Birch growing on old stump pic

[Andrew Reed]

Someone suggested in the General Tree pics area that this was such a good example, it should have a thread of its own. Well here it is:-

 

Located above the river Barle in Exmoor. Was wondering if someone planted it there.

[armchairarborist]

looks more like a rowan to me haha:biggrin:, i'd say self seeded. spotted these in northern california, just below oregon. growing on the old growth stumps, it was amazing how many there were, some were left standing even though the stump had rotted away.

[Fungus]

this was such a good example ... Was wondering if someone planted it there.

 

No, probably not. Because they have tiny wind spread seeds, birches can germinate on/in all kinds of substrates, including moist dead wood, cracks in the pavement and gutters, which have not been cleared of debris of leaves.

In it's pioneer phase, as a seedling this birch could rely on the ever present mycelia of endomycorrhizal microfungi for water and nutrients supply.

Later on, its roots must have been colonised by the mycelium of one of the three ectomycorrhizal macrofungi, i.e. Paxillus involutus, Scleroderma citrinum or Thelephora terrestris, which have not lost their ability to decompose dead wood and often are present in stumps and subsurface wood, while waiting for new symbiotic tree partners to arrive.

Once the roots reached and penetrated the soil, according to the life cycle of the tree species, the succession of tree species specific ectomycorrhizal macrofungi could start resulting in the "adolescent" tree as shown in the pictures.

[Fungus]

one of the three ectomycorrhizal macrofungi, i.e. Paxillus involutus, Scleroderma citrinum or Thelephora terrestris, which have not lost their ability to decompose dead wood and often are present in stumps and subsurface wood, while waiting for new symbiotic tree partners to arrive.

 

Photo 1. Paxillus involutus fruiting as a saprotrophic from the heart wood inside an dead branch.

Photo 2. Scleroderma citrinum fruiting as a saprotrophic from a dead stump of an oak.

Photo 3. Thelephora terrestris fruiting as a saprotrophic on a dead stump.

---

[Fungus]

Scleroderma citrinum fruiting from dead roots, that before had been surrounded by ectomycorrhizae from the same species, after the oak tipped over.

---