Vegetation dynamics and seed banks of a monsoonal wetland overgrown with Paspalum distichum L. in northern India

Published source details Middleton B.A., van d.V.A.G., Mason D.H., Williams R.L. & Davis C.B. (1991) Vegetation dynamics and seed banks of a monsoonal wetland overgrown with Paspalum distichum L. in northern India. Aquatic Botany, 40, 239-259.
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This study is summarised as evidence for the following.

	Action	Category
	Physically remove problematic plants: freshwater marshes Action Link

Physically remove problematic plants: freshwater marshes

A before-and-after, site comparison study in 1984–1986 in an ephemeral freshwater marsh invaded by knotgrass Paspalum distichum in northwest India (Middleton et al. 1991) reported that an area cleared of vegetation developed similar vegetation cover to uncleared areas within nine months, but with different dominant species. Statistical significance was not assessed. Before intervention, the marsh had 69–70% total vegetation cover, 49–51% cover of knotgrass, <1% cover of water snowflake Nymphoides indicum and 2–4% cover of algae. After nine months, and at the same time of year, cleared areas had developed 68% total vegetation cover. This included <1% knotgrass cover, 29% water snowflake cover and 24% algal cover. Meanwhile, uncleared areas had 64% total vegetation cover, 49% knotgrass cover, 1% water snowflake cover and 6% algae cover. Methods: In June 1985, knotgrass-invaded vegetation was cleared, using bulldozers, from a marshy area in Keoladeo National Park. Comparable estimates of vegetation cover were made before clearance (March 1984 and 1985; ≥638 quadrats across whole marsh in each survey) and after clearance (March 1986; 55 quadrats in cleared area and ≥638 quadrats across rest of marsh). All quadrats were 1 m².

(Summarised by: Nigel Taylor)