Heydon-Laurence Building A08
University of Sydney
Sydney 2006
Ph: +61 02 9351 8683
Email: mwilliam@bio.usyd.edu.au
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Project Title: The invasive potential of Pinus radiata
My main research interest lies with invasion ecology. Biological
invasions are a major conservation issue in Australia and preventing
future invasions and managing current threats needs to be a research
priority. As well as this, the study of invasion processes can provide
insight into the factors driving community composition. It is this
combination of both practical and theoretical applications that
I enjoy working on and thinking about. Much of the attention of
invasion biology is focused on identifying attributes of invaders
and invaded communities in the hope of better understanding some
of the mechanisms underlying invasions. Ideas about what makes a
community more or less susceptible to invasion by exotic species
saturate the literature. However, efforts to identify a suite of
characteristics common to invading organisms and vulnerable communities
have largely been unsuccessful.
Pines are considered major environmental problems in New Zealand
and South Africa threatening biodiversity. Research suggests that
the ecological impacts of pine invasion are significant, ranging
from suppression of native vegetation to changes in hydrology and
the alteration of fire regimes. Here in Australia, Pinus radiata,
our most commonly planted pine, has successfully naturalised in
all states it is grown, spreading from large commercial plantations
into adjacent native vegetation. Nearly a million hectares of pine
plantations are cultivated in Australia resulting in a high potential
for invasion. Despite this, little is known about the extent of
infestation or the potential impacts of spread. The species maintains
a low profile as an invader and control efforts are limited. Quantification
of the specific impact of pine invasion in Australian systems is
crucial for the prioritisation of pines as invaders of concern in
this country.
I am also interested in testing ideas regarding community invasibility
using pine invasion as a study system. The nature of plantations
means that pine spread differs markedly from most other invasion
processes where the source population is often unknown. Plantations
have been established at multiple times at different localities
exposing a wide range of communities with varying species composition,
soil type, climate and disturbance history, resulting in a unique
opportunity to investigate the role of these factors in community
invasibility. More recently it has been suggested that propagule
pressure has been previously underestimated as a determinant of
invasion success. Few studies have attempted to directly quantify
propagule pressure. By using plantation age and area as a measure
of seed production within each plantation it becomes possible to
investigate the role of propagule pressure in pine spread.
The specific aims of my project are:
- To determine the current extent of Pinus radiata invasion in
Australia
- To investigate the factors facilitating pine spread (with a
specific focus on the role of fire and propagule pressure)
- To determine the ecological impacts of invasion
Pinus radiata invading native eucalypt woodland
in Blue Mountains National Park
Mature pine overtopping Eucalypt canopy in Mullions
Range State Forest
- Australian Geographic
- Ecological Society of Australia
Want your name up in lights? Why not volunteer? Send
me an email to find out about upcoming trips
Williams, MC and Wardle, GM (2005) The invasion of two native
Eucalypt forests by Pinus radiata in the Blue Mountains,
NSW, Australia. Biological
Conservation 125: 55-64
Williams, MC and Wardle, GM. The influence of vegetation
of vegetation structure and composition on invasibility by Pinus
radiata in the Blue Mountains NSW, Australia. Cunninghamia
(In Press)
Williams, MC Attack of the Pines! Pinus radiata as
an invasive species. 2004. Feral Herald Volume 1 Issue 7
Reprinted in The Tasmanian Conservationist 295 September 2004
http://www.tct.org.au/n34g.htm
Wardle, GM, Williams, MC and Ironside, J. 2005 The invasive
potential of Pinus radiata; seed production, dispersal and
the role of fire. Ecological Society of America Conference, Austin,
Texas (Oral presentation)
Williams, MC and Wardle, GM. 2004 What are the ecological
impacts of Pinus radiata invasion in native Eucalypt forest?
Ecological Society of Australia Conference, Adelaide, Australia
(Oral presentation)
Williams, MC 2003 Attack of the pines! Pinus radiata
invades native Eucalypt forest. Ecological Society of Australia
Conference, Armidale, Australia (Poster presentation)
Wardle, GM, Ironside, J. and Williams, MC 2003 The invasive
potential of Pinus radiata; seed production, dispersal and
the role of fire. Ecological Society of Australia conference, Armidale,
Australia (Oral presentation)
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