Unique plants discovered in Chinese caves


This video says about itself:

3 October 2013

A group of explorers discovered a cave in China that is so big that it has its own weather system.

From Royal Botanic Gardens Kew in England:

New research reveals plant wonderland inside China’s caves

February 7, 2018

Summary: Over five years (2009-2014) researchers have delved into the depths of some of China’s most unexplored and unknown caves in the largest ever study on cave floras. Surveying over 60 caves in the Guangxi, Guizhou and Yunnan regions, they were able to assess the vascular plant diversity of cave flora in more detail than ever before.

Exciting new data on cave flora has been published today in PLOS ONE in a paper by researchers from the Royal Botanic Gardens, Kew and the Guangxi Institute of Botany in China.

Over five years (2009-2014) the researchers delved into the depths of some of China’s most unexplored and unknown caves in the largest ever study on cave floras. Surveying over 60 caves in the Guangxi, Guizhou and Yunnan regions, Kew’s Alex Monro and his colleagues from Guangxi were able to assess the vascular plant diversity of cave flora in more detail than ever before.

From the 1950’s to the 1970’s, forests in SW China were virtually wiped out due to the demand for charcoal associated with rapid industrialisation during China’s Great Leap Forward and the Cultural Revolution. This study documents 31 species known only from caves, leading the team to speculate that cave populations are all that remain of species which once grew in the ‘understory’ (the layer of vegetation between the forest canopy and the ground), which has been wiped out by recent deforestation. This discovery makes these caves and their flora significant and valuable for species conservation in South West China.

Lead researcher Alexandre Monro, at Royal Botanic Gardens, Kew says; “This collaboration with the Guangxi institute of Botany in China is a first attempt to document the presence of vascular plants in caves in Southeast Asia. Before we started we had no idea of the diversity of plants in caves, or that so many species are known only from caves. We hope that this work will lead to a greater interest in caves amongst botanists, and also to a greater interest in plants amongst cave biologists, prompting more study of cave-rich landscapes in Southeast Asia.”

Over the course of the study, 418 species of vascular plants were recorded, with 7% of these species being endemic to caves and 37% of the species endemic to China. Once all caves have been samples in the region, the real figure is likely to be between 500 and 850 species, based on modelling conducted by this team.

The other conclusion of the study is that the twilight zones in caves can be considered distinct biomes for plants based on a combination of constant and aseasonal climate, as well as very low light. The authors document plants growing in some of the lowest light levels recorded for vascular plants, suggesting a broad range of plants can photosynthesise at much lower light levels than originally thought.

Whilst exploring the entrance caverns, the team observed that almost half of the caves sampled were impacted by tourism or agriculture, with tourism being the more frequent and impactful.

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Carboniferous-Permian plant extinction harmed amphibians, helped reptiles


This video says about itself:

30 March 2015

Dave and Palaeo After Dark’s James explore the Carboniferous forests in the ‘Carboniferous Forest Simulator‘!

This fantastic software is free for educational, museum or personal use. We really need to get our full support behind this project!

The programme, in its ‘alpha testing’ stage can be downloaded here.

Details of the development of the project can be found here.

From the University of Birmingham in England:

Rainforest collapse 307 million years ago impacted the evolution of early land vertebrates

February 7, 2018

Researchers at the University of Birmingham have discovered that the mass extinction seen in plant species caused by the onset of a drier climate 307 million years ago led to extinctions of some groups of tetrapods, the first vertebrates to live on land, but allowed others to expand across the globe. This research is published today (7th February 2018) in the journal Proceedings of the Royal Society B.

The Carboniferous and Permian periods (358 — 272 million years ago) were critical intervals in the evolution of life on land. During the Carboniferous Period North America and Europe lay in a single land mass at the equator which was covered by dense tropical rainforests. These rainforests flourished because of the warm humid climate, providing an ideal habitat for early tetrapods (vertebrates with four limbs), allowing them to diversify into a variety of species.

But towards the end of this period a major global environment change took place — just as the number of tetrapod species began to increase, the rainforests started to disappear. The climate became much drier causing the mass extinction of many species within the dominant plant groups, such as horsetails and club mosses. Despite this being a catastrophic event for plants, it has been unclear how this affected the early tetrapod community.

Previous attempts to estimate the diversity changes during this period have been hindered by the fossil record, which has not been sampled equally in different time intervals or geographic areas. To fill these gaps in the data, the Birmingham researchers compiled a new dataset from the Paleobiology Database and used advanced statistical methods to estimate diversity and biogeographic changes.

The results of the study show that tetrapod diversity decreased after the rainforest collapse and the onset of drier conditions, largely due to the reduction in suitable habitats for amphibians which needed wet environments to survive.

However they also found that after the rainforest collapse surviving tetrapod species began to disperse more freely across the globe, colonising new habitats further from the equator. Many of these survivors were early amniotes, such as early reptiles, whose generally larger size relative to early amphibians allowed them to travel longer distances, and their ability to lay eggs meant they were not confined to watery habitats.

Emma Dunne, from the University of Birmingham’s School of Geography, Earth and Environmental Sciences, said: ‘This is the most comprehensive survey ever undertaken on early tetrapod evolution, and uses many newly developed techniques for estimating diversity patterns of species from fossil records, allowing us greater insights into how early tetrapods responded to the changes in their environment.’

Dunne continued: ‘We now know that the rainiforest collapse was crucial in paving the way for amniotes, the group which ultimately gave rise to modern mammals, reptiles and birds, to become the dominant group of land vertebrates during the Permian period and beyond.’

Carnivorous plants avoiding eating pollinating insects


This video says about itself:

Venus fly trap – The Private Life of Plants – David Attenborough – BBC

9 February 2007

David Attenborough looks at how this well known carnivorous plant captures its prey.

By Sarah Zielinski, 7:00am, February 6, 2018:

Pollinators are usually safe from a Venus flytrap

Out of the hundreds of species of carnivorous plants found across the planet, none attract quite as much fascination as the Venus flytrap. The plants are native to just a small section of North Carolina and South Carolina, but these tiny plants can now be found around the world. They’re a favorite among gardeners, who grow them in homes and greenhouses.

Scientists, too, have long been intrigued by the plants and have extensively studied the famous trap. But far less is known about the flower that blooms on a stalk 15 to 35 centimeters above — including what pollinates that flower.

“The rest of the plant is so incredibly cool that most folks don’t get past looking at the active trap leaves”, says Clyde Sorenson, an entomologist at North Carolina State University in Raleigh. Plus, notes Sorenson’s NCSU colleague Elsa Youngsteadt, an insect ecologist, because flytraps are native to just a small part of North and South Carolina, field studies can be difficult. And most people who raise flytraps cut off the flowers so the plant can put more energy into making traps.

Sorenson and Youngsteadt realized that the mystery of flytrap pollination was sitting almost literally in their backyard. So they and their colleagues set out to solve it. They collected flytrap flower visitors and prey from three sites in Pender County, North Carolina, on four days in May and June 2016, being careful not to damage the plants.

“This is one of the prettiest places where you could work”, Youngsteadt says. Venus flytraps are habitat specialists, found only in certain spots of longleaf pine savannas in the Carolinas. “They need plenty of sunlight but like their feet to be wet,” says Sorenson. In May and June, the spots of savanna where the flytraps grow are “just delightful” he says. And other carnivorous plants can be found there, too, including pitcher plants and sundews.

The researchers brought their finds back to the lab for identification. They also cataloged what kind of pollen was on flower visitors, and how much.

Nearly 100 species of arthropods visited the flowers, the team reports February 5 in American Naturalist. “The diversity of visitors on those flowers was surprising”, says Youngsteadt. However, only three species — a sweat bee and two beetles — appeared to be the most important, as they were either the most frequent visitors or carriers of the most pollen.

The study also found little overlap between pollinators and prey. Only 13 species were found both in a trap and on a flower, and of the nine potential pollinators in that group, none were found in high numbers.

For a carnivorous plant, “you don’t want to eat your pollinators”, Sorenson says. Flytraps appear to be doing a good job at that.

There are three ways that a plant can keep those groups separate, the researchers note. Flowers and traps could exist at different times of the year. However, that’s not the case with Venus flytraps. The plants produce the two structures at separate times, but traps stick around and are active during plant flowering.

Another possibility is the spatial separation of the two structures. Pollinators tend to be fliers while prey were more often crawling arthropods, such as spiders and ants. This matches up with the high flowers and low traps. But the researchers would like to do some experiments that manipulate the heights of the structures to see just how much that separation matters, Youngsteadt says.

The third option is that different scents or colors produced by flowers and traps might lure in different species to each structure. That’s another area for future study, Youngsteadt says. While attraction to scent and color are well documented for traps, little is now known about those factors for the flowers.

Venus flytraps are considered vulnerable to extinction, threatened by humans, Sorenson notes. The plant’s habitat is being destroyed as the population of the Carolinas grows. What is left of the habitat is being degraded as fires are suppressed (fires help clear vegetation and keep sunlight shining on the flytraps). And people steal flytraps from the wild by the thousands.

While research into their pollinators won’t help with any of those threats, it could aid in future conservation efforts. “Anything we can do to better understand how this plant reproduces will be of use down the road,” Sorenson says.

But what really excites the scientists is that they discovered something new so close to home. “One of the most thrilling parts of all this”, Sorenson says, “is that this plant has been known to science for [so long], everyone knows it, but there’s still a whole lot of things to discover.”

Lichens, what are they?


This video says about itself:

25 January 2018

For 150 years, scientists believed lichens were defined by a symbiotic relationship between a fungus and algae. Meet the team of researchers who upended this belief in this short film by Andy Johnson, Talia Yuki Moore, Chris A. Johns, and Kate Furby.

How Alaskan bears help plants


This video about Alaska is called The Land of Giant Bears.

From Oregon State University in the USA:

Great scat! Bears — not birds — are the chief seed dispersers in Alaska

January 16, 2018

It’s a story of bears, birds and berries.

In southeastern Alaska, brown and black bears are plentiful because of salmon. Their abundance also means they are the primary seed dispersers of berry-producing shrubs, according to an Oregon State University study.

The OSU team used motion-triggered cameras to record bears, birds and small mammals eating red berries of devil’s club, and retrieved DNA in saliva left on berry stalks to identify the species and sex of the bears. Researchers found that bears, while foraging, can disperse through their scat about 200,000 devil’s club seeds per square kilometer per hour. Rodents then scatter and hoard those seeds, much like squirrels hoard acorns.

The study was published today in the journal Ecosphere.

In most ecosystems, birds generally are thought of as chief dispersers of seeds in berries, said Taal Levi, an ecologist in OSU’s College of Agricultural Sciences and co-author on the study. The researchers found that birds accounted for only a small fraction of seed dispersal.

This is the first instance of a temperate plant being primarily dispersed by mammals through their gut, and suggests that bears may influence plant composition in the Pacific Northwest.

It was well-known that bears were dispersing seeds through their scat, Levi said, but it was not known that they were dispersing more seeds than birds, or the relative contribution of brown and black bears to seed dispersal, or whether the two species bears were eating berries at different times of the year.

“Devil’s club is extremely abundant in northern southeast Alaska, so it didn’t seem plausible that birds were dispersing all this fruit”, Levi said. “Bears are essentially like farmers. By planting seeds everywhere, they promote a vegetation community that feeds them.”

The researchers found that in the study area along the Chilkat and Klehini rivers in southeastern Alaska, brown bears dispersed the most seeds, particularly before salmon became widely available. They also found that after the brown bears switched from eating berries to salmon later in the season, black bears moved in and took over the role as principal seed dispersers. Black bears are subordinate to brown bears and avoid them.

The fruit on a devil’s club stalk is clustered into a cone containing berries. The researchers observed through the camera recordings that brown bears can swallow an estimated 350 to 400 berries in a single mouthful. Birds, on the other hand, consumed on average 76 berries per plant that they visited.

“That’s pretty remarkable,” Levi said. “When birds visit these shrubs, they take a few berries and fly off. They don’t eradicate the cones like a bear.”

Laurie Harrer, Levi’s co-author, swabbed devil’s club to retrieve environmental DNA from residual saliva left by animals and birds that ate the berries. Harrer, a master’s student in OSU’s Department of Fisheries and Wildlife, analyzed the samples to determine that female brown bears ate more berries than male brown bears, female black bears ate more than male black bears and brown bears ate more than black bears.

Brown bears, also known as grizzlies, are extinct in Oregon and California and are nearly extinct in Washington.

“The indirect effect of salmon is that they support abundant bear populations that then disperse a lot of fruit”, Levi said. “We’ve lost the salmon-bear ecosystem that once dominated the Pacific Coast. That has implications for the plant community. These seed dispersal pathways through brown bears are all but eliminated. The degree to which black bears can fulfill that role is not clear.”