Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 

Young kauri keep 'grandpa' kauri alive through root systems


AUT scientists have described how a kauri stump is keeping itself alive by holding onto the roots of neighbouring trees; exchanging water and resources through the grafted root system. New research, to be published on July 25 in iScience, details how surrounding trees keep tree stumps alive, possibly in exchange for access to larger root systems. The findings suggest a shift from the perception of trees as individuals towards understanding forest ecosystems as “superorganisms.”

“My colleague Martin Bader and I stumbled upon this kauri tree stump while we were hiking in West Auckland,” says study co-author, AUT’s Associate Professor Sebastian Leuzinger. “It was odd, because even though the stump didn’t have any foliage, it was alive.”

Leuzinger and co-author Bader, an AUT senior lecturer, decided to investigate how the nearby trees were keeping the tree stump alive by measuring water flow in both the stump and the surrounding trees belonging to the same species. They found that the water movement in the tree stump was strongly negatively correlated with that in the other trees.

These measurements suggest the roots of the stump and surrounding conspecific trees were grafted together, Leuzinger says. Root grafts can form between trees once a tree recognizes that a nearby root tissue, although genetically different, is similar enough to allow for the exchange of resources.

“This is different from how normal trees operate, where the water flow is driven by the water potential of the atmosphere,” Leuzinger says. “In this case, the stump has to follow what the rest of the trees do or else use osmotic pressure to drive water flow, because since it lacks transpiring leaves, it escapes the atmospheric pull.”

But while root grafts are common between living trees of the same species, Leuzinger and Bader were interested in why a living kauri tree would want to keep a nearby stump alive.

“For the stump, the advantages are obvious—it would be dead without the grafts, because it doesn’t have any green tissue of its own,” Leuzinger says. “But why would the green trees keep their grandpa tree alive on the forest floor while it doesn’t seem to provide anything for its host trees?”

One explanation, Leuzinger says, is that the root grafts formed before one of the trees lost its leaves and became a stump. The grafted roots expand the root systems of the trees, allowing
them to access more resources such as water and nutrients. They also increase the stability of the trees on the steep forest slope. When one of the trees loses its leaves and stops providing carbohydrates, this may go unnoticed and so the “pensioner” is able to continue its life on the backs of surrounding, intact trees.

“This has far-reaching consequences for our perception of trees – possibly we are not really dealing with trees as individuals, but with the forest as a superorganism,” Leuzinger says.

During a drought, for example, trees with less access to water might be connected to those with more access to water, allowing them to share the water and increase their chances of survival. However, this interconnectivity could also allow for the rapid spread of diseases such as kauri dieback, Leuzinger says.

To better understand how root systems are formed between kauri stumps and living trees, Leuzinger says he hopes to find more instances of these types of stumps and to explore root grafting in intact trees, which will help expand their scope of research.

“This is a call for more research in this area, particularly in a changing climate and a risk of more frequent and more severe droughts,” Leuzinger says. “This changes the way we look at the survival of trees and the ecology of forests.”

© Scoop Media

 
 
 
Business Headlines | Sci-Tech Headlines

 

Science Media Centre: Funding For R&D In New Zealand – Expert Reaction

Research, Science and Innovation Minister Dr Megan Woods has today announced $401.3 million funding for research and development through Budget 2020 and the COVID Response and Recovery Fund. The fund includes $150 million for an R&D loan scheme, ... More>>

ALSO:

Maritime NZ: NZ Joins Global Initiative Keeping Ports Open And Freight Moving

New Zealand has joined an international port authorities’ global initiative for safe and efficient movement of goods and shipping during the COVID-19 crisis. World-wide, 56 port authorities have agreed how they will work together facilitating maritime ... More>>

ALSO:

National: National Backs Businesses With $10k JobStart

National will provide a $10,000 cash payment to businesses that hire additional staff as part of our commitment to keeping New Zealanders in jobs, National Party Leader Todd Muller and Finance spokesperson Paul Goldsmith have announced. Our JobStart ... More>>

ALSO:

DIY Law: Government Exempts Some Home Improvements From Costly Consents

Homeowners, builders and DIYers will soon have an easier time making basic home improvements as the Government scraps the need for consents for low-risk building work such as sleep-outs, sheds and carports – allowing the construction sector ... More>>

ALSO:

Media Awards: The New Zealand Herald Named Newspaper Of The Year, Website Of The Year At Voyager Media Awards

The New Zealand Herald has been labelled a “powerhouse news operation” as it claims the two biggest prizes – Newspaper of the Year and Website of the Year – along with many individual awards at the 2020 Voyager Media Awards Website of the ... More>>

ALSO:

ASB Bank: ASB Takes The Lead Again With New Low Home Loan Interest Rate

ASB has moved again to support its customers, cutting a number of home loan rates, including the two-year special rate to a new low of 2.69% p.a. Craig Sims, ASB executive general manager Retail Banking says the reduced rate will be welcome news for many ... More>>

ALSO:

Nathan Hoturoa Gray: The Problems With Testing And Case Statistics For Covid-19

To begin to understand disease transmission in a country requires adequate testing of your population with properly vetted, accurate tests. As the world struggles to find what 'adequate percentage' of the population is necessary, (estimates predict ... More>>

ALSO:

RNZ: Fletcher Building To Lay Off 1000 Staff In New Zealand

The construction company will cut around 10 percent of its workforce as it struggles with the fallout from Covid-19. More>>

ALSO:

Can Pay, Won't Pay: Cashflow Moves Urged

Government Ministers are asking significant private enterprises to adopt prompt payment practices in line with the state sector, as a way to improve cashflow for small businesses. More>>

ALSO:

Gordon Campbell: On Why We Should Legally Protect The Right To Work From Home

For understandable reasons, the media messaging around Level Two has been all about “freedom” and “celebration”, but this is not necessarily going to be a universal experience. When it comes to workplace relations, Level Two is just as likely to ... More>>

ALSO:



New Zealand Government: Supporting Kiwi Businesses To Resolve Rent Disputes

The Government will legislate to ensure businesses that suffered as a result of the COVID-19 response will get help to resolve disputes over commercial rent issues, Justice Minister Andrew Little announced today. More>>

ALSO:


Science Media Centre: Understanding 5G Concerns – Expert Q&A


Recent attacks on cell phone towers have brought concerns over the rollout of 5G technology into sharp relief.
While scientific research has consistently shown that the technology does not adversely affect human health, public concerns about its impact have spread around the world, fueled in part by growing misinformation online. The SMC asked experts to comment... More>>

ALSO:


Trade: Record Monthly Surplus As Imports Dive

Imports in April 2020 had their biggest fall since October 2009, resulting in a monthly trade surplus of $1.3 billion, Stats NZ said today. “This is the largest monthly trade surplus on record and the annual goods trade deficit is the lowest ... More>>

ALSO:


Media Blues: Stuff Chief Executive Buys Company For $1

Stuff chief executive Sinead Boucher has purchased Stuff from its Australian owners Nine Entertainment for $1.
The chief executive was returning the company to New Zealand ownership, with the sale is expected to be completed by 31 May.
"Our plan is to transition the ownership of Stuff to give staff a direct stake in the business as shareholders," Boucher said in a statement.... More>>

ALSO:

RNZ: Bar Reopening Night 'much, Much Quieter'

Pubs and bars are reporting a sluggish first day back after the lockdown, with the fear of going out, or perhaps the joy of staying home, thought to be a reason for the low numbers. More>>

ALSO:

Stats NZ: New Zealand’s Population Passes 5 Million

New Zealand's resident population provisionally reached 5 million in March 2020, Stats NZ said today. More>>

NIWA: Seven Weeks Of Clearing The Air Provides Huge Benefits: Scientist

Seven weeks of lockdown has provided evidence of how pollution can vanish overnight with benefits for the environment and individuals, says NIWA air quality scientist Dr Ian Longley. Dr Longley has been monitoring air quality in Auckland, Wellington ... More>>

ALSO:

Government: Milestone In Cash Flow Support To SMEs

A significant package of tax reforms will be pushed through all stages in Parliament today to throw a cash flow lifeline to small businesses. More>>

ALSO: