The influence of changes in the degree and frequency of disturbance on the annual salt marsh plant (Suaeda maritima, Artemisia fukudo) communities in estuarine tidal flats: A case study of the Kushida River in Mie Prefecture, Japan

Korehisa Kaneko, Seiich Nohara

Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba City, Japan.
Ecosystem Conservation Society—Japan, Tokyo, Japan.

DOI: 10.4236/oje.2014.41001                

Abstract

In this study, we examined the influence of changes in the degree and frequency of disturbance in estuarine tidal flats on the annual salt marsh plant communities (Suaeda maritima, Artemisia fukudo) in Mie Prefecture, Japan. Suaeda maritima and Artemisia fukudo communities occur in the branch river of the Kushida River. Although the areas occupied by these communities were very small in 2006, the Suaeda maritima community expanded significantly to 3609 m² in 2008, and the Artemisia fukudo community expanded significantly to 2726 m² in 2008 and 10,396 m² in 2010. Before the onset of the investigation period in 2006, the overflow warning water level (3.5 m) and the flood fighting corps standby water level (3.0 m) each occurred on one day in August 2004 and October 2004, respectively; at those times, the water volume exceeded 1000 m³·s^-1 and 1500 m³·s^-1, respectively. We suggest that because much of the estuarine tidal flat erodes when the water volume exceeds 1000 m³·s^-1, the establishment of the Suaeda maritima and Artemisia fukudo communities is delayed until sufficient substrate is formed by the deposition of new sediment. In contrast, a water level of 2 - 3 m was observed on one day each in 2005, 2007 and 2009, with average water volumes of 488.5, 566.4 and 690.1 m³·s^-1, respectively. We suggest that following the repeated disturbances caused by water levels of 1 - 3 m and flow volumes of 500 - 700 m³·s^-1 over the bare ground exposed after flooding and erosion, Suaeda maritima is a pioneer species that colonizes on bare ground deposited by sediment transported from upstream and the sea during high tides, and following the same level of disturbance, Artemisia fukudo is secondary colonizer that has germinated and grown on the sediment deposited on the Suaeda maritima community.

Keywords

Annual Salt Marsh Plant; Disturbance; Flow Volume; Water Level; Vegetation Change

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Mie Prefecture, Environmental Conservation Agency. (2005) Threatened wildlife of Mie 2005. Plants Mushroom, Mie Prefecture.
[2]	Ministry of the Environment Government of Japan (2007) Revision, list of threatened wildlife of Japan. Wildlife Division, Nature Conservation Bureau, Ministry of the Environment, Tokyo.
[3]	Kaneko, K., Yabe, T. and Nohara, S. (2005) Vegetation changes and topographic feature in the delta of Obitsu River in Tokyo Bay. Japanese Journal of Landscape Ecology, 9, 27-32.
[4]	Araki, S. and Kunii, H. (2011) Halophyte communities along the estuarine riverside of Ota river. Bulletin of the Hoshizaki Green Foundation, 14, 251-256.
[5]	Ohnuma, K., Endo, M., E, Amano, K. and Kishida, H. (2011) Analysis of vegetation distribution and its relation to tidal oscillation in riverine estuaries. Japanese Journal of Hydroscience and Hydraulic Engineering, 55, 1345-1350.
[6]	Delaune, R., Patrick, W. and Buresh, R. (1978) Sedimentation rates determined by 137 Cs dating in a rapidly accreting salt marsh. Nature, 275, 532-533. http://dx.doi.org/10.1038/275532a0
[7]	Deleeuw, J., Demunck, W., Olff, H. and Bakker, J. (1993) Does zonation reflect the succession of salt marsh vegetation—A comparison of an estuarine and a coastal island marsh in the Netherlands. Acta Botanica Neerlandica, 42, 435-445. http://dx.doi.org/10.1111/j.1438-8677.1993.tb00719.x
[8]	Dijkema, K.S. (1997) The influence of salt marsh vegetation on sedimentation. In: Eisma, D., Ed., Intertidal Deposits River Mouths, Tidal Flats and Coastal Lagoons, CRC Press, Boca Ration, 403-414.
[9]	Hatton, R.S., Delaune, R.D. and Patrick, W.H.J. (1983) Sedimentation, accretion, and subsidence in marshes of Barataria Basin, Louisiana. Limnology and Oceanography, 28, 494-502. http://dx.doi.org/10.4319/lo.1983.28.3.0494
[10]	Kaneko, K. and Nohara, S. (2013) Vegetation communities in estuarine tidal flats in the different river and basin environments of the four major rivers of Ise Bay (Suzuka, Tanaka, Kushida), Mie prefecture, Japan. Open Journal of ecology, 3, 205-213.
[11]	Water Information System in Ministry of Land, Infrastructure, Transport and Tourism, Japan. http://www1.river.go.jp/
[12]	Miyawaki, A., Okuda, S. and Suzuki, N. (1975) Vegetation in der Umgebung der Bucht von Tokyo. Institution for Transport Policy Studies, Tokyo.
[13]	Kusanagi, T. (1986) Diagnosis of primary color weed. Rural culture association, Tokyo.
[14]	Shimizu, T. (2003) Naturalized plants of Japan. HEIBONSHA, Tokyo.
[15]	Huiskes, A.H.L., Koutstaal, B.P., Herman, P.M.J., Beeftink, W.G., Markusse, M.M. and Munck, W.D.E. (1995) Seed dispersal of halophytes in tidal salt marshes. Journal of Ecology, 83, 559-567. http://dx.doi.org/10.2307/2261624
[16]	Hutchings, M.J. and Russel, P.J. (1989) The seed regeneration dynamics of an emergent salt marsh. Journal of Ecology, 77, 615-637. http://dx.doi.org/10.2307/2260974
[17]	Kamata, M. and Ogura, Y. (2006) Habitat evaluation for plant communities as a salt marsh in the Naka River, Shikoku Japan. Ecology and Civil Engineering, 8, 245-261. http://dx.doi.org/10.3825/ece.8.245
[18]	Kitamura, S. (1942) Ecology of Artemisia scoparia. Acta Phytotaxonomica et Geobotanica, 11, 59-60.
[19]	Kitamura, S., Murata, G. and Hori, M. (1963) Colored illustrations of herbaceous plants of Japan Vol.1, Sympetalae, reserved edition. HOIKUSHA Publishing, CO., LTD., Osaka.
[20]	Makino, T. (1996) Revised Makino’S illustrated Flora in colour. Gamopetalae. In: Ono, M., Ooba, H., Nishida, M. and Murata, J., Eds., Hokuryukan Publishing, CO., LTD., Tokyo.
[21]	Satou, Y., Fujita, F. and Ohnuma, K. (2007) Classification from river engineering viewpoint of the river in flats of tidal flats in Otagawa discharge channel. Conference Abstract in Annual Scientific Conference of Japanese Society of Civil Engineers, 62, Division, 127-128.
[22]	Araki, S., Kunii, H. and Suyama, S. (2009) Growth environment of salt marsh plants well established in artificial channel. Proceedings of the 53th Annual Meeting of the Chugoku-Shikoku Branch of the Ecological Society of Japan, 16-17 May 2009.