La Inmaculada Ranch, Hermosillo Mexico before Holistic Management - 77% bare soil, 23% soil crust, 3 species of perennial grasses |
Every now and then I find a concept that just blows my mind.
Not because it is difficult to understand, but because it shifts my worldview
and causes me to see the world around me in a whole new light. Often, the new
information latches onto a generally accepted concept that just bothers me. It
nags at the back of my mind because it doesn’t feel true, but everyone accepts
it as true because they have been told it is. But then this new idea comes
along and adds clarity to the issue.
In this case, the idea that never made sense to me is that
agriculture, particularly the raising of cattle, is responsible for some huge
percentage, about 9%, of global production of greenhouse
gasses. In reading most articles, the assumption is that it isn’t just poorly
managed stocks. Most make the assumption that it is the cows themselves and it
couldn’t possibly be any other way. That makes no sense to me. Pretty much all
of the grasslands of the world were home to great herds of large hoofed
animals before man came along. Herds of bison in the North American Great
Plains were reported to be in the tens of millions of animals. So how could it
possibly be that the natural, healthy condition was home to that many large
animals, but now we can’t possibly handle a similar number without doing severe
damage to our atmosphere and environment?
The answer came from a biologist named Allan Savory. I have
written about him before, but have since learned much more about his ideas and
methods and I have to say that I am sold. The answer is quite simply that, as
humans, our centers of population and learning are mostly in areas that have
consistent moisture throughout the year. These are very productive ecosystems
that support large populations and we know well how to keep them healthy and
productive. They also tend to be conducive to growing forests.
The grasslands of the world, on the other hand, operate
completely differently. The inconsistent
moisture won’t support as many trees, but rather favors a completely different
type of environment, one dominated by perennial grasses. As I mentioned before, this cycle of plant growth and decomposition is the primary cycling of nutrients in an ecosystem, and the primary driver of life. Because of the inconsistent availability of moisture, the moisture required to biologically break
down organic matter and foster the creation of the soil is simply not present
for much of the year. This means that as a plant (in this case, the grasses)
grows during the wet season, it produces body mass. As it runs through its
annual cycle and sheds biomass, the biomass doesn’t simply fall to the ground
and decompose. So how does the grassland ecosystem function?
It turns out that a completely different method of
decomposition is utilized by the grasslands. The decaying grasses get the
moisture they need to decompose in the gut of large ruminant animals, such as
cows and bison. The animals then deposit the proto-soil in the form of urine
and dung. This then continues to decompose and fertilize the soil.
Same location as above, after 36 years of using Holistic Management practices. 25% bare soil, 1% soil crust, 11 species of perennial grasses |
However, the whole process is very fragile and is contingent
on several factors. The right kind of animal impact needs to be maintained. The
grasses rely heavily on the top of the plant being removed by the animals
between the completion of the growing season and the beginning of the next
growing season. Some of this happens via eating and some happens via trampling.
This happens best in the presence of huge herds that are bunched and excited
because of the presence of pack hunting predators, such as lions. In this
configuration, huge numbers of animals are constantly on the move. They consume
the bulk of the tops of the plants, trample on the rest, and fertilize what’s
left. When the next rainy season comes around, the perennial grasses are ready
to leap off and complete their life cycle.
But when this cycle is disrupted, such as is the case over
most of the land masses on the planet, the grasses don’t get the cycle of
stress and rest they need to best complete their life cycle. Most of the
grasslands of the world are either overgrazed or over-rested, both equally
damaging to the perennial bunching grass.
This is an important environmental factor. As I mentioned
previously, the soil is a living thing. It needs to be fed, and it eats
decomposing organic matter, mostly plant. In the grasslands, a small percentage
of this comes from the animal dung, but really, the bulk of it comes from the
grasses themselves. See, in order to take advantage of the brief rainy season,
the grasses store a huge amount of energy in their roots. At the start of the
rains, the grasses shoot skyward, sacrificing those roots. They pull the energy
from the roots and allow them to die. Once the grass is to the proper height,
they begin the process of storing energy, growing new roots. The old roots then
decompose and feed the soil. This happens every year. The bunch grasses in
essence pump carbon into the ground to feed the soil.
As you might imagine, this is the single biggest carbon sink
on the planet, one that is currently not functioning, causing the soils to lose carbon to the atmosphere rather
than storing it in almost every grassland on the planet (about 60% of Earth’s
landmasses). But the effects aren’t just damaging to global warming. See, the
carbon in the soil, stored as humus, turns the soil into a giant sponge. When
the monsoon rains come, healthy grasslands with heavy amounts of humus in the
soil soak up the bulk of the rain. This stores the water in the soil, allowing
more and healthier grass to grow and creating a positive feedback loop. But
when the process is disrupted, the carbon disappears from the soils, causing
the soils to form a water-repelling crust, which increases flooding and erosion
while exacerbating the problem.
Holistic Management was developed by Allan Savory as a
series of techniques to best replicate the impact of the great herds without
actually restoring the great herds. Cows, sheep, and goats are typically used
to create the restoration, but have to be managed carefully to simulate the correct type of
impact.
There are a bunch of really important concepts from Holistic
Management, many more than can be outlined on a blog. I’ll select a couple of
the more important concepts to delve deeper into over the next several blog
posts. Over the next couple of posts, I will talk about the Brittleness Scale,
Animal Impact, and the concept of Solar Dollars. After that , I can delve into
some of the possible ways Holistic Management can be used to make real,
positive change in the world.
No comments:
Post a Comment