Effects of watershed land-cover on the biogeochemical properties of estuarine tidal flat sediments: A test in a densely-populated subtropical island

被引：3

作者：

Morita, Akiko ^{[1
,2
]}

Touyama, Shouji ^{[1
]}

Kuwae, Tomohiro ^{[3
]}

Nishimura, Osamu ^{[2
]}

Sakamaki, Takashi ^{[1
,2
]}

机构：

[1] Univ Ryukyus, Dept Civil Engn & Architecture, 1 Senbaru, Nishihara, Okinawa 9030213, Japan

[2] Tohoku Univ, Dept Civil Engn, 6-6-06 Aramaki Aza Aoba, Sendai, Miyagi 9808579, Japan

[3] Port & Airport Res Inst, Coastal & Estuarine Environm Res Grp, 3-1-1 Nagase, Yokosuka, Kanagawa 2390826, Japan

来源：

ESTUARINE COASTAL AND SHELF SCIENCE | 2017年 / 184卷

基金：

日本学术振兴会;

关键词：

Watershed land cover; Estuarine tidal flat; Carbon and nitrogen stable isotope; Particulate organic matter; Okinawa Island; ORGANIC-MATTER; INTERTIDAL ZONE; CARBON CONTENT; NITROGEN; QUALITY; RIVER; CHLOROPHYLL; LANDSCAPE; ISOTOPE; SYSTEMS;

D O I：

10.1016/j.ecss.2016.11.019

中图分类号：

Q17 [水生生物学];

学科分类号：

071004 ;

摘要：

The effects of watershed land cover on the biogeochemical properties of estuarine tidal flat sediment were examined in estuarine tidal flats of 16 watersheds in a densely populated, subtropical island of Japan. Despite the small sizes of the watersheds (<16.5 km(2)), a redundancy analysis showed that river water quality explained 62% of the cross-estuary variation in the biogeochemical properties of estuarine tidal flat sediment by the first two ordination axes. We also found that the dissolved nutrient concentrations of river water and pheophytin a content of tidal flat sediment were positively related to agricultural and urbanized land cover in the watersheds. These results indicate that human nutrient inputs significantly increase algae-derived deposits in estuaries with relatively more developed watersheds. The 813C of particulate organic matter (POM) was negatively related to watershed forest cover. This suggests that terrestrially derived-origin POM deposits are substantial in the estuaries connected to watersheds with relatively high forest cover. However, the chemical properties of tidal flat sediment were not related to chemical indicators of POM in the base flow. We hypothesize that substantial terrestrially derived POM is discharged to estuaries of high-forest-cover watersheds during high flow, and this partially controls the chemical properties of estuarine sediments. Our results demonstrate that the chemical properties of estuarine tidal flats are associated with watershed land cover, and that the dominant processes controlling estuarine sediment properties differ among watersheds depending on land cover composition. (C) 2016 Elsevier Ltd. All rights reserved.

引用

页码：207 / 213

页数：7