Let’s talk about natural bonsai or dwarf plants environmentally. We will take the example of the plant that grows, nailed to the side of a mountain. This article is not intended to be a scientific article, therefore I have no need, let alone the desire, to go into every variation of every sub-theme.
Any plant, given the required growing conditions, will survive, if not flower, for the expected number of years for that particular species, if not longer. However, before the seed of a plant can germinate, it requires: soil, sunlight, moisture in some form, and nutrients. In addition, the pre-emergence seed must deal with:
– extreme temperatures and exposure,
– inappropriate final resting place (in a tree, cave, between a rock and a hard place, etc.),
-lack of available moisture,
-unsuitable soil types,
-and be consumed by any of the myriad other elements in nature, from: birds and animals large (bears) or small (rodents), insects, bacteria, molds, fungi in general and various other pathogens.
An experiment was carried out in the 1980s, using 1 1/2 kilograms of irradiated seed (for monitoring purposes) (seed size is about the size of the head of a pin) of a species of river casuarina. This species grows at the water’s edge and most of the tree hangs over the water. Most of the seed was released at tree height (approx. 20 feet) into the river, as this is the natural seeding event for the plant, with wind playing a role. From this release and up to 5 years later, 3 trees were found to have survived. Think about that, 1 1/2 kilos of seed the size of the head of a pin. That’s a lot of seed that didn’t survive, under optimal circumstances.
This simple fact of seed predation and chance in nature is why plants are so prolific seed producers. It’s a great chance that something will actually survive – it’s just a jungle out there.
Now as long as a seed lands where it has a chance and survives, this is all well and good. But what about our poor thing on the mountain? Multiply the chances of being eliminated exponentially. So how can a plant survive in this situation?
In harsh environments, a plant requires a few tricks to survive:
Germination speed and establishment:
Once the right conditions are met, they may only be fleeting. If a plant lands, under the lee of a rock, in viable soil, with some moisture, thus meeting most requirements, this may be the only day of the year that it actually rains. Seed germination and establishment must be rapid, under adverse conditions.
An adaptation to the germination and establishment process includes the development of taproots. This is the main taproot from which the roots of the smaller branches originate. In harsh environments, this taproot will be the first part of the plant to develop, digging as deep into the soil as possible, as quickly as possible. This not only allows for a more stable plant, but more importantly, it allows access to reserves of moisture and nutrients that are not available to plants with a lesser root system.
Fluctuations in temperature:
There are those places on earth that experience the full range of seasonal weather in one day. Melbourne, Australia easily comes to mind. On a mountainside, depending on aspect to the sun, a plant may very well experience freezing temperatures at night and scorching temperatures during the day.
In order to survive this, plants, through natural selection, have evolved a series of protective adaptations to compensate. This can take the form of:
-a wax-like coating on the leaves that minimizes water loss,
-a covering of hair on the leaves to reflect or dissipate heat,
-modified leaves, or needles, reducing leaf surface and water loss,
-rhizomatous root systems, such as deeply buried roots to escape such extremes,
-smaller leaves to reduce moisture loss,
-and latex-like sap, which further reduces evaporation, palatability of plants and, in some cases, acts as a kind of antifreeze.
Let’s not forget about annuals and herbaceous perennials. In harsh environments, once conditions are right, annuals can grow, flower, set seed, and then die, all in a matter of weeks, only to repeat the process the following year. Herbaceous perennials will die back to ground level, possibly with a rhizome, to counter the effects of expansion and contraction due to freezing and thawing.
predation:
There are a host of plants that avoid predation, particularly grazing, by having unsightly leaves. This can take the form of spines, toxic sap, etc. Or for that matter, the sheer inaccessibility of the plant.
general habitat:
If the plant has settled in a location that meets all the requirements, but is subjected to disruptive winds on a regular basis, adaptation may take the form in which the plant grows or forms. These plants will regularly grow very close to the ground, or indeed along it, to reduce wind resistance. The shape of the plant creates a better environment for continued growth, and subsequent soil shading can go a long way toward saving or regaining moisture.
Some species, such as juniper and cypress, will easily lose bark on the windward side of the trunk, sometimes surviving with only a thin vein of viable bark feeding the tree. Hmm, starting to look like bonsai.
Nutritious:
No plant will not survive without some kind of nutrient. Again, in a hostile environment, this comes down to luck. If a base is found in the lee of a rock, there is a much higher probability that nutrients are available, as organic debris will accumulate in these places due to the action of wind and rain and eventually decompose to form a bedrock. kind of scarce fertilizer. Certainly not enough to grow vegetables, but enough to sustain a plant that already knows what a rock and a hard place is.
Developing:
As these hardy plants develop, the actual act of surviving becomes a bit easier. The branches are tempting for creatures to perch on, adding their dung, the fact that the shelter provided will do the same. A larger plant will retain much more moisture in its leaves and branches, either after rain showers or morning dew. This moisture, when found on waxy leaves or needles, will spill into the drip line, further increasing moisture levels and the chance of survival.
Animals may burrow under or around the plant, mixing up manure, soil, minerals, and organic matter as they do so. All of which may just sound rosy to the plant in question, however, improving the physical aspects of the place where it grows will not make it a Christmas tree. The decisive factor is still the environment. The improved habitat will keep it alive longer.
Most of the above happens incrementally, on a molecular scale, and is therefore painfully slow. The fact that a plant that survives in a harsh environment seems very, very old is probably because it is. The rapid growth is soft, full of sap, fully exposed and in no way capable of withstanding the depredations of harsh environments.
This is the reason why, under those conditions, the plants become natural bonsai or environmentally dwarf plants. It is purely a matter of survival.