Giant balsa trees

This flower was nowhere to be found here 150 years ago. The exotic giant balsam will now be seen popping up and spreading in many places in Alpbachtal. This plant originates from the Himalayas, mainly from Tibet and also from India. The species also occurs in Western Europe as an invasive alien species. Around 1850, the species was introduced to North India in Europe. Since 1915, the plant has become wild in Europe as an invasive species, and it can now be found throughout Western Europe. Since 2017, the species has been included on the list of invasive species that are concerning for the European Union.

The giant balsam grows in soil that is rich in nitrogen and basic. But what is remarkable is that soils on slate (which we have here) produce acidic soils and not basic ones. This has everything to do with the limestone brought in from higher up the limestone cliffs, which mixes as colluvium with the soil material. This way, you still get a basic soil. The fact that so many giant balsams grow here indicates that there is also a nitrogen problem in the soil here.

The dissemination of the seeds occurs mechanically when the ripe fruit is touched, the five parts of it roll up and launch the seeds away. At the same time, the fruit falls from the plant.

Pascal Brackman