Trees and their energy interactions.

Trees are central to ecosystems because they are large elements that affect the local climate. WATER flows across the landscape differently due to trees. The WIND is blocked, deflected, slowed or funneled depending upon details of how trees are arranged. LIGHT can be blocked, or it can be focused into specific areas with arragements of trees. SOIL is built, enriched, and protected by trees. Animals, insects, and other LIFE FORMS all rely on trees to thrive. Trees are the largest contributor of the energy entering, absorbed, and being dispersed by the natural systems they are a part of.
Let's dive deeper into what exactly trees do...

A TREE'S BIOMASS ZONES

Trees have what is called biomass zones. 

What is biomass?

All life forms, all elements, and all their forces are part of the biomass of the tree. Animals are the trees' messengers, trees are the gardens of the animals. Life depending on life. Tens to hundreds of thousands of individual growing tips of each tree can display different characteristics. These growing tips are found in the soil, and in the crown. All growing tips can be different individuals. The tree is a mixture, and a blend of, many individuals. Some individuals are of the tree itself, but most are free living agents that interact with the tree.

It is very important to realise just how crucial the involvement of trees are with our climate, to our water cycles, and to our soils. Did you notice the preceding 'our' ? We are part of nature. We are not separate to it. We can't be separate to it as we're living in the biosphere, neither can we live without nature.
Nature is an integral part of us, even if we aren't aware of it. We are part of nature.
We are nature. 

THE  3  BIOMASS ZONES?

A tree has three biomass zones, and they're  all quite different. 

Zone I is the trunk out to the crown.

Zone II is the detritus.
This is where organic material builds up and interacts with the soil and air.
It is the humus at the soil boundary surface to the air. It is specifically a zone to itself.

Zone III is the root zone.
The root zone has as many interactions with other 'associates' as the crown zone. These underground associates are invisible to us - because, guess what! We aren't underground, so we can't see them! You can think of it similarly to the birds and other animals (associates) up in the sky interacting with the crown.

Over its lifetime, a tree sheds it own weight many, many times, and this in turn helps build the soil it stands in. The tree is literally building this zone, by standing in a zone of its own decomposition. Material is being transferred, is being transported, and is being reborn. Conversions are happening. A lot of the fungi flower up at the surface but go many kilometres away from a tree. Insect life, birds, and mammals; they're all involved in conversions around these zones, and they act as extension agents of seed and associates to the tree. Root fungi create cell nutrients through interactions with water, soil and air. Think of this like the internet of the soil going out kilometres away from this zone. Insects are continuously pruning and surplus foliage is raining down from the tree towards the decomposition zone. Some of these are quite valuable bacteria stimuli and types of sugars

Root fungi create cell nutrients through interactions with water, soil and air. Think of this as the internet of the soil going out kilometres away from this zone. Insects are continuously pruning and surplus foliage is raining down from the tree towards the decomposition zone. Some of these are quite valuable, bacteria stimuli, and types of sugars.

WIND EFFECTS ON TREES..

Trees adjust their shape to the wind. The leaf surface area is reduced and the tree becomes more aerodynamic.  Wind can be analysed by walking around a tree that's out in the open and observing towards which direction it is leaning. The tree will actually bend away from the wind. It adjusts its shape to the aerodynamic resistance to the wind.

So, we can see the intensity of the wind and we can see the direction of the wind. Under heavy wind conditions a tree will spread its roots wide and use its weight to weigh itself down. It may even anchor itself down further by gripping on to underground rocks. We can learn to design with this effect. Some trees have leaves that are white on their backside, and they turn over and reflect more light when the wind blows. This reduces the evaporation effect. These trees occur on the forest edges mostly, and rarely within a forest. 

The tree will add a lift to the wind. So as the wind comes up over a bank of trees, we've lift on the wind. About 40 percent of the wind is going to permeate through to the forest, and roughly 60 percent is given a smooth lift. When we're doing a tree 'walkaround' you can observe this when you're at right angles to the tree. You'll see the front row shaping up like an airplane's wing. So there's a divergence in the slower flow, and a higher pressure as the air comes over. That just means that the air is cooler as a compression and release causing differentials in pressure, and heat often cause rain.

So, on the leeward side, post lift, we often get rain, especially if this now bounces and lifts again, and bounces and lifts again. With every lift we can potentially get a shower of rain because we get heat differentials around the changes in pressure. Particles carried by the wind, such as ice, dust, even sand and larger particles are often found deposited just upwind of the forest edge as a hump. There's a mound sitting right behind the first rows of trees on the forest edge. This is where the wind is starting to slow and it's dropping out material. Within 100 metres inside of the forest, the air is now clean since it has released moisture, particles and pollutants, and within 1000 metres there's no wind at all.

So, if we know wind strengths and direction, we can design windbreaks for shelter and wind funnels for energy. Wind can be funneled for cooling in hot climates, for wind energy, for aeration over water, or for a windbreak in a cold climate, or even suntraps.  We have to know how to read the wind effects, and be able to read this in the landscape, and that's what permaculture designer's learn - to read into the wind effects in the environment. On average, leaves are 86% water, and cooler than soil by day and warmer by night. This can have a significant effect when we're designing these multi functional elements. Tree clumps upwind of a house modify temperature, cooler in summer and warmer in winter.

 So, depending which climate you're in, you can set up your tree belts, to be either sheltering or sun trapping. Housing in an area where you've got shelter to a garden and you've got a woodlot surrounding you is a major part of your temperature control. 

In hot, humid tropics, trees can dehumidify the air by direct absorption - they directly absorb the humidity out of the air. This makes the air feel cooler. We are the designers. We can use these effects to our benefit, and that's what we do with good permaculture design. We work with elements in the natural system that already exists, and we put them to our advantage, which reduces our need for energy. It reduces energy input, it reduces our cost, and it increases our energy effect in our favour. 

EKMAN SPIRALS & TEMPERATURE EFFECTS

Here's a constant to remember. evaporation cools and condensation warms. Evaporation cools the air locally during the day around trees, or in amongst tree system, and condensation warms the night air, so trees can work both ways, cooling during the day and warming during the night by evaporation and condensation effects. So, tree clumps upwind of a house modify temperature. Depending on which climate you're in, you can set up tree belts, to be either sheltering from the poleward side or sun trapping from the sun side.

TREES & PRECIPITATION

Precipitation is way more than just rain. Condensation in particular plays a large part in precipition, but also ice and snow. Trees have played a major part in creating our soils and our atmosphere. They have root pressure and humid acid breaking down the rocks and geological material, and humus supporting soil micro organisms are all taken apart in creating our soils, and their actions have created out atmospheric conditions. Oxygenating the atmosphere and creating an active water vapour is a cycle essential to life, and that's what trees do. They are the major interaction in those cycles. The creative and reactive process of trees make more than 80% of the work maitaining our atmosphere.

70 percent of our landscape, on average, needs to be in some sort of forage farm in trees. The oceans, and water bodies of the earth do the rest of the work. And of course, if we have our forested landscape, our water bodies and our oceans, usually they stay in good condition.

On sea facing coasts in the evening, it's warmer because of the warmer latent airflow. The winds coming off the ocean are carrying the moisture, and that is the warmer air, and you have the cooler surfaces on the leaves causing condensation and water droplets to occur. There's actually bacteria on the leaves - pseudomonus syringae, one of the main organic nucleii that cause rain.  So, it's a nucleii event created by leaf surface bacteria.

Condensation drip can be as high as 86% of the total precipitation. On upland slopes, on sea coasts, that's where you'll get maximum condensation drip, where the moisture is coming directly off the ocean. If you cut those slopes you greatly reduce the rain down on the inland side. Some of the richest forest environments in the world are sea facing slopes, like the Californian Giant Redwood, grown on condensation from ocean. How does that work? Well, one large tree can easily have 40 acres (17ha) of laminate surf area. I'll say that again. ONE TREE can have a leaf surface area of FORTY ACRES. That's 17 hectares!

This leaf surface area interacts with the moist air. It's not just the leaf surface itself, but when you inspect it closer, there are indentations that greatly increase the leaf surace areas, and then there's indentations of the indentations. Trees generally, and continuously, rain at night on clear cloudless evenings, and a well planted forst garden in these conditions can catch their own water, because almost every night it's raining. But, in one lifetime, if we can fell enough trees to destroy all of this, and the rivers, and the swamps, and the ponds, and the lakes, all can dry up. In one lifetime's felling.

So, a flood and drought regime could become the new normal, and such a regime may get accepted simply because people won't remember what climate we used to have prior. We have a cultural obligation to pass on the detailed knowledge of forested landscape, because forests are long term elements and true sustainability is an understanding of the interactions of forests and particularly in relation to precipitation.

Precipitation through fog is even higher than just condensation. During clear nights, sky's condensation drip is quite intense, but fog drip can be even higher. It can be higher than the rain itself. On some coasts or mountains that have fog, you can have larger contributions to precipitation than rainfall. So when we're working with systems, we have to realise the power a long term effect that we're designing, cause this really is designing a major part of the abundance for the future generations.

HOW A TREE INTERACTS WITH RAIN

Rainfall has incredible powers. Rainfall has powers to erode landscape, especially where there are bare trees, or bare soils thinly spaced or cultivated crop. It can be 80 tonnes to the hectare of soil erosion - up to 1000 tonnes of soil erosion in an extreme event to the hectare, and it all runs with the water cycle.

It all goes down stream, down towards the ocean. It runs off the field. When we clear land we increase this effect considerably. And what happens is the following:

Dams fill quickly but they silt quickly. That means that rivers stop. They silt up and stop, and they flood, and then drought.

We go into a flood and drought regime, instead of long, regulated, steady, clean water supply systems with good regular flow rates, with clean life-rich water. We go into a silt-mud flow flood, and then a cracked mud drought. Trees intercept the water. It's caught in the crown.

So, rain on a forest is absorbed. The impact is literally absorbed on the crown of the forest, the canopy, and it's a very complex process. It breaks the rain into a mist and takes the power out of the rain, and then the runoff is miniscule. This will vary with the thickness of the crown, the density, the season, because some forests are gonna be deciduous and lose their leaves. It also varies with the rain intensity and of course the evaporation after the rain event.

What you get is an absorption of the impact, and you can actually shelter under a tree for about 20 minutes, and the rain pciks up and runs down the leaves. The hydraulics actually picks up and carries the rain down the leaves, down the branches, towards the trunk. It becomes a feed, like a stream running towards a tract, feeding the tap root ladder, but then there's a point where the tree is completely saturated, and at that point you get through fall, the water actually goes through the tree. 

At that point you can't shelter under the tree anymore cause the rain is coming through, but at that point it's no longer rain. It's changed. It's picked up all kinds of energy. It's coming down the branchs and it's dripping through. It's getting caught in the bark fissures and in the ledges. It's not straight forward flow, but it has picked up all kinds of exudates off the leaves, all kinds of different elements, and it's measurably very different. It can be up to 50 times more nutritious, and that's going through to the humus layer, which will hold one-third of its volume in water. 

The humus under the forest is one-third water, as a sponge, and then you get the fungal hyphae and the bacterial gels. The fungal hyphae will swell like sponges and hold more water, the living element in the soil in amongst the humus layer and below. The bacteria colonies create crumb structures which are formed by sticky gels. This all absorbs water.

So, 30 percent to 40 percent of the tree's bulk is actually in the soil. 1000 kgs of root hairs is in the top 60 centimetres, and around 10 to 12 percent below that, and some of those roots go down 40 meres. There are literally thousands of kilometres of root hair. The top centimetres is where the trapping and the sponging of the soil takes place.

So, the root map absorbs the solutions that's coming through as through fall. That water has become a very, very nutritious solution, but trapped in the top root map it's actually recycled up to be transpired to the air again. It's recycled into the tree. The tree feeds on that nutrition recycle, and the air can be transpired through evapotranspiration back to the atmosphere.

The forest above the ground, 90 to 95 percent of the mass is water. Then, add soil, humus, root mass, and suddenly you start to realise that the forest is a giant, managed lake of actively recycled water folding over the landscape with infiltration maximised because when the sponge is full, everything goes through to the deep ground storage systems. So it's a recharge system when full at a steady flow rate because it's a leaking sponge.

Humus is a storage, swollen microrhizal storage, spongy detritus storage, all in humus. On average, 2,5 to 7 centimetres of rain can be stored per 30 centimetres of soil, but in high organic content soil up to 10 to 30 centimetres of rain per 30 centimetres.

Forests give soil time to hold water, and that's what can alleviate the droughts and recharge storages, and at the same time benefit the sforests themselves. Trees are responsible for more water in streams than rainfall alone provides, and that's why the streams keep flowing when you're in a forested environment. It's also why they're clean and full of life.

We have to realise that it's reevaporation and transpiration of trees that multiply rainfall many times. Air rising inland creating moss forests and standing clouds on mountains, adding to the precipitation and infiltration to the lower slopes and streams. That is almost like a continuous tap running on the mountains in those moss forests that are cloud covered. Winds over tree lines form the Ekman Spirals and parallel rain bands adding up to 40 percent extra rainfall down wind.

It is more likely that organic particles from nucleii make more rain than any other reason for it to rain. That is the nucleii blown off forests - organic nucleii - mostly pseudomonus syringae, the cloud seeding bacteria that sits on leaves. But industrial aerosols don't do this, they're too small to cause rain. So, the dust from the industry and the aerosol pollutants from industry create cloudy conditions that are dry. Dry, cloudy conditions. So there's not much hope there. 

If we clear all the forests, we end up in a dust bowl.

Credits: Geoff Lawton '22 Online PDC.