Trees - Klinkman Solar

As of the end of 2022 the Horn of Africa is in its third year of megadrought. Most of the wild animals and goat herds are dead because of no more available vegetation at all. There's no future prospect of food other than saltwater fishing. If this trend should spread worldwide, the planet would be seeing chronic multiple breadbasket failures. I don't look at forests as particularly useful tools for carbon sequestration. Rather, I look to forests for their ability to prevent or temper megadroughts and permanent desertification of much of the planet's arable land.

Regional megadrought has a somewhat controllable component, mature tree cover. See, for example, the explosion of 200 million new trees in Niger, in sub-Saharan Africa. Almost all individual nations need to rethink their regional megadrought plans right now -- re-planning in the middle of the megadrought will be rather late and more painful. Megadrought is going to become the ultimate third rail of politics.

Land trusts need to face up to tough climate questions. Waves of extreme heat and incredibly low humidity aren't going to stop at each small plot's property line. Allowing the regional climate to turn every local plot of balanced ecology into a relative wasteland is, in the end, going to be painful for any conservation effort. When we protect our own little pieces of earth, are we fated to fail? Does it make more sense to protect an entire region of the planet from megadrought?

Southern Europe already knows that wind storms will eventually blow every dust particle of the remaining topsoil away. Bare soil absorbs the sun's heat, and then the topsoil dries out. Italy has tiny 10 meter plots of land surrounded by stone walls to keep the little remaining soil in place and to reduce wind evaporation. Entire Mediterranean growing regions have been abandoned over history. This denudation affects the rest of the region. Tunisia, formerly Carthage, used to feed Roman armies, but desertification has pretty much destroyed the growing of wheat in Tunisia.

New seed planting machines have been invented that only minimally break the topsoil for less water loss and for less windborne soil erosion. Permaculture, growing perennial crops as opposed to annual crops, won't have this replanting problem each year. Soil-friendly agriculture captures runoff silt in dams and screens. Proper agricuture puts more rainwater in the ground. Terracing reduces topsoil runoff.

Tall plants in hedgerows and perennial plants can reduce the effects of long droughts.

It's possible for net carbon sequestration to be enhanced in almost every biome on earth. Often, certain improvements will work at a reasonable cost and won't interfere that much with the land's current human purpose.

Water management starts with trees. Trees have evolved to support their own water needs in a world of drought.

Trees are camels. Trees store a surprising amount of water within their roots and branches after a rainfall. A mature oak tree can absorb and hold 100 gallons of water after a heavy downpour. [https://insideclimatenews.org/news/23022022/baltimore-maryland-faith-congregations-stormwater/]
Trees keep their leaves cool and moist by transpiring this water back into the atmosphere on dry days. The Amazon jungle creates much of its own rainy environment because billions of trees in the jungle are re-humidifying the regional atmosphere, which causes more rain each day. Trees turn solar heat into water vapor.
Ttrees create their moist but not hot air at 5 to 50 meters above the ground, humidifying a thick layer of air. . Moist air actually weighs less than dry air. Look at the molecular weight of a mole of H2O molecules versus a mole of 80% N2 molecules and 20% O2 molecules. It's not so much that hotter air rises, rather, moister air forms rising currents of air because moist air is lighter. Sooner or later updrafts of vapor-saturated air pull themselves up into thundershowers, tropical storms or temperate low pressure systems. The water vapor releases heat high in the atmosphere as it condenses and as rain falls, and the heat released by condensation causes these thermal air currents to rise further. At stratospheric altitudes a relatively high percentage of this newly released heat will radiate quickly back into space. In sum, forests are a key player in transporting solar energy into the stratosphere and off into space. Updrafts cool the planet.
Trees provide shade. They keep their own local soil cooler and moister, which impedes drought and which stores usable water against a long drought.
Trees cool humans and neighborhoods at ground level. Conversely, sunshine on bare ground creates warmer topsoil, which dries out the topsoil rather quickly. Sunshine on bone-dry bare topsoil creates extremely hot topsoil, which over a number of dry days creates extremely hot surface-level air. An enhanced regional drying out process continues into the hotter-than-normal evening hours.
Tree leaves absorb the impacts of large rain droplets. Leaves split large droplets into smaller droplets which land more gently on the soil, or large drips drop from low branches onto the soil or run down tree trunks. Leaves absorb some rainfall directly. Coast redwood needles capture fog droplets and so they absorb nearly all of a coast redwood's water each summer.
Each tree lays a fluffed up layer of leaf litter down on the ground each year. The leaf litter inhibits raindrops from washing away the tree's topsoil. The layer of leaves insulates the bare ground from solar heating and from evaporation so that the soil holds onto rainwater. The fluffed up leaf litter lets rainwater percolate slowly down into the soil instread of running downhill as surface water. Eventually the accumulating leaf litter turns into additional topsoil for the tree and for its own nearby seedlings.
Tree roots near the surface of the ground can create small obstacles to water flow beneath the leaf litter, so that more rain has time to sink into the local soil. Tree roots hold the topsoil in place against erosion. More topsoil equals more water retention into the region's drought periods.
Deep roots can permanently sequester carbon deep in the subsoil for thousands of years after any plant dies or dies back partially.
Tree roots reach relatively deep into the soil for long-lasting water. In this way, trees fight prolonged regional droughts.
The higher water vapor levels that trees create helps to inhibit the spread of tree-killing wildfires
Trees can act as windbreaks. Less wind means that less water is evaporated from the soil downwind from a tree or from a hedgerow. After the Dust Bowl, the U.S. Department of Agriculture recommended the planting of wind breaks in the Midwest, both to provide crops with more water and to control the amount of topsoil blowing away in dust storms.
Collectively, trees can somewhat reduce flooding downstream.

Half of the planet is experiencing notable droughts. Every tree that dies from drought or from insect infestation becomes a new burnable fuel source for the next megafire. Also, extreme rainfall in winter increases early spring ground cover, which dries out in summer and that creates more dry fuel. This trend seems to be getting exponentially worse.

A new generation of insects might be born every month; trees might spawn a new generation every 20 years or so. The climate has changed and the bugs have adapted first. Now they're killing many trees. Billions of trees have died or are weak.

When the summer sun shines on too much bare ground, that causes record heat waves. Extreme droughts combined with heat waves can kill trees.

Billions of dead tree trunks, large vertical dried-out logs, will tend to fuel megafires. Megafires kill most of the remaining trees. No tree can grow back in a megadrought, just annual grasses and brush.

People are burning down sections of forest to create more agricultural land. Logging clear-cuts forests. War and grinding poverty can tend to make people desperate, so that they cut down the nearest and safest trees for their cooking fuel and for a warm shelter. Overall, humans are currently the major factor in denuding the land.

And so, we're likely to someday see unimaginably bad heat waves. We're currently seeing a major drying up of numbers of the world's rivers in summer due to many regional megadroughts. Most of the world's agriculture won't produce in terrible drought conditions and with less water for irrigation, and that's a mission-critical problem for humankind.

Saving regions of the earth from megadrought seems to be intimately tied to saving individual trees. Trees hold water. Trees create more steady rainfall patterns. Topsoil created by the trees holds water and encourages more rainwater to become longer-lasting groundwater.

A swale is a pond or container where surface water collects and later sinks into the ground.

One design used in the African Great Green Wall Project is digging tiny drainage channels on hillsides and tiny swales that allow rainwater to sink into the ground next to one particular young tree. This water helps the young tree to survive a drought.

The African Great Green Wall project has been trying to inhibit the desertification of countries on the southern edge of the Sahara Desert. Kenyan lakes are flooding into nearby villages, although this may be in part an effect of more local clear-cut logging on nearby hillsides. This hints that net regional tree planting may not be what local governments want it to be. Water levels in Lake Chad, south of the central Sahara Desert, have lately been plummeting toward absolute zero.

Millions of tiny runoff swales are more effective than one huge swale because each micro-swale uses many cubic feet of surrounding topsoil and subsoil to store quick rainfall runoff for days or for a month, until the hillside tree needs the water or until the groundwater percolates down in a month or so to a local stream.. A huge swale or reservoir far downstream can't do this saving of water. Millions of tiny swales will be relatively easy to construct.

If 1 million microswales with 1 million trees can effectively give each tree a good opportunity to grab water while storing even more water in the ground, retaining an extra 100 million gallons of a downpour in hillside soil and in trees, that would be a positive start to better flood control downstream.

A one tree microswale could be a hollow stake perforated with drainage holes that can be hammered into the soil until it's flush with the ground or possibly deeper. A permanent microswale might be a terra cotta pipe-like cylinder with many tiny holes, pushed vertically into the soil after some type of widening tool or augur digs the hole. This cylinder would leave room for early runoff to accumulate and might function for many years. Long, thin horizontal terra cotta cylinders sunk just below the surface of the ground might act as rather permanent runoff collection channels. I might hope that such microswales will last perhaps 1 century before they decay and become part of the forest soil.

Alternatively a hand shovel or a Pulaski firefighting tool could dig a pair of 2 inch deep drainage ditches that might then be backfilled with pea stone for appearances. If the drainage canals should in time get buried under several years of leaves, they still will channel some hillside rainwater into the microswale.

Almost as a rule, the smaller and more widespread the water sequestration systems, the more cost-effective the water sequestration.

Micro-swales can help to stabilize water flow through run-of-the-river small hydro projects.

The less surface water flowing into rivers from extreme precipitation events, the less flooding downstream. It's better to have groundwater coming out of springs into rivers during dry periods, during droughts. A steadily flowing river is good for generating ecologically friendlier run-of-the-river hydropower during dry periods. A more steadily flowing stream is good for the local fish populations and is good for local agriculture in summer.

Elsewhere the African Great Green Wall Project builds rice paddy-like terraces on hillsides. The more elaborate Green Belt system of building wide terraces on hillsides also efficiently captures rainwater in the local topsoil, up to a certain amount of rainfall. Perhaps high-walled terraces capture a higher percentage of surface runoff water than tiny swales. The terraces also create new, properly watered cropland out of hill slopes.

In the 1960s our new suburban house in Rhode Island was built on part of an ancient hillside apple orchard which was already returning to a maple and oak forest. Two of the original farmer's apple trees still struggled to survive among the taller maple trees. Many decades ago a farmer had created a parallel series of earth berms across the hillside orchard land, to capture a bit more rainwater than otherwise and to limit soil erosion. The earth berms were swales. One day, a powerful thunderstorm sent great amounts of water off of the street above us, down a neighbor's driveway, over these small earth berms and into our basement through our bulkhead basement door. The lesson is, always prepare for the day when you get a flood larger than the system was designed to handle.

Above that limit, say, an enormously flooding rain, 100 centimeters of rain created by a major, slow-moving hurricane, would most likely overwhelm a terraced hillside's capacity to absorb rain. Then the doubled flow of rainwater could probably also cut large gullies through the sides of each of the succeeding hillside terraces. With climate change we're unfortunately more likely to see a few 100 centimeter rainfall events. Also, the creation of small ponds on hillsides could lead to an explosion in the local mosquito population, so allowing enormous amounts of rain to safely escape the terrace system might be a good idea.

One way to preserve the hill's soil is to run terraces or earth berms in a spiral around the contours of the hill and always gently downward. A minimal slope within each spiral hillside channel will slow down the water built up from a quick, intense cloudburst. The first 10 centimeters of rain might be absorbed by local topsoil, and then the last 100 centimeters or so of rainfall will still flow off of the hill, but the excess rain will drain gently off the hill, back and forth across the sides of the hill, with minimal soil erosion and with almost zero long term damage to the hill's existing water retention system.

Assuming a rather gentle slope to the spiral runoff channel, the wider and shallower the spiral runoff channel, the less soil will erode. A side effect of gentle hillside drainage is the elimination of any standing water pondage on the hillside, which is beneficial for both crops and trees. The optimal runoff channel slope is a compromise between draining the topsoil on major rain events within each spiral terrace for proper treatment of plant roots, versus not letting water escape downstream that should soak into the local topsoil and groundwater.

I read that Afghanistan is covered with fairly large swales, built hundreds of years ago, that let rainy season water from small streams soak into the ground, providing water for agriculture in dry seasons. The ruins of ancient water projects and a few still-working projects can be found from southern France to India, also in New Mexico and Peru.

If the laws are written correctly, and that's never a given, groundwater is the best way to store water. Groundwater reservoirs take up no land. Dams don't need to be constructed, where building a dam often has climate implications. Groundwater doesn't evaporate. Dams create ponds that absorb solar heat on sunny days, which increases pond evaporation. Storage of water in the ground looks to be more water-efficient than impounding the water behind a dam.

At least one First Nation in Arizona has cut a deal with state and U.S. authorities to store Colorado River water underground near Tuscon, using acre-sized swales to sink the water.

For several years I've been pushing chronic worldwide agricultural decline as the alarm clock that finally wakes up the world from incessant climate delay. I'm not at all sure that I want to be correct but unfortunately the scientific consensus continues to skew in that direction.

'Jägermeyr, a crop modeler and climate scientist, also at GISS, noted that the projected yields of corn dropped by more than 20 percent globally compared to current production levels. “That’s a completely new realm,” he said. “Across the world and in many bread basket regions, this is going to occur in the next couple years. The main message here is: This is right around the corner.” ' -- Complex Models Now Gauge the Impact of Climate Change on Global Food Production. The Results Are ‘Alarming’, insideclimatenews.org/news/27032022/climate-change-food-production-famine/

Sandy soil can lose its groundwater in hours or days. Carbon-rich soil with 80% or 90% carbon content can retain groundwater for up to a month. -- [https://www.livingobservatory.org/learning-report]

Local committees take care of trees, but oligarchs tend to just embezzle the funds set aside for caring for trees. I've heard that even street gangs will take good care of neighborhood trees if they see the trees as their trees in their neighborhood.

The country of Niger has few natural resources and a climate that ranges from full Sahara desert to sub-Saharan scrub with seasonal rains. Mass collectivization of agriculture didn't work in Niger because of the harsh climate, so most farming is on small plots of land. A good deal of Niger, especially river valley land, has year-round groundwater several meters below ground level. The winter thorn tree has evolved an especially deep tap root that reaches down to this groundwater layer.

In the 1980s, small farmers and aid workers discovered that after cutting down winter thorn trees in their fields, if they let the trees grow back from the stumps, crops performed better around the stumps. The trees reduced moisture losses by acting as windbreaks. The trees restored nitrogen to the soil. In dry months the trees transpired water into the air, raising the local humidity. Local ground temperatures dropped. The trees laid down an annual layer of leaves that helped to retain usable soil moisture for plants. The tree's fruits are an animal feed and the trees produce firewood.

40 years later, it has been conservatively estimated that 200 million new winter thorn trees are on farmland. The value of each tree to the small farmer is proverbially said to be equal to ten cattle. The word is spreading internationally. In a world where forests are being clear-cut or burned, Niger is an anomaly.

First, reliance on one species of acacia tree is attracting predators. The Guardian article cites a report of a tree-killing disease that could wipe out the nation's agricultural crop of acacia trees. Are there perhaps ten other species of trees that would work almost as well? A farm planted with ten species of trees can better handle a disease that kills one species, and spreading the various species around makes it harder for a species-specific predator to find that species.

Also, different trees will have different crop values. Some trees have edible fruit or nuts. U.S. farmers sometimes like to grow a crop rotation that includes soybeans because soybeans can fix nitrogen into the soil. What pioneer protective trees might best grow in near-desert conditions for reclaiming various patches of near-desert? What species have the best wood for lumber? What species are good for feeding cattle or goats? What species are elephant-resistant if a farm is near a national wildlife preserve? I was just reading of a strange type of elephant fencing to keep elephants out of cropland. A single wire runs around the farm's perimeter, and the wire is connected to beehive boxes and also to a few fake beehive boxes. When an elephant breaks the wire or pushes the wire, the shaking disturbs the bees, and even elephants don't like angry African bees. It turns out that the elephants never forget.

In pictures of Niger cropland I see trees scattered randomly over the fields. This would naturally leave various dry spots and extra-shady spots in the cropland. Trees might be more effective at cutting wind if they are arranged in hedgerows, where the hedgerows in the Oklahoma Dust Bowl were arranged at a 90 degree angle to the strongest prevailing winds.

If mature trees are to be harvested down to the stump, I'd recommend that alternating hedgerows of trees be harvested at any one time. Harvesting two adjacent hedgerows of trees at the same time will allow too much wind to dry out a section of field.

Centuries ago, English woodlot managers would often leave the trunk of a veteran tree in place while harvesting all of the major horizontal branches above perhaps the 8 foot level. New vegetation would sprout out of the top of the trunk, above where the local deer could chew the vegetation off. Leaving a tree's trunk and one vertical leafy branch above that further guarantees that the remaining tree has enough energy to come back from a major pruning, and one well-tended large-diameter straight tree trunk will someday be worth more to a sawmill operator than two or three tiny tree trunks. Professional fruit tree pruners understand that pruning is an art. A well-pruned tree is a stronger tree that will yield more fruit. Also, a thicker tree trunk might be more elephant-resistant.

Even at perhaps 13 degrees north latitude, a tall hedgerow of trees or even one tree is going to have a sunnier than normal southern side and a shadier northern side. Would it help to grow south-side and north-side crops adjacent to hedgerows? Would coffee or cacao bushes/trees fit the bill on either side?

I've asked a good number of solvable practical questions here. Now I'll ask another type of question: How does an organization of all of the stakeholders best go about solving all of these practical questions? Obviously somebody, or lots of people, has to first find out if the research has already been done elsewhere. If no answer yet exists, who is going to do the hard work of trial and error experimentation?

Was there a financial motive for somebody to do all of the hard work quickly, or did the stakeholders all roll the dice on an intellectual savior appearing for free or for dirt cheap? What's the cost if ten years pass and the stakeholders discover that nobody at all has yet to do any of the mission-critical work? Was the problem, in retrospect, to everybody's lasting regret in retrospect, that nobody at all could make a living doing the mission-critical work, and so nobody did the work, and in the end nobody at all can make a living farming? Was that the problem? Wasn't there an effective lobbying effort to save the stakeholders from the coming megadrought where several bad things are most likely going to continue to happen to trees.

I have just posed the key question that runs through this entire website. Specifically, which person do you see doing any of the mission-critical work?

The recently referenced Guardian and National Geographic articles note that the African Great Green Wall strategy has largely failed. Reasons range from government indifference to the fate of the planted seedlings to herders allowing their livestock to eat the seedlings.

Nevertheless we're going to need some variant of "great green wall" strategy in North America. U.S. forests are burning down and so megadrought and desertification creeps across the western U.S. states. Because the typical atmospheric frontal boundary between wet atmosphere and dry atmosphere has now moved eastward about 150 miles across the Great Plains and because this frontal boundary typically spawns thunderstorms, the epicenter of U.S. tornado damage has moved eastward from Oklahoma to roughly Alabama.

The term "great green wall" is a bit of a misnomer. Walls don't keep out extremely hot and extremely low humidity air. The Sahel reports that a thin "wall" strategy doesn't work, as the desert grows in patches. We want to rehumidify entire regions, typically with as many transpiring trees as possible.

U.S. farmers burn the fuel equivalent of 92% of a gallon of gasoline in order to produce the equivalent of one gallon of gasoline in corn ethanol, plus we see notable environmental losses from current corn production methods. The corn ethanol program might make a certain well-connected group of people richer but it's not effective in preventing climate change. In general we need to ask whether various programs are driving greenhouse gas sequestration forward. Have they become standing cash cows whose main outcome these days is blind inertia? We have a problem – human civilization can't afford a climate-driven gradual collapse of worldwide agriculture. We need to blur the line between agriculture and carbon sequestration.

Natural wildlife refuges aren't going to be that natural within a few decades. As with much of the rest of the world, the refuges can become bone-dry and hot during megadroughts, which defeats part of their purpose. We unfortunately may need to think about finding a balance between having fewer wildlife refuges and not enough greenhouse gas sequestration. We might need to blur the line between wildlife reserves and carbon sequestration. Fortunately for many such refuges, wetlands are already a climate priority.

Which species puts the most moisture back into the local atmosphere? Which shelter the local topsoil the best? What is the projected survival rate of a newly planted species given the new megadrought reality for a particular region, and also given any newly built microswales depositing groundwater in the immediate area of the tree? Does the species also have other benefits for human survival such as good wood, good forage for goats, maple syrup, commercially usable nuts or berries?

Is a mixture of several tree species hardier in the event of a drought or a climate-driven insect infestation?

Current industrial-scale carbon sequestration systems tend to be at best overpromoted and at worst worthless. They're some industry's wish list. Trees replant themselves in the natural world. Claiming something called a “carbon credit” for having a person plant a four inch seedling sounds like little more than an exercise in rhetoric.

For every sequestration plan, the number of years of sequestration is vital. A quality sequestration effort should take a certain amount of carbon out of play for at least 2,000 years. That's how long it would take the earth to naturally sequester all excess carbon dioxide currently in the atmosphere. If the carbon leaks out in 2,000 years, it can be naturally re-sequestered by the planet's environment. I don't consider ten years or one hundred years of sequestration to be an honest sequestration scheme.

Some tree species, oak trees for example, take perhaps 20 years to grow tall enough to bear many acorns, and blue jays will carry the acorns a maximum of about 1 mile and bury them in stashes to be used as food during the winter. From the oak tree point of view, this plants a next generation of oak trees in open fields a mile away. Unfortunately, oak trees somehow need to migrate northward at a velocity of perhaps 1000 miles in 50 years, not 1 mile in 20 years, to keep up with the speed of climate change.

I look for most of the world's mature trees to soon be growing in inappropriate climates. These trees will be stressed. On top of this stress, we're seeing entire species of trees ravaged by climate-driven insect explosions. I conclude that looking forward several decades, most of the world's trees are likely to be dead. They'll become vertical dried out white sticks waiting to fuel a megafire. But then, more of the remaining trees are likely to burn down in a megafire.

We may need trees native to North America to migrate northward up to 1000 miles in North America. Otherwise, in a climate changed world we're going to have few living trees, and that leads to extreme summer high temperatures and extremely low topsoil moisture levels. No bird and no squirrel is expected to help us with the long migration. However, if we humans move a few tree seeds north ourselves, specifically just beyond the far northern edges of their traditional ranges, the moved trees can re-seed themselves and colonize within perhaps a one mile radius after perhaps 20 years. In this way a tiny colony of mature oak trees can create a few square miles of forest in its second generation. Magnolia trees can move into coastal southern New England. Magnolias in New England might be better than someday having almost no trees at all, which would lead to violent heat waves and agriculture-ruining drought periods.

Ascension Island in the tropical Atlantic Ocean was a treeless volcanic cinder in 1843. Per Wikipedia, a British botanist imported 40 species of trees in order to improve the island's water supply. Ascension Island thereupon became a cloud forest and has stayed so to this day.

Some research group is experimenting with reforesting a logged-over stretch of land using drone-dropped tree seeds. I don't see why human volunteers can't drop a few seeds - it sounds cheaper and more effective to me.

The drone seeding project claims that tree seeds such as acorns will be more likely to succeed if we pre-compress them inside little soil balls. One dozen seed balls will carry well inside a recycled egg crate. Because non-flowering trees need to cross-pollinate. we'd want to plant colonies of perhaps one dozen acorns or other tree seeds reasonably close to each other. If an average of 40% of a new colony of twelve seeds of one species come up and survive to maturity, I'm hoping that all five won't be male pollen-scatterers the first year and all female acorn-growers the second year.

Volunteers would plant or drop the cubes a certain minimum distance apart so that the trees don't fight each other for sun and water. A micro-swale next to the tree seed would often tend to assure us that the tree won't die of drought.

Much of the weight of shipping can be saved by using locally sourced seed ball ingredients: clay, grass and sand. It's more economical to mail large boxes of acorns, chestnuts or other seeds plus a key seed ball ingredient, dry chili peppers, to regional accomplices. The chili will keep wild pigs and smaller animals from eating the acorns. Print special labels telling people where to drop or plant a particular species.

Regionally, roll or compress into balls. Next, get individuals to drive egg crates of seed cubes around to local distribution centers, and the locals will find supporters to take and plant/drop the seed cubes.

Consider sending several competing species of trees north, as monocropping sometimes leads to insects or diseases wiping out one particular species. Within two generations an ecologically well-mixed forest should start growing in that square mile, or at a longer distance downwind for wind-borne seeds. Some species such as poplar are better at long-range re-seeding than others.

To make sure that at least some trees are growing after a major fire or dieoff, we might want to prioritize establishing first generations of early colonizer species. We'll also find that some species are better at resisting droughts and extreme temperatures than other species, and some species resist fires well.

For further reading: Croatia's seed-scattering drones replant forests hurt by fire. This web page has already been removed by msn.com, but you might try looking for any similar story with a search engine.

(9/25/23) See also my blog at paulklinkman/substack.com . I'm still working on that link.

A good trellis might deliver vastly more square-meter-years of green canopy shade per lifetime dollar than a street tree.

- A trellis delivers results in a tiny fraction of the time that a tree needs to grow. In a climate-changed world, speed is important.

- A trellis is better designed for greenery control. It keeps its size decade after decade. It doesn't grow a hundred foot tree that can crash over onto a nearby building. Each trellis can be sized to fit specific space needs such as non-interference with trucks on the street, non-interference with electric wires and non-interference with safety lighting at night, unlike a tree that simply wants to grow everywhere.

- If two or more vines are planted on one trellis and if one vine dies, almost nobody notices. If a big tree gets sick or dies it's always a danger to fall over on something and it always costs a fortune to remove..

- The trellis can be built to extreme hurricane standards. An extremely dangerous hurricane is likely to rip all of the leaves off of the vines but the trellis won't blow over and the vine should re-leaf in just a month.

- The trellis has thicker light-blocking foliage. A trellis will achieve a notably cooler local urban temperature than a street tree, and coolness counts.

Trees cool cities. Trees turn the sun's heat into water vapor through transpiration, and that water vapor soon drifts downwind. Trees provide shade at ground level. They can reduce a neighborhood's afternoon temperature by 30 degrees. The lack of trees causes the sun to heat urban blacktop and urban building walls, making each street less livable on a late afternoon in July, and each neighborhood and the entire city in turn becomes less livable because the stored radiant heat gets released all night. That's why people recommend maximum green shade for every urban neighborhood.

Unfortunately, trees have hidden costs. Sometimes thousand dollar street trees are planted and then they die from lack of ground water, from too much standing water or from bicycle chains. Huge trees have to be taken down with tall cranes when they die. Huge trees can destroy house roofs when they fall on the houses during tornadoes and hurricanes, or crashing trees can block major streets and tear down power lines. Hurricanes can uproot trees or snap trees. In time trees can block the light from street lights especially in spots where their own tree roots tend to have raised a section of sidewalk, creating a dangerous, pitch-dark trip and fall hazard on the sidewalk at night.

A good street tree might cost $1000 or more and the average urban tree only survives an average of 7 years. Bicycle chains can kill or damage saplings. When kids try to climb tree saplings they break the saplings. Vehicle collisions can kill curbside trees. Street trees start

branching from their trunks at the six foot level, but then 14 foot tall trucks can snap off the large branches that lean out over the street, sometimes with fatal consequences to the street tree. A utility company might repeatedly saw off half of a tree's foliage in order to protect electric wires, sometimes cutting right through the middle of the tree's foliage. Building owners repeatedly saw off the sides of trees that touch their buildings. At times nobody cares if curbside trees get any of the local rainwater that should drain down from sidewalks to the tree's roots, preferring that 100% of the rainwater flows into a storm drain.

To the left is a geodesic dome structure for a trellis. The steel pipe rafters of the dome should be able to support individual swings, cables holding up a soft, cable-based climbing gym and perhaps a whale sculpture suspended in the air. This trellis has two large holes in the middle for sunshine (which will get partly filled in by vines), because trellises can block out 95% of the sunlight over a large area and sometimes 95% is too shady on cloudy days.

The goal is to quickly grow perennial summer green canopies exactly in the positions, heights and shapes that we need them. Trees take many years to adequately shade a huge area. Many trees provide spotty shade coverage. We can do better.

I recommend, as a matter of total cost and effectiveness, that we experiment with vines and urban trellises as an alternative to street trees. Trellis canopies fit specifically into tighter urban spaces and the trellises stay in their places. Trellises grow many times faster than trees can grow. They grow horizontally so that we can cover, for example, an entire basketball court from the two sides of the court. Certain vines can thicken their coverage into an unbeatable 98% solar shading ability. If planned properly, vines are less likely than large trees to eventually interfere with street light coverage. Because a vine only grows to the height of its trellis, a vine will never fall onto a power line or through a house in a hurricane.

We need to learn to get the vines to grow exactly where we want them to grow and then grow no further. If we succeed in this task, everybody will be substituting trellises for trees in various tight urban spaces.

For this description I'll choose an Asian wisteria vine. This choice may not be optimal because Japanese wisteria is an aggressive, invasive species, but on the other hand I've seen a nice example of a wisteria trellis up the street from my house. One of the world's largest wisteria vines in Japan spreads out laterally an average of 85 feet away from its trunk. [[wikipedia, wisteria]] To have vines provide 98% shade for a standard basketball court if the vines are planted on each of the court's two sides, the vines would need to grow a lateral distance of about 40 feet across the court at about a 30 foot elevation above the court.

A more suitable vine native to North America might be honeysuckle or perhaps a North American variant of wisteria which isn't quite as aggressive.

Four foot vine tendrils can be pruned off of existing vines because residents don't want the tendrils, then can be kept in water with rooting hormones until roots form, then planted in root ball-sized pots for easier transportation and planting.

A vine will grow up an inexpensive, compostable string ladder, two heavy strings held apart with tiny sticks and with a connecting string woven back and forth between the two main strings. Two poles will hold up a rope that can support several string ladders.

At some height wrap the bottom of the vine's trunk with a roll of flexible wrap, to discourage the growing of leaves and branches from the lower trunk. As the vine gets higher, wrap more and more of the trunk, always leaving lots of foliage at the very top for continued vine growth.

When about ten feet of trunk has been grown, you can probably take down the vine ladder. coil the trunk in a wide 10 foot coil and allow the vine foliage to keep growing preparatory to planting. Truck the vine out to the site with its trunk coiled, plant the root ball, uncoil the trunk and fasten the top of the vine onto the trellis. The vine will further attach itself to the trellis in the next two years.

I suggest that if you always plant two vines together, not just one vine, one vine can die sooner or later and nobody will ever worry. It makes sense to grow the two vines within the same root ball, even to start three vines within the same root ball and then cull the weakest of the three in a week.

You would never try this double vine trick with street trees. When a single street tree dies you must replant.

I see three ways to keep the first ten feet of a vine in control. The default method is to prune all branches of the vine every year, up to the ten foot level. Better is to wind a long-lasting flexible wrap around the leafless trunk of the vine so that no sunlight gets to the trunk and then new branching is never stimulated. In tough urban spots the 10 foot trunk of the vine can be encapsulated in a 12” diameter vertical steel pipe. The steel pipe protects against trunk damage from bicycle chains and other trunk-destroying urban problems.

Below ground level, for certain species a layer of wire screening might be needed to keep any suckers from coming up near the root ball. Mowing the nearby lawn will also stop the vine from spreading along the ground.

The single tree trellis at the top of section S12 self-shades the trunks growing up the center of the trellis.

Especially on the south, east and west edges of a trellis, vine tendrils getting full sun might possibly grow downward toward the ground. One method of tendril control uses a five foot wide sun shield mounted at least five feet above the edge of the trellis. The vine should hopefully be smart enough to not try to grow through an extended layer of shade. I'm assuming that a particular species of vine can't achieve a 5 foot leap upward onto a slippery surface, in order to access the sunlight shining on top of the sun shield.

A sandpaper cable would be a cable with an extremely fine sawtooth-like edge protruding in all four directions around the cable. Coating the cable with particles of fine sandpaper sand should work. If the wind pushes a soft vine tendril back and forth across a sandpaper cable 100 times, the tendril will be at least halfway sawed through and the end of the tendril can't get any sap to continue growing. The extremely fine sandpaper surface shouldn't be a problem if kids occasionally touch the sandpaper cable.

Otherwise, a perfect trellis needs a local committee or a small business owner to manually prune the tendrils back every November. The committee doesn't have to cut through any trunks, just lop off little tendrils with a 10 foot aluminum pole and a cord-operated lopper on the end of the pole. They sell branch lopping poles.

An A-frame of pipes, similar in shape to a playground swing structure, can support tension at the ends of a cable trellis overhanging a long walking or bicycle path. Once the trellis cables become fully loaded with vine weight, the cables will need strong lateral support at both ends. Between the two ends, simpler pipe support structures of one cross pipe between two vertical support pipes should support the trellis cables. In the diagrams the trellis cables are 1 foot apart and each cable runs 80 feet in the direction of the bikeway.

I drew the vines encased in steel jackets here, first to keep the vines from spreading at ground level and second to keep the vine trunks protected from bicycle locks and from kids carving initials into the wood. If these problems don't occur in practice, then naked vine trunks will work fine.

The most important siting feature in any trellis is avoidance of existing trees. A vine will by its nature climb a tree and then shade out the tree. That can kill the tree. Vines can also climb wooden telephone poles and guy wires. They can't climb smooth vertical metal poles. I can think of a section of bike path near my home that runs alongside the edge of a soccer field with no nearby trees.

Given a flat trellis, vines will take over the top of the trellis and shade out any downward-hanging vine tendrils, but at the edges of the trellis tendrils can hang down and profit from early morning sun or from late afternoon sun. I've seen trellises that raise up at their edges so that the tendrils have farther to hang down at the edges.

On an east-west bikeway or sidewalk trellis I would tip the trellis roughly 30 degrees up toward the south side to get winter sunlight and night lighting onto the walkway but provide 98% shade all day in the summer. A north-south trellis would have a flat top.

If an urban sidewalk trellis hangs out above the street a few feet at a trellis height of 16 feet above the street, 14 foot high trucks will occasionally come along in the parking lane and damage any hanging vine tendrils at the 14 foot level or lower, just as trucks currently can rip off large branches of street trees at this level. With vine tendrils, a bit of tearing off at the street edge is all for the good.

For a large-scale coverage of a basketball court, a wide city street or a tot lot, we don't want near-zero ambient light below the trellis on cloudy days and just after sunset. Holes in the trellis cable network, perhaps 10 feet in diameter, would permit shafts of sunlight to penetrate the trellis and illuminate the area in the daytime. It's possible to build 10 foot diameter empty circles in the cabling, too large for the vines to fully cover.

A metal pipe trellis framework can be a good platform on which to mount floodlights for night uses and to mount basketball backboards. All of the vines' sunlight-related growth should take place on top of the trellis where full sun is available, leaving the space below the trellis free of streetlight-blocking vines.

In the event of a rare category 5 hurricane, the wind will pass right through the trellis cables and through the large wooden vines. The metal frame will be constructed to withstand the hurricane far better than most of the surrounding trees. Most of the vine leaves will probably be ripped away by wind gusts but the vine branches can re-leaf later.

Because vines can grow long distances laterally, a trellis can effectively shade a downtown sidewalk where planting spots for street trees are fewer and farther between. It can overshade 90% of an entire downtown street that sometimes gets used for street vendors and pedestrian use, as long as the trellis edges are built 5 feet away from any buildings and well away from trees. It can cover a tot lot or a set of bleachers. It can cover an urban area full of restaurant tables for cool summer outdoor dining.

Portland, Oregon plants fruit trees where local neighborhood organizations can tend them. There's no reason why a grape trellis can't simultaneously provide a neighborhood with table grapes and shade some parkland, refrigerating the rest of the neighborhood.

A brave city, or if the truth be told a city that is 80% skinflint and also somewhat cowardly but 20% brave is good enough, will find allies such as master gardeners, a local nonprofittree planting group or a local arboretum. These allies will find answers to fairly easy vine research questions such as,

- What are good candidates for tot lot canopy vines? Are vines native to North America preferred?

- Is there a recipe for propagating vine whips? how big a root ball is enough for transplanting?

- How do we keep the first 10 feet of vine from branching? Will wrapping tape around the trunk of the vine help?

- If the trellis's cables are strung 3 feet apart, is that too wide apart? Will the vines handle a jump of 3 feet?

- Will the vines operate 20 feet up? How far across a trellis can they spread? Will vines interlace across a trellis so that if one vine dies, the other vine soon takes up the slack? If the demonstration coverage target is, say, one picnic table, how thick is the coverage after 12 months? What are the annual trimming and pruning costs? Can local neighborhood volunteers do the annual pruning?

- If we have street vines covering concrete sidewalks, will the vines get enough water in drought times? Will the vines flood out?

- Are there any deadly fungus diseases or pests that we need to be aware of? Does the trellis attract too many little birds?

Armed with all of this valuable information, hopefully acquired at a low cost, a progressive city or a nonprofit can more safely move on to a larger demonstration project such as building the city's shadiest and coolest outdoor tot lot.

I've read that when herbivores eat certain perennial tallgrasses, each deep-rooted plant then pulls nearly all of its remaining carbohydrate and sugar energy out of its 30 foot deep root system in order to grow new leaves quickly and not die. Each root system dies back to within one inch of the earth's surface, leaving dead cellulose (carbon) roots extending 30 feet down. The bottom 29 feet of the root system becomes sequestered carbon. The old root system is deep enough in the ground that the hydrocarbons should stay in place for at least 2000 years. This process would get repeated each year.

Mature forests are lousy at sequestering carbon because most of a forest's carbon is above ground in tree cellulose. That part burns down regularly.

Bamboo, technically a tall grass, is reportedly several times better per acre at sequestering carbon than trees. We might not want to import Asian species of bamboo to North America but there are three species of bamboo native to North America. Bamboo hedgerows are dense and would reduce wind evaporation on fields downwind, improving agriculture by increasing local soil moisture. Mature bamboo stalks can be harvested annually from the hedgerows, to be replaced by younger stalks that come up naturally. Mature bamboo stalks can be used to produce bamboo laminates, a good substitute for wood flooring.

Because bamboo, technically a grass, keeps a greater percentage of its carbon in its extensive root system, bamboo is reportedly better at long-term sequestration of carbon than trees. With trees, most of the carbon is above ground holding up a canopy far above the ground. Most of this above-ground carbon storage will soon enough burn up in a wildfire.

Note: bamboo is an aggressively spreading plant. Control of underground spreading is a side issue that needs to be better-solved. Would a deep enough layer of tough underground netting stop the spreading?

A field with 20% photovoltaic panels might lose 20% of its crop-growing sunlight. However, the windbreak and moisture advantage might roughly offset this 20% loss in terms of crop yields. In particular, having the solar windbreaks 20 feet apart will reduce soil moisture losses from prevailing winds.

My heliostats are designed to be quite lightweight and to have resistance to hurricane-force wind gusts. A heliostat array built over a parking lot or over an agricultural field can generate useful building heating/cooling energy, can cool the land underneath the heliostats a bit and can cut wind-related evaporation from a field.

Fixed east-west rows of photovoltaic panels might be interspersed with tractor-width rows for raising crops at Frost Belt latitudes. In winter the sun approaches at a low angle, and so spacing the rows of photovoltaic panels apart from each other makes the PV part of the farm more cost-effective in winter . In summer, leaving one tractor width row of a farmable crop between rows of PV panels means that the extra summer sun can grow a crop and also full power the PV panels.

Solar tracking PV panels could benefit from wind holes. Reducing the wind load on the PV panel can translate into a larger panel on the same mount.

If the farm has flood drainage canals for better crop growth, they could be situated under the PV panels.

Nebraska gets adequate rainfall but the Oglalla aquifer below Nebraska has been tapped out. This doesn't make sense.

A farm that drains excess water levels down from its cropland should make an effort to recharge local aquifers. This might be as simple as drilling short wells at the bottoms of drainage ditches and having small swales in the ditches to give the water a chance to settle.