Global Change Ecology (BIO347)

Domesticated ecosystems and their tradeoffs

Nowadays in the greater part of Europe food is something trivial, something omnipresent, something you don’t waste time to think about it’s origin. You just buy it in the supermarket and then you eat it. That’s it. Of course people are thinking and talking about food all the time, but if we are honest, it is more about, what we want to eat and what we should eat in order to maintain or gain our dream body. I can’t remember the last time, I had a conversation with a friend about how this trivial thing „food“ is produced, or even more: Which consequences could it entail to domesticate and tame not only crops and animals in order to gain food, but to domesticate whole landscapes in order to increase food production? And furthermore, what tradeoffs are we willing or not willing to accept in order to satisfy our everlasting desire for what we are used to: food at any given time and in any amount.

The fact alone that around 24% of the Earth’s terrestrial surface is occupied by cultivated systems, in order to satisfy the increasing demand for food, feed and fibre(1), makes it quite clear that the question of foodproduction is a very important one, when it comes to man-made landscape change. Therefore I decided to discuss some major points of the article „Domesticated Nature: Shaping Landscapes and Ecosystems for Human Welfare“ by Peter Kareiva et al.(2) in my blog.

In order to see the topic of domestication and land-use in general a bit more in context, I had a closer look on the planetary boundaries. In figure 1 you can see an illustration for the planetary boundaries, which are showing the risks of destabilizing the Earth system, as we know it in the Holocene, at a planetary scale. (3) As you can see Land-system change is one of the areas, that already have reached the zone of increasing risk, which means, that it has exceeded the boundary. Moreover, the area of Biochemical flows, which is by fertilization closely related to intensive cultivation of crops, is already in the high risk zone. Especially the nitrogen cycle is strongly out of balance.

Figure 1: Shows the exceeded and not exceed boundaries of the earth system. picture from: see (3) (http://www.sciencemag.org/content/347/6223/1259855.full)

Nevertheless, the reasons why humans are domesticating landscapes are easy to understand: The three main goals of domestication are increased overall productivity, promoted commerce and protection from predators and nature events, as for example storms.(2) If you only consider these three aims, then domestication is significantly enhancing the well-being of humans. But we must not forget, that there is a known price we pay for these benefits and what is perhaps even more important, that there could be so far undiscovered risks. Therefore it is most crucial to go on researching in this field, so that the tradeoffs in ecosystem services can be better understood. This is the only way I see to decide, what is a desirable management of these tradeoffs, not only for now, but also with regard to future generations.

In order to illustrate, what is meant by tradeoffs, I have chosen one example mentioned in the article for each of the three aims. The first example has the aim to maximize productivity. As mentioned before the nitrogen cycle has been strongly damaged in order to reach an increase of food production. The massive use of fertilizers in agroecosystems leads to water pollution and as a consequence to destroyed coastal zones and algal blooms (2). An example for the impacts and tradeoffs, resulting from our pursuit of promoted commerce, is the rapid spread of deseases and invasive species, indebted by the enhanced trade. (2) The third and last example is an example for the aim to avoid risks: By the removal of top carnivores, the danger for hikers, farmers and ranchers to get attacked is decreasing. But on the other hand missing predators, can lead to an enormous increase of herbivore populations, which can cause overgrazed landscapes and other damages to the ecosystem.(2) At least after these examples we can see, that the idea of tradeoffs in ecosystem services is not only crucial but also quite complex, what makes it most likely, that there are still tons of unknown consequences of domestication.

In the debate about what the best form of stewardship for the nature is, the first idea probably most people have in mind, is the conservation of wild and pristine nature.

But because of the fact, that today only 1% of the Earth’s terrestrial surface is set aside as real wilderness (4), this is quite utopian. Moreover, I think that this idea also neglects that humans will always do, what benefits them the most. Basic human needs, like food, will always be rated higher than other desirable matters.

For me that means, that we need to spend more money on research of tradeoffs and that we need to do a greater affort to understand how the ecosystems, that we are shaping, are working. This can give us better awareness of how our decisions are influecing not only the ecosystems by themselves, but also the current and prospective well-being of humankind. This personal opinion of mine fits well together with the conclusion of Kareiva et al., that an understanding of tradeoffs made in ecosystem services is important, in order to do the step away from only trying to protect nature from human influences, towards a well-conceived management of tradeoffs among ecosystem services, from which humans and nature can simultaneously thrive. (2)

By: Bianka Mertins

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References:

(1) Millennium Ecosystem Assessment, Ecosystems and Human Well-Being: Current State and Trends, Chapter 26, Island Press, 2005: http://www.unep.org/maweb/documents/document.295.aspx.pdf (accessed: 16.02.2015).

(2) Kareiva, P., et al., Domesticated Nature: Shaping Landscapes and Ecosystems for Human Welfare, Science, 2007.

(3) Steffen, W.,Planetary boundaries: Guiding human development on a changing planet, Science, 2015: http://www.sciencemag.org/content/347/6223/1259855.full (accessed:16.02.2015).

(4) UCN,World Database on Protected Areas(IUCN, Washington, DC), 2007.