Close-up of the L, H,, Ah, Bm horizons in a Dystric Brunisol at Dorset.

Algal growth on soil surface which is fixing Nitrogen

Microsection of the cortical cells of an Alnus nodule to show the vesicles (stained red) within the cell which are thought to be the site of Nitrogen fixation

Microsection of Alnus nodule to show the infected cortical cells; n.b. the mycelia of the actinomycete which terminate in the vesicles. cf. slides # 213-217

Cross-section of nodule on Alnus glandulosa showing infected cortical cells (actinomycetes?) stained red; central red tissue are the vascular elements.

Nodules from roots of Alnus glutinosa in Dorset area; n.b. scale

Nodules on roots of Alnus glutinosa from Dorset area; x10.

Comptonia peregrina plant in Plonski Forest; this is the plant which had the nodules shown in slide #210.

Mycelium of Phytophthora cinnamomi in W. Australia

Nodules of Comptonia peregrina N-fixing