Species-Specific Impacts of Invasive Plant Success on Vertical Profiles of Soil Carbon Accumulation and Nutrient Retention in the Minjiang River Tidal Estuarine Wetlands of China

Sardans

et al. 2018

Global Change Biology

Self Cite

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.

Section: The Relationships Between Species Invasion In Mangrove Commentioning

confidence: 51%

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

Sardans

et al. 2018

Global Change Biology

Self Cite

Section: Collection and Analysis Of Soil Samplesmentioning

confidence: 99%

“…Soil pH and salinity were determined using a multiparameter metre (CyberScan PC 300), after equilibration of soil with deionized water (soil: water, 1:5) [35,36]. Soil N content was determined using Kjeldahl digestion procedure [35,36]. Bulk density (Db) was determined by drying a known volume of soil sample (determined from the dimensions of the core) at 105 °C until it reached a constant weight, cooled to room temperature in a desiccator, and weighed again.…”

Section: Collection and Analysis Of Soil Samplesmentioning

confidence: 99%

“…Plant biomass density was expressed as the dry weight of plants per unit area. To determine plant N content, plant samples were oven dried at 65 °C until constant weight and ground [37], after which N content was determined using Kjeldahl digestion procedure [35,36]. Plant organic C content was determined from the weight loss on ignition (LOI) procedure, as described for determination of SOC.…”

Section: In Situ Measurements and Collection And Analysis Of Plant Smentioning

confidence: 99%

See 1 more Smart Citation

A natural tropical freshwater wetland is a better climate change mitigation option through soil organic carbon storage compared to a rice paddy wetland

et al. 2020

The high productivity together with hypoxic conditions in sediments enables wetlands to accumulate large amounts of soil organic carbon (SOC). However, natural tropical freshwater wetlands are increasingly being converted into other land uses, mainly rice cultivation. In this study, we investigated the impact of conversion of a natural tropical freshwater wetland into a rice paddy wetland on SOC, by determining SOC content, density and storage potential in the natural section (under different vegetation communities dominated by Cyperus papyrus [Papyrus], Typha latifolia [Typha] and Phragmites mauritianus [Phragmites]) and in the converted section (under rice cultivation). The SOC contents (g kg −1) and densities (kg m −2) of the 3 vegetation communities (Papyrus; 123.7 ± 2.6 [SE] and 7.22 ± 0.11, Typha; 85.3 ± 1.1 and 6.71 ± 0.12, and Phragmites; 78.2 ± 3.4 and 6.20 ± 0.06, respectively) of the natural section of the wetland were significantly higher (p < 0.05) than those (39.7 ± 0.7 and 3.90 ± 0.06, respectively) of the converted section. Similarly, for the entire sampled soil depth (0-50 cm), SOC storage potentials (Mg ha −1) of Papyrus (361.18 ± 5.53), Typha (335.31 ± 6.18) and Phragmites (310.17 ± 3.16) significantly exceeded (p < 0.05) that obtained in the converted section by nearly 46%, 42% and 38%, respectively. Soil physico-chemical characteristics: bulk density, salinity, pH and temperature, showed comparably significant correlations (p < 0.05) with SOC in both the natural and converted sections of the wetland. We strongly believe that exploration of alternative options for increasing rice production outside wetlands is paramount if natural tropical freshwater wetlands are to remain important ecosystems in climate change mitigation.

“…Quantifying the effects of S. alterniflora invasion on SOC storage and its vertical distribution is thus an important task for carbon accounting and coastal protection. Some previous studies on the responses of SOC dynamics to S. alterniflora invasion have shown that the introduction of S. alterniflora has led to an increase in SOC storage (e.g., Liao et al, ; Wang et al, ; Yang et al, ; Yuan et al, ; Zhang et al, ). A primary mechanism for the net accumulation of SOC in wetlands is the rising quantity and quality of biomass inputs in soils influenced by S. alterniflora (Liu et al, ; Yuan et al, ).…”

Section: Introductionmentioning

confidence: 99%

Interacting Effects of Plant Invasion, Climate, and Soils on Soil Organic Carbon Storage in Coastal Wetlands

Yang

2019

JGR Biogeosciences

Coastal wetland soils store large amounts of organic carbon, which is becoming vulnerable to environmental changes such as exotic species invasion and climate change. Soil organic carbon (SOC) is also related to soil biogeochemical factors. To understand the mechanisms of these changes in regulating SOC, it is necessary to characterize the direct and indirect effects of exotic species invasion, climate, and soil variables on SOC. We used a structural equation model to identify the key driving mechanisms of SOC storage to a depth of 1 m at 15 sites on the East China coast, where Spartina alterniflora Loisel. (S. alterniflora) invasion has significantly influenced SOC storage. The model revealed several patterns that are expected to explain the enhanced SOC storage. Spartina alterniflora invasion had a direct effect on SOC storage mainly due to its impacts on biomass production. Temperature had an important influence on SOC storage and the subsurface SOC content. SOC storage was also related to the interacting effects of S. alterniflora invasion and soil biogeochemical properties such as soil salinity, fine soil fraction, and bulk density. The relative contribution of SOC in the topsoil to SOC storage at a depth of 1 m decreased over time, while the contribution increased for the SOC below the surface. These results highlight the interactions among S. alterniflora invasion, climate, and soil properties in regulating SOC dynamics. Our results imply that the relative importance of vertical patterns to SOC storage associated with S. alterniflora invasion and temperature fluctuations will change over time.Plain Language Summary The world's largest invasion of S. alterniflora is occurring in the coastal wetlands of China. Coastal wetland soils, which are vulnerable to exotic species invasions, contain large amounts of organic carbon. The controlling mechanisms of soil organic carbon (SOC) associated with S. alterniflora invasion and climate change may be complex due to the interrelationships that exist among ecological factors. In our study, we investigated the effects of plant invasion, climate, and soils on SOC storage and its vertical distribution. We found that SOC storage was enhanced over time. Spartina alterniflora invasion had a direct effect on SOC storage mainly due to its impacts on biomass production. Temperature had an important influence on SOC storage and the subsurface SOC content. The interacting effects of S. alterniflora invasion and soil biogeochemical properties such as soil salinity, fine soil fractions, pH, and bulk density were also identified as having crucial impacts on SOC storage. Our results suggest an interesting possibility that the relative contribution of vertical patterns to the SOC pool is likely to change over the invasion period. Citation: Yang, R.-M. (2019). Interacting effects of plant invasion, climate, and soils on soil organic carbon storage in coastal wetlands.