A global synthesis of the effectiveness and ecological impacts of management interventions for Spartina species

Invasions by Spartina species pose serious threats to global coastal ecosystems. Although many studies have examined the effectiveness and ecological impacts of invasive Spartina management, no comprehensive global synthesis has been conducted to assess the effects of management on Spartina per se and on wider non-targets. Here, we conducted a global meta-analysis of 3,459 observations from 102 studies to quantify the effects of different management interventions (physical, chemical, biological, and integrated control) on Spartina per se and native biodiversity and environments. We found that physical measures quickly suppressed Spartina but that their effectiveness declined over time. By contrast, chemical measures decreased the abundance and growth of Spartina to a lesser degree in the early stage, but the effectiveness increased over time. Different management measures did not significantly decrease the diversity of native biota on the whole, but native-plant diversity significantly decreased with time after physical control. Different management measures did not affect abiotic factors differently. These results support the use of chemical measures to control invasive Spartina , although their effectiveness would depend on the time since the management intervention. Addressing the problem of Spartina regrowth following physical control requires improved techniques. We hold that initial states of invaders and subsequent environmental changes after management interventions should be weighed in evaluating control efficacy.