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Fen Management Handbook - Scottish Natural Heritage

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variability and how these relate to areas supporting particular features or habitats of<br />

interest. An informed walk-over survey (preferably with hydrologist and ecologist) is<br />

the best starting point.<br />

Make sure you understand how the fen works hydrologically (i.e. how water enters,<br />

moves through and leaves a fen and its chemistry and quality), how it has changed<br />

in the past, or might change in future. Don’t forget man-made structures such as<br />

ditches and work out how they affect the fen. The next step is to consider the ecohydrology,<br />

i.e. how the hydrology interacts with the fen flora and fauna.<br />

Newbald Becksies is a spring-fed fen on the edge of the chalk of the<br />

Yorkshire Wolds. It once supported plants typical of rich fen, such<br />

as butterwort, Grass of Parnassus and mosses such as Scorpidium<br />

cossonii. Investigations are underway to find out whether abstractions<br />

from the chalk aquifer have starved the rich fen of lime-rich water, or<br />

whether it is ‘simply’ that quantities of agricultural fertiliser have entered<br />

the aquifer which has encouraged stronger plants around the springheads.<br />

A more detailed case study of this site is included at the end of<br />

this section (5.1)<br />

5.6 Identify past and future changes<br />

Past changes in presence and population of key species, extent and condition<br />

of habitat, hydrological and nutrient regime should all be identified. Changes in<br />

hydrology or nutrients and how these might have affected fen flora and fauna, or<br />

how they might affect it in future, should be considered. Interest features may be<br />

in very poor condition, or even absent from a site, because of historical changes in<br />

the hydrological regime or other factors. Under these circumstances, other forms<br />

of evidence, including field observations (e.g. landscape situation, presence and<br />

type of peat or recent alluvial sediments), historical maps or aerial photographs,<br />

anecdotal evidence or old photographs can be used to identify the fen’s potential.<br />

Predictions for climate change are for drier, hotter summers and wetter, warmer<br />

winters which would have implications for the sustainability of wetlands, should<br />

be taken into account in setting management objectives. However, unlike rain-fed<br />

bogs, fens are dependent on the behaviour of water after it has run over the soil,<br />

infiltrated it and emerged again as groundwater. The effect on fens of seasonal<br />

changes in precipitation patterns may be even more difficult to predict.<br />

Biglands Bog, Cumbria<br />

This 12 ha mixed valley and basin fen historically supported a small<br />

raised bog, base-rich seepage and floodplain fen. More recently the<br />

flow characteristics of the input stream have changed, depositing much<br />

silt and spreading nutrients into all but the raised bog, which probably<br />

floats. <strong>Management</strong> must address factors upstream of the fen, such as<br />

changes in agriculture and nutrient-rich discharges. For more about this<br />

site see Case Study 4.1.<br />

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