Height (h) Taller trees intercept more light but cost more energy to maintain and are easily wind-toppled. Evolves shorter when wind is strong.

Girth (g) Wide trunks anchor trees against wind, but are expensive. Key in windy environments. Tall, narrow silhouette = conifer; short, wide silhouette = deciduous.

Canopy width (cw) How far branches spread, independent of trunk girth. Wide canopies capture more light and cast deeper shade on neighbours, but cost more energy and catch more wind.

Root depth (r) Deep roots extract water when rainfall is low. Costly to maintain; favoured as rainfall decreases.

Bark thickness (b) Thick bark resists fire ignition and slows burning. Energetically costly; evolves rapidly when fire rate is high. Trunk colour ranges from cream/sandy (thin bark) to near-black (thick bark).

Seed strategy (s) Low values: few large seeds that germinate under shade. High values: many small seeds that colonise open ground. Tree colour ranges from deep emerald (low) to bright lime-yellow (high). Dispersing seeds appear as small coloured dots arcing through the air.

Dispersal (d) How far seeds travel from the parent. Wind biases the direction. High dispersal finds empty slots; low dispersal clusters offspring nearby. A thin blue arc on the ground shows each tree's seed-reach radius.

Allelopathy (a) Trees produce chemicals that suppress germination in nearby slots. Costs energy; pays off when the forest is dense and slot competition is intense. A sickly yellow-brown dead zone with withered grass marks spreads around the base of high-allelopathy trees.

Serotiny (sr) Seeds are sealed in resin and released only by fire heat. Useless in fire-free forests; in fire-prone ones each burn floods clearings with stored seeds before competitors can arrive. Orange-brown elongated cones hang from conifer branches; dark pod clusters appear on deciduous canopies.

Light preference (ls) 0 = shade-tolerant: photosynthesises efficiently in dim light, grows slowly, can establish under a closed canopy. 1 = sun-loving: highly productive in full light but starves in deep shade. Coevolves with height — short shade-tolerant understory trees and tall canopy trees tend to emerge as distinct strategies.

Dormancy (dorm) How long seeds remain viable in the soil. Low dormancy: seeds germinate quickly or die. High dormancy: seeds persist for a very long time, acting as a long-term genetic reservoir — strategies that disappear from the living forest can re-emerge decades later from buried seeds.