Why be a shrub?

Artikel i vetenskaplig tidskrift, 2017

We describe advantages for a shrub compared to a small tree with the same above-ground woody volume, based on larger cross-sectional stem area (Fig. 2b), larger area of photosynthetic tissue in bark and stem, larger vascular cambium area, larger epidermis (bark) area (Fig. 2c) and larger area for sprouting, and faster production of twigs and canopy. We predicted higher growth rate for a small shrub than a small tree, which was supported by empirical studies. Also, a shrub will produce seeds faster than a tree, multiple stems in shrubs insure future survival and growth if one or more stems die, and several structural traits improve survival, compared to tall tree stems. Multi-stemmed trees may be distinguished from shrubs by more upright stems, reducing bending moment (Fig. 6).