The response of stocks of C, N, and P to plant invasion in the coastal wetlands of China

Abstract

The increasing success of invasive plant species in wetland areas can threaten their capacity to store carbon, nitrogen, and phosphorus (C, N, and P). Here, we have investigated the relationships between the different stocks of soil organic carbon (SOC), and total C, N, and P pools in the plant–soil system from eight different wetland areas across the South‐East coast of China, where the invasive tallgrass Spartina alterniflora has replaced the native tall grasses Phragmites australis and the mangrove communities, originally dominated by the native species Kandelia obovata and Avicennia marina. The invasive success of Spartina alterniflora replacing Phragmites australis did not greatly influence soil traits, biomass accumulation or plant–soil C and N storing capacity. However, the resulting higher ability to store P in both soil and standing plant biomass (approximately more than 70 and 15 kg P by ha, respectively) in the invasive than in the native tall grass communities suggesting the possibility of a decrease in the ecosystem N:P ratio with future consequences to below‐ and aboveground trophic chains. The results also showed that a future advance in the native mangrove replacement by Spartina alterniflora could constitute a serious environmental problem. This includes enrichment of sand in the soil, with the consequent loss of nutrient retention capacity, as well as a sharp decrease in the stocks of C (2.6 and 2.2 t C ha‐1 in soil and stand biomass, respectively), N, and P in the plant–soil system. This should be associated with a worsening of the water quality by aggravating potential eutrophication processes. Moreover, the loss of carbon and nutrient decreases the potential overall fertility of the system, strongly hampering the reestablishment of woody mangrove communities in the future.

Contrasting latitudinal clines of nematode diversity in Spartina alterniflora salt marshes between native and introduced ranges

“…Grasses in the genus Spartina have been aggressive invaders of coastal habitats worldwide (Strong & Ayres, 2013). In these new habitats, S. alterniflora typically transforms intertidal mudflats into high‐intertidal salt marshes, with profound consequences for above‐ground plant communities (Biswas et al, 2018; Li et al, 2009), migratory shorebirds (Ma, Gan, Choi, & Li, 2014), macroinvertebrate communities (Neira, Levin, Grosholz, & Mendoza, 2007), hydrologic and edaphic parameters (Adams et al, 2012), and soil biochemistry (Wang et al, 2019). Our work has shown that the geographic structure of nematode communities is also affected (Zhang, Pennings, et al, 2019; this paper), emphasizing both the importance of examining the soil food web and the importance of taking a geographic approach to studying species invasions.…”

Anthropogenic global shifts in biospheric N and P concentrations and ratios and their impacts on biodiversity, ecosystem productivity, food security, and human health

“…The impacts of invasive species on N and P cycles and stoichiometry on the plant–soil system may vary between nutrient‐rich and nutrient‐poor ecosystems (Gonzalez et al, ; Matzek, ; Sardans, Bartrons, et al, ). For example, successful invasive species have higher capacities to take up and efficiently use nutrients that are limited (Aragon, Sardans, & Penuelas, ; Sardans, Bartrons, et al, ; Ulm et al, ; Wang, Sardans, et al, ; Wang, Wang, et al, ), so the concentrations of N and P in photosynthetic tissues tend to be higher in invasive than native species. Total soil N concentrations and availabilities of N and P correlated with higher mineralization capacity are higher for invasive species, particularly in nutrient‐poor environments (Sardans, Bartrons, et al, ).…”

Salinity Affects Topsoil Organic Carbon Concentrations Through Regulating Vegetation Structure and Productivity

“…Since its initial appearance on the Chongming Dongtan salt marsh during the 1990s, S. alterniflora has gradually colonized the bare mudflats and invaded the habitat historically occupied by native P. australis and S. mariqueter communities (Li et al, ; Tang et al, ). The S. alterniflora was therefore identified as a coastal invasive plant by the State Environmental Protection Administration of China in 2003 (Li et al, ; Wang et al, ). The distribution area of S. alterniflora reached about 1,500 ha in the Chongming Dongtan salt marsh and more than 6,000 ha in the Yangtze River Estuary in 2012 (Ge et al, ).…”