A silver-lining in a man-made ecology?

I wanted to demonstrate to The Family that my vision had not improved after my surgery. I nodded at the trees on the ridge half a kilometer above us. “I was able to see those white flowers more clearly before,” I said. She was surprised. “I hand’t seen them.” She raised her binoculars to her eyes as I took a photo. My eyes were truly bad. Those weren’t flowers, just the white underside of the silver oak (Grevillea robusta) leaves, as the wind ruffled its canopy. We laughed at that, my point made. Thank you, unknown colonisers who disrupted the ecology of this ridge in the mid-19th century CE, barely a decade after the discovery of these pseudo-oaks in eastern Australia, by planting them across the Deccan plateau.

Invaders are usually bad, but the silver oak, planted right across India and Kenya, have been generally regarded as benign. They do not immediately have an advantage in competition with local plants. They provide shade and support for multi-culture of pepper in coffee plantations (these British colonial-era plantations devastated the ecology of the Nilgiris). In Kenya they are used very similarly, and also provide useful hard wood in regions that lack them. Newspapers carry happy reports of their integration into the local ecology. Through Africa there are studies of increased productivity in agro-forestry when silver oak is used to provide a high canopy. However, new elements are always disruptive. It is a second host for the mealy bugs which infest mango trees, and can act as reservoirs for the pest. What seems to be a good neighbour one century can turn out different in another. The story of silver oaks in Asia and Africa is still beginning.