Litter of an alien tree, Casuarina equisetifolia, inhibits seed germination and initial growth of a native tree on the Ogasawara Islands (subtropical oceanic islands)

Litter from the invasive tree Casuarina equisetifolia significantly inhibits the germination and early growth of Schima mertensiana, a native species on the Ogasawara Islands. Field experiments showed fewer seedlings emerged in areas dominated by C. equisetifolia compared to native forests, with litter removal slightly increasing seedling emergence. Greenhouse trials further demonstrated that increased litter cover—regardless of soil or litter type—suppressed germination and biomass accumulation. The study concludes that the primary factor behind this suppression is the higher volume of litter under C. equisetifolia, rather than differences in soil composition or litter chemistry between native and invasive species.

Hata, K., Kato, H., & Kachi, N. (2010). Litter of an alien tree, Casuarina equisetifolia, inhibits seed germination and initial growth of a native tree on the Ogasawara Islands (subtropical oceanic islands). Journal of Forest Research, 15(6), 384–390. https://doi.org/10.1007/s10310-010-0199-4