The latest report by the Intergovernmental Panel on Climate Change (IPCC) treats all mountains as equally sensitive and responding in the same way to climate change. However, this approach is not correct,” said Professor Knight. “Mountains with snow and ice work completely differently to low-latitude mountains where snow and ice are generally absent. This determines how they respond to climate and what future patterns of mountain landscape evolution we can expect.”&nbsp;



Globally, mountain snow and ice provide water for hundreds of millions of people. This water supply is now under threat as changing weather patterns cause glaciers to get smaller. This is expected to get worse into the future, leading to a water crisis in dry continental areas of Asia, North America, South America and Europe.



The potential impacts of climate change and human activity on mountain landscapes include an increasing risk of hazards such as avalanches, river floods and landslides. These risks are further elevated by glacier retreat and the warming of permafrost.



Mountain slopes are also becoming greener as lowland forests spread to higher altitudes. This has already threatened Alpine ecosystems and species with local extinction.&nbsp;



“As snow and ice shrink, mountain land surfaces are getting darker and this dramatically changes their heat balance, meaning they are warming up faster than the areas around them. Therefore, climate change impacts are bigger on mountains than they are anywhere else. This is a real problem, not just for mountains but also for the areas around them,” said Professor Knight.&nbsp;



 Indigenous mountain communities and cultures are also affected by climate change. Livestock and traditional agriculture are dying out as grazing areas shrink and as water becomes scarcer. These traditional practices are also impacted by tourism, mining, urbanization and commercial forestry.&nbsp;



By demonstrating the connection between mountains and people, the study highlights the importance of protecting mountains against future change. “Understanding these connections can help us better protect them against the worst impacts of climate change,” said Professor Knight.&nbsp;&nbsp;



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By <a href="mailto:katherinebucko@gmail.com">Katherine Bucko</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Mountain landscapes are being transformed by climate change

Mountain landscapes across the world are threatened by climate change....

Endangered plants