Blick, Ray

Bricher, Phillippa

Brownstein, Gretchen

Cooke, Jessica

Erskine, Peter

Fletcher, Andrew

Johns, Caitlin

University of Queensland eSpace

1 
Plant functional groups: An effective indicator for 
detecting drawdown in groundwater-dependent 
wetlands? 
Caitlin Johns, Gretchen Brownstein, Jessica 
Cooke, Ray Blick, Phillippa Bricher, Andrew 
Fletcher & Peter Erskine, November 2013 
2 
• Newnes Plateau, Blue Mountains, NSW 
 
• Underground coal mining has occurred in this 
region since 1838 
 
• Centennial Coal have monitored wetland 
condition since 2003 
 
• In 2005, wetland vegetation listed as part of an 
Endangered Ecological Community under the 
EPBC Act 1999. 
 
 
Background & study area 
(Map: Lechner et al (2012)) 
3 
Potential impacts of undermining on wetlands 
Ground water 
Seepage 
Groundwater confined by claystone bands between more 
permeable sandstone strata 
Wetlands occur 
in groundwater 
discharge areas 
Undermining leads to 
cracking & subsidence 
Potential for diversion of ground 
or surface water flow paths 
4 
Q. Which indicator species or groups should could be 
monitored across all wetlands to detect the effects of drying? 
 
LINKING VEGETATION COMMUNITY CHANGES 
TO HYDROLOGICAL IMPACTS 
5 
Analyse available wetland vegetation and hydrology data 
 
 
Determine main differences in vegetation between wetter and drier sites 
 
 
Identify potential indicators of wetland drying 
 
 
Refine monitoring program design 
 
Conceptual approach 
6 
• 52 site condition 
monitoring plots  
(20m x 20m) 
 
• Plots established 
between 2003 & 2012 
 
• Surveyed seasonally 
 
• Additional species 
point intercept data 
collected Spring 2012 
(~160 points / plot) 
 
Vegetation & hydrology data sources 
7 
Site condition notes indicate surface water levels relatively stable across 
surveys 
 
Plots classified by: 
 
•water level (inundated or damp) and  
 
•position (edge or middle) 
 
 
Broad hydrological classification 
Damp x Middle plot 
20m x 20m plots 
Inundated x Edge plot 
Inundated x Middle plot 
8 
SPECIES LEVEL 
• Generalisations at plateau scale difficult due to high variability 
between plots (including within the categories wet/dry and 
edge/middle) 
 
• Could not identify suitable indicator species for monitoring across 
multiple wetlands 
9 
Of 222 taxa recorded, 50% were found in 3 plots or less 
0
10
20
30
40
50
60
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
N
u
m
b
e
r 
o
f 
ta
xa
 
Number of wetland plots taxon detected in 
10 
1. Life forms 
 
2. Water plant functional groups (WPFG), after Brock & Casanova 
(1997) 
– Inundation tolerance data from experiments & field observations 
 
3. Wetland indicator categories (WIC), after Reed (1997) 
– Herbarium record collection frequencies (in wetlands / other habitats) 
Functional group classification methods 
11 
Functional group Definition 
Terrestrial  Tdr Dry habitat spp. 
Tda Damp habitat spp. 
Amphibious Ate Emergent (e.g. sedges & rushes) 
Atw Woody (shrubs & trees) 
Atl Low-growing 
Arp Plastic growth form 
Aquatic 
Water plant functional groups (WPFG) 
Brock, M. and M. Casanova. 1997. Plant life at the edge of wetlands: ecological responses to wetting and drying 
patterns. Pages 181-192 in N. Klomp and I. Lunt, editors. Frontiers in ecology: Building the links. Elsevier Science, 
Oxford 
12 
Wetland indicator categories (WIC) 
Reed, P. B. 1997. Revision of the national list of plant species that occur in wetlands. Report produced by the U.S. 
Fish and Wildlife Service, Washington, DC, in cooperation with the National and Regional Interagency Review Panels 
(U.S. Fish and Wildlife Service, U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, Natural 
Resources Conservation Service)  
Tiner, R. W. 2012. Defining hydrophytes for wetland identification and delineation. Report prepared by the U.S. Fish 
and Wildlife Service for the U.S. Army Corps of Engineers. 
Indicator category Definition 
Obligate Upland (UPL) Almost never (>99%) found in wetlands 
Facultative Upland (FACU) Usually not (67-99%)  found in wetlands 
Facultative (FAC) Equally likely (34-66%) to occur in wetland or non-wetland habitats 
Facultative Wetland (FACW) Usually does (67-99%) occur in wetlands 
Obligate Wetland (OBL) Almost always (>99%) occurs in wetlands 
13 
SIMPER analyses: Within-group similarities 
14 
nMDS: Life form relative abundances 
Resemblance: S17 Bray Curtis similarity 
Plot categories 
Inundated Edge 
Inundated Middle 
Damp Edge 
Damp Middle 
BNS01 
BS01 
CCS01 
CLA01 
CLA02 
CLA03 
CLA04 
CLW03 
CLW04 
CLW05 
EW01 
EW02 
KC01 
KC02 
KC03 
KC04 
LGG01 
NS01 
NS02 
NS04 
SS01 
SS02 SS03 
SS04 SSE01 
SSE02 
TG001 
TG002 
TRI01 
TRI02 
UGE01 
WC01 
WC02 
WC03 
WC04 
WW01 
WW02 
WW03 
WW04 
WW05 
WW06 
CLW02 
SSE03 
SSE04 
Fern 
Forb 
Grass 
Sedge/Rush 
Shrub 
2D Stress: 0.15 
15 
nMDS: Water Plant Functional Group relative abundances 
Resemblance: S17 Bray Curtis similarity 
Plot categories 
Inundated Edge 
Inundated Middle 
Damp Edge 
Damp Middle 
BNS01 
BNS02 
BS01 
CCS01 
CLA01 
CLA02 
CLA03 
CLA04 
CLW02 
CLW03 
CLW04 
CLW05 
EW01 
EW02 
KC01 
KC02 
KC03 
KC04 
LGG01 
NP007 
NS01 
NS02 
NS04 
SS01 
SS02 
SS03 
SS04 
SSE01 
SSE02 
SSE03 
SSE04 
TG001 
TG002 TRI01 
TRI02 
UGE01 
WC01 
WC02 
WC03 
WC04 
WW01 
WW02 
WW03 
WW04 
WW05 
WW06 
Arp 
Ate 
Atl 
Atw 
Tda 
Tdr 
2D Stress: 0.15 
(Amphibious woody spp.) 
(Amphibious emergent spp.) 
(Terrestrial damp and 
amphibious low-growing spp.) 
(Terrestrial dry habitat spp.) 
16 
nMDS: Wetland Indicator Category relative abundances 
Resemblance: S17 Bray Curtis similarity 
Plot categories 
Inundated Edge 
Inundated Middle 
Damp Edge 
Damp Middle 
BNS01 
BS01 CCS01 
CLA01 
CLA02 
CLA03 
CLA04 
CLW02 
CLW03 
CLW04 
CLW05 
EW01 
EW02 
KC01 
KC02 
KC03 
KC04 
LGG01 
NS01 
NS02 
NS04 
SS01 
SS02 
SS03 
SS04 
SSE01 
SSE02 SSE03 
SSE04 
TG001 
TG002 
TRI01 
TRI02 
UGE01 
WC01 
WC02 
WC03 
WC04 
WW01 
WW02 
WW03 
WW04 
WW05 
WW06 
FAC 
FACU 
FACW 
OBL 
UPL 
2D Stress: 0.16 
(Facultative or obligate 
wetland spp.) 
(Facultative or obligate upland spp.) 
(Facultative, 
generalists) 
17 
•2 factor PERMANOVAs (water table depth x plot 
position) 
 
•Significant differences (p<0.05) were detected 
between: 
 
• Inundated & damp plots (for both WPFG & life 
forms) 
 
• Edge & middle plots (for WPFG only) 
 
• (no sig. interactions) 
 
Life forms & WPFGs 
18 
SUMMARY 
•Functional groups were much more 
broadly applicable than species 
 
 
•Life forms and WPFG both show promise 
as indicators of drying 
 
–Showed much clearer trends than WIC based on water 
availability 
–WIC classification very time-consuming, with higher 
degree of classification uncertainty than alternative 
methods 
 
•WPFG appear best overall 
–Discriminated inundated habitats from damp 
–Discriminated wetland edge from core vegetation 
(potentially useful for detecting early signs of dryland 
vegetation encroachment) 
 
 
19 
CMLR staff: Phill McKenna, Cameron Kilgour & Nic McCaffrey 
 
Volunteers: Kathleen Coelli, Jessica Cooke, Kelly Dobson, Lucy 
Gramenz, Sasha Jooste & Ashley Lawson 
 
Project funding provided by Centennial Coal 
 
 
 
 
Acknowledgements 


Plant functional groups: An effective indicator for detecting hydrological disturbance in groundwater-dependent wetlands?

https://espace.library.uq.edu.au/view/UQ:344102/Johns_etal_ECOTAS13_Conference.pdf

Plant functional groups: An effective indicator for detecting hydrological disturbance in groundwater-dependent wetlands?

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