The Effect of Artificial Mowing on the Competition of Phragmites australis and Spartina alterniflora in the Yangtze Estuary

Abstract

Spartina alterniflora Loisel. is one of the most invasive species in the world. However, little is known about the role of artificial mowing in its invasiveness and competiveness. In this work, we studied the effect of mowing on its interspecific interactions with native species Phragmites australis (Cav.) Trin ex Steud of the Yangtze Estuary, China. We calculated their relative neighbor effect (RNE) index, effect of relative crowding (Dr) index, and interaction strength (I) index. The results showed that the RNE of Phragmites australis and Spartina alterniflora was 0.354 and 0.619, respectively, and they have competitive interactions. The mowing treatments can significantly influence the RNE of Phragmites australis and Spartina alterniflora on each other. Concretely, the RNE of Spartina alterniflora in the removal treatments was significantly higher than the value in the controls. But the RNE of Phragmites australis in the removal treatments was significantly lower than the value in the controls. Meanwhile, Dr of the two species on the targets was higher in the removal treatments than that in the controls, and the opposite was for I. We concluded that artificial mowing could promote the invasion of Spartina alterniflora by increasing its competitive performance compared with native species.

The spatial overlapping regulated by nitrogen promotes the Spartina alterniflora potential regenerated invasion in coastal wetlands

“…One of the threats of invasive species to native ecosystems is their competitive effects on native plants, which may lead to a decrease in the number of native species or even extinct in local area (Zheng, Liao 2017). Since S. alterniflora was introduced into Dongtan wetland, it has produced a large number of seeds through sexual reproduction due to its high adaptability to the environment, which provides convenient conditions for the long-distance transmission of S. alterniflora (Yuan et al 2017). The S. alterniflora invasion process has coevolution with native species.…”

Combining Multi-Indices by Neural Network Model for Estimating Canopy Chlorophyll Content: a Case Study of Interspecies Competition between <i>Spartina alterniflora</i> and <i>Phragmites australis</i>

“…Owing to the influence of interspecies competition, it is insufficient to estimate CCC with a single spectral index. Beyond that, previous studies mainly focused on the mechanism and propagation between interspecies interaction among salt marsh vegetation [23,[58][59][60][61][62]. As clearly shown in Fig.…”

“…Therefore, information on CCC is critical for monitoring the growth situation of S. alterniflora and P. australis, especially for this specific mixed region. As of late, studies have been focused on vegetation observation and monitoring, and the retrieval of chlorophyll content via non-destructive remote sensing methods, achieving many scientific results [22][23][24][25][26][27]. Due to the complexity of the radiative transfer model and growth conditions at the canopy level, the estimation of CCC has typically been carried out by combing multi-indices that can be found in many cases [28][29][30][31][32][33].…”