Reproductive capacity of the invasive tree Ailanthus altissima
Ailanthus altissima (Simaroubaceae: EPPO List of Invasive Alien Plants), commonly known as tree of heaven, is a small to medium sized tree (6 – 10 m in height) native to Asia. In the introduced range, habitats invaded by the tree include managed grasslands, natural grasslands, managed and natural forests, and riverbanks/canalsides. A. altissima establishes itself readily on artificially disturbed sites such as roadsides and ditches, particularly in the Mediterranean region, such as in Southern France. It is the most widespread woody invasive species invading forested areas in the USA, occurring wherever moisture allows. In the current study, 55 female seed-bearing trees were sampled at various locations along transportation corridors throughout south-central Pennsylvania (US) between 2011 and 2012. Trees were felled and the age of the tree was determined by sampling one cross section disk removed at breast height. Seeds were collected and taken to the laboratory. Existing data on seed production was combined with the novel dataset. The reproductive window of A. altissima is shown to be long spanning more than 100 years. Seed viability of a 104-year-old individual was 65 % and individuals can produce over 1-million seeds annually. Seeds are dispersed over long distances by wind and thus management should concentrate on controlling individuals before they are mature and produce viable seed.
Sources
Wickert K, O’Neal ES, Davis DD, Kasson MT (2017) Seed production, viability, and reproductive limits of the invasive Ailanthus altissima (Tree-of-Heaven) within invaded environments. Forests, DOI: 10.3390/f8070226.