RYDE FLORA and FAUNA STUDY 2007 - City of Ryde - NSW ...

Biosphere Environmental Consultants Pty Ltd
Ryde Flora and Fauna Survey 2007 60
general, however, replanting should be considered only when native plants cannot
naturally re-establish themselves. Replanting is most often used:
i) to quickly cover an area that is bare or has been cleared
ii) to create a buffer zone around bushland areas
iii) to create habitats that have been lost from an area
iv) to replace non-breeding or diseased endemic plants (through seed
collection and propagation)
The use of controlled planting to create buffer zones will be discussed below (in 6.6)
while their use in creating habitats will be discussed in 6.7.
6.6 Buffer Planting to Combat Edge Effects
One of the problems that all bushland reserves suffer from is “edge effect”. This term
describes a variety of impacts that are experienced by bushland that is in contact with
non-bushland areas. In Ryde, this usually means contact with residential areas, streets
and recreational parkland. The bushland areas that follow creek catchments are more
susceptible to edge effect because of their narrowness.
The plants along the boundary of reserves are subject to much more physical damage
and changes than the plants deeper in the reserve. Damage is caused by greater
exposure to strong winds, sun and rain, and by regular contact with walkers who
accidentally knock leaves and small branches or deliberately break off projecting
shoots or stems. In addition, the fringes of reserves are constantly bombarded with
exotic seeds (borne by wind or storm water) and are further assaulted by mowing and
slashing of regrowth. Garden wastes and rubbish is also deposited along the edges of
the reserves. The combined effects of these pressures are to eliminate the more
sensitive native plants and create gaps in the vegetation (that are later exploited by
fast-growing weeds).
Disturbance to the plants along the edges of reserves is a problem that will not end.
Ideally, bushland reserves need to be shielded from these impacts by a wall of more
resilient, native plants that can tolerate greater physical damage and exposure. Such
plants can create a buffer between the natural bushland and the urban interface. Buffer
plants must be hardy, native, non-invasive and easy to maintain. In short, they must
not have the potential to become a pest in themselves.
Many of the bushland reserves in Ryde contain woodland with an open understorey.
The wide spacing of the ground plants makes it easy for weeds to become established
and to eventually become the dominant ground cover. A buffer comprising tall, dense
shrubs and other understorey plants that are locally endemic to the area would greatly
reduce the seed load entering the reserves and block off areas containing sensitive
plants.
6.7 Creating Habitats
Open and semi-closed woodlands were a feature of the Ryde landscape (Howell and
Benson, 2000). While these woodlands were widespread in the area in pre-European