Ligustrum sinense negatively impacts ecosystem processes in the USA
Ligustrum sinense (Oleaceae – Chinese privet) is a shrub species native to Asia and has been introduced throughout the world as a garden ornamental species. It is reported as invasive in Argentina and a number of states in the USA. In the USA, L. sinense was introduced as a garden species as early as the mid-1850s, often as an ornamental hedge species. Since its introduction, the species has spread out of confined areas where it can invade riparian systems. L. sinense currently occupies more than 1 million ha of riparian forest habitat. In Georgia (US), a study was conducted to evaluate phenological patterns of L. sinense litterfall, litter chemistry, and changes in availability of mobile soil nutrients within riparian zones invaded by Chinese privet. Comparisons of native and invaded sites showed that L. sinense invasion alters the timing but not quantity of litter deposition. In contrast to native species, total litterfall displayed little seasonal variation however invaded sites had similar total litter mass compared to native sites. Within invaded sites, L. sinense litter was 26% of total litterfall in spring. L. sinense leaf litter was seasonally enriched in nitrogen during winter as compared to fall and spring. Compared to native sites, invaded sites had significantly increased soil nitrate availability and decreased soil carbon:nitrogen ratios. In contrast, dissolved organic matter and dissolved nitrogen in soil solution was lower in invaded sites compared to native sites. The results suggest that L. sinense enhances litter and inorganic nitrogen availability in ways that have potential to impact decomposer and detritovore communities in the invaded riparian zones and adjacent aquatic systems.
Sources
Weand M (2020) Chinese privet (Ligustrum sinense Lour.) alters the timing of litterfall and nutrient quality of leaf litter inputs in invaded riparian forests. Biological Invasions. https://doi.org/10.1007/s10530-020-02335-0