Fast growing neophytic trees in Southern Switzerland

Fig. 1: Broken Tree of heaven (Ailanthus altissima) in a forest protecting from natural hazards near Avegno TI.

Fig. 2: High resolution point dendrometer for continuous growth measurements near Minusio TI.

Fig. 3: Band dendrometer for weekly growth measurements near Minusio TI.

Summary

In this project, we apply a combination of ecophysiological and dendroecological methods to elucidate the competition dynamics and physiological decay of two fast growing neophytic tree species with different life-history strategies that are currently expanding in the forests of Southern Switzerland: the deciduous short-lived pioneer Ailanthus altissima of low to intermediate shade tolerance and the evergreen late-successional Cinnamomum glanduliferum of high shade tolerance. Both may accelerate their expansion in a warmer world with unknown consequences for forest ecosystem goods and services such as biodiversity, carbon storage, turnover rate, and protection of humans and infrastructure from natural hazards.

At two plots near Locarno TI (Minusio and Avegno), we measure the growth and decay status of A. altissima and C. glanduliferum and their native competitors (Castanea sativa, Ilex aquifolium, Fagus sylvatica) along with environmental variables at different temporal scales, from annual to sub-hourly resolution. First observations on tree decay indicate that many large A. altissima trees are rotten inside along with an unexpected high number of C. glanduliferum trees. This suggests that the enormous growth rates of both neophytic trees may come at the cost of their defences against pathogens such as wood decaying fungi. We test this hypothesis and quantify both the growth and decay patterns of neophytic vs. native tree species resulting in a better understanding of the invasion potential – ultimately contributing to a more informed management of neophytic tree species in Southern Switzerland and beyond.

Real-time data

High-resolution measurements of growth and climate at the two flagship-sites

1) Minusio

2) Avegno

Contacts

• Jan Wunder

• Andi Rigling

• Patrick Fonti

• Marco Conedera