Burial effects on seed germination and seedling emergence of two halophytes of contrasting seed size

ABSTRACT

Background

Germination and especially emergence can decrease significantly with depth.

Aim

Our main goal was to examine the effects of sand burial depth on seed germination and seedling establishment of two halophytes, Spartina densiflora and Atriplex portulacoides, with contrasted fruit traits.

Methods

The effects of sand burial to depths of 0 to 6 cm on seed germination and seedling establishment were studied in a greenhouse experiment. Sediment erosion/accretion dynamics were also recorded at a salt marsh colonised recently by both species.

Results

Germination percentage for both halophytes was higher at a depth of 1 cm than at the surface, and decreased gradually with increasing depth below 1 cm. Emergence of seedlings was similar between 1 and 3 cm (ca. 20–60 %) for both species. The highest seedling survival rates (ca. 100 %) were recorded for seeds sown at a depth of 2 cm for S. densiflora and between 1 and 3 cm for A. portulacoides. Recorded erosion and accretion rates was large enough to modify germination and establishment patterns in both halophytes.

Conclusions

Spartina densiflora showed higher germination rates than A. portulacoides at greater depths, which seemed to be related to its growth form.

KEYWORDS:

• Atriplex portulacoides
• invasion
• salt marsh
• Spartina densiflora
• seed bank

Acknowledgements

The authors would like to express their gratitude to King Khalid University, Saudi Arabia for providing administrative and technical support. We are grateful to Jesús López and José María Carranza at the greenhouse facility of the University of Seville. This work was supported by a Ph.D. scholarship from the Egyptian Government-Ministry of Higher Education (Cultural Affairs and Missions Sector).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Ahmed M. Abbas

Ahmed M. Abbas, is an associate professor; his research interests include invasive plant ecology.

Alfredo E. Rubio-Casal

Alfredo E. Rubio-Casal, teach and research ecology and ecophysiology.

Alfonso De Cires

Alfonso De Cires, teach and research ecology and ecophysiology.

Enrique M. Figueroa

Enrique M. Figueroa, teach and research ecology and ecophysiology.

Andrea J. Pickart

Andrea J. Pickart, is a coastal ecologist.

Jesús M. Castillo

Jesus M. Castillo, teach and research ecology and ecophysiology.