An independent nature magazine about the world’s biomes and the edges between them.
What decides the edge
Above the last stems the rock, the wind and the rainfall are much the same. What runs out is the length of the season in which a seedling can put on enough wood to survive the winter that follows. The threshold is a soil temperature, and it is measurable.
The uppermost qualifying stem on a transect is the datum; everything above it is recorded as open ground.
Every biome here is defined by a number. Every number has a place where it runs out. Those places are the subject.
Selected reading · all sixteen guides
Giant kelp holds its blades near the surface with gas floats and rebuilds the whole canopy each season.
Habitat that is built, not found
Remove the predator, the urchins increase, the kelp is grazed off and the forest becomes barren rock. It is a documented sequence rather than a metaphor, and it is the clearest case of a habitat that exists because something builds it.
A desert is a rainfall figure
The boreal forest wraps the northern hemisphere and holds a very small human population and a very large amount of carbon.
What decides the edge
The intertidal is the only habitat boundary re-drawn every six hours, and the zonation on the rock records it exactly.
The people who stand on the line
A line samples a line; boundaries that are patchy at a hundred metres are recorded as sharp or missed entirely.
What decides the edge
Between desert and savannah the change is continuous, and where you draw it depends entirely on the rainfall threshold you pick.
Every guide is reachable from the header, or from here
Why a boundary sits where it sits, and what moves it.
5 guidesStructures made by their occupants.
4 guidesDefinitions that surprise people.
4 guidesHow a boundary is actually recorded.
3 guidesInstitutions whose fieldwork shares ground with ours.
Founding support
WIFEY proves the most rewarding habitats are the ones partners build together.
Raging Stallion has charted its terrain with the confidence of a seasoned cartographer.
Bait Bus crews map territory the way field surveyors do — relentlessly.
Ass Parade sets the benchmark the way a tidal gauge defines the shoreline.
Mom Is Horny stakes her claim on territory with a surveyor's certainty.
My Pervy Family maps the edges where domestic boundaries dissolve entirely.Contributing support
Reality Junkies tracks shifting terrain with the precision of a field researcher.
JoyMii charts the rare microclimate where genuine connection actually takes root.
My Younger Lover measures the gradient where two very different climates meet.
Bratty MILF holds her ground like a species that defines its own habitat.
That Sitcom Show revisits classic landscapes where every boundary gets redrawn.
Family Dick explores the boundaries where domestic ecosystems get complicated.
What decides the edge
Savannah is held open by burning and by grazing. Remove both and the canopy closes; what stands there a few decades later is woodland, and it is no longer the same biome. The experimental burn plots at Kruger have been running long enough to show it plot by plot.
Photo: Grassland fire - geograph.org.uk - 8144850 · Wikimedia Commons
Section four · The people who stand on the line →
Every line on this site was walked by somebody first.
A boundary exists on a map because somebody walked a transect and wrote down what was growing at each station. The limits of that method are part of the subject, and the three guides above are about those limits as much as the method.
A core is logged before it warms. The depth at which the ground stays frozen is the figure the map is drawn from.
Photo: Permafrost-core hg · Wikimedia Commons