michelle casanova federation university, ballarat€¦ · seeds, spores, propagules buried in the...

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