Succession is a major issue in current pond conservation management since it may eventually result in the loss of valuable habitats due to terrestrialization, especially in eutrophicated systems.

They were sucking off whatever adhered to the floating stems and leaves of the plants. They went from plant to plant and mouthed over each branch from base to tip until the whole plant had been gone over.

Given a mandate to build a new railway from the trackbed up, the Japanese have seized an unpredecented opportunity, not only to apply to its equipment their immense technological resources, but to incorporate in its operational scheme the Utopian concepts which those modernising an existing line can at best realise partially.

In the third case, the need to provide retractable shoegear on the power bogies to pick up current from the third rail, and the equipment to use low-voltage supply, has complicated the design of the Eurostar trains.