Farming has always been an activity of mixed feelings. All a farmer’s hopes and dreams can paint an exhilarating image over a fertile landscape. The growing season can turn those dreams into reality as much as it can turn them into dust.
Such was the story for western settlers who ventured in land of Australia or more than a century earlier into the heart of the U.S., reaching open plains of long grass. Who would have blamed them for their confidence in what they perceived as rich fertile land?
The recent rains were above the yearly average and over the coming decade, many hard lessons were learnt. Now, for example, when you travel through much of South Australia, as I frequently do, you cannot help but stumble on ruins of stone houses where a farm went bust.
Once, a number of years ago, my father took me on a detour through the lesser travelled roads of the Murraylands, stopping in what I perceived as the middle of nowhere. On his insistence, we climbed a rusty old gate, into a field of nearly waste high dried yellow grass. Heading towards a small hill range, we came upon once such ruin. It was still structurally sound, yellow to red stone, but the windows and doors were long since gone.
It was then that he informed me that his had been one of his earliest homes. He and his siblings would walk a fair distance, along the roads between neighbouring properties, to reach the pick-up point for the school bus. He shared some of his memories of childhood on the farm. It was yet another bust venture and the family eventually moved to Murray Bridge.
Sometimes you stumble upon a massive infrastructural undertaking, like a dugout dam or piping that stretches for many kilometres. It’s mindboggling to think just how much effort these people of previous generations went to, simply hoping to tame the land for their agricultural use.
Here, I want to use a hypothetical example of effort in agriculture to explain a principle of ecology.
One such farmer, scanning across the landscape, notices a massive bolder, about 2kms to the North West. If this bolder is able to be moved 500m towards the homestead, it could be pushed into the creek, creating a basic dam which, after a good rain upstream, would cause the banks to be broken and water to run across the farm, and collect in a small recess on the eastern side of the plot.
Having no other means to irrigate the landscape in such a short term, this seems like a wonderful way to transfer both water and nutrients to the plot and create a pond for thirsty livestock.
The rock moves easily enough, under the guidance of a horse and two people, until it reaches the bank. The western edge of the creek is on a small rise – small, but enough to be too much for the farmers and the horse to overcome.
One option might be to ask a neighbour for assistance – it might be done with two horses.
Another option might be to dig out the rise, however, would it be more efficient to just use the horse to dig out channels instead?
If time wasn’t an issue at all, give it a century or two and the rise might erode away.
This is an example of what occurs on all levels of biology; where the effort needed is greater than can be provided by the entity at hand. Within cells, enzymes assist with chemical reactions to reduce the energy require. Within the gut of termites bacteria brake down cellulose into digestible sugars. Pollinators vastly improve the likelihood that pollen reaches its target, thereby reducing the need for expensive of pollen production (but the trade off is producing nectar as payment instead).
The last case, regarding erosion, is a case where physical processes provide the effort. This includes important processes, such as the oceanic conveyor belt, atmospheric water transfer, river transfer (which also causes erosion, thereby transferring nutrients and minerals) for instance. Seed dispersal could not happen without being carried in the gut of animals, river ways and by the wind. Physical processes are arguable as important as the many ecological services that feed from it.
Effort is an important aspect of ecology and something too often taken for granted by our species. Here are some examples;
- Until a century ago, the effort provided by trade winds was incredibly important for human endeavours.
- We’ve forgotten the art of using architecture to control a building’s climate. The shape of the structure and the material used was such to improve the temperature within the dwelling, regardless of the temperature, without much influence (such as heating and cooling).
- In no other field is outside effort more exploited than in agriculture. Be it, the plant cover that protects and keeps moist the top soil; solar energy input that permits growth of plants; meteorological events that bring rain or flood water and minerals; and pollinators (globally, 60% of which is done naturally ). In more organic practices, extra effort is also provided by, legume species which provide useable nitrogen; natural pest control; soil aeration and nutrient input by animals; and sustainable natural harvest.
All effort requires energy. On the back of cheap fuel, we have been able to move beyond the limitations of our ancestors by using labour saving devices. Such devices have displaced ecological services, leaving situations that now only function on this equipment. This can be seen in the copious amounts of ammonia fertilisers used, the myriad of machines required to work broad mono-culture farms and the near constant heating and cooling required in modern buildings. It’s a self-feeding loop of dependence.
One species could not be expected to spend all the energy required to produce a habitat suitable for its own existence. A habitat is a diverse community of species that all spend energy on a few forms of effort that together produce a whole host of benefits to the ecosystem.
Ecological succession is a wonderful example of this, where over time, the generalists and opportunistic species move into a disturbed area. Over time these species tend to alter the environment in such ways that eventually suit more specialist species. It is a series of events that can radically change an environment and over time, becoming increasingly productive and abundant with diverse life, yet could only happen due to the different efforts made by a number of species in response to former species and physical inputs.
Even soil, rich with nutrients, is often the result of thousands of years of physical effort, such as nutrient rich water movement and ecological effort, such as organic compost, soil preparation and protection . Even the cheap energy we currently exploit is energy accumulated from the sun by ancient forests. Biodiversity doesn’t simply appear, but is built up over time, by the efforts of the growing community.