michelle casanova federation university, ballarat€¦ · seeds, spores, propagules buried in the...
TRANSCRIPT
Michelle Casanova
Federation University, Ballarat
Mechanisms for resilience
Diversity (diversity resilience)
Connectivity (local, regional, national, global)
Functional seed bank (ecosystem integrity)
What is a seed bank? Seeds, spores, propagules buried in the soil
Dormant (i.e. don’t germinate immediately)
Innate dormancy (i.e. born with it)
Enforced dormancy (i.e. imposed by conditions)
Lets also include animal bits…….
Cysts (aestivating adult animals)
Eggs (sexual reproductive organs)
Asexual reproductive organs
We need to consider seed banks when we try to restore wetlands
How does the seed bank compare with what is in the extant vegetation?
How does the seed bank compare with what we want to be there?
Can we use existing information to predict the contribution seed banks might make to restoration?
Dormant
seed bank Seedlings
local pool of
soil organic carbon
Distant vegetation
Local vegetation
Dispersal and germination
Death
Change in dormancy status
Dispersal andgermination
Dispersal and entryinto
dormancy
Dispersal and entryinto dormancy
Germination
Death
Decision Support Tool Literature Review....Roberts et al. 2016
Cropping swamps, Casanova and Casanova 2016
Seed bank Vegetation
Comparison of seed bank and existing vegetation
No. species SB Overlap Study
6 85 % Permanent Lake Casanova 2005
17 32 % Seasonal Herbaceous Wetlands
Casanova 2012
22 - 28 32 – 43 % Fleurieu SwampsCasanova 2016
115 43 % RiparianGreet et al. 2013
55 32 % Riparian Williams et al 2008
69 18 -21 % Seasonal riparianCasanova 2015
Contribution of seed bank to different Ecological Vegetation Communities (EVCs)
EVC No. indicator spp Potential contribution of seed bank
Cane grass wetland/aquatic herbland
14 100
Sedge wetland 6 50
Lignum swampy woodland
4 0
Decision Support Tool User Guide....Roberts et al. 2016
What about Winton Wetlands? Historical vegetation (prior to inundation)
History of water regime
A mosaic of different habitats
Current restoration project
Number of other vegetation records, on-going studies
Species list (Helen Aston 1962) Characeae (5 spp) Pilularia nova-hollandiae Azolla (2 spp) Isoetes humilior Typha angustifolia Potamogeton (2 spp) Najas tenuifolia Triglochin procera Damasonium minus Otellia ovalifolia 5 grasses 6 sedges Lemna minor 8 rushes Polygonum (2 spp) Euphorbia drummondii Alternanthera denticulata
Callitriche hamulata Elatine triandra Lythrum flexulosum Eucalyptus (3 spp) Haloragis heterophylla Myriophyllum (2 spp) Anagalis arvensis Glossostigma elatinoides Gratiola pedunculata Limosella aquatica Utricularia flexulosa Goodenia gracilia Centipeda cunninghamii Gnaphalium luteo-album Hypochoeris glabra Inula graveolens Sonchus asper
Other studies that refer to vegetation Souter and Lewin 1999
Australian Water Technologies 2000
Vegetation
Seed bank (Duck pond)
Carr and Conole 2006
Roberts and Hale 2007
Roberts and Hale 2008
Roberts, Kobryn and Osler 2008
Detecting species
Species not
identified
Species not found
Species found and identified
Time
Ob
serv
ed N
o. s
pec
ies
Regularly fluctuating environment
Stable environment
Specific trigger
Potential use of data What species (groups of species) remain?
What other species can we detect?
Are there any differences among the sites?
Can one site be considered as a potential ‘donor’?
Has the vegetation changed over time?
What happens to a temporary wetland seed bank after many years of inundation?
How does seed bank analysis compare with other measures of wetland function/quality?
But wait, there’s more……….. Thanks to the Winton Wetland CoM
Mariagrazia Bellio, Anthony Casanova
Jane Roberts
Lance Lloyd