A tree stump that should be dead is still alive

  The Kauri tree stump in the study. Credit: Sebastian Leuzinger / iScience

Within a shrouded New Zealand forest, a tree stump keeps itself alive by holding onto the roots of its neighboring trees, exchanging water and resources through the grafted root system. New research, publishing 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 corresponding author Sebastian Leuzinger, an associate professor at the Auckland University of Technology (AUT). “It was odd, because even though the stump didn’t have any foliage, it was alive.”

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

These measurements suggest that 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, 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  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, as well as increase the stability of the trees on the steep forest slope. As one of the trees stops providing carbohydrates, this may go unnoticed and thus allow the “pensioner” 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  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.”

city of trees

Tree Health and Planting

Planting Tips

When trees are planted too deep the roots may decline or they may grow upward and ruin
lawns and crack sidewalks. It is better to plant where water must be added rather than
drained. On wet or clay sites, plant on a mound.
• Plant at the depth the tree grew in the nursery.
• Prepare a large planting site, not just a small hole.
• Loosen the soil deep and far beyond the drip line.
• Do not add peat moss unless soil structure is poor.
• Cut wires if tree is in a wire basket and remove all non-biodegradable material.
• Remove only dead and injured branches and roots.
• Mulch with a thin layer of composted material
• Do not fertilize until the next growing season.
• Keep annuals and grass away from the new tree.
• Tree wrap is cosmetic only.

• Plant at the depth where roots spread from the trunk.
• Prepare a planting site, not just a hole in the ground.
• Loosen the soil far beyond the dripline of the tree.
• Brace the tree only if it will not remain upright in a moderate wind.
• Brace with broad, belt-like materials that won’t injure the bark.
• Mulch away from the trunk with composted material.
• Keep soil moist, not water-logged to the depth of the roots.
• Remove dead and dying branches.
• Wait until the second growing season to begin training cuts for shaping and to
begin fertilizing.

Trees provide many benefits for people and many other living things. The major benefit
is that they trap more of the sun’s energy than any other group of living things on this
In a sense, trees bring in a great amount of “biological money” to our earth.
When your money is spent on treatments that hurt rather than help the tree, your money
and the tree’s biological money are both wasted.
Saving money for everybody is easy. All we need to do is learn a little about trees. Then
we should base our treatments on this information.
Start saving money by making the 5 simple adjustments. Then give your attention to
these other problems that waste biological money and your money.
1. Soil compaction by walkways, car parking, play areas.
2. Construction injury, no protection and no prior plans with the developer.
3. Holes, holes and more holes for repeated injections and implants.
4. Wounds inflicted by lawnmowers and string trimmers.
5. Over watering, especially in dry climate areas of the world.
6. Road, roads and more roads in forests and parks.
7. Roots cut for sidewalks and for lawns.
8. Soil rototilled near trees so flowers can be planted.
9. Digging deeply into cavities and filling with abrasive materials.
10. Over use and incorrect use of herbicides.
11. Changing grade and excessive fill over roots.
12. Excessive use of salts for removal of ice.
13. Neglect.
Trees support more communities of wildlife than any other living thing. When trees are
destroyed, wildlife habitats are destroyed. Proper tree care benefits wildlife too. Big,
old, healthy trees are best for wildlife

The Effects of Flooding on Trees

With the flooding upon us, one might wonder what are the effects of the flooding on our tree health. One might think lots of water is good for trees but you know the saying too much of a good thing can be bad. Flooding presents a few issues to trees. It can leave the tree vulnerable to secondary pest, suffocate the tree, and loosen up the root foundation.

The soil has space in between each soil particle. For example picture sand versus rocks, the rocks have more space between each other than sand particles do. And likewise, it is the same with soil. The spaces or pores contain air or oxygen pockets where the tree roots get their oxygen. When the soil becomes flooded, these pores fill up with water and the roots can’t get any oxygen. Oxygen deprivement can cause stress, stunt growth, injury and/or death of the tree. Several factors like the tree’s natural flood tolerance ability, soil drainage, and soil pore quality ( more porous vs less porous soils) can affect the tree’s survival ability. What you may want to consider when planting a new tree is the tree’s flood tolerance, soil, and location (up-slope as opposed to down-slope).

Flooding can also cause the soil to loosen up and wash away causing the tree’s root foundation to become structurally unstable. A weak root foundation can be very dangerous with high winds. We recommend having a tree care professional come and inspect the structural quality of your tree during this flood season. Having a 50-100 foot tree fall on your house can cause expensive structural damage to your home not to mention the injury this could inflict on your family or pets.
After the flooding has dried up, there are still dangers to your tree called Secondary Pest. “Flooding, drought, and premature defoliation impair tree defense mechanisms and trigger biochemical responses that release carbohydrates, sugars, and other nutrients which seem to invite insect and fungal pathogen attack,” According to an article in University of Florida’s Hillsborough County scholarly journal. Fungus and insects can attack your tree after the floods. Some culprits include water mold, ambrosia beetles and bark beetles. Contacting a tree professional can help determine if your tree is infected with any of the aforementioned.

If your tree exhibits any of the following symptoms, yellowing of the leaf, leaf thinning, and stunted leaf and tree growth. Please contact S & J Treecare to help diagnose and treat your tree.

tree fell on house

Emergency Tree Removal-Top 5 Tips

Emergency Tree Removal-Top 5 Tips

Emergency Tree Removal-Top Five Things to Know

Emergency tree removal situation are stressful, that is a face. But a little bit of knowledge in dealing with them can go a long way in helping alleviate that stress.

  1. Don’t make an emergency tree removal situation more dangerous by getting too close.  You want to be a witness, not a victim. Trees that appear solidly supported, or stuck fast on the ground often shift or roll, causing personal injury or worse. Let our expert arborists check it out. Stay clear and keep passersby clear as well. Often blocking off the area with sawhorses or a parked car can keep pedestrians from harm. If there is a downed powerline or a tree is leaning on a powerline, call 9-1-1 immediately and advise your local utility provider. These are the people whose name is on your power bill usually PG-E or SMUD.
  1. In what is potentially an emergency, the best thing you can do is to Be Calm. Neighbors may be escalating the drama. Well-meaning people who do not understand the forces inherent may offer advice on how the emergency could be best handled. Remember that they aren’t professionals. People might ask if they can just go under the leaning tree for a minute. If it isn’t a matter of life and death, don’t make it into one by allowing anyone too near. Is it really an emergency if the birdbath or fence is wrecked? After all, this is why we carry homeowner’s insurance. But if the tree can further slip, fall, or endangers your house, that is an emergency tree removal. And a word about the many companies who profess to do a safe job, for less than the professionals: Check that they have a current insurance certificate. One sure way to escalate costs is to let a self-appointed expert on your property with a chainsaw and little experience. Insurance picks up the pieces, but it does not prevent accidents.
  1. Call us as soon as possible. We can make a determination about relative danger and can often mitigate the situation with tools we carry for these specific purposes. The sooner we can get an expert out to view the situation, the better. Often a decision can be reached-by you-on whether or not to remove the tree, just because of the clear way it is explained.
  1. If the tree in question hit your house or another tree, insurance will normally pay. We take care of the problem and bill insurance, which is time consuming as well. More information on this cost/damage is explained here.
  1. Storm damaged trees are by nature more of a challenge, and more work. It is normal to assume that the work will cost more, sometimes double what a similar project might cost that is scheduled through normal channels. We try to keep the costs competitive, while providing you with safe, professional work. We think you’ll see the difference in how we handle your emergency.



Vacant lots in the city must be maintained or will be subject to fines.

As the summer heats up, weeds are drying quickly posing a potential fire hazard in our communities. Property owners must take immediate measures to ensure their vacant parcel is clear of weeds, debris and maintained throughout the year, primarily between the months of April to October.

The Weed Abatement Program has been active since 2013 and sends out notices each year to all known property owners of vacant parcels within the City of Sacramento in February.

What property owners need to know:

  • It is a violation to allow dry weeds to grow in excess of 12 inches in height.
  • It is the property owner’s responsibility to ensure that their vacant parcel is clear of weeds, debris and maintained throughout the year.
  • Weeds must be cut to two inches in height or disked. Disking is the preferable method as it prevents weed growth for a longer period of time.
  • Property owners that fail to maintain their property are subject to administrative fines of up $25,000.

For more information, call 916-808-5417, or visit the Weed Abatement web page.

For Professional services, call S & J Tree Care @(916) 730-3399 to schedule an appointment.