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Phosphorus biological cycle in the different Suaeda salsa marshes of the Yellow River estuary, China

Author:
Sun, Zhigao, Mou, Xiaojie, Tian, Hanqin, Song, Hongli, Jiang, Huanhuan, Zhao, Jinyong, Sun, Wanlong, Sun, Wenguang
Source:
Environmental earth sciences 2013 v.69 no.8 pp. 2595-2608
ISSN:
1866-6280
Subject:
Suaeda, aerial parts, estuaries, marshes, phosphorus, plant growth, roots, seasonal variation, water salinity, China, Yellow River
Abstract:
Much uncertainty exists in the phosphorus (P) cycle in the marshes of the intertidal zone. This study explored the P cycling in the two Suaeda salsa marshes [middle S. salsa marsh (MSM) and low S. salsa marsh (LSM)] of the Yellow River estuary during April 2008 to November 2009. Results showed seasonal fluctuations and vertical distributions of P in different S. salsa marsh soils, and variations in P content in different parts of plants due to water and salinity status. The N/P ratios of the different S. salsa were 9.87 ± 1.23 and 15.73 ± 1.77, respectively, indicating that plant growth in MSM was limited by N, while that in LSM was limited by both N and P. The S. salsa litter in MSM released P to the environment throughout the year, while that in LSM immobilized P from the environment at all times. The P absorption coefficients of S. salsa in MSM and LSM were very low (0.0010 and 0.0001, respectively), while the biological cycle coefficients were high (0.739 and 0.812, respectively). The P turnovers among compartments of MSM and LSM showed that the uptake amounts of roots were 0.4275 and 0.0469 g m⁻² year⁻¹and the values of aboveground parts were 1.1702 and 0.1833 g m⁻² year⁻¹, the re-translocation quantities from aboveground parts to roots were 0.8544 and 0.1452 g m⁻² year⁻¹, the translocation amounts from roots to soil were 0.0137 and 0.0012 g m⁻² year⁻¹, the translocation quantities from aboveground living bodies to litter were 0.3157 and 0.0381 g m⁻² year⁻¹, and the annual return quantities from litter to soil were less than 0.0626 and −0.0728 g m⁻² year⁻¹(minus represented immobilization), respectively. P was an important limiting factor in S. salsa marshes, especially in LSM. S. salsa was seemingly well adapted to the low-nutrient condition and the vulnerable habitat, and the nutrient enrichment due to the import of N and P from the Yellow River estuary would be a potential threat to the S. salsa marshes.
Agid:
373184