Offwell Wetland Survey

Comparison of Species Lists from the Wetland Surveys 1991 and 2000

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Plant Species List 1991 and 2000

A number of points emerge from comparing the two species lists generated by the 1991 and 2000 surveys. These are continued from a
previous page below.  

3. Differences between the surveys

  • Mosses

    Thirteen mosses were recorded in the 2000 survey, in contrast to only three in the 1991 survey. This is likely to be partly due to the difference in the methods of surveying, in that the 2000 survey was far more comprehensive. However, it is also likely to reflect real differences in the amount and number of moss species present in the wetland nearly ten years after the first survey.

    Soon after restoration, there would have been little time for mosses to recolonize the disturbed ground in the wetland. What moss there was would probably have covered a very small area and was likely to have been fairly inconspicuous. Nearly ten years later, mosses have had plenty of time to become well-established in the wetland.

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Most of the moss species are found in the wet woodland margins of the wetland. The species here are typical of damp woodlands in general. Only four species colonized substantial areas in the marsh zone of the wetland. These were, in order of dominance, Eurhynchium praelongum, Brachythecium rivulare, Thuidium tamarascinum and Sphagnum subsecundum. Brachythecium rivulare and Sphagnum sebsecundum are both characteristic of marsh areas, whereas Eurhynchium praelongum and Thuidium tamarascinum are commonly encountered in most woodlands, but also have marsh forms. Eurhynchium praelongum was the only moss to occur in the swamp zones. Here it could be found clothing the bases of plant stems.

Brachythecium rivulare in the marsh area

Before and After  A comparison of the wetland before restoration and nearly ten years after restoration.

Wetland Survey Contents