Aaand that reaches your ears thanks to the voice kidnapped via a voodoo-wireless trick to a dumb human being, oh jesus he’s so very dumb, poor thing…
Today, dear listener, you're going to be told the second part of the story of roads, roadless areas, and their ecological value!
So quick recap of the last episode/post:
an international bunch of science dudes headed by professor Nuria Selva Fernandez (who works at the Institute of Nature Conservation Polish Academy of Sciences) publishes a paper on the journal Science and in the paper the researchers tell us they created a map of the world’s roadless areas, namely, according to the definition given by the same science bunch, “terrestrial areas not dissected by roads […]” “that are at least 1 km away from all roads and, therefore, less influenced by road effects” (Ibisch et al, 2016 (P)).
The map shows that roadless areas with a 1-km buffer to the nearest road cover about 80% of Earth’s land (105 million square kilometers circa). These roadless areas, though, are hyper-dissected into 600,000 patches more than half of which is less than 1 square kilometer big (for more numbers and details check the previous episode/post).
Once done this, professor Selva Fernandez and companions - aka the SF bunch - use their beloved map to check where the roadless areas precisely are, and they find out that
roadless areas distribution is very heterogeneous in relation to both biomes and anthromes (P).
Ok, sure, you don’t need to say it, I got this, listener: what the hell biomes and anthromes are?
Let’s start with biomes. Biomes are "the most basic units that ecologists use to describe global patterns of ecosystem form, process, and biodiversity. Historically, biomes have been identified and mapped based on general differences in vegetation type associated with regional variations in climate” (1).
So the SF bunch finds that, among our planet’s biomes, the ones that are almost entirely covered by roadless areas are the tundra and rock and ice covered ones (99% and 98% respectively), while the temperate broadleaf and mixed forests have the lowest share of roadless areas (41%) (P).
As for the other biomes, well, boreal forests of North America and Eurasia have an 89% of share of roadless areas (P_supp-mat), while, in the tropics, roadless chunks bigger than 1000 square kilometers (that is bigger than the total surface of the 20 national parks of the Netherlands) still exist in Africa, South America and Southeast Asia (P).
Nooooow, let’s get to what anthromes are. Anthromes, or anthropogenic biomes (anthropos in ancient Greek means “man”) are “defined as biomes shaped by human land use and, infrastructure” (P).
Aaaand are you wondering, dear listener, why such a definition is used? Well, such a concept is necessary, dear pal, since the impact humankind had and has on biomes.
And now, dear listener, grab to something solid, or to something semisolid but elastic and glued to something solid, or semisolid inelastic not glued but stitched to something yellow with stitches of a new league of copper and donuts, or to a marshmallow screaming in pain over a campfire around which red stitches tell ghost stories or to… No wait a minute listener, I got confused. Whose stitches are you talking about? Bah, anyway, where was I? Oh right, the anthromes thing. Well, dear listener, grab whatever you want, I sincerely don’t care after all that stitches mess, as you’re going to be overwhelmed by a fall of numbers, percentages and stuff.
Why the concept of anthromes is important. Here we go.
As a matter of fact by the past 10,000 years, with the invention of agriculture, vegetation across about half of Earth’s ice-free land surface has been wiped out or has become dominated by human activity (2).
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| The background image is a free to use pic by Todd Quackenbush (source: Unsplash) |
[Adapted by @sciencemug]
The clearance of vegetation by burning started in the Neolithic period (5000–3000 years before zero), but the pace of habitat clearance dramatically raised in the last three centuries (2), as from 1700 on, the global human population has burst from 600 million (2) to the present 7 and a half billion. Therefore, with the sole exception of the colder and drier biomes (like boreal and mixed woodlands, tundra and deserts) that didn’t change much in wild area over time (less than 20% of their wildlands have been transformed indeed), the rest of the planet did change, a lot (3).
In the XVIII century about 95% of Earth’s ice-free land surface was basically human free: the 50% of earth’s ice-free land was infact in wildlands, and the other 45% in semi-natural anthromes (3). But by 2000, that 95% has plummeted, since less than 20% of the biosphere is still semi-natural and only the 25% of the biosphere is wild (3).
As a matter of fact, among world’s last surviving wildernesses there are the Amazon, New Guinea, Siberia and the Congo Basin (4).
So the wild biosphere is a quarter of the total biosphere, and of this quarter, only one fifth is forests and more than a third is barren (2).
From 1700 to 2000, agriculture and urban settlements land usage increased from 5% to 39% of total ice-free land area, rangelands expanded from 3% of ice-free land in 1700 to 26% in 2000, and crop areas went from 2% in 1700 to 12% of global land area in 2000 (3).
Grasslands, savannas and shrublands are the biomes most affected by humankind as more than 80% of their surface has been converted to used anthromes (3).
Three pandas enter a bar each with a pink suitcase and a traffic cone as a hat… Oh ok, you haven’t zoned out, ok, just checking… Back to the numbers.
By now more than 80% of all people live in densely populated urban and village anthromes, one in four of humans lives in an agricultural village (2) and, as a consequence, urban lands are the most wildly changed lands of the planet and they stretched by a factor of 40 in the last three centuries. They indeed went from being almost null in 1700 (0.01% of all land) to be the 0.4% of all land in 2000: that is about half a million square kilometers, as to say that Sweden is a single, giant, never ending urban conglomerate (3).
Soo, dear listener, as you can see, it’s more than reasonable to develop the concept of anthromes.
And professor Selva Fernandez science gang, with is brand new global roadless map, finds that, in relation to anthromes, these roadless areas cover mostly rangelands (28% of them are roadless) and woodlands (17%) (P).
Sooo, dear listener, to sum up all this numbers, let’s say that our eco researcher and their roadless map tell to the world that - and I fully quote here -:” about two-thirds of the world’s roadless areas can be described as remote and unmodified landscapes [26% uninhabited or sparsely inhabited treeless and barren lands; 21% natural and remote semi-natural woodlands, with 17% wild woodlands therein [...]]. The remaining one-third [of the world’s roadless areas] consists of rangelands, indicating that roadless areas can also occur in anthropogenically modified landscapes” (P).
Now, let’s recap what professor Selva Fernandez and colleagues have done till now:
first they elaborate a data-based definition of “roadless areas”.
Then they create a global map of these “roadless areas”.
Finally, they check the distribution of the roadless areas across the biomes and anthromes of the planet.
Now what (as sooner or later said by one of the characters of the 93.8% of the movies with a weak screenplay and cheap cliffhanger and sometimes a good cast)?
Now our tireless researchers find a way to rate the ecological relevance of all these roadless areas.
They indeed create the Ecological Value Index of Roadless Areas aka EVIRA, a unitless index, which ranges from 0 to 80 (0 being the center of Gotham City, 80 being a pristine chunk of the forest where Tarzan used to live and scream his scream in front of the microphone at “King-Kong’s” the karaoke bar next to his home-tree).
So how our eco-scientists come up with this Ecological Value Index of Roadless Areas aka EVIRA? Well my clever listener, that’s the next part of the tale and it comes after the commercial break!
In a wild land at the edge of the world, where violence is the only fruit that grows and that of the strongest the only law there is, a young road named Roady bravely unrolls itself bend after bend, forced to fight for its right to exist, in search of the meaning of its own asphalt.
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| Roady's first day of shooting |
The background image is a free to use pic by Kamil Lehmann (source: Unsplash)
[Adapted by @sciencemug]
“The Roady’s road diaries”, this summer, in every theater, I mean, in every city planning office of the planet.
[Adapted by @sciencemug]
“The Roady’s road diaries”, this summer, in every theater, I mean, in every city planning office of the planet.
For their EVIRA index, professor Selva Fernandez and her buddies start from physics.
Now I know my just stated foreword is probably giving you a powerful headache already, and at least one of your fingers is going to push a button to end this episode while I’m still saying this, but bear with me a minute, will ya, it’ll be quick, I promise. By the way, if you’re a physicist, well, sorry pal for my next oversimplification/murdering of concepts.
Ok, let’s start.
The more a system is organized, the higher its degree of order is, the lower its degree of disorder is. I mean, you, dear listener, are a complex system, a highly organized one. But you’ve to admit that there’re just very few ways your internal organs can be arranged inside yourself in order for you to keep being a living sentient creature, while there’re almost infinite ways the above mentioned dear dear internal organs of yours can be placed across the universe (or even just in your kitchen, eww, gross, sorry…) ending, like this, your, well, functionality. Right?
So, simply put, dear listener, in order to stay alive you have to keep down your own degree of disorder, and the degree of disorder of a system in physics is called entropy.
So how do you do that? How do you keep yourself together, keep being alive and kicking and therefore keep entropy low? Well, you keep your local level of order up (your internal organs at their optimal position) at the expense of producing disorder - that is entropy - in the larger system of which you’re part (like, the universe, ooor your kitchen).
And how do you do that? Well, pal, as you do anything: you use energy.
So things work like this with systems in general, thus ecosystems included.
The basement for the brand new Ecological Value Index of Roadless Areas aka EVIRA of our beloved eco-scientists focuses right on the capability of ecosystems to self-order and regulate abiotic and biotic conditions.
To do this, as just said, ecosystems use energy. And the availability of energy in a system is called “exergy” (5, 6).
To sum up, then, an ecosystem’s health, according to professor Selva Fernandez and colleagues, is very much linked to the capacity this ecosystem has to uptake and store exergy (P_supp-mat).
The researhers, thus, evaluate all the roadless areas of their map for three properties somehow linked to the capability of ecosystems to uptake and store exergy. These three ecological properties are: patch size, connectivity and ecosystem functionality. These are properties important for biodiversity, ecological functions, and ecosystem resilience (namely “the capacity of complex systems with multiple stable states to absorb disturbance, reorganize, and adapt to change” (7)).
So let’s dig into them.
Number one: patch size. Patch size is the size of those pieces into which the percentage of Earth without road is dissected. Remember? The 80% of our planet’s land is covered by 1km buffer roadless areas, but these are dissected into 600,000 patches of different dimensions.
Ok, larger roadless area patch size indicates “less human disturbance, [...] higher populations of road-sensitive species, as well as higher ecological integrity and self-regulating capacity” (P_supp-mat). In other terms “large roadless areas provide a much wider range of ecological benefits than smaller ones where road edge effects impact a larger share of the roadless patch” (P_supp-mat). For example in highly fragmented forests the hunting pressure is higher, moreover some species avoid areas with even minimal anthropogenic disturbance.
Number two: connectivity. Connectivity is the “ratio between the size of a roadless area patch and its surrounding” (P_supp-mat). “The larger […] the connectivity value, the closer neighboring roadless patches can be found. This is important for the integrity of ecological landscape-scale processes [like, for instance, the] genetic exchange of populations confined to roadless areas” (P_supp-mat).
“Roaded forest ecosystems [besides], are far more vulnerable than intact ones to predatory logging, wildfires, illegal mining, exotic species invasions, and other [human driven] threats” (P_supp-mat).
Number three: ecosystem functionality. The ecosystem functionality is defined as “the state of ecosystems, characterized by inherent structures, ecological functions and dynamics, that provide ecosystems with both, the necessary efficiency and resilience to develop without abrupt change of system properties and geographical distribution, and allows for flexible response to external changes” (P_supp-mat). In short it means being robust, complex, organized and structured well enough to thrive (or at least not to degenerate) and to stand with success the pressure coming from the changes that happen around and within.
Some of the main indicators of the good functionality of a system are linked to its biomass, its capability to endure environmental changes and its success in capture and dissipate solar energy. Among such indicators there are the ecosystem vegetation density, its trees height, carbon storage capability, variety of species and even its slope as the “topographical heterogeneity is connected to habitat diversity and [therefore] species richness” (P_supp-mat).
Anyway, good tuned in sir and madam, the SF bunch goes on and perform a further analysis by which it discovers that, among the just described three parameters, the most relevant for the EVIRA index are the patch size and the ecosystem functionality.
Sooo, once done with the setting of their fancy EVIRA index that can assign unbiased ecological values to the ecosystems, prof Selva Fernandez & company use again their fancy global map of the roadless areas and evaluate the areas according to their brand new fancy EVIRA scores, that range from a neasty 0 to a great 80. And they find this: 35% of the roadless areas have low EVIRA values (meaning from 0 to 37, that is less than the 50% of the maximum value). That happens because they score low in patch size and connectivity ‘cause these areas are “small, fragmented, isolated, or otherwise heavily disturbed by humans” (P); or because they score low in ecosystem functionality, since they are in dry lands of northern Africa and central Asia, or they cover lands with rare vegetation and low biodiversity.
But our sicence map pack of researchers finds out also that roadless areas with high EVIRA values exist both in tropical and boreal forests.
Our scientists in the end conclude that: “the relative conservation value of roadless areas is context-dependent. Comparatively small or moderately disturbed roadless areas have higher conservation importance in heavily roaded environments, such as most of Europe, the conterminous United States, and southern Canada” (P).
Ok then, at this point our science map gang goes a step even further. It checks the percentage of their beloved roadless areas that is inside protected areas.
The idea is this: roadless areas are ecologically important (at least those with a high EVIRA scores), so how many of them are inside a protected area?
Da da da daaaaa! Suspense!
The answer, my dear listener, will come with the next episode.
Ciao!
The paper this post is about (P)
Ibisch et al (2016). A global map of roadless areas and their conservation status. Science 354, 1423–1427.
Bibliography
1 - Ellis, E.C., and Ramankutty, N. (2008). Putting people in the map: anthropogenicbiomes of the world. Frontiers in Ecology and the Environment 6, 439–447.
2- Boakes, E.H., Mace, G.M.,
McGowan, P.J.K., and Fuller, R.A. (2010). Extreme contagion in globalhabitat clearance. Proceedings of the Royal Society of London B:
Biological Sciences 277, 1081–1085.
3- Ellis, E.C., Klein
Goldewijk, K., Siebert, S., Lightman, D., and Ramankutty, N. (2010).
Anthropogenic transformation of the biomes, 1700 to 2000. Global
Ecology and Biogeography 19, 589–606.
4- Laurance, W.F., Clements,
G.R., Sloan, S., O’Connell, C.S., Mueller, N.D., Goosem, M.,
Venter, O., Edwards, D.P., Phalan, B., Balmford, A., et al. (2014). Aglobal strategy for road building. Nature 513, 229–232
5- Freudenberger, L., Hobson,
P., Schluck, M., Kreft, S., Vohland, K., Sommer, H., Reichle, S.,
Nowicki, C., Barthlott, W., and Ibisch, P.L. (2013). Natureconservation: priority-setting needs a global change. Biodivers
Conserv 22, 1255–1281.
6- Freudenberger, L., Hobson,
P.R., Schluck, M., and Ibisch, P.L. (2012). A global map of thefunctionality of terrestrial ecosystems. Ecological Complexity 12,
13–22.
7- Nyström, M., and Folke, C. (2001). Spatial Resilience of Coral Reefs. Ecosystems 4, 406–417.
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