Biotic soil factors affecting the growth and development of Ammophila arenaria

Abstract

To study the origin of replant disease of Ammophila arenaria (L.) Link the growth and development in sand originating from the rhizosphere of a natural Ammophila vegetation was compared with the growth in sand from the sea-floor. In a greenhouse experiment, the growth of Ammophila seedlings in rhizosphere sand, when compared with that in sea sand, was significantly reduced. As sterilization by means of gamma-irradiation increased the biomass production of Ammophila seedlings significantly, it was concluded that the rhizosphere sand contained biotic factors that were harmful to Ammophila. In rhizosphere sand the roots of Ammophila were brown and poorly developed, and the specific uptake rates of N, P and K were reduced. The shoot weight proportion of the total plant dry matter was hardly influenced. In an outdoor experiment with Ammophila seedlings and cuttings, using both sands, the mortality was high and the plants were feeble in rhizosphere sand whereas plants in sea sand grew vigorously. It seems plausible that the plants in rhizophere sand were dessicated because the root system was shallow and badly developed. In the greenhouse experiments, Ammophila cuttings were less sensitive to the inhibiting factors in the rhizosphere than seedlings. This was confirmed in the outdoor experiment. Calammophila baltica (Fluegge ex Schrader) Brand, however, was hardly affected by the harmful biotic factors in the greenhouse. These results are discussed with reference to the ecology of Ammophila. It is assumed that the catching of fresh windblown sand provides Ammophila with a way to escape from harmful biotic soil factors, and it was concluded that degeneration of Ammophila is caused mainly by self-intolerance due to these biotic soil factors.

How Soil-Borne Pathogens May Affect Plant Competition

“…arenaria takes over dominance in the vegetation Taylor 1979, Huiskes 1979). Plant-parasitic nematodes and pathogenic fungi in the root zone of A. arenaria are implicated in this degeneration (Van der Putten et al 1988, De Rooij-Van der Goes 1995, De Rooij-Van der Goes et al 1995a and F. rubra is relatively tolerant to the pathogens of its predecessor ( Van der Putten et al 1993).…”

Accommodation space indicates dune development potential along an urbanized and frequently nourished coastline

“…The latter condition is not disputed, as the reinforcing feedback between the 5 growth response of marram grass and burial by wind-blown sand is well documented (Huiskes, 1979;Disraeli, 1984;Maun and Lapierre, 1984;Van der Putten et al, 1988;Hesp, 1991;Maun, 1998) and recognized to be fundamental to coastal dune development in temperate regions around the world (e.g., Baas and Nield, 2010;Durán and Moore, 2013;Keijsers et al, 2016;Nolet et al, 2017). The positive feedback mechanism is thought to originate from a trait that all beach grasses of the genus Ammophila possess, namely potentially unlimited horizontal and vertical growth through its rhizomes (Gemmell et al, 1953;10 Ranwell, 1972).…”

“…its leaves and roots, but it will in fact grow much more vigorously because of regular burial in sand (e.g., Disraeli, 1984;Van der Putten et al, 1988;Hesp, 1991;Nolet et al, 2017). This introduces a reinforcing feedback crucial to coastal dune development:…”

Plant ectoparasitic nematodes prefer roots without their microbial enemies

“…The soil was collected from ten transects parallel to the beach and 50 m apart. At each sampling point, 10 kg of soil was collected from the youngest root zone of A. arenaria (van der Putten et al 1988). The soil was sieved (0.5 cm mesh size) to remove plant parts and debris, and stored in plastic bags at 4°C until used (van der Stoel et al 2002).…”