Eleven biomes · nine claims each · not peer reviewed
Eleven biomes, nine claims each. The earlier volumes treated ecology as one discipline; this one treats each habitat as its own laboratory, because the constraints that organise a bog are not the constraints that organise a savanna.
The ice-albedo feedback tips at a critical melt-pond fraction, not at a critical temperature, so the same warming produces very different ice loss depending on pond coverage.
Polar bear body condition is set by the ratio of ice-free days to hunting days rather than by total ice extent.
The thickness distribution of sea ice is set by the ratio of deformation to thermal growth, so a thinner pack can be more variable without being warmer.
Coastal polynyas remain open only while the ratio of ocean heat flux to atmospheric cooling exceeds a threshold, so they close abruptly when cooling intensifies.
Antarctic bottom water formation is set by the ratio of brine rejection to meltwater input rather than by surface temperature.
Under-ice phytoplankton blooms occur only above a threshold in light transmission, set by snow depth relative to ice thickness.
Ice algal production is set by the ratio of snow depth to ice thickness, with an optimum where light reaches the bottom of the ice without melting it.
Coastal stratification in the Arctic is set by the ratio of river discharge to wind mixing, so a windy year can erase a large freshwater input.
Carbon release from thawing permafrost is set by the ratio of thaw depth to active layer depth, not by the absolute area thawed.
The boreal treeline is set by the ratio of growing degree days to frost damage rather than by temperature alone.
The boreal fire return interval is set by the ratio of fuel accumulation rate to decomposition rate rather than by climate alone.
Peat accumulation occurs only where the ratio of plant production to decay exceeds one by a margin set by waterlogging.
Boreal insect outbreaks occur when the ratio of drought stress to host defence exceeds a threshold, not when insect populations are large.
Lichen recovery after fire requires a threshold in the ratio of recovery time to grazing pressure, so heavy grazing can prevent recovery entirely.
The boreal forest carbon balance tips from sink to source above a winter warming threshold, because soil respiration responds while photosynthesis does not.
Moss dominance on the boreal forest floor is set by the ratio of light transmission to moisture, so a thinned canopy can reduce moss despite more light.
Boreal lake carbon emission is set by the ratio of terrestrial carbon import to in-lake processing rather than by import alone.
Treeline advance is set by the ratio of seedling establishment to herbivory, so a warmer climate without reduced browsing produces no advance.
Temperate forest diversity peaks at an intermediate disturbance frequency because both competition and mortality limit diversity at the extremes.
Mast seeding occurs only when stored resources exceed a threshold, so masting years follow years of high photosynthesis rather than years of warm weather.
Forest regeneration collapses above a threshold in browse pressure, and the threshold depends on light availability rather than on deer density alone.
Temperate forest soil carbon is set by the ratio of root input to microbial turnover rather than by litter input.
Spring leaf-out occurs when the ratio of accumulated forcing to remaining chilling requirement exceeds a threshold, so warm winters delay rather than advance leaf-out.
The depth of forest edge effects is set by the ratio of canopy height to the fetch of the opening, so a small clearing has a shallower edge than a wide one.
Old-growth structure develops only above a threshold in gap formation rate, because large trees and deadwood require repeated small disturbances.
Invasive shrub dominance occurs above a threshold in canopy openness, so a thinned forest can be invaded without any change in propagule pressure.
Temperate forest drought mortality is set by the ratio of rooting depth to hydraulic risk, so deep-rooted species survive droughts that kill shallow-rooted ones at the same site.
The tree-grass balance in savanna is set by the ratio of fire frequency to rainfall, so a wet savanna with frequent fire has the same cover as a dry one without.
Grassland productivity is set by the ratio of growing season length to grazing pressure rather than by rainfall.
Migratory herds move when the ratio of grass quality to predation risk falls below a threshold, not when grass is exhausted.
Grassland soil carbon is set by the ratio of root turnover to fire loss, so frequent burning can offset a productive system.
Shrub encroachment occurs above a threshold in grazing removal, because grass competition is what keeps shrubs from establishing.
Savanna tree cover is set by the ratio of rooting depth to rainfall seasonality, so deep-rooted trees persist where rainfall is strongly seasonal.
Grassland recovery after drought is set by the ratio of seed bank to surviving tillers, so a system with few tillers and no seed bank recovers slowly.
Grazing maintains grassland diversity only above a threshold in grazing patchiness, so uniform heavy grazing reduces diversity despite high pressure.
Savanna carbon emissions are set by the ratio of fire to decomposition, so fire-prone systems emit more than decomposition alone would predict.
Desert vegetation stripes form only within a range of slope-to-infiltration ratios, appearing where runoff concentrates without eroding.
Dryland productivity pulses occur above a threshold in rain event size relative to infiltration capacity, so many small events add nothing.
Dust emission is set by the ratio of wind shear to surface crust strength rather than by wind speed alone.
Woody encroachment in drylands follows a threshold in grazing removal, because grass roots are what exclude shrub seedlings from surface water.
Biological soil crusts recover only when the disturbance interval exceeds the time needed to rebuild the community, so frequent trampling keeps them in an early state.
Dryland carbon exchange is set by the ratio of respiration to assimilation in the days after rain, not by annual rainfall.
Oasis persistence requires groundwater flow above a threshold, set by the ratio of recharge to evaporation from the water table.
Desert plant establishment is gated by the ratio of rain event size to seed mass, so large-seeded species need larger events to germinate.
Fire in drylands spreads only above a threshold in grass connectivity between shrubs, so fuel amount matters less than its arrangement.
Tropical rainforest drought sensitivity is set by the ratio of rooting depth to dry-season length, so deep-rooted forests tolerate seasons that kill shallow-rooted ones.
The tropical forest carbon sink turns to a source above a vapour pressure deficit threshold, even at high soil moisture.
Rainforest regeneration requires a threshold in seed dispersal, so a forest that has lost its frugivores cannot recover its composition even if the soil and climate are intact.
Tropical tree diversity is set by the ratio of niche differentiation to neutral drift, so a forest with weak niches can still be diverse if drift is strong enough to delay competitive exclusion.
Liana dominance increases above a threshold in canopy disturbance, because lianas exploit gaps faster than trees can close them.
Forest fragmentation causes biodiversity collapse above a threshold in edge-to-area ratio, independent of total area lost.
Tropical forest leaf flush is gated by the ratio of irradiance to soil moisture, so flush occurs at the dry-season peak of light if moisture permits.
Tropical peat accumulation requires a threshold in waterlogging, below which decomposition outpaces accumulation regardless of productivity.
Fire enters tropical rainforest when the ratio of drought severity to fuel connectivity exceeds a threshold, so a dry year with fragmented fuel still does not burn.
The alpine treeline is set by the ratio of growing season length to frost frequency, not by mean temperature.
Mountain diversity peaks at intermediate elevation because both area and climatic favourability are maximised there rather than at the base.
Alpine plant phenology is gated by snowmelt date rather than by temperature, so a warm spring under deep snow produces no advance.
Mountain streamflow is set by the ratio of snowpack storage to glacier storage, so two catchments with the same precipitation have different seasonal timing.
Alpine grassland carbon is set by the ratio of growing season to grazing pressure rather than by temperature.
Rock glacier creep occurs above a threshold in ice content, below which the debris behaves as a rigid mass.
Post-fire regeneration in mountain forest requires a threshold in surviving seed source, so a large severe burn can remain unforested for decades.
Alpine soil depth is set by the ratio of weathering rate to erosion rate, so steep warm slopes can have thinner soils than gentle cold ones.
Avalanche return interval is set by the ratio of snowpack accumulation rate to slope stability, not by snowfall alone.
Wetland methane emission is set by the ratio of methanogenesis to methanotrophy rather than by water table position alone.
Bog formation requires a threshold in peat accumulation rate that exceeds the rate at which groundwater delivers nutrients.
A shallow lake becomes turbid when the ratio of nutrient load to grazing pressure exceeds a threshold, so nutrient reduction without grazing recovery can fail.
Wetland nutrient retention is set by the ratio of hydraulic load to wetland area, so a small wetland receiving high flow retains little regardless of its vegetation.
Amphibian population persistence is set by the ratio of hydroperiod to larval development time, so a pond that dries a week earlier can eliminate a species.
Lake stratification breaks down when the ratio of wind energy to density difference falls below a threshold, so a deep lake can mix in a windy year and stratify in a calm one.
Freshwater carbon burial is set by the ratio of deposition rate to respiration rate, so a productive lake can bury little if respiration is fast.
Wetland restoration succeeds only above a threshold in hydrological connectivity, because a disconnected wetland cannot maintain its own water regime.
Riverine fish assemblage diversity is set by the ratio of flow variability to habitat complexity, so a variable river with simple habitat supports fewer species than a stable one with complex habitat.
Floodplain sediment deposition is set by the ratio of sediment supply to flood duration, so a sediment-rich river with short floods deposits less than a moderate one with long floods.
River channel form is set by the ratio of bank strength to flow energy, so a cohesive-bank river is narrow and deep where a sandy one is wide and shallow.
Flood risk downstream increases above a threshold in floodplain disconnection, because floodplains that no longer store water pass the peak downstream.
Riparian vegetation composition is set by the ratio of flood tolerance to drought tolerance, so flow regulation that removes floods favours upland species.
Riverine nitrogen removal is set by the ratio of residence time to uptake rate, so a slow river with modest uptake removes more than a fast one with high uptake.
Meander migration rate is set by the ratio of bank erodibility to flow energy, so a moderate river in weak banks migrates faster than a large one in resistant banks.
Floodplain carbon storage is set by the ratio of deposition rate to decomposition rate, so a rapidly accreting floodplain stores carbon even if decomposition is fast.
Riverine fish metapopulations collapse above a threshold in dam density, because barriers fragment the network faster than recolonisation can compensate.
Sediment starvation downstream of a reservoir is set by the ratio of trap efficiency to sediment supply, so a small reservoir with high trapping can starve a coast more than a large one with low trapping.
The estuarine turbidity maximum forms where the ratio of salinity gradient to tidal mixing exceeds a threshold, so a well-mixed estuary has no maximum.
Salt marsh survival requires the ratio of sediment accretion to sea level rise to exceed one, and the margin depends on tidal range.
Mangrove range limits are set by the ratio of frost frequency to propagule supply, so a single cold event can set a boundary that propagules cannot cross.
Seagrass meadow persistence requires light above a threshold set by the ratio of water clarity to depth, not by nutrient level.
Estuarine hypoxia forms when the ratio of stratification to oxygen demand exceeds a threshold, so a well-mixed system can carry a large load without hypoxia.
Coastal wetland carbon burial is set by the ratio of accretion to subsidence, because a drowning wetland stops accumulating.
Oyster reef survival is set by the ratio of salinity to predation pressure, so low-salinity refuges persist where predators cannot.
Tidal flat morphology is set by the ratio of tidal range to sediment supply, so a mesotidal coast with low supply erodes while a macrotidal one with low supply builds.
Coastal fish recruitment is gated by the ratio of nursery habitat to predation risk, so restoration without predator management can fail.
Urban tree survival is set by the ratio of soil volume to crown size, so a large crown on a small pit dies regardless of watering.
Urban heat island intensity falls sharply above a threshold in green cover fraction, rather than declining gradually with vegetation.
Urban biodiversity is set by the ratio of habitat area to isolation, so many small connected patches support more species than one large isolated one of the same total area.
Stormwater retention fails above a threshold in impervious fraction, because infiltration capacity is lost faster than storage is added.
Urban pollutant concentration is set by the ratio of emission flux to mixing height rather than by emissions alone.
Urban carbon storage is set by the ratio of soil sealing to vegetation cover, so a green city on sealed soil stores less than its canopy suggests.
Wildlife roadkill is set by the ratio of traffic volume to habitat continuity, so a busy road through continuous habitat kills more than the same road through fragmented habitat.
Noise propagation along a street canyon is set by the ratio of building height to street width, so a narrow canyon can amplify sound at height.
Urban green space use is set by the ratio of access distance to population density rather than by the amount of green space provided.
A field-by-field catalogue tells you what each discipline thinks. A mechanism-by-mechanism catalogue tells you what kind of argument a discipline is making, and lets you check whether the same argument holds somewhere else. Each family here is a distinct causal shape; the eleven instances test whether it generalises.
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Publication records: source hashes · original README · original manifest · additive publication note