Decomposition and Carbon and Nitrogen Dynamics of Phragmites australis Litter as Affected by Flooding Periods in Coastal Wetlands

Abstract

To investigate the effects of flooding periods on decomposition and carbon and nitrogen return of Phragmites australis litter, we examined the dynamic of P. australis litter decomposition in short‐, medium‐, and long‐flooding coastal wetlands (HN, HS, and LL wetlands, respectively) in the Yellow River Delta, China. Our results showed that the percentage of dry weight loss of P. australis litter increased gradually as the decomposition proceeded and the percentage of dry weight loss was highest in LL wetland, followed by HS wetland, while the percentage of dry weight loss was lowest in HN wetland. Similar to the percentage of dry weight loss, the relative return indices (RRIs) of carbon of P. australis litter also increased with the increasing days of decomposition, following the order LL wetland > HS wetland > HN wetland. With the exception of little accumulation in both HS and HN wetlands in a certain period, the RRIs of nitrogen increased generally with increasing days of decomposition. However, the C/N ratios decreased rapidly in the first 40 days and retained steady after 40 days.

Spatial distribution and stoichiometry of soil carbon, nitrogen and phosphorus along an elevation gradient in a wetland in China

“…In our study, the soil at low elevation sites contained larger proportions of sand particles, which limited the capacity for nutrient storage (Pan, Zhang, Li, & Xie, ). In addition, long‐term flooding promoted the movement of plant litter, leading to subsequent reduction in nutrient input at low elevations (Zhao, Bai, Liu, Gao, & Wang, ). The relatively larger SOC concentrations at intermediate and high elevations may be attributed to strong plant productivity.…”

Effect of ground water level on the release of carbon, nitrogen and phosphorus during decomposition of Carex. cinerascens Kükenth in the typical seasonal floodplain in dry season

“…The percentage of litter dry weight loss was calculated using the following equation (Zhao et al 2015):…”

“…Because of the waterlogging and anaerobic characteristics of wetlands, as well as their low nitrogen utilization efficiency, and lower decomposition rate, wetlands become an important carbon reservoir (Currey et al 2009). Accordingly, acceleration or slowdown of the litter decomposition process can cause significant changes in carbon and nitrogen pools locally, regionally, and even globally (Zhao et al 2015;Mueller et al 2018), which in turn affects climate change. These problems have been fully investigated in forest ecosystems, grassland ecosystems and farmland ecosystems, but little information is available for wetland ecosystems (Sun et al 2012).…”

“…Research regarding decomposition of litter in wetlands conducted to date has focused on the changes in material components (Davis et al 2003;, element release features during the process of decomposition (Neckles and Neill 1994;Davis et al 2003;Kalbitz et al 2006;Zhao et al 2015), influence factor analysis (Rejm ankov a and Houdkov a 2006; Ferreira and Chauvet 2011;Alexandra et al 2013) and responses to global change (Mueller et al 2018). However, few studies have investigated the regulate factors of litter decomposition and the characteristics of nutrient release such as carbon, nitrogen and phosphorus under different ground water conditions.…”

“…Anderson and Smith found that the decomposition rate of litter was the lowest during long-term flooding and the highest in short-term flooding (Anderson and Smith 2002). Zhao et al found that the dry weight loss rate of litter was the highest in areas subjected to long-term flooding, followed by wetlands subjected to flooding for a moderate length of time and then those subjected to short-term flooding (Zhao et al 2015). However, Edward and Day studied that the root decomposition of plants was the slowest in the places in which soil water supersaturation was the longest (Tupacz and Day 1990).…”