Biology Reference
In-Depth Information
Box 3.9.
Are areas of native vegetation and plantings interchangeable?
Much of our work over the past decade has indicated that areas of remnant native
temperate woodland and replanted areas are not interchangeable environments.
On average, areas of remnant native vegetation support three times more bird
species than plantings.
7
Therefore it is not possible to clear an area of remnant
native woodland from one part of a farm and then attempt to offset its loss by
establishing a planting elsewhere on that farm, without having a significant net
negative effect on biodiversity.
28
We have found that for an average farm, while
the establishment of plantings will increase overall bird diversity by two extra
species, clearing native vegetation will reduce bird diversity by at least seven
species and many of these will be species of conservation concern. Species at risk
of being lost from farms where native vegetation is cleared include the Hooded
Robin and Jacky Winter.
7
A key reason why remnant native temperate woodland and replanted areas are
not interchangeable environments is because they provide distinctly different kinds
of habitat for native animals; that is, these two broad kinds of vegetation are char-
acterised by quite different sets of animals and plants.
6, 7, 9, 19
The Common Ringtail
Possum (see Figure 3.23), the Common Brushtail Possum and the Brown Treecreeper
are examples of species rarely found in plantings. This is because the trees in plant-
ings are typically not old enough to provide critical nesting resources like hollow-
bearing trees. Similarly, plantings lack large fallen trees that are part of the habitat of
the Brown Treecreeper. This further underscores why: (a) it will take a long time
before the features which characterise patches of old-growth woodland will eventu-
ally develop in replanted vegetation, and (b) it is important to protect existing areas
of native vegetation.
In summary, it has become increasingly clear that while both patches of remnant
native vegetation and plantings are valuable habitats on farms, it is inappropriate to
substitute one for the other.
28
Rather, it is far better to consider them as complemen-
tary habitats which, when considered in combination, will contribute significantly
greater diversity and numbers of animals on a farm than will either one in isolation.
7
of native vegetation, such as old-growth woodland. Such complementarity means
that it is not ecologically appropriate to substitute plantings for cleared remnant
native vegetation on a farm (Box 3.9).
The effectiveness of plantings for wildlife conservation can be maximised
through careful consideration of two key factors when they are being established.
These are where plantings are established on a farm and what kinds of trees and
understorey plants are used to establish a planting. Once plantings are established,
the way they are managed also can have a substantial effect on their habitat
suitability for wildlife. Management activities to maintain the suitability of
