Monday, March 26, 2012

Roots: 'Hydraulic Lift and Redistribution'

I love this animated Illustration. It looks like something an informed young elementary school student would have done for a class science project. Sadly the webpage it appears on and the short description of the post was merely followed by 3 spam comments from the usual culprits in cyberspace. So I'm hoping something more intelligent happens here when it comes to comments. Much of my experience has been with Southwestern Native USA Plants, especially desert plants like Mesquite which are well known and important Mother Trees or Foundation Trees to their environments. A similar type species and one that African readers will recognize are the many Acacia Trees from the African Savanah landscapes which serve an identical function in their native habitats. People from other countries such as India, Pakistan, Vietnam, Australia or even residents from other continents like South American who have their own Dominant Mother Trees like Brazilian Nut or desert Mother Tree like Huarango will know what I'm talking about here. These key ecosystem foundational trees when removed have proven their worth when these local ecosystems collapse. Tale a look at some of the common deep rooted species I'm referring to and again, as I many of my posts on Desert Southwestern USA plants, you should all recognize similar applications within your own territories around the globe.

Image - Amboseli National Park

Iconic Acacia giants on African Savanna (Acacia Tortilis
Those mighty looking Acacia Tortilis on the African Sanna lands have incredibly deep roots. Actually some of the deepest in the world. They are huge hydraulic lifters and redistributors of water for other plantlife on the savanna when the rainy season is absent.


Harold Laudeus/Flickr

Tree of Life in Bahrain (Prosopis cineraria)
The above photo is a tree out in the middle of nowhere in the Persian Guld island nation of Bahrain next to Saudi Arabia. They label it a mesquite, but I imagine in that part of the world it's more of an Acacia tortilis. However it is indeed a variety of Mesquite tree (Propsopis cineraria) but I'll have to look it up further. Still it is an extremely deep rooted tree which easily lists it as an important mother type tree for others around it. This one appears to be all by itself on a moonscaped hot desert surface. One wonders how it got there in the first place. Especially without a mother tree or nurse shrub to protect it. Where did the seed come from ? Perhaps a human planted it many many years ago. Who knows. 


So much of our scientific literature or research papers and it's terminology content blow right over the average person's head. Yes I understand the need for massive volumes of data, etc, but why should it be up to journalists to make some type of interpretative story line which may itself may even be coloured and tainted by the Media Journalist's own preferential biases. Let's be honest, most of these papers are only meant for the eyes and ears of other scientists and the Panel of Peers who give their stamps of approval within a scientific world that is out of touch with the reality and needs of the common man, who actually needs to know and understand these amazing mechanisms and make their own practical applications. It therefore is a great challenge for the researcher to grasp the language of the average world citizen of mankind and in simple illustrative terms that bring it down to their level. 

 It is of course an extremely important for all involved in the gardening , landscaping, environmental restoration industries to grasp understanding how all soil Networked Solutions work and function which is the continued purpose of this blog and another very important subject here as indicated by the above titled mechanism called 'Hydraulic Lift & Redistribution'.  I'll introduce another very important topic of 'Hydraulic Descent' at a later date, but for now I'll stick to this topic. My first taste of the terminology came from trying to find logical ways of replicating nature in restoring environments and also how plants would have operated mechanically in an ancient world's minerotrophic hydrological cycle.  There was an old time favourite experiment I tried back in the late 1970s. It was the old take a very large glass jar, put a paper towel all around the edges, put a couple inches of water in it and after the paper towel absorbs enough water to saturate the entire towel, place a seed near the top and watch it grow. This is what teachers did for us kids in elementary school to illustrate to us how a plant grows. Remember those sweetcorn or bean seed germination projects ? 

Image - first-learn.com

Ever do one of those seed germination experiments in elementary school where a jar and paper towel allows young kids to see in real time just how a seed germinates and becomes a plant ? It all starts wit a single taproot. I was once down in the Coachella Valley near Palm Springs California one summer and ran across some Catsclaw Acacia seed pods. Now they look some what like Mesquite or Paloverde, certainly in that Pea family. Live in almost identical habitat under the most harsh of conditions. But here's what happened in that experiment. I placed the seed almost exactly as you see above. It was a month or so and one of the Catsclaw seeds germinated, but just the root only. I must have had it in there for a couple months before I really gave it any thought again. By this time it had actually sprouted a tiny compound leaf, but not more than half and inch high. It stayed that way for another couple of months. I didn't feed it anything because the seed itself has it's own nutritional package in the form of the bean or pea itself that it feeds off till nature takes over. Funny though I really hadn't realized that on the bottom, this tap root which had at first very quickly reached the bottom that first month by now was growing and spinning multiple revolutions around the bottom of this rather large jar. I hadn't noticed this as the white paper towel had obscured from view the also white taproot of the Catsclaw Acacia. When I went to transplant it up in the mountain somewhere above my parents house that next winter, I pulled it out of the jar and the taproot was almost one meter long. Incredibly the sprout or sprig of leaf was still an incredible one inch high. Small compared to the resources this plant put into creating an extensive root system.

I pondered for a moment why. Then realized where this species of Desert Tree prefers to grow. It was clear the the genetic instructions encoded in this plant's DNA for it's genetic survival blueprint demanded that it first throw down all resources necessary to build a deep root system till it's hits the moisture layers of the subsoil or even as far as the water table. These types of trees can send their tap root 40-50 meters deep into the soil. Not all in that first year of course, but over time. The seed really depends on luck in being planted in the ground in exactly the right place. Once germinated, it almost likely needs what it called a nurse plant or at least some sort of rock crevices to shelter it in those first few years of growth. Once it taps into the soil's subsurface moisture layers, then it will explode in growth. Meanwhile, prior to this explosion of growth, all resources dictate as per genetic instructions for successful survival that it build an extensive root system. The illustration below shows something a little more speeded up than what I experienced, but nevertheless you get the idea. The seedling itself is hardly tough. In reality it's very delicate.

Animation - watching the world wakeup

The main point that you need to walk away with here is that such species as Prosopis (Mesquites), Acacias (Thorntrees, Wattles, etc), Parkinsonias (Paloverdes) and many others are foundational trees for other plant life within any community across the globe. For example, in the Sonoran Desert environments of Arizona and northern Mexico, the Saguaro Cactus actually needs the shelter of such trees as these in order to make it through early life. Try growing some Saguaro seed you've obtained from one of those novelty packages at some gift shop in the southwest and you'll notice that when they germinate, they ARE NOT the tough stickery spiny looking formidable plant you see in the wild as adults. When young and first emerging, they look like nothing more than Ice plant or Sea Fig. They need all the help and protection they can get. The other disadvantage they have by comparison is that they have no deep roots. Their survival mechanism and strategy is to storage water quickly in spongy fleshy material after major downpours. However this is not enough when they are tiny. What I've personally observed with many of the hydraulic water lifting plants that extract water from deeper layer in the Earth is that often just under the immediate surface, the ground is quite often damp or moist as this moisture is slowly released through the lateral roots during the night. This was true of a foundational large shrub or small tree where I lived in the high desert country of Anza, CA. Having tried to dig several out by hand following months of hot dry season, I can attest to the moisture content of the earth beneath them. They have two to three, maybe four major tap roots that often if located strategically in the right soil structure go straight down deep into the soil. In fact trying to dig on of these major taproots is like a dentist trying to extract a deeply set wisdom tooth. Incredibly there are a number of small species of plants and mosses that live nowhere else but under these trees. The Shrub/Tree is Redshanks or Ribbonwood (Adenostoma sparsifolium), but more on that at a future post.

In some Continents like Africa, Asia, Australia, the various varieties within the Mesquite, especially Prosopis juliflora have taken over and become an invasive nuisance in those countries as an invasive threat to native populations of plants, shrubs and trees. Yet, like so many other places where there seem to be uncontrollable invasive plants, Mesquite pods may just be a blessing as animal fodder. The pods unlike other Pea Family pods do not split open and release their seeds. They have to be eaten by an animal whose digestive juices may actually scar the hard outer seed coating which only then allows water to actually penetrate to the actual seed germ. In my area of the Southwest, native Big Horn Sheep love these pods, as do cattle and other browsing herbivores. I'll get more into the Mesquite and Mesquite Dune Projects in a future article for  which new findings actually look promising as agricultural windbreaks to replace another one of those invasive plants brought in for windbreak purposes, and that is the Tamarisks.


Some Concluding comments:
There is another equally important component to this hydrological process and it has something to do with what is called "Hydraulic Descent",in which Mesquite and other trees will pump abundant water after rainstorms deep into the earth's subterranean soil layers. This phenomena also takes place when these trees are in their dormancy state in winter time. So please follow along in the further reading of this article here linked below:

4 comments:

  1. Interesting article. I would hope to see more of African ideas for restorations. Africa is dying and needs helps.
    When can we here more from this opportunities in the African continent.

    ReplyDelete
  2. This may be down the road Sir. Possibly Acacia Tortilis, but I have a few other subjects to create before that.

    Thanks for reading.

    ReplyDelete
  3. Good article, and helpful. I'm trying to learn more about Redshanks and other native plants that grow here in Anza. Some of the photos would not open, but that may be due to my computer.

    ReplyDelete
    Replies
    1. Glad you enjoyed the post and thanks for the feedback. I've since fixed that.

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