Invasive Plants and Species Richness Impact Litter Decomposition in Riparian Zones

Abstract

Natural ecosystems generally include litter decomposition as part of the natural cycle since the material properties and the environment greatly influence the decomposition rate. The invasion of exotic plants alters the species diversity and growth characteristics of plant communities, but its impact on litter decomposition is unknown in the riparian zone. This study examines how invasive plants affect the early stages of litter decomposition and how species richness impacts them. This experiment involved a random litter mixture of exotic (Alternanthera philoxeroides and Bidens pilosa) and native species in the riparian zone of the Three Gorges Dam Reservoir in China. There were 43 species mixture types, with various species richness ranging from 1 to 6. Litterbags were placed in the hydro-fluctuation zone and terrestrial zone, where they decomposed over the course of 55 days. Invasive plants decompose rapidly compared to native plants (35.71% of the remaining mass of the invasive plant). The invasive plant A. philoxeroides has the potential to accelerate native plant decomposition (0.29 of non-added synergetic effect), but Bidens pilosa cannot. Nonetheless, species richness had little effect on the decomposition rate. These effects are dependent upon differences in chemical functional characteristics among the species. The initial traits of the plants, specifically C, N, and C/N, were significantly and linearly correlated with the loss of mixed litter mass and mixing effect strength (P < 0.01). In addition, submergence decomposition conditions reduce the disturbance of invasive plants and predict decomposition rates based on litter characteristics. Invasive plants can therefore impact the material cycle of an ecosystem. There is a need to examine decomposition time, which may also involve considering other factors.

Impacts of Stressors on Riparian Health Indicators in the Upper and Lower Indus River Basins in Pakistan

“…Similar results have been documented by Arif et al [ 2 ] within the Three Gorges Reservoir, China. In other studies, those indicators have shown different patterns as situations change everywhere [ 14 , 36 , 37 ], which is consistent with the results obtained in the current study. Changes in riparian zones are influenced by geographical locations and stressors [ 38 , 39 ].…”

“…Various factors influence the dynamics of stressors, and hydro-morphological changes are critical to exacerbating their effects [ 16 , 45 ]. When environmental conditions and land use change, these changes may influence the structure and growth of plant communities [ 36 ]. Nevertheless, the impact on riparian zones can vary according to the location of the transect and the magnitude of stressors [ 22 ].…”

“…Because of their loadings, examining each group separately confirmed that indicators of riparian health and stressors are closely related. Studies have shown that PCA can be applied to a limited number of indicators without requiring wider sets [ 14 , 36 ]. This test likely contributed to the selection of indicators based on the geographical areas within the IRB in terms of contribution and effectiveness.…”

Plant-soil interactions and C:N:P stoichiometric homeostasis of plant organs in riparian plantation

“…Due to the unique hydrological conditions in the TGR region, the plants in this region have a special growth pattern that is continuously submerged in a cycle that repeats each year ( Chen et al, 2021 ; Li J. J. et al, 2021 ). Consequently, most of the riparian plants could not withstand these huge water level changes and gradually died ( Gul et al, 2022 ; Hu et al, 2022 ), resulting in severe degradation of the ecological environment in the region and, thus, the functional decline of the riparian ecosystem, which seriously jeopardized the operation of the TGR. Therefore, it is important to know how the riparian plant community responds to dam inundation and to restore vegetation within the hydro-fluctuation zone to improve the area’s ecosystem quality and ecosystem services.…”

Effects of hydrological regime on Taxodium ascendens plant decomposition and nutrient dynamics in the Three Gorges Reservoir riparian zone

“…To be sure, this large constructed wetland ecosystem, especially the aquatic environment, will be disturbed by hydrological rhythms. Meanwhile, the plants in the wetland ecosystem play an important role in the nutrient cycle of the TGR area, which can regulate soil nutrient availability as well as the aquatic environment (Ding et al, 2021;Hu et al, 2022;Yuancai et al, 2022).…”