I've been trying to identify a tree in my garden. Visually, it seems to fit all the descriptions of a Tree of Heaven (Ailanthus altissima) except for the odour they're supposed to have. I've tried crushing leaves and snapping twigs, but this tree only smells of general "plant".
It's about 45' tall, but I've no idea how old it is. This is the 4th summer we've lived here, and the first time it's produced seed pods. Last year it produced tiny white flowers for the first time.
There's a few photos here (ignore the unrelated leaves on the photo of the trunk)...
Is there any reliable information regarding its ability to suppress competitors? We've had problems growing a few things nearby, but that could easily be a result of insufficient sun and rain, as it's right under the Ailanthus's thickest growth.
Modes of competition suppression in AIlanthus...
Pioneer success: simply getting established first enables many plants to develop sufficient root system and canopy (light deprivation) to inhibit growth of competitve plants.
But Ailanthus also pruodcues a root exudate called ailanthone, as discussed here - http://en.wikipedia.org/wiki/Ailanthus_altissima
See also allellopathy, as regards suppressive chemicals produced by roots and leaf decay.