# Volume XVIII — biomes 5-7 (theories 37-63), new file
THEORIES = [
# Desert & Dryland
{"n":37,"slug":"vegetation-stripes-slope","field":"Desert & Dryland","subject":"Vegetation bands","title":"Stripes Need a Slope Ratio","claim":"Desert vegetation stripes form only within a range of slope-to-infiltration ratios, appearing where runoff concentrates without eroding.","mechanism":"Bands form where water runs off bare ground onto vegetated strips; too flat and water pools, too steep and it scours.","prediction":"Stripes should appear within a slope window.","refute":"Stripes forming across all slopes would remove the ratio."},
{"n":38,"slug":"dryland-pulse-infiltration","field":"Desert & Dryland","subject":"Productivity pulses","title":"Pulses Follow Event Size","claim":"Dryland productivity pulses occur above a threshold in rain event size relative to infiltration capacity, so many small events add nothing.","mechanism":"Small events evaporate before reaching roots; the event must exceed the soil's uptake capacity to contribute.","prediction":"Pulses should track event size relative to capacity.","refute":"Productivity tracking total rainfall would remove the size threshold."},
{"n":39,"slug":"dust-wind-crust","field":"Desert & Dryland","subject":"Dust emission","title":"Dust Needs Wind Over Crust","claim":"Dust emission is set by the ratio of wind shear to surface crust strength rather than by wind speed alone.","mechanism":"Crusts bind particles; emission requires the shear to exceed their strength, which depends on composition and age.","prediction":"Emission should track the ratio.","refute":"Emission tracking wind speed would remove crust strength."},
{"n":40,"slug":"dryland-encroachment-grazing","field":"Desert & Dryland","subject":"Woody encroachment","title":"Shrubs Take Grazing Gaps","claim":"Woody encroachment in drylands follows a threshold in grazing removal, because grass roots are what exclude shrub seedlings from surface water.","mechanism":"Grasses intercept infiltration in the upper soil; when removed, water reaches deeper and favours shrubs.","prediction":"Encroachment should track grazing pressure.","refute":"Encroachment tracking rainfall would remove competition."},
{"n":41,"slug":"biocrust-recovery-interval","field":"Desert & Dryland","subject":"Biological soil crusts","title":"Crusts Need a Disturbance Interval","claim":"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.","mechanism":"Crusts are slow-growing communities of cyanobacteria, lichens and mosses; recovery requires an interval without disruption.","prediction":"Recovery should track the interval.","refute":"Recovery tracking total disturbance would remove timing."},
{"n":42,"slug":"dryland-respiration-assimilation","field":"Desert & Dryland","subject":"Carbon exchange","title":"Dryland Carbon Is a Pulse Balance","claim":"Dryland carbon exchange is set by the ratio of respiration to assimilation in the days after rain, not by annual rainfall.","mechanism":"Both fluxes respond to moisture but with different thresholds; the ratio determines whether a wet event is a net gain or loss.","prediction":"Net exchange should track the ratio.","refute":"Net exchange tracking rainfall would remove the balance."},
{"n":43,"slug":"oasis-groundwater-flow","field":"Desert & Dryland","subject":"Oases","title":"Oases Need Flow","claim":"Oasis persistence requires groundwater flow above a threshold, set by the ratio of recharge to evaporation from the water table.","mechanism":"A discharge feature exists only while flow exceeds evaporative loss; below it, the water table falls and the oasis disappears.","prediction":"Persistence should track the ratio.","refute":"Persistence tracking water level would remove the flow term."},
{"n":44,"slug":"seed-mass-event-ratio","field":"Desert & Dryland","subject":"Establishment","title":"Seedlings Need Big Events","claim":"Desert plant establishment is gated by the ratio of rain event size to seed mass, so large-seeded species need larger events to germinate.","mechanism":"Germination requires sufficient water penetration relative to the seed's reserves; the ratio sets which species can recruit in a given event.","prediction":"Recruitment should track the ratio by species.","refute":"Recruitment tracking event number would remove seed mass."},
{"n":45,"slug":"dryland-fire-grass-connectivity","field":"Desert & Dryland","subject":"Fire regime","title":"Dryland Fire Needs Connectivity","claim":"Fire in drylands spreads only above a threshold in grass connectivity between shrubs, so fuel amount matters less than its arrangement.","mechanism":"Fire requires continuous fine fuel; once connectivity is broken by bare ground, the front stops regardless of total biomass.","prediction":"Spread should track connectivity.","refute":"Spread tracking fuel load would remove arrangement."},

# Tropical Rainforest
{"n":46,"slug":"rainforest-drought-rooting-season","field":"Tropical Rainforest","subject":"Drought sensitivity","title":"Rainforest Drought Is Depth Against Season","claim":"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.","mechanism":"Access to deep water determines whether the canopy can be maintained through the dry season; the ratio sets the margin.","prediction":"Sensitivity should track the ratio.","refute":"Sensitivity tracking rainfall deficit would remove rooting depth."},
{"n":47,"slug":"carbon-sink-vpd-threshold","field":"Tropical Rainforest","subject":"Carbon sink","title":"The Sink Tips on Dry Air","claim":"The tropical forest carbon sink turns to a source above a vapour pressure deficit threshold, even at high soil moisture.","mechanism":"Dry air closes stomata, which reduces photosynthesis while respiration continues; the deficit sets the crossover.","prediction":"The sink should flip at a VPD threshold.","refute":"The sink tracking soil moisture would remove atmospheric demand."},
{"n":48,"slug":"regeneration-dispersal-threshold","field":"Tropical Rainforest","subject":"Regeneration","title":"Regeneration Needs Dispersers","claim":"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.","mechanism":"Large-seeded trees depend on animals; without dispersal, seedlings are concentrated under parents where competition and mortality are high.","prediction":"Recovery should stall below a dispersal threshold.","refute":"Recovery independent of dispersers would remove the mechanism."},
{"n":49,"slug":"diversity-niche-neutral","field":"Tropical Rainforest","subject":"Tree diversity","title":"Diversity Balances Niche and Drift","claim":"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.","mechanism":"Niche differences promote coexistence while drift prevents any one species from dominating quickly; the ratio determines the equilibrium richness.","prediction":"Richness should track the ratio.","refute":"Richness tracking productivity would remove the balance."},
{"n":50,"slug":"liana-disturbance-threshold","field":"Tropical Rainforest","subject":"Lianas","title":"Lianas Follow Disturbance","claim":"Liana dominance increases above a threshold in canopy disturbance, because lianas exploit gaps faster than trees can close them.","mechanism":"Lianas grow rapidly in high light and climb established stems; repeated disturbance favours them over tree regeneration.","prediction":"Liana cover should track disturbance frequency.","refute":"Liana cover tracking rainfall would remove disturbance."},
{"n":51,"slug":"fragmentation-edge-area","field":"Tropical Rainforest","subject":"Fragmentation","title":"Fragments Fail on Edge","claim":"Forest fragmentation causes biodiversity collapse above a threshold in edge-to-area ratio, independent of total area lost.","mechanism":"Edges change microclimate and allow generalists inward; when edges dominate the fragment, interior species have nowhere to persist.","prediction":"Collapse should track the ratio.","refute":"Collapse tracking area alone would remove edge effects."},
{"n":52,"slug":"phenology-irradiance-moisture","field":"Tropical Rainforest","subject":"Phenology","title":"Leaf Flush Follows Irradiance","claim":"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.","mechanism":"Flush requires both carbon and water; the ratio determines whether the high-light period can be exploited.","prediction":"Flush timing should track the ratio.","refute":"Flush timing tracking rainfall would remove light."},
{"n":53,"slug":"peat-waterlogging-threshold","field":"Tropical Rainforest","subject":"Tropical peat","title":"Peat Needs Waterlogging","claim":"Tropical peat accumulation requires a threshold in waterlogging, below which decomposition outpaces accumulation regardless of productivity.","mechanism":"Peat forms where anoxia suppresses decay; the water table position relative to the surface sets that.","prediction":"Accumulation should track waterlogging depth.","refute":"Accumulation tracking productivity would remove decay."},
{"n":54,"slug":"fire-drought-fuel-ratio","field":"Tropical Rainforest","subject":"Fire","title":"Rainforest Fire Is Drought Against Fuel","claim":"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.","mechanism":"Humidity resists ignition while fuel carries it; both must be favourable, which is why rainforest fires are rare and episodic.","prediction":"Fire occurrence should track the ratio.","refute":"Fire tracking drought alone would remove fuel."},

# Mountain & Alpine
{"n":55,"slug":"alpine-treeline-season-frost","field":"Mountain & Alpine","subject":"Alpine treeline","title":"Alpine Treeline Is a Season Ratio","claim":"The alpine treeline is set by the ratio of growing season length to frost frequency, not by mean temperature.","mechanism":"Trees need a season long enough to harden before frost; the ratio determines whether any cohort can establish.","prediction":"Treeline should track the ratio.","refute":"Treeline tracking mean temperature would remove frost."},
{"n":56,"slug":"mid-elevation-diversity","field":"Mountain & Alpine","subject":"Elevation gradients","title":"Diversity Peaks Mid-Slope","claim":"Mountain diversity peaks at intermediate elevation because both area and climatic favourability are maximised there rather than at the base.","mechanism":"Low elevations are hot and dry, high ones cold and small in area; the product of area and favourability peaks between.","prediction":"Richness should peak mid-elevation.","refute":"Monotonic decline with elevation would remove the area term."},
{"n":57,"slug":"snowmelt-phenology-gate","field":"Mountain & Alpine","subject":"Alpine phenology","title":"Phenology Is Gated by Snowmelt","claim":"Alpine plant phenology is gated by snowmelt date rather than by temperature, so a warm spring under deep snow produces no advance.","mechanism":"Growth cannot begin until the plant is exposed; the snowpack sets the start independent of air temperature.","prediction":"Phenology should track snowmelt date.","refute":"Phenology tracking spring temperature would remove snow."},
{"n":58,"slug":"streamflow-snow-glacier","field":"Mountain & Alpine","subject":"Mountain water","title":"Streamflow Is Snow Against Ice","claim":"Mountain streamflow is set by the ratio of snowpack storage to glacier storage, so two catchments with the same precipitation have different seasonal timing.","mechanism":"Snow releases water in spring and glaciers in late summer; the ratio determines the shape of the hydrograph.","prediction":"Hydrograph shape should track the ratio.","refute":"Flow tracking precipitation would remove storage."},
{"n":59,"slug":"alpine-carbon-season-grazing","field":"Mountain & Alpine","subject":"Alpine grassland","title":"Alpine Carbon Balances Season and Grazing","claim":"Alpine grassland carbon is set by the ratio of growing season to grazing pressure rather than by temperature.","mechanism":"Carbon accumulates over a short season and is removed by herbivores; the ratio determines the net balance.","prediction":"Carbon should track the ratio.","refute":"Carbon tracking temperature would remove grazing."},
{"n":60,"slug":"rock-glacier-ice-threshold","field":"Mountain & Alpine","subject":"Rock glaciers","title":"Rock Glaciers Need Ice","claim":"Rock glacier creep occurs above a threshold in ice content, below which the debris behaves as a rigid mass.","mechanism":"Deformation requires ice to connect the debris; below the threshold, friction between clasts dominates and movement stops.","prediction":"Creep should track ice content.","refute":"Creep tracking slope angle would remove ice."},
{"n":61,"slug":"postfire-seed-source","field":"Mountain & Alpine","subject":"Post-fire regeneration","title":"Regeneration Needs a Source","claim":"Post-fire regeneration in mountain forest requires a threshold in surviving seed source, so a large severe burn can remain unforested for decades.","mechanism":"Recovery depends on seed arriving from unburned edges or from serotinous cones; below the threshold, distance dominates.","prediction":"Regeneration should track source distance.","refute":"Regeneration tracking burn severity would remove the source term."},
{"n":62,"slug":"soil-weathering-erosion","field":"Mountain & Alpine","subject":"Alpine soils","title":"Soil Depth Balances Weathering and Erosion","claim":"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.","mechanism":"Soil accumulates from weathering and is removed by erosion; the ratio determines the steady-state depth.","prediction":"Depth should track the ratio.","refute":"Depth tracking time since deglaciation would remove erosion."},
{"n":63,"slug":"avalanche-return-snowpack-slope","field":"Mountain & Alpine","subject":"Avalanche regime","title":"Avalanche Return Is a Load Ratio","claim":"Avalanche return interval is set by the ratio of snowpack accumulation rate to slope stability, not by snowfall alone.","mechanism":"Slabs fail when load exceeds strength; the ratio determines how often that is reached on a given slope.","prediction":"Interval should track the ratio.","refute":"Interval tracking snowfall would remove stability."},
]