Amazonian garden dissected

In Charles C. Mann's '1493' (earlier) we find this glossed picture of an Amazonian garden in N.E. Brazil. It shows the detailed and intricate knowledge behind a good garden. 

Utrecht is the nature reserve of the Netherlands

All major newspapers featured the headline "Amsterdam is becoming a nature reserve". The original source on the story goes even further and states that "Amsterdam is becoming the nature reserve of the Netherlands" (Sargasso, source of image). The article tells us about new data on the number of species on the red list (species threatened with extinction) for every municipality in the country. The general trend is clear: urban areas do a lot better than agricultural areas. The focus on Amsterdam however is misleading for two reasons. Amsterdam is not doing that well in comparison to the other big cities, and the big cities themselves are not the big scorers. Of the four biggest cities Amsterdam has the least red list species, if you would factor in size and population it does even worse. 

Cities by population and species on the Red List

1. Amsterdam: 139
2. Rotterdam: 155
3. The Hague: 144
4. Utrecht: 140

Bergen does best with 325 species. Other big scorers: Apeldoorn 226, Ede 266, Enschede 206. Almere, in the race of becoming the fourth Dutch city, only has 48 red list species within its borders.

Disturbance and diversity in grass

Romanian field with 43 species in 0.1 square meter.

A reader with no name left a link to a news article on a study on comparative plant biodiversity between ecosystems. The paper claims to be looking at biodiversity world records but that is really not that interesting; rainforests are the biodiversity hotspots of the world, what is fascinating is that when the size of the area researched shrinks grasslands rise to the fore with a spectacular number of species crammed in a tiny space. Examples: a 49-square-meter patch of Czech grassland contained 131 plant species, a patch of Argentine grassland of 1 square meter contained 89 species,  0.1 square meter of Romanian grassland contained 43 species.

 Even more fascinating is the reason for this diversity: human disturbance, read: 10.000 years of mowing. Citing 'Plant species richness: the world records'

The co-existence of large numbers of species is also of theoretical importance as a challenge to the ‘Paradox of the Plankton’. The principle of Gause states that two species occupying the same niche cannot co-exist long term, so how do 942 plant species co-exist in 1 ha of tropical rain forest? Can there be 942 niches?
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The difference in vegetation type at which record richnesses are known parallels the size of the plants – grass tillers vs rain forest trees – but may also reflect intrinsic differences in the community. The high-richness short grasslands are all subject to repeated disturbance – mowing, grazing or fire – and this leads to more symmetric competition, and hence slower competitive exclusion. The most common management of these grasslands has been by mowing, practiced regularly for many years. For one of these extraordinarily rich, semi-dry grasslands, that in the Czech part of the White Carpathians, which holds the record at five spatial scales, continuity as a managed grassland since Neolithic times has been suggested, giving thousands of years for the immigration and sorting of species and for evolution to occur. Tropical rain forests have a more stable environment, the disturbances being mainly occasional windthrow. Their richness has been explained in many ways, including continuous speciation in a ‘stable’ ecosystem and high energy input. Wright (2002) highlighted niche differentiation, pest pressure and lifehistory differences.

The loss of diversity is the long tail of the agricultural revolution

Diversity is in an undisputed worldwide crisis. In Europe, where we have long ago eradicated a staggering amount of it, we take biological and cultural poverty for granted, as a normal, even desirable, fact. We are conditioned to think of our mind as a single-language engine, learning another language is difficult and always far from perfect. Anthropological evidence however suggests that in a language-diverse social environment a good working knowledge (even if only passively) of 5, 6, 7 languages (and not just dialects) is routine. Scarcity of diversity, in our social and economic climate, is a downhill process of shifting baselines; quoting John Waldman:

Every generation takes the natural environment it encounters during childhood as the norm against which it measures environmental decline later in life. With each ensuing generation, environmental degradation generally increases, but each generation takes that degraded condition as the new normal. Scientists call this phenomenon “shifting baselines” or “inter-generational amnesia,” and it is part of a larger and more nebulous reality — the insidious ebbing of the ecological and social relevancy of declining and disappearing species.

The above Ethnologue statistics put a number on the linguistic impoverishment of Europe. In 'Farmers and Their Languages: The First Expansions' (2003) Jared Diamond and Peter Bellwood add many complicating factors obscuring the picture, but the general trend is clear: by exploiting a few selected types of plants and animals agriculture created power and this power translated into linguistic monocultures.

Until the end of the Pleistocene, all people on all continents lived as hunter-gatherers. Then, at different subsequent times between about 8500 and 2500 B.C., food production based on domestication of relatively few wild plant and animal species arose independently in at most nine homelands of agriculture and herding, scattered over all inhabited continents except Australia. Because food production conferred enormous advantages to farmers compared with hunter-gatherers living outside those homelands, it triggered outward dispersals of farming populations, bearing their languages and lifestyles. Those dispersals constitute collectively the most important process in Holocene human history.

The agricultural expansions ultimately resulted from three advantages that farmers gained over hunter-gatherers. First, because of far higher food yields per area of productive land, food production can support far higher population densities than can the hunter-gatherer lifestyle. Second, whereas most hunter-gatherer societies are mobile, most food-producing societies are sedentary and can thus accumulate stored food surpluses, which were a prerequisite for the development of complex technology, social stratification, centralized states, and professional armies. Third, epidemic infectious diseases of social domestic animals evolved into epidemic infectious diseases of crowded farming populations, such as smallpox and measles— diseases to which the farmers evolved or acquired some resistance, but to which unexposed hunter-gatherers had none. These advantages enabled early farmers to replace languages and societies of hunter-gatherers living in their main paths of expansion.

The city as cryptoforest

The argument proposed by Robert Sullivan in his NY Magazine article 'The concrete jungle' is that the city of New York is a hotspot for biological diversity is not in itself new. It reminded me of the shifting emphasis in Amazonian anthropology from artefact to landscape.

Listen to Robert Sullivan:

In fact—and this may seem implausible—nature is in many ways more plentiful in New York City than it is in the surrounding suburbs and rural counties. New York is again a capital of nature; we are an ecological hot spot. 

How can this be possible? What does the grimy coast of Queens have over the fields and forests of Dutchess County? The answer is the same thing the city has: variety. While upstate nature may be robust and all-encompassing, it is also, from an ecological point of view, relatively barren—a small and fairly static number of species coexisting in a scenic but manicured wilderness. This is true for most of America’s wide-open spaces. “People think of the rural as this pristine, untouched place, when it’s actually highly controlled and highly engineered space,” says Nette Compton, a senior project manager at the Parks Department. “The fact is urban areas are not as well controlled. They are messy. There is diversity.”

In the city, we live in a nature that is even more resourceful and resilient than we have ever imagined. And when you look at nature that way, of course there are coyotes in New York. Look at all the forests and small mammals—not just rats, but also voles, chipmunks, and small red foxes—with whom we share the city. The question becomes: Where has the coyote been, and why are we so reluctant to have him? Why can’t we see the nature that we are living in?

In other words, the city’s forests are mostly an accident. “In a lot of ways, they are here because we are lucky,” says Wenskus. “After 300 years of Western man basically doing his thing, we still have these amazing forests that are predominantly intact—or as intact as they can be with 8 million people.” Recently, however, scientists have come to suspect that urban forests have thrived not despite their urban environment but because of it. “The old idea was that urban areas are not ecologically interesting or don’t have ecological processes, and that’s false,” says Richard Pouyat, who studies urban forests for the U.S. Forest Service. “The difference is, it’s been altered.” And altering the natural landscape isn’t always a bad thing.



Take fires. Alley Pond experienced many car fires over the years, and this is now understood to have played an important role in the forest’s ecological health. In some parts of Alley Pond Park, as well as in forests in the Bronx and Staten Island, open forest canopies encouraged sensitive species like upland sandpipers or a threatened suite of plants like purple and green milkweeds. In a 1996 article in Restoration & Management Notes, Marc Matsil and Mike Feller, an early NRG naturalist, called arsonists “New York City’s incidental restorationists.”



Urban forests are healthier than their suburban peers in other ways, too. The flora scene is more diverse. Much of the soil found in places like Alley Pond Park is pristine compared to suburban areas. Perhaps more interesting, from the point of view of the larger urban ecosystem, our forests have evolved to become more productive. According to a study comparing oak-tree stands in rural Connecticut with ones in New York City, city forests carry more of the metals associated with air pollution into the soil.