Richness vs wealth, for plants and people

Why would poor soils and difficult environmental conditions lead to more, rather than fewer, plant species?  Or human cultures?

Once again, MinuteEarth gives us a fun and clear explanation of a great topic in this quick video:

Does this all make sense?


Although the Fynbos of South Africa and the Kwongan of western Australia are completely isolated from one another, these two regions both support really high numbers of (different) plants within similar ecosystems, due to a combination of historically mild climate and very infertile soils, together with a natural fire regime, in each place.

Many plant species living on poor soils, Fynbos of the western Cape, South Africa

Many plant species living on poor soils, Kwongan region of western Australia

It's ironic that even the lush, highly productive plant life in tropical rain forests exists on soils that, compared to other regions, are very thin and poor in nutrients. In the Amazon, you can actually find high numbers of tree species in areas of both poor and less-poor soils; the key factor may be the immense amount of rain in both types of areas, both now and historically.

Similarly, across most of sub-Saharan Africa and New Guinea, areas with more species tend to have more rain, warmer temps, higher plant productivity, and more human languages.

bird (of paradise) diversity matched by human cultural diversity in Papua New Guinea. The boat driver from Wagu (left) and the farmer from Mt. Hagen would have to use the national language, not their own tribal tongue, to communicate, as would speakers from the country's 600+ other languages. birds image: National Geographic

There is also, of course, diversity at the individual level of both people and plants. In our case, we are all a single species, with similar general features, but we certainly aren't clones of one another. Different features among plants and animals, including people, give them advantages in certain situations (for example, a plant's better-than-average ability to store water helps it survive in the desert and a person's darker hair, eye, and skin color lessen damage and incapacity from rays of the tropical sun).

Gaining an advantage in a particular ecological niche, such as the poor wet soils of the rain forest or the poor dry soils of the Kwongan and Fynbos ecosystems, allows species to maintain themselves, even when they face competition.

How do they do it?  Have a look at the concept of niches used in this post to make an enlightened comparison of biodiversity to beer.

And here are some questions:  in the video above, is the comparison  of plant communities in good vs bad soils to Walmart vs. local markets valid?  Does a "fertile" economic environment enable a few fast-growing businesses to outcompete many smaller-growing ones?