*Appendix A.2. Bottom-Side Position*

Fungi was inoculated at the bottom-side position of the jar. The vertical face of the jar where the fungi was inoculated was denoted as North face, their adjacent faces as East and West, and the opposed vertical face denoted South. Colonisation patterns fell into three main cases:

1. First mycelial expansion not observable on either the East or West faces. The colonisation was assumed to follow a quarter of ellipsoid (Equation (A3)):

$$V\_t = \frac{1}{3}\pi \cdot a \cdot b \cdot c,\tag{A3}$$

where *a*, *b* and *c* are elliptic radii. Radius *a* was obtained on the North face as the mean value of the colonisation shown along the Z-axis. Radius *c* was obtained on the North face as the maximum minus the minimum coordinates showing colonisation along the X-axis divided by two. Radius *b* was obtained on the bottom face as the mean value of the colonisation shown along the Y-axis, assuming a minimum value of 1 square.

2. Mycelial expansion observable on either the East or West faces. The growth was assumed to follow a cylindrical shape (Vc) and an ellipsoid shape (Ve) as expressed in Equation (A4):

$$V\_t = \frac{V\_\varepsilon}{8} + \frac{V\_\varepsilon}{4} = \frac{1}{12}\pi \cdot a \cdot b \cdot \left(c - \frac{L\_W}{2}\right) + \frac{1}{4}\pi \cdot a \cdot b \cdot \frac{L\_W}{2},\tag{A4}$$

where *LW* is the wide of the jar (5.5 cm).

3. Mycelial expansion observable on the top or South faces. Colonisation front was assumed to follow a cylindrical shape until the end of the colonisation (Equation (A5)) according the expression:

$$V\_t = L\_W a \cdot L\_T + L\_W \cdot L\_S \cdot (b - L\_T) + \frac{1}{4} \pi \cdot (b - L\_T) \cdot (a - L\_S) \cdot L\_W \tag{A5}$$

where *LT*, and *LN* are the colonisation length attained by the fungi on the top and South faces, respectively. These were computed as the mean value of the colonisation shown along the Y-axis of the top face (*LT*) and the Z-axis of the South face (*LS*).
