Wildlife habitats
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The river, Ditches and dykes, Grassland, Woodlands, Hedgerows and copses, Heathlands, Disused railway lines, Open Water, Arable wildlife habitat
The River
The River Wensum is an enriched calcareous lowland river. The plant
communities comprise dense beds of submerged and emergent vegetation,
with variations in the aquatic plant community reflecting the alteration
of fast-flowing shallows with deep slow-moving water. The marginal and
bankside communities are particularly characteristic, often with dense
and continuous stands of reed or sedge. Where adjacent land is
seasonally inundated and grazing is restricted, extensive areas of
reedbed and tall mixed fen communities have developed. Associated with
inundated sites are alder and willow swamps. The tributaries to the
Wensum, although lesser in scale, reflect this pattern of plant
community development.
Ditches and dykes
Many of the grassland fields are divided by dykes and have ditches
around their edges. These small water
ways are often of high wildlife
interest, as they can comprise the floristically richest parts of
grassland sites, particularly where their waters were clean. The ditches
and dykes are important habitats for aquatic animals.
Grassland 
The grassland County Wildlife Sites are an important wildlife
resource in Norfolk. Some of those in the Wensum Valley are considered
to be of exceptional value to wildlife. All are unimproved grasslands,
and most of them are wetland, and comprise an excellent mix of
wildflowers, grasses and sedges. Such sites are becoming increasingly
rare, not only in Norfolk and East Anglia, but throughout Britain. These
wetland grassland sites are not only disappearing, they are also
impossible to recreate. Roadside verges can often represent a vestige of
the once widespread wildflower meadows
Woodlands
The woodland component constitutes the other main habitat type in the
Wensum Valley, beside the wetland grasslands. The woodland County
Wildlife Sites in the valley are mixed in origin and nature, and
include secondary birch and oak woodland on former heathland sites,
alder and willow carr on wet sites and mixed broadleaved woodland, some
of which contain up to seventeen native tree species.
Hedgerows and copses
Hedgerows, small copses and orchards contribute to the overall varied wooded habitat matrix in the Wensum Valley.
Heathlands
The sandy soils of the Wensum Valley once supported extensive
heathland habitat, most of which has been lost to farmland, forestry and
development. All the remaining heathland sites are County Wildlife
Sites, which gives an indication of their rarity. These sites are all
common land, and would have been managed by commoners as part of the
local economy for firewood, grazing and animal husbandry. Most of the
sites are in need of management, being invaded by gorse, bracken,
rosebay willowherb and birch/oak woodland, leaving fragments of heather
and grass-heath within the site.
Disused railway lines
A number of disused railway lines run through the Valley, the remains
of the Midland and Great Northern and the Great Eastern Railway.
Although man-made, when the lines were in use they were not intensively
managed, and today often represent areas of semi-wild habitat forming a
corridor across the farmed or developed countryside. Some sections are
designated as County Wildlife Sites, and are classified as a combination
of grassland and woodland. Some sections are official paths (eg; the Marriotts
Way), others are used unofficially for walking, whilst elsewhere the
lines can be overgrown and almost impenetrable. In a few places, the
line has been ploughed into the land, the clinker having first been
removed as aggregate.
Open Water
Gravel pits are particularly characteristic of the eastern half of
the Wensum Valley. Although they provide habitat for wetland birds, and
for some common dragonflies, they are usually of less importance than
the habitats they have replaced (most frequently heathland and wet
grassland).
Many villages have ponds, which were once used for watering horses and washing down carts. The condition of the ponds varies; some have large numbers of resident ducks and gulls, others lying close to roads are subject to road run-off.
Arable wildlife habitat 
Currently, there is much interest in the contribution that arable land can make to wildlife conservation. Arable fields would have once supported a range of weeds (now wildflower rarities), when chemical fertilizers and herbicides were not used. Today these arable weeds are valued due to their rarity, and schemes to de-intensify food production and encourage wildlife, often incorporate specific measures for managing arable land. The disturbed and poor soils in and around gravel workings can often flourish temporarily with wildlife of a less-intensive arable regime.