Erick the Red's Exchange [The biological consequences of the Norse presence in Greenland]

The Columbian Exchange (as coined by Alfred Crosby), the process of two separate ecosystems mixing, is something that continues to this day. But what biological exchanges took place with the Norse exploration of the new world around 1000AD? Greenland and beyond: Baffin Island, Labrador and New Foundland. The Norse colony in Greenland always was an isolated and precarious undertaking and the answer is very little. It has long been argued that the Norse brought with them, along with grains and livestock, many plants new to Greenland. Weeds that remained long after the colonists left.

"Palynology supports ‘Old Norse’introductions to the flora of Greenland" by Schofield, Edwards. Erlendsson and Ledger (2013) takes up this question and answers it affirmative: yes, according to their pollen research, some plants did not occur until the Norse colonists settled in Greenland. In a table (above) they show how, through the ages, ever smaller numbers of plants were suspected to be invasive. Their research is for only three plants: Rumex acetosella (sheep's sorrel), Polygonum aviculare (common knotgrass) and Achillea millefolium (common yarrow) which is perhaps not much but still fascinating. These are plants that are weedy almost everywhere but the Norse connection still makes it something magical. The conclusion from the paper:

In this paper we have demonstrated the utility of integrating pollen-analytical data from a network of sites as a series of maps in order to add an objective historical perspective to a long-standing debate over which plants were introduced to Greenland by the Norse settlers. A convincing case has been shown for three taxa – Rumex acetosella, Polygonum aviculare and Achillea millefolium. The patterns that have emerged from this exercise, particularly those for R. acetosella, appear to open wider debates related to the pattern and character of the Norse colonization of Greenland. For example, were there key differences in the function/role of some ‘farm’ sites that led to the creation of more favourable habitats for ‘Old Norse’ flora in some locations relative to others, and could differences in the patterns of colonization and the spread of ‘Old Norse’ elements in the flora of Greenland be accounted for through the initial introduction of these plants at only a few key sites? Palaeoecology may be able to pose but never fully answer these questions. A next step would be for geneticists to try and advance this debate by exploring the links between the floras around the Norse farms of western Iceland (or further afield), and those sites in Greenland where it is believed that the first settlers disembarked around ad 985.

The weeds in my Colosseum

In 1855 Richard Deakin published a study of the wild flowers growing in and on the Colosseum in Rome. It is available online. There was an earlier study and there has also been done a recent study and what it allows for is a study of place through the study of plants. Deakin's book contains a list of plants with descriptions. In the preface he writes: 

The object of the present little volume is to call the attention of the lover of the works of creation to those flocal productions which flourish, in triumph, upon the ruins of a single building. Flowers are perhaps the most graceful and most lovely objects of the creation but are not at any time, more delightful than when associated with what recalls to the memory time and place, and especially that of generations long passed away. They form a link in the memory, and teach us hopeful and soothing lessons, amid the sadness of by- gone ages : and cold indeed must be the heart that does not respond to their silent appeal ; for, though without speech, they tell of that regenerating power which reanimates the dust of mouldering greatness, and clothes their sad and fallen grandeur with graceful forms and curiously constructed leaves and flowers, resplendent with their gay and various colours, and perfume the air with their exquisite odours. The plants which we have found growing upon the Colosseum, and have here described, amount to no less a number than 420 species ; in this number there are examples of 258 Genera, and illustrations of 66 of the Natural Orders of plants, a number which seems almost incredible. There are 56 species of Grasses, 47 of the order Compositea or Syngenesious plants — and 41 of the Leguminous or Pea tribe.
The collection of the plants and the species noted has been made some years ; but, since that time, many of the plants have been destroyed, from the alterations and restorations that have been made in the ruins ; a circumstance that cannot but be lamented. To pre- serve a further falling of any portion is most desirable ; but to carry the restorations, and the brushing and cleaning, to the extent to which it has been subjected, instead of leaving it in its wild and solemn grandeur, is to destroy the impression and solitary lesson which so magnificent a ruin is calculated to make upon the mind.

Native trees have more insects.

The above table compiled by the Offwell Woodland and Wildlife Trust shows clearly that native trees in park bring with them a higher level of biodiversity in comparsion to introduced species. I have been going on and on recently about the joys of the anthropocene. Here is a reminder of the downsides of the great species bonanza. Found via Monbiots Return of the Native.
 

Invasive species in NL

When rereading an old post on 'novel ecosystems' I wondered in what way statistics could illustrate the point of rapidly changing environments. The above graph shows the number of invasive vertebra, molluscs and lobsters. That the trend is toward acceleration is impossible to miss. I am looking for similar data on plants. There are an approximate 27.000 animal species in NL (2010 Data, graph on the right). The use of this is limited as presence of a specie and the frequency of a specie are two entirely different things.

   
The rising presence of invasive species happens against a decline in biodiversity: 

The 2005 'Audit of non-native species in England' has the following table on introduction dates for invasive species. It does not seem to show the same pattern from the Dutch data.

 

Botany exercises the memory without improving the mind

To The Honourable Daines Barrington

Selborne, June 2, 1778.

Dear Sir,

The standing objection to botany has always been, that it is a pursuit that amuses the fancy and exercises the memory, without improving the mind or advancing any real knowledge: and where the science is carried no farther than a mere systematic classification, the charge is but too true. But the botanist that is desirous of wiping off this aspersion should be by no means content with a list of names; he should study plants philosophically, should investigate the laws of vegetation, should examine the powers and virtues of efficacious herbs, should promote their cultivation; and graft the gardener, the planter, and the husbandman, on the phytologist. Not that system is by any means to be thrown aside; without system the field of nature would be a pathless wilderness: but system should be subservient to, not the main object of, pursuit.

Vegetation is highly worthy of our attention; and in itself is of the utmost consequence to mankind, and productive of many of the greatest comforts and elegancies of life. To plants we owe timber, bread, beer, honey, wine, oil, linen, cotton, etc., what not only strengthens our hearts, and exhilarates our spirits, but what secures from inclemencies of weather and adorns our persons. Man, in his true state of nature, seems to be subsisted by spontaneous vegetation: in middle climes, where grasses prevail, he mixes some animal food with the produce of the field and garden: and it is towards the polar extremes only that, like his kindred bears and wolves, he gorges himself with flesh alone, and is driven, to what hunger has never been known to compel the very beasts, to prey on his own species.* (* See the late Voyages to the South-seas.)

The productions of vegetation have had a vast influence on the commerce of nations, and have been the great promoters of navigation, as may be seen in the articles of sugar, tea, tobacco, opium, ginseng, betel, paper, etc. As every climate has its peculiar produce, our natural wants bring on a mutual intercourse; so that by means of trade each distant part is supplied with the growth of every latitude. But, without the knowledge of plants and their culture, we must have been content with our hips and haws, without enjoying the delicate fruits of India and the salutiferous drugs of Peru.

Instead of examining the minute distinctions of every various species of each obscure genus, the botanist should endeavour to make himself acquainted with those that are useful. You shall see a man readily ascertain every herb of the field, yet hardly know wheat from barley, or at least one sort of wheat or barley from another.

But of all sorts of vegetation the grasses seem to be most neglected; neither the farmer nor the grazier seem to distinguish the annual from the perennial, the hardy from the tender, nor the succulent and nutritive from the dry and juiceless.

The study of grasses would be of great consequence to a northerly and grazing kingdom. The botanist that could improve the sward of the district where he lived would be an useful member of society; to raise a thick turf on a naked soil would be worth volumes of systematic knowledge; and he would be the best commonwealth's man that could occasion the growth of 'two blades of grass where one alone was seen before.'

I am, etc.

An untypical letter from Gilbert White's Natural History of Selborne (1789). Richard Mabey's biography paints White as an amiable country dumpling, a landlord with little land, a prospected vicar who never managed to become one, a man who arranged his financial security with a few miserly tricks: the portrait of a minor caricature in a Jane Austen novel. White travelled throughout Britain but in the end preferred to stay home, tend his garden and study the plants and birds around Selborne the village where he was born and where he died. The special contribution of his History is that he is the first one to dwell on the simple, mundane things in nature without apology and with complete relish. His book, he wrote only one, is reminding us that we do not see anything out of the ordinary, we already see so much. To use the phrase of Robert Walser.

Earlier posts on Richard Mabey include posts on his forage guide, and his journeys through wasteland ecology.

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.

The great albatros wanders

From google scholar one can lean a lot about the wander-pattern of the great albatross. No wonder shooting them is such a bad idea.

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?
...

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.

Activities of the wild urban euro-woodlands

The Don of the fabulous Green Hermeticism blog pointed me to research on 'Wild urban woodlands' ages ago but only now have I managed to have a proper look. I think most of it deals with the controlled reforesting of abandoned landscapes (empty cities, decommissioned coal mines, etc). In a section on 'industrial fallow lands' as pedagogic challenges (the cryptoforest as a free school?) the following table is given. 

Dog walkers as an unrecognized class of urban explorers? 100 Lingerers? 152 Acts of adolescent activity (sex?)?? 33 Foraging acts (berries plus mushrooms)??? Seven arsonists???? One hunter, hunting for what????? & who can tell what somebody is up to?   

The forest has no climax, the cryptoforest is a meeting-place

Rotterdam cryptoforest hut spotted by Petr.

You and me have been taught at school that the forest is the stable and inevitable end result of biological succession. This turns out to be a now discarded approximation of an earlier age.  Biologists today speak about the high forest but not about pristine forests. The forest keeps changing after it has reached maturity. Here is how Andrew Revkin puts in The Burning Season (a book about Chico Mendez):

When a Tree Falls it can create in microcosm the same kind of disruption caused by a strong storm. Such tree falls may be a crucial element in shaping the mix of species in the forest. A tropical forestry scientist named Gary Hartshorn studied tree-fall rates around the tropics and found that in many areas, the time it takes for a section of forest to be completely replaced can be as little as eighty years. The overall effect is that the forest is perpetually off kilter, in a continual state of recovery but never quite returning to some inanimate state—a condition that opens up opportunities and lets no organism settle too comfortably into a static niche.

The climax state is really 'late successional'. Here is the byline: disturbance creates diversity, diversity happens when the Teutonic stranger gets a chance to shine. The cryptoforest reminds the city that it won't last forever.

Also see.

Let the monkeys teach you what to eat

My soft spot for Marc van Roosmalen started when I read in the first book of his autobiography that he had great admiration for Provo as a biology student in Utrecht. He didn't take part of the things Provo is best known for, as far as I can tell, but I do think he is still embodying the spirit where many others haven't. The above shows his Amazonian camp-site/field station.


The following quote is instructive to all edible city proponents. This is how the pro's do it:


Listen to Marc van Roosmalen:

 “Most of what I have learned about survival in a neo-tropical rainforest I have learned from the red-faced spider monkeys from Surinam. I also learned a lot from other animals. From mammals, reptiles and birds who, like me, live on the ground. Agouties, agouties and peccaries led me to those seeds and seedlings you can eat without risk, and to others that are poisonous enough to kill you by touch alone if you happen to have a scratch or small wound. Tapirs and deer taught me which seeds and seedlings to avoid. They also taught me which green leaves from which trees I could eat with relish. By studying the food habits of a wide variety of animals, by observing what foods they are looking for, what foods they eat, and from which foods they sometimes accidentally die, I soon started to feel comfortable in my new daily surroundings. More and more I started to look like a native of the forest“.