Fighting Invasive Alien Species
Invasive alien species can harm ecosystems by competing aggressively with native species for scarce resources. In Ise-Shima National Park, invasive flora pose the greatest threat. Rangers and Visitor Center staff work constantly to uproot invasive plants and protect Ise-Shima’s satoyama and satoumi ecology. Park volunteers also participate.
Fighting invasive species is hard, labor-intensive work. Every part of the plant must be disposed of properly to prevent viable seeds or roots from growing somewhere else.
One invasive plant species that is particularly problematic in Yokoyama is montbretia (hime-hiogi-zuisen), a tough garden hybrid with distinctive orange flowers. Montbretia is recognized as an invasive weed all across the Pacific region, from New Zealand to California. It can thrive in the shade and is sometimes even found growing under Yokoyama Tenkū Café Terrace.
Invasive aquatic plants like the parrot feather (o-fusamo) are also a problem for the park’s ponds and wetlands. Aquatic species pose a particularly acute danger. If they overrun a body of water, they can prevent frogs and other animal species from reproducing there.
Another common exotic plant in Ise-Shima National Park is the lance-leaved coreopsis (o-kinkei-giku). This relative of the sunflower was originally introduced to Japan as an ornamental plant but has since been recognized as a threat to native ecosystems. It must be uprooted before it blooms in May and its seeds begin to disperse.
