Byron Flora and Fauna Study 1999 - Byron Shire Council

BYRON FLORA AND FAUNA STUDY, 1999
• frequently occur in remnant, regrowth or planted rainforest in northern NSW
• have a detrimental effect on indigenous rainforest vegetation
• disrupt the ability of rainforest to regenerate and expand unaided
• are difficult to control
• are able to spread rapidly
The common weeds of northern NSW rainforests are described and illustrated, and control methods described
by The Big Scrub Rainforest Landcare Group (1998b). Buchanan (1989) is a useful reference for weeds of
other communities.
Environmental weeds such as Camphor Laurel, Bitou Bush, Lantana, Large-leaved Privet and Small-leaved
Privet are well recognised in the Shire. Many others are known to occur, but may not be recognised as such
by the general community. They include common garden plants such as the Asparagus Fern’s Protasparagus
spp., Glory Lily Gloriosa superba, Mother-in-Law’s Tongue Sansevieria trifasciata, Cherry Guava, Coffee Coffea
arabica, Japanese Honeysuckle Lonicera japonica, Cocos Palm Syagrus romanzoffiana, Broad-leaved Pepper Tree
Schinus terebinthifolia and Umbrella Tree Schefflera actinophylla.
Exotic creepers are particularly invasive and amongst a range of other weeds pose a significant threat to high
quality vegetation communities in the Shire. Species of concern include; Madeira Vine Anredera cordifolia
(Photo 34), Dutchmen’s Pipe Aristolochia elegans, Balloon Vine Cardiospermum grandiflorum, Cape Ivy Delairea
odorata, Five-leaved Morning Glory Ipomoea cairica, Blue Morning Glory Ipomoea indica, Cats Claw vine
Macfadyena unguis-cati, Corky Passionfruit Passiflora suberosa, Ground Asparagus Protasparagus aethiopicus (Photo
33), Climbing Asparagus Fern Protasparagus africanus, Asparagus Fern Protasparagus plumosus, Kudzu Pueraria
lobata and Wandering Dew.
This study has demonstrated the extent of occurrence of Camphor Laurel in the study area (Section 4.6.3).
A large area of Large-leaved Privet at Mt Chincogan was also mapped. Many other species of environmental
weeds were recorded at sites surveyed during the plot-based vegetation survey. However, most environmental
weeds cannot be detected using API, and systematic ground-based surveys are required. Hence this study
provides only limited information about the distribution and abundance of environmental weeds, and further
work is recommended. For instance the area mapped for Large-leaved Privet does not reflect the true
extent of its distribution in Byron Shire. Both Large-leaved Privet and Small-leaved Privet are considered to
be much more widespread in Byron Shire, and commonly occupy the mid to lower strata and edges of
remnant and regrowth forest.
Fortunately, there are a number of serious environmental weeds that are notable for their absence, or
presence only in small localized infestations in the Shire. Where areas are currently free of problematic
weeds, there is an excellent opportunity to keep those areas free of weed problems by early detection and
eradication of any infestation.
In controlling environmental weeds, due consideration for their positive characteristics is required. Some
weeds like Tobacco Bush may act as colonizers, providing suitable nurse conditions for the introduction of
native species of later successional stages, but unless these areas are managed and/or suitable seed sources
are close by, it is likely that other weed species will move in and permanently dominate the site. Weeds may
stabilize soil and build soil fertility and biomass in degraded sites. However there is, without exception,
always a native species that can fulfil the same role without the disadvantage of acting as an undesirable seed
source.
Environmental weeds can provide valuable fauna habitat. Camphor Laurel, and to a lesser extent Largeleaved
and Small-leaved Privet, are important food sources for frugivorous birds. Lantana provides shelter
for ground-dwelling fauna species. A general strategy of gradual removal and replacement with appropriate
native species is suggested.
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