Page 231 - Freshwater-Biology-and-Ecology-Handbook

3.1.11 MIS-index

(Monitoring Intermittent
Streams index)

The MIS-index describes the total invertebrate community
response to intermittent flow (England et al. 2019). (93)
It incorporates invertebrate taxa from fully aquatic to
terrestrial, all of which are collected during standard Goera pilosa larva
biomonitoring surveys undertaken by regulatory agencies Table 5. 5
(standard RIVPACS methods, sampling all wet habitats in Weighting factors for each MIS-group, with different values
proportion to their occurrence). for autumn and spring

MIS-group Autumn Spring
MIS-index – Monitoring
Intermittent Streams index Lotic (fast) 13 13

Lotic 7 11
The MIS-index describes the total invertebrate
community response to intermittent flow in rivers. Generalist -2 2

Lentic -10 -3

Early indications are that the MIS-index complements Semi-aquatic -10 -7
existing indices used to assess aquatic invertebrate
community responses to drought (ie DEHLI; Chadd Terrestrial -17 -21.0
et al. (2017) (92) ) and to changes in flow (LIFE; Extence
et al. (1999) (89) ), by characterizing responses to flow
intermittence and changes in flow state. Developed for MIS-index scores are calculated as an ASPT using the
lowland groundwater-fed streams in southern England, formula:
the MIS-index requires testing to see how applicable
the taxa-habitat associations and weightings are across
different regions and different types of intermittent rivers
and ephemeral streams.

Invertebrate taxa (family, genera and species) are assigned
to one of six MIS-groups based on their association
with lotic (fast), lotic, generalist, lentic, semi-aquatic, and 1..6 denotes the six MIS-groups
terrestrial habitats. Weighting factors are applied to the is the season (separate weighting factors for spring
richness of each group to give a single score, with different and autumn samples)
weighting factors used in spring and autumn. is the weighting factor for MIS-group in season
is the number of taxa in group in sample
is the total number of taxa in sample

Higher MIS-index values indicate a dominance of flowing
water conditions. Lower MIS-index scores indicate drier
conditions. Freshwater ecologists are encouraged to
identify semi-aquatic and terrestrial taxa collected in their
surveys, to provide data to test the index in intermittent
rivers and ephemeral streams across Europe.

Recognizing and understanding responses to natural
intermittence will inform our understanding of the
biodiversity value of these systems and their responses
to human pressures that alter ecological quality.

Serratella ignita nymph

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