The soil of abandoned farmland, Cumberland Plain Woodland and restored vegetation

290 Pages·2013·5.09 MB·English

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Jennifer Kit Fitzgerald

A thesis submitted in fulfilment of the requirements of the
degree of Doctor of Philosophy, University of Western Sydney,
Australia.

July, 2009.
Cumberland Plain Woodland at Hoxton Park. Photo by Jennifer Kit Fitzgerald

Abandoned farmland at Scheyville National Park. Photo by Jennifer Kit Fitzgerald

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This thesis does not incorporate, without acknowledgement, any material
previously submitted for a degree or diploma in any university and to the best of
my knowledge and belief it does not contain any material previously published or
written by another person except where due reference is made in the text.

Jennifer Kit Fitzgerald,
July 2009.
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The restoration and management of Cumberland Plain Woodland, an „Endangered
Ecological Community‟ found only in western Sydney, has occurred without a sound
understanding of soil-vegetation relationships within this community. Since 1992, large
tracts of abandoned farmland, which were originally covered with Cumberland Plain
Woodland, have been planted with native trees and shrubs to facilitate woodland
development. This approach was based on the theory of (small-scale) patch dynamics
since it was envisaged that the developing overstorey would facilitate changes to the
soil environment, which would advantage native woodland species and disadvantage
exotic pasture species.

To date, this approach has had limited success and importantly, the restoration of
Cumberland Plain Woodland has ignored: (a) characterisation of the soil environment;
(b) how different patch types (e.g. tree and shrub) influence the soil; (c) how past land
use has affected the soil; and (d) the effects of revegetation on soil properties and
processes. These issues are of the utmost importance since soil-related barriers to
natural regeneration and restoration may exist as a result of a very long history of
agriculture. This thesis addressed these issues by investigating the soils of abandoned
farmland, Cumberland Plain Woodland and restored areas of various ages. In addition
to this, the impacts of various patch types (woodland tree, shrub and open, as well as
improved perennial pasture) on soil properties and processes, as well as the ground flora
were examined.

Several soil chemical properties and ecological processes were identified as being of
particular importance for the ecology of Cumberland Plain Woodland and its restoration
on abandoned farmland. The greatest impact on the soil from past agricultural land use
was an increase in the concentration of nitrate, ammonium and total nitrogen within the
pasture compared to the woodland patch types, although there was an appreciable
amount of site-to-site variability. Despite this, data from two different studies, which
were carried out over different spatio-temporal scales, suggest that the abandoned
pasture and Cumberland Plain Woodland function differently with respect to the cycling
of nitrogen and this may hinder restoration efforts.
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Special thanks to my Supervisor, Dr. E. Charles Morris (UWS), for his support and help
in securing much-needed funds for this research. Thanks also to Associate Professor
David Eldridge (DNR/UNSW), who co-supervised this work during 2006 and part-way
through 2007. The financial support I received from the University of Western Sydney,
by way of a Postgraduate Research Award, was invaluable. I am also grateful to the
Penrith Lakes Development Corporation and the Linnaean Society of New South Wales
for funding.

A very big thank you is extended to those who helped with field and laboratory work,
namely: Mark Emmanuel (UWS), Dorothy Yu (UNSW) and Chris Myers (UNSW) for
their assistance with soil chemical determinations and analytical techniques; Nyree
Webster (UNSW) for her untiring field assistance; Adam Birnbaum (UNSW) for his
help with respiration measurements and Peter Nichols (UWS) and Alison Hewitt (UNE)
for assistance in the field. Thanks also to Frank Hemming (UNSW) for his help with
plant identification, Monique de Barse (UWS) for help with PRIMER, Dani Drewry
(UWS) and Penny Watson (UWS) for early discussions on Cumberland Plain Woodland
and Graeme Hastwell (UWS) for his input on various topics relating to this research.

I gratefully acknowledge the National Parks and Wildlife Service (Col Davidson and
Jonathon Sanders), the Botanic Gardens Trust (Peter Cuneo), the Department of
Defence (Marina Peterson and Daryle McKone), the Sydney Catchment Authority (Jane
MacCormick) and Greening Australia (Tim Beshara) for allowing me access to land that
was under their control. Special thanks to Debra Little, Lotte von Richter and Doug
Benson (all Royal Botanic Gardens) for sharing their knowledge on the Cumberland
Plain Woodland at Mount Annan.

Very special thanks to my dear friend Carolyn Stonham, my mother Jan Smith and my
nanna Kitty Fitzgerald, for their continued support and encouragement. Most
importantly, I thank my partner Scott Mooney.

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CHAPTER 1: The significance of Cumberland Plain Woodland and the need for
soil-based research ..................................................................... 1
1.1 The importance of Cumberland Plain Woodland ............................................... 1
1.2 The New South Wales Threatened Species Conservation Act 1995 ................... 3
1.3 Recovery of threatened species, populations and ecological communities ......... 4
1.4 Previous research on the soils and vegetation of the Cumberland Plain ............. 7
1.5 The attempted restoration of Cumberland Plain Woodland ................................ 9
1.6 The impacts of agriculture on the soil and vegetation ...................................... 13
1.7 Changes to the soil and vegetation during old field succession ........................ 15
1.8 Potential effects of fire on the soil environment .............................................. 18
1.9 The restoration and management of degraded woodlands ................................ 20
1.10 Aims of this thesis .......................................................................................... 24

CHAPTER 2: Description of the Cumberland Plain and study sites ....................... 25
2.1 The Cumberland Plain .................................................................................... 25
2.1.1 Location ................................................................................................... 25
2.1.2 Climate .................................................................................................... 26
2.1.3 Physiography ........................................................................................... 31
2.1.4 Geology ................................................................................................... 32
2.1.5 Soil associations and soil landscapes ........................................................ 33
2.1.6 Soil types and soil materials ..................................................................... 35
2.1.7 European land use history ........................................................................ 36
2.1.7.1 Discovery and settlement of the Cumberland Plain 1789-1821 .......... 36
2.1.7.2 Agricultural consolidation of the Cumberland Plain 1821-1858 ......... 42
2.1.7.3 Industrialisation of the Cumberland Plain 1858-1900 ........................ 43
2.1.7.4 Urbanisation of the Cumberland Plain 1880-present day ................... 44
2.1.8 Vegetation ................................................................................................ 46
2.2 The study sites ................................................................................................ 49
2.2.1 Hoxton Park ............................................................................................. 49
2.2.1.1 Location ............................................................................................ 49
2.2.1.2 Climate and physical geography ........................................................ 49
2.2.1.3 Vegetation ........................................................................................ 51
2.2.1.4 European land use history ................................................................. 51
2.2.2 Mount Annan Botanic Garden .................................................................. 52
2.2.2.1 Location ............................................................................................ 52
2.2.2.2 Climate and physical geography ........................................................ 52
2.2.2.3 Vegetation ........................................................................................ 52
2.2.2.4 European land use history ................................................................. 53
2.2.3 Orchard Hills Defence Estate ................................................................... 53
2.2.3.1 Location ............................................................................................ 53
2.2.3.2 Climate and physical geography ........................................................ 53
2.2.3.3 Vegetation ........................................................................................ 54
2.2.3.4 European land use history ................................................................. 54
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2.2.4 Prospect Reservoir ..................................................................................55
2.2.4.1 Location ........................................................................................... 55
2.2.4.2 Climate and physical geography ....................................................... 55
2.2.4.3 Vegetation ....................................................................................... 55
2.2.4.4 European land use history ................................................................ 56
2.2.5 Scheyville National Park ......................................................................... 56
2.2.5.1 Location ........................................................................................... 56
2.2.5.2 Climate and physical geography ....................................................... 56
2.2.5.3 Vegetation ....................................................................................... 57
2.2.5.4 European land use history ................................................................ 57

CHAPTER 3: The soil of abandoned farmland and Cumberland Plain Woodland. 61
3.1 Introduction ................................................................................................... 61
3.2 Methodology ................................................................................................. 62
3.2.1 Experimental design ................................................................................ 62
3.2.2 Field and soil sampling ............................................................................ 63
3.2.3 Soil physical and chemical determinations .............................................. 69
3.2.3.1 Bulk density ..................................................................................... 70
3.2.3.2 Soil moisture content ....................................................................... 70
3.2.3.3 pH .................................................................................................... 70
3.2.3.4 Electrical conductivity ..................................................................... 71
3.2.3.5 Active C .......................................................................................... 71
3.2.3.6 Extractable P .................................................................................... 72
3.2.3.7 Nitrate and ammonium ..................................................................... 72
3.2.3.8 Total C, total N and total S ............................................................... 73
3.2.4 Statistical analyses .................................................................................. 73
3.3 Results ........................................................................................................... 74
3.3.1 Bulk density and soil moisture content .................................................... 74
3.3.2 pH and electrical conductivity ................................................................. 75
3.3.3 Active C and total C ................................................................................ 80
3.3.4 Extractable P and total S .......................................................................... 82
3.3.5 Nitrate, ammonium and total N ............................................................... 82
3.4 Discussion ..................................................................................................... 87

CHAPTER 4: The ground flora of abandoned farmland and Cumberland Plain
Woodland and its relationship with soil chemical properties .. 102
4.1 Introduction ................................................................................................. 102
4.2 Methodology ............................................................................................... 104
4.2.1 Experimental design .............................................................................. 104
4.2.2 Vegetation and soil sampling ................................................................. 104
4.2.3 Univariate analysis ................................................................................ 105
4.2.4 Multivariate analyses ............................................................................. 105
4.2.4.1 Examining the floristic similarity of samples using cluster analysis and
ordination .................................................................................................. 106
4.2.4.2 Investigating the effects of site and patch type on ground species
composition and cover with analysis of similarity and the SIMPER routine
................................................................................................................... 106
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4.2.4.3 Linking the floristic and soil data using the BVSTEP procedure ..... 108
4.3 Results ......................................................................................................... 109
4.3.1 Univariate analysis ................................................................................ 109
4.3.2 Multivariate analyses ............................................................................. 109
4.3.2.1 Cluster analysis and ordination ....................................................... 109
4.3.2.2 Analysis of similarity and SIMPER analysis .................................. 113
4.3.2.3 BVSTEP analysis ........................................................................... 118
4.4 Discussion ................................................................................................... 121

CHAPTER 5: Soil chemical fertility and biotic processes of abandoned farmland,
endangered woodland and restored vegetation at Hoxton Park
.............................................................................................. 131
5.1 Introduction ................................................................................................. 131
5.2 Methodology ............................................................................................... 133
5.2.1 Site description ...................................................................................... 133
5.2.2 Experimental design .............................................................................. 134
5.2.3 Soil sampling ........................................................................................ 137
5.2.3.1 Chemical properties and respiration ............................................... 137
5.2.3.2 Decomposition ............................................................................... 139
5.2.4 Statistical analysis ................................................................................. 142
5.3 Results ......................................................................................................... 143
5.3.1 Variables measured once during the year ............................................... 143
5.3.1.1 Bray 1 P ......................................................................................... 143
5.3.1.2 Total C ........................................................................................... 143
5.3.1.3 Total N .......................................................................................... 144
5.3.1.4 C:N ratio ........................................................................................ 144
5.3.2 Variables measured twice throughout the year ....................................... 144
5.3.2.1 pH .................................................................................................. 144
5.3.2.2 Active C ........................................................................................ 148
5.3.2.3 Respiration ..................................................................................... 148
5.3.3 Variables measured four times throughout the year ............................... 150
5.3.3.1 Soil moisture content ..................................................................... 150
5.3.3.2 Nitrate ............................................................................................ 150
5.3.3.3 Ammonium .................................................................................... 153
5.3.4 Decomposition ...................................................................................... 157
5.4 Discussion ................................................................................................... 159

CHAPTER 6: The implications of this research for the management and restoration
of Cumberland Plain Woodland ............................................. 167

REFERENCES .................................................................................................... 172

APPENDICES ..................................................................................................... 204

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TABLE 1.1 The recovery strategies and priority actions for Cumberland Plain
Woodland .................................................................................6
TABLE 1.2 Previous research on the soils of the Cumberland Plain ......................8
TABLE 1.3 Previous research on the vegetation of the Cumberland Plain ........... 10
TABLE 2.1 Size of the Local Government Areas associated with the Cumberland
Plain and the proportion of their area located within the region
................................................................................................ 26
TABLE 2.2 The dominant processes contributing to the formation of profile
morphology in brown, red and yellow podzolic soils and their
degree of development for each soil type ................................ 36
TABLE 2.3 Morphological properties of the soil materials from the Blacktown soil
landscape and their limitations ................................................ 37
TABLE 2.4 The pre-1750 and current (2002) extent of the vegetation communities
on the Cumberland Plain and the date they were listed on the
TSC Act ................................................................................. 46
TABLE 2.5 The diagnostic floral species for the various strata within Shale Hills
Woodland and Shale Plains Woodland ................................... 48
TABLE 2.6 Attributes and limitations for urban and rural development of the
Blacktown and Luddenham soil landscapes ............................ 50
TABLE 2.7 Indicators of the extent and nature of agricultural activities on
abandoned farmland at Scheyville .......................................... 59
TABLE 3.1 Sampling dates for each site, along with the mean minimum and
maximum temperatures and total rainfall during the four week
period (28 days) prior to sampling .......................................... 68
TABLE 3.2 Mean concentrations and the upper (L2) and lower (L1) 95%
confidence limits for the physical and chemical soil properties,
averaged over all patch types and soil depths, at each site ....... 76
TABLE 3.3 Mean concentrations and the upper (L2) and lower (L1) 95%
confidence limits for the physical and chemical soil properties
for the main effects of patch type ............................................ 78
TABLE 3.4 Mean concentrations and the upper (L2) and lower (L1) 95%
confidence limits for the physical and chemical soil properties
for the main effects of soil depth ............................................ 78
TABLE 4.1a Results of the 2-way crossed ANOSIM for the site factor based on
ground species composition and cover .................................. 114
TABLE 4.1b Results of the 2-way crossed ANOSIM for the patch type factor based
on ground species composition and cover .............................. 114
TABLE 4.2 The percentage dissimilarity, based on fourth root transformed data,
for all pair wise combinations of sites and the individual and
cumulative contributions from the top three species for each
comparison ............................................................................ 115
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