dieback

Nearly all US forests threatened by drought, climate change

Forests nationwide are feeling the heat from increasing drought and climate change, according to a new study by scientists from 14 research institutions.

“Over the last two decades, warming temperatures and variable precipitation have increased the severity of forest droughts across much of the continental United States,” said James S. Clark, lead author of the study and Nicholas Professor of Environmental Science at Duke University.

“While the effects have been most pronounced in the West, our analysis shows virtually all U.S. forests are now experiencing change and are vulnerable to future declines,” he said. “Given the high degree of uncertainty in our understanding of how forest species and stands adapt to rapid change, it’s going to be difficult to anticipate the type of forests that will be here in 20 to 40 years.”

Drought-induced forest diebacks, bark beetle infestations and wildfires are already occurring on large scales across the West, and many models predict droughts are likely to become more severe, frequent and prolonged across much of the United States.

There is also mounting evidence that climate is changing faster than tree populations can respond by migrating to new regions. Clark said that as conditions become drier and warmer, many tree populations, especially those in Eastern forests, may not be able to expand rapidly enough into new, more favorable habitats through seed dispersal or other natural means.

Clark and his colleagues published their paper today (Feb. 22, 2016) in the Early View online edition of the peer-reviewed journal Global Change Biology.

“The Impacts of Increasing Drought on Forest Dynamics, Structure, and Biodiversity in the United States,” James S. Clark, Louis Iverson, Christopher W. Woodall, Craig D. Allen, David M. Bell, Don C. Bragg, Anthony W. D'Amato, Frank W. Davis, Michelle H. Hersh, Ines Ibanez, Stephen T. Jackson, Stephen Matthews, Neil Pederson, Matthew Peters, Mark W. Schwartz, Kristen M. Waring, Niklaus E. Zimmerman. Global Change Biology, early online Feb. 22, 2016. DOI:  10.1111/gcb.13160

Little is more formidable than a walk in a Kauri tree forest. These giants with their skin-like bark and their straight trunks are truly impressive. Only 2% of the original Kauri forests remain today, so help us protect what is left and help fight Kauri Dieback

So spray your goddamn shoes, it only takes half a minute of your precious time and really is important to save these often millennia old trees!

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Breakthrough on ash dieback

UK scientists have identified the country’s first ash tree that shows tolerance to ash dieback.

Ash dieback is spreading throughout the UK and in one woodland in Norfolk, a great number of trees are infected. 

The team compared the genetics of trees with different levels of tolerance to ash dieback disease. From there, they developed three genetic markers which enabled them to predict whether or not a tree is likely to be tolerant to the disease. One tree named Betty, they discovered, was predicted to show strong tolerance.

The findings raise the possibility of using selective breeding to develop strains of trees that are tolerant to the disease to help safeguard our forests. 

Read more

Images: Close-up infected ash petioles (leaf stems) - Copyright: John Innes Centre

The Bibbulmun track just south of the Canning Camp.

The Marri/Jarrah forest here was heavily logged, and then logged again. There is regrowth, but with regular burning by Department of Environment and Conservation, this small part of a once great forest has little chance of rejuvenating.

Much of it also suffers from Dieback, a fungal disease which slowly kills vegetation

The log across the track has been cut in such a way as to allow walkers but to discourage motor/bicycle riders.

This ash tree is dead. One of the many here in Norfolk that have been infected by chalara fraxinea. Drawing it I feel like a pathologist as I notice it’s old injures. Twenty years ago, or so, it lost one half of its crown in a storm, the strong new growth from the trunk on the left could only have been produced by a healthy tree, an act of  characteristically vigorous recovery. It seems that rude health and the prime of life mean nothing in a globalised world where cheep goods trump all environmental considerations.

Tor Falcon

Healing Bridge Graft

About three months ago, I did a bridge graft to bypass a fungal lesion on my European Ash tree, to prevent the tree from being girdled. 

I took off the electrical tape today, to find the white mass of callus cells that indicate healing is in progress!

This tree should live to fight another year, despite being riddled with a disease that has killed so many other ash trees.

Ash Trees; UK Crisis.

The Ash tree is on the verge of being wiped out in England. Chalara is a disease which has been imported from Europe and has infected sites across the whole country. Its devastation has been measured in some countries as taking out 90% of the ash population. An estimate of 80 million ash trees in England and it being our 4th most common trees means the forests will become sparse. Since the ash plays an important part in the life cycle of various plants and animals, they will also suffer.

The environmental balance is going to be shook up.

Ash is in my top 5 most magikal trees, it has always played a very important role in British witchcraft. If your in the UK please take some time to look around your local nature reserve and if you see any ash trees with the disease report it.

Camera-carrying turtles reveal seagrass decline

Sea turtles fitted with video cameras have revealed a decline in seagrass health in Shark Bay following a catastrophic marine heat wave in 2011.    

Animal-borne videos have previously been used to study animal behaviour, but this is believed to have been the first use of such videos to assess ecosystem health.

Florida International University post-doctoral researcher Jordan Thomson says the footage, combined with traditional standardised seagrass surveys, reveals that the heat wave caused more than 90 per cent dieback of the dominant seagrass, Amphibolis antarctica, in several regions of Shark Bay.

“Turtle-borne video footage provides unique insights into the health of seagrass meadows from the perspective of resident wildlife that depend on these habitats,” Dr Thomson says.

Green sea turtles are being used to provide images of seagrass meadows, with the data being used to monitor ecosystem health monitoring. Credit: Peter Forster

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Paw Paw Seeds have been requested!

I sent our list in to the KSU Paw Paw Program: this germplasm repository is where your seeds will be coming from if you are participating in the #Paw Paw Project.

The harvest was poor last year, and this year, the temperatures were low enough to cause some dieback in their orchards, so seed supplies are limited: please be patient: it may be a year before you get your seeds.

I will do my best to make sure anyone who donated to the postage fundraiser is first in line to get seeds: the fundraiser is still open for those of you who would like to contribute to postage costs, and a donation to the KSU program!

I am looking forward to hearing about how these trees grow around the world: we are planting over 30,000 seeds being planted with this project!

Help this blog plant 10,000 trees in 2015

Kauri Forest by Steve Janosik
Via Flickr:
Kauri Forest - Northland, New Zealand (March 2015). Kauri trees are isolated to this part of the North Island, and they are in danger from dieback. It was a fortunate experience to hike through several trails within kauri forest, and I hope they remain for a return journey.

Paw Paw (Asimina triloba) sapling

This yearling tree has been to hell and back, but now that I’ve clipped off the tip dieback, a new leading stem is emerging to replace the dead one.

It is my oldest Paw Paw tree, and even though it is an understory tree, I am nursing it under the warm grow lamp in the bathroom closet. The other eight trees I have planted (direct-sown) should be emerging outdoors in a few months.

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137 Days Later: Both the Aloe top, and the stem cutting have survived, both with minimal leaf dieback; the stem from which they were cut also send out at least 6 new offsets. 

With just two cuts into the stem of a leggy succulent, I turned one Aloe plant into at least nine! At some point, I will move a few of them out of the communal pot into a space where they can flourish.


#Aloe vera #succulents #propagation