Getting to the Root of why Natives rule & Exotics struggle or outright fail

For those particularly interested in Landscapes in the Southwest, you need to seriously pay attention

animation: Beatrice the Biologist

Whenever I am out anywhere in Nature, I am often intrigued with the natural underground networks which I believe make the beauty above ground all possible. Although usually unseen, I know there is something more going on with a luxuriant Chaparral shrub, especially when it first off appears to the eye to be in an impossible hot dry setting. In any event, it's always in the back of my mind and when I stumble upon a prime example while exploring, I record the scene straight away. I did recently stumble across these exact circumstances last week as my wife and I revisited Torrey Pines State Reserve between  Del Mar and La Jolla California. While walking the Park road back to Visitor Lodge from the Guy Flemming Trail, I noticed along the road cut out where the bank was crumbling and fractured rock debris was falling down to the road, there were numerous chaparral plant roots exposed as a result. This sand stone here looks to be a fairly dense impenetrable material where even water would merely run off the surface rather than percolate. Yet there they were, the cracks and fractures underneath being exploited by the plant's root system. It brought back to mind something that was reported on in a recent article and which I wrote about (Here) with the importance of plant roots being able to open up not only the surface ground layers, but also the sub-soils which further allows water percolation and deeper earth penetration by means of hydraulic descent. If course they exploit the hidden cracks and crevices with the Earth through their spiral drilling mechanisms. Take a look at three interesting photographs I took at Torrey Pines State Reserve which illustrate the intense natural engineering lengths at which California Chaparral species will take in order to survive.

Image: Torrey Pines State Reserve Park Rd

image: Torrey Pines State Preserve Park Rd

image: Torrey Pines State Reserve Park Rd

I was also further amazed by something I found regarding California Fan Palms this past weekend west of Ocotillo California in a canyon between Dos Cabezas Springs and Mortero Palms Oasis. To be honest, I never really paid much attention when it came to Fan Palm root structure and viewed their network as something which never strayed far from the tree. I mean after all, they always seem to be located near springs or seeps which run close to the surface. But I again stumbled upon something interesting again and in a location most hikers normally avoid or pay little attention to. The parking area for setting out on the long strenuous hike to Mortero Palms Oasis is in a separate canyon from that of the Oasis, but up that canyon there 5 or 6 good medium sized California Fan Palms along with smaller ones. There does also exist an older fallen log of a grand daddy which I can tell you has been there for years. The dry hot desert air tends to mummify wooden things in a sort of preservation phenomena. But aside from the usual placement of the odd palm here and there, it was the root system with in the area's fractured granite rock strata which actually caught my eye. First off, there was this one interesting fan Palm which was the first palm you come to climbing up the wash. Everything looked pretty much normal until you squeezed around to the back behind it. This is where I started paying attention once again to the ground and the network of root systems. Take a look at the photo below here where all is not what it seems from a visual perspective

This California Fan Palm was intriguing for one particular reason. I actually had to squeeze by this granite boulder here where I saw an interesting growth anomaly which took place decades back history where flood waters had knocked this tree down flat on the wash bottom as a youth, but through gravitropism it was able thereafter to right itself back up where from a frontal view looks perfectly normal and opposite in the back door. Nothing out in the wild can be attributed to ideal conditions. Everything is a tough struggle with some slight ideal conditions which allow for the success and survival. Of course in the urban landscape, things can be ideal, but understanding the mechanisms by which things succeed out in the wild will enable you to establish a landscape which will be more likely to flourish on it's own, especially during times of water availability and uncertainty. This is the goal that should be sought after anyway under any conditions. A landscape developed and maintained on a life support scenario, otherwise known as welfare, will not survive such tough times. The degradation of 75% of Southern California yards is proof that something has to change.

For the moment, take a look at this Fan Palm to the right. This tree was at the top of a rocky outcropping higher in the wash with it's roots extending downwards and also broadly running in a side pattern horizontally almost 15 feet away from the base of the tree. As solid as the granite bedrock was, it had numerous fracture lines running vertically as well as horizontally. This is where these delicate, yet tough fan palm roots found a conduit channel for seeking out further water seepage. I never though the roots ever went that far away from the tree and actually they went further beyond down the wash, but these pictures are of what I could verify on the surface. I have no real idea of how deep a setting the Fan Palm roots will venture. It would seem however they may go some feet in deep sandy wash type soils where aeration is exceptional. Given their presence in washes with regular flash flooding and debris sediment movements, I have seen some which have been buried far above their normal root line. Also there is the fact that many in a sheltered landscape setting, as they age and mature do start showing the protrusion of roots growing down from the trunk a foot or two above the ground level higher up on the trunk base. So who knows what the possibilities of actual depth with which could be obtained by these trees as long as there is good healthy aeration.

image: Mine

PalmBob 2009

The photo above of the fan palm roots are about 12-15 foot at the bottom of the wash away from that tree above. The roots actually followed the cracks and fractures within the exposed granite bedrock and have been revealed by continual ongoing natural flooding within the wash. They actually proceed beyond this picture on the left to deep down inside the level sandy wash down stream to the right in the photo where the original large ancient palm trunk has fallen over. Although I didn't photograph them, there were also lateral roots which grew at great distance sideways across the wash to the other side, once again following the cracks in the bedrock. The other photo of a Mexican Fan Palm to the right is for illustrative purposes only. Older Palms develop roots a foot or two above the soil line where the bark splits and reveals root growth expansion which not only adds to it's water and nutrient uptake if it's successful in reaching the ground, but also adds a wider base for the strength of the larger tree as well. Under natural normal wild conditions, the palm frond skirting would hide these roots and protect them from the drying elements of the harsh sun, making it possible for them to expand all the way down into the soil. It's important in understanding how things actually work or have the potential to work out in Nature. Without practical application, for me none of this would be of any real value. This is important in understanding the physiology of any plant's growth, especially in later life and the geology of your own landscape and what can and cannot be planted and why or with what in a community planting. How does everything work and harmonize for the benefit of the other plants ? Which mycorrhizal applications should I use to further enhance the plant's ability to thrive in the landscape ? While I never thought it possible, recent research has uncovered that palms can be colonized by ecto-mycorrhizae and not just endo-mycorrhizae. This is an important find and one I'll share later in another post. It's incredible because one of my favourite fungi are mentioned as doing the colonization, Pisoliths tinctorius (Dog turd Fungus).

Below here is one final photo. This is the bottom of the canyon where the wash opens up and fans out in the alluvial plan. This is a specimen of Holly Leaf Cherry (Prunus ilicifolia). Most of you won't believe this, but this particular old chaparral plant was present in the late 1960s when I first ventured here as a Boy scout. It is also a fascinating phenomena considering it's placement in the wild landscape. This area is extremely hot and dry, often well over 100 F or 40+ C. It's root infrastructure is clearly tapped into a permanent water source. It's the only Holly Leaf Cherry I have ever found near here and mostly likely was placed here by means of Coyote scat as opposed to being washed downstream. The placement above the wash may support this. The main point here is this chaparral species and the giant Sugarbush (Rhus ovata) in the next wash over can succeed in harsh climates given access to regular water. This is why natives should be used more often in the landscapes where as time pants on to the end, survival is becoming more and more of an issue than at any time previously.

image: Mine

I've benefited tremendously from observation and replication of various plant community scenarios observed in Nature. Despite recent climate change and drought in California, I have been successful in three landscape examples I installed last year (2013) in the interior valleys and mountains of San Diego County. I'll reveal the photos and report on them later. Of course everything is native plants and respect for underground root infrastructure and the interconnections between plants of the same community. Sadly, many of my techniques I fear will not work in remote wild places without human intervention, as the ongoing climate shifting and drought have changed the rules. In the landscape however, you have more control and success can be easily achieved by respect for some basic fundamentals and principles. If the climate were to ever change by way of improvement, then the native landscape will also respond in kind. The genetic information and detailed instruction are still in place, just waiting for this to happen. Sadly, I also fear that this year Torrey Pines State Reserve could and will be lost to wildfire if circumstances don't change. The chaparral and pines up there look terrible. The chaparral in many areas hasn't put on new growth and is struggling to maintain what's left by shedding well over half their leaves. The pic below says it all.

image: Mine

The chaparral everywhere here was suffering terribly and sadly it will be blamed when a disastrous wildfire strikes and it will, trust me. This should also be a wake-up call to home owners whose landscapes are in horrible condition and I say this from first hand on the ground observation. While the incredible amazing root infrastructure is all still there and in existence within all the plant communities, it means nothing without a normal rainfall pattern coming back again.

image: Mine

There were many stressed Torrey Pines, especially on the highest points where annual needle bundles located along the yearly growth whorls were from this years growth and that of last year. Most healthy pines in general should have as far back as six year's needle growth still present. The fact that these trees here exhibited only two or three years at best proves the stress they are under as they eliminate what they are incapable of maintaining. Armed with this knowledge, folks should inspect their own home landscape and be observant to the tell tale signs of a weakening system within their landscape. This is one of the main problems with the recent San Marcos Fire last month where News Helicopters revealed many neglected stressed or outright dead trees in their landscape which caused a greater firestorm. Although the State Park by it's very rules won't allow trimming of branches and dead material, in the interest of the park as a whole, something of a maintenance plan should be devised. There should be a rethinking of all Park and Wilderness rules where the conditions of climate and ecosystem health under which those rules originally formulated do not any longer exist. The conditions and rules by which Nature once operated no longer exist and humankind changed the rules.

image: Mine

Further Reading Interest:

Old Growth Tree Roots are far far more than Nature's Climate Thermostat

How much Reverse Engineering of Earth happens before Humans Admit there's a Problem ?

Hydraulic Lift and Redistribution of Water for the Benefit of other Plants in San Diego County

Deep Irrigation Methods for Training Deeper Rooting networks

YouTube: Planting trees with "deep pipe" irrigation