The Journey Of Native Seedlings Beginning At Our SPAs

With inputs from Angela S., hobby botanist, database lead and volunteer at the Wetlands Centre.

The thriving native plant life is what makes our wetlands places of immense beauty and wonder. Their roots nourish the land and help with nutrient recycling and removal of toxins.  Their lush cover provides shelter and habitat for our wildlife. 

They add so much character to the wetlands, reflecting seasonal changes like wetland moods – flowering, and shedding. These plants have evolved to adapt to the cyclical nature of wetlands so well, coping in ever-varying conditions of dryness, wetness, salinity or freshness. And if you observe the wetlands you will catch their different tones. 

It is incredible to imagine that these plants start their life as tiny seedlings that then grow into sturdy saplings and mature plants. We, at The Wetlands Centre, do our bit in helping our native plants flourish – by ascertaining the best times to collect seeds and factors for maintaining genetic diversity, collecting seeds, storing and cataloguing seeds, propagating seeds, potting on seedlings, and then planting and rehabilitating the bushland and wetland with native plants.

We work hand-in-hand with our team of volunteers, community members, and our primary sponsors – The City of Cockburn, who are keen supporters of our work. Our established wet and dry Seed Propagation Areas or SPAs and our fully equipped “Norm’s Nursery” is where the magic happens. We’ve been maintaining detailed records of all our efforts in a comprehensive database that is proving to be very helpful in our endeavours. All the collected data can be analysed for some fascinating trends and interesting insights. 

In this blog post, we offer you a tour of our SPAs and nursery, as well as our seed store and database. While we’re expanding our knowledgebase, we are eager to learn and incorporate from your experience. We hope you’ll be able to join us in our effort to preserve, conserve and rehabilitate our precious wetlands. 

 

Collecting and Storing Seeds

It takes special knowhow to collect seeds from native plants. Some seeds are incredibly toxic, like the bright red seeds from the Zamia, and collecting them can be tricky. A whole bucket of Banksia seedpods may produce just 10 seeds (or fewer) while, Juncus and Lobelia are more prolific and only one teaspoon worth of seeds may produce over 20,000 plants!

Norm Godfrey, a wetland visionary, was a pioneer in this science. We, till date, use the list that he compiled of what seeds are best collected when. For this and for his enormous love for the wetlands we have named our water-wise garden – “Norm’s Garden” and our nursery – “Norm’s Nursery”, in his loving memory.

We collect seeds from the bushland and wetland, and we involve volunteers in all tasks, including seed collection. The collected seeds are then catalogued and stored. They are sorted by the year of their collection when they are stored. We have seeds going back to the years 2002/2003 in our seed store!

 

The SPAs and Norm’s Nursery

The centre has one wet and one dry seed propagation area (or SPA). It is here that the seeds are propagated and transplanted. We use a handy (unofficial) zone guide to determine and pick the zones. 

Norm’s nursery is a little haven for our native plants. There are 139 native plants that are officially confirmed as local to our area (there may be more that are not confirmed yet) and we grow all of these. We currently have a maximum holding capacity of up to 22,000 plants!

The City of Cockburn is our primary sponsor and most generous supporter. We grow native plants for them that they then use to rehabilitate predetermined areas. Over and above this we also use the plants to rehabilitate areas within our precinct, such as Horse Paddock Swamp. We often announce our planting day events in advance and are joined by many involved and enthusiastic members of the community.

   

Our Comprehensive Database

Our comprehensive database is the cornerstone of our management efforts. We use the database to maintain records of all our seed collection, propagation, germination, transplanting and planting activities. 

We can use the database to extract specific insights – about the timelines for the various phases of seed propagation and if these coincided with any major weather events, about the yield for each batch and if there were factors contributing to an especially high/low yield, about the best methods and techniques for growing native plants, and about the amount of seed that will give us acceptable returns in terms of plant maturation. 

The database is also helping us make our operations more economical. For example, we now understand the quantity of seeds that we need to sow for the output we require, and we are not over-sowing or over-producing. We are also gathering information on seed viability and the various factors that affect plant health. For example, we were able to keep records of how much sodium bicarbonate we added per watering can and eventually worked out the best amount to bring liverwort and other mosses under control in the nursery. 

We are assimilating this information, gathering context and improving our processes continuously. This makes management a little more scientific, precise and predictable. 

 

Planting and Propagation Events

In our 26 years of landcare, education and conservation work, we have built a considerable knowledgebase. We are learning more and more about the behaviours of our native plants and the best ways of supporting them.

We are interested in sharing all the knowledge we have collected and we welcome groups and individuals to contribute, assist and partake. There is so much to learn and do together!

If you’re interested in what we do and want to help us in our efforts, come join us as a vollie. We will be delighted to have you. Optionally, you can join us for general landcare work on Thursdays and Fridays. 

No formal qualification or working knowledge of plants is required to volunteer.  Just an open mind and a willingness to learn and embrace new stuff. There are a range of diverse and interesting activities to indulge in. And our friendly team of staff and vollies will make it up to you with laughter, fun, a warm cuppa and lots of bikkies.

We encourage you to visit us or have a chat with us at The Wetlands Centre Cockburn – about how you can participate and help your local wetlands!

Saving Bibra Lake

An aerial view of Bibra Lake on a sunny day

Cradled in the swales of the ancient dunes of the Swan Coastal Plain, and spanning over 384 hectares are the Beeliar Wetlands! They are bustling with stunning biodiversity, that include some of the most unique and fragile lifeforms on earth. Here, the calm, placid Bibra Lake stands as a timeless testament to our heritage and cultural values.

Historically, North Lake – Coolbellup and Bibra Lake – Walliabup, have served as important locations for the Aboriginal Nyoongar people. They are associated with the mythology of the ‘Waugal‘– the rainbow serpent, and Dreamtime tales of the ‘Spirit Children’.  Numerous Aboriginal campsites have been documented adjacent to the lakes. The Beeliar mob had semi-permanent camps on the land, caring for the boodja (country), precisely where the controversial Roe 8 tollway was proposed.

While we closely evaded that disaster, there are still a number of factors that continue to impact our precious wetlands. Over 90% of Perth’s once ample and abundant wetlands have been lost to agricultural pursuits, urbanisation, and development & infill. Bibra Lake and the surrounds are a reminder of what we’ve lost and what we stand to lose unless we take strong action. Together.

 

Changing wetlands in a changing climate

Our wetlands are dynamic in nature and they transform with changing seasons. Water levels in the wetlands, such as Bibra Lake, rise and fall with rainfall and the seasonal movement of groundwater. Bibra Lake experiences this seasonal flooding and drying, and oftentimes, this leads to alterations in the depth and area of the body of the lake. The transient wetlands are designed to cope, redistributing their animal and plant life in accordance with these changes.

However, with a decrease in rainfall and an increase in human activity surrounding our wetlands, the natural variations are becoming exaggerated. Causing alarming fluctuations in the wetland zonation. Introducing irreversible expansions and contractions of the wetland area.

 

Comparisson of flooded zones of Bibra Lake from 1995 to 2005
Figures depicting altered wetland zonation for Bibra Lake

Looking back, we remember the water levels of Bibra Lake during the 1980’s and 1990’s to be much higher than they are now. Many of us believe that those water levels were “proper”. However, the higher water levels of Bibra Lake at the time were actually an aberration caused by the removal of vegetative cover for the development of surrounding suburbs.

On the other hand, we also see prolonged drying of the wetlands in some years. The reduced rainfall has impacted the recharging of groundwater. And since the groundwater is also our source of drinking water for the Perth metropolitan area, this has caused a further shrinkage of the precious resource.

Bibra Lake has suffered adverse impacts. Usually, maximum water levels were seen around October and minimum levels during April. However, Bibra Lake and North Lake are now breaching these standards. This has significant implications for planting and weed control.

 

Two pictures comparing seasonal water levels of Bibra Lake
Snapshots comparing maximum and minimum seasonal water levels in Bibra Lake

A thorough understanding of these circumstances is essential towards developing a successful restoration program for Bibra Lake. We need to take the variations and on-ground conditions into account, adjusting when and where we weed and plant as we maintain and restore the lake and its surrounds.  The focus as we move forward must be on adaptive management.

We must also accept that we are moving into a period of some uncertainty, with climate change and global/local weather events becoming unpredictable. We may not get this 100% right 100% of the time. But every failure is a learning and a step forward.

 

Weeds and invasive species

Weeds are one of the most pressing problems we face at Bibra Lake, and weed control is an ongoing initiative. Often, the removal of one weed creates space for another. In some cases, it even allows the overgrowth of opportunistic native plants which can pose additional challenges. We see this most starkly in the constant balancing act of Typha control on our lakes. But that is a story for another day…

A combination of manual and chemical control along with mulching and saturation planting has been the most effective method in combating weeds. (Saturation planting is when native vegetation is planted densely and in large numbers so as to saturate and give little scope for invasive species to spread.)

At Bibra Lake, the following have been our findings:

  • Weeds must be actively growing before initiating weed control.
  • The revegetation plan should be in place prior to weed management to make the best use of the weed control efforts.
  • A monthly weed control commitment is required with a plan for the whole year.
  • At The Wetlands Centre, we have developed Seed Production Areas (SPAs) and refined propagation techniques to grow plants in our nursery.
  • The weed biomass in the seasonal zone degrades during one flooding and receding event. Slashing is sometimes required to make the area suitable for planting.
  • Mulching of the lower damp to upper seasonal zone (the weediest zone) with Typha mulch reduced the frequency of weed control.

 

Satelite images of Bibra Lake from 1953 to 2018 showing vegetation cover
Satellite images showing revegetation of Bibra Lake by The Wetlands Centre Cockburn over the years

Invasive species such as feral bees, foxes and cats are also detrimental to our wetlands. The feral cats and foxes prey on vulnerable native animals. Foxes are an introduced species and our lizards, turtles and quenda are especially susceptible since they have not developed any specific defences to stay protected.

 

Runoff and Algal Blooms

Human activity is primarily responsible for the degradation of our wetlands. Our urban developments are placed closer and closer to the wetlands, with little or no buffer. Roads and tracks crisscross the perimeter. And our wetlands are losing their lush cover, that helps protect wildlife from noise, light and other forms of pollution. All this further challenges their survival, exposing our species to danger and disease, and putting them at a risk of endangerment.

This also means that there is a greater impact on how nutrients, sediments and pollutants are naturally filtered by the wetland. The degraded quality of some of the fringing and upland vegetation around Bibra Lake is causing alterations in the water-quality of the catchment. However, Bibra Lake still fairs better than other heavily impacted lakes within the Beeliar Wetlands.

Runoff, whether it is the chemical runoff from roads or the phosphorus, potassium and nitrogen from fertilizers that we use in our gardens, leads to a nutrient explosion, and subsequently, algal blooms. The algae reduce temperature and light penetration in the catchments, suffocating and dominating over aquatic life. The algae also spread rapidly and give off an unpleasant odour as they break down. There is a direct link between the excessive use of garden and horticulture fertilizers and algal blooms in our waterways.

Reducing the use of chemicals in our gardens, keeping our storm drains clear of unwanted litter, conserving water and using it judiciously, and using landscaping practices that benefit wildlife and their habitats – every little step you take can lead to positive outcomes for our lake.

 

Join The Wetlands Centre Cockburn

At ‘The Wetlands Centre Cockburn’, we are fortunate to be located adjacent to the resplendent Bibra Lake, within the Beeliar Regional Park. This places us in an ideal position to lead by example in the care of our natural surroundings. We recognize that we bear a great responsibility to inspire, reinforce and connect, and to work with the community to safeguard and protect this amazing area.

The issues we have highlighted in this article are very real. They are threatening the health of our wonderful lake and its bountiful surrounds. We are working hard to understand and combat these issues while spreading awareness of core problems. Our team of volunteers and staff are dedicated and ever-vigilant.

In working with the land and connecting with its nurturing ways, we have come to cherish it deeply. And we want to share this connection with the greater community. Come, get involved with us. Learn. Plant. Protect. Conserve. And spread the joy.

 

This article is adapted from and based on notes and insights shared by Denise Crosbie, Wetlands Officer, The Wetlands Centre Cockburn.

Wetlands & Water. Rehabilitation & Conservation.

A bird's eye view of a wetland and its evirons

Watching our wetlands transform is an awe-inspiring experience. We may see change with seasons. Or, through circulation of life-giving water and rainfall. The transformation is evident in the way their vegetation thrives, blooms and blossoms. Within the catchments where delicate ecosystems flourish as diverse organisms interact with each other and with the environment. And, in the cacophony of bird and animal sounds that fills the air with every favourable shift.

Water brings out the unique character of our wetlands.

Not all wetlands are waterlogged all the time, some depend on groundwater and others on surface water flows and still others are coastal wetlands that are revived by the seas. They may be seasonally, intermittently or permanently drenched. They may be saline or freshwater. They may be still or flowing. No matter what the nature of the wetland, water plays a central role.

 

Wetlands – A Living System

Wetlands support complex and diverse bionetworks. They shelter and sustain wildlife. Here landforms and soils are created, nutrients are naturally recycled and waterways are filtered and cleaned.

The specialized wetlands vegetation helps in stabilizing the soil, cleaning the water and providing resources and habitat. From upland vegetation – shrubs and trees, to fringing vegetation – sedges, rushes and paperbark trees, and floating and submerged aquatic plant-life – adequate vegetation is fundamental to wetland health.

Leaves or branches that fall from overhanging trees and shrubs are broken down by microbes, bacteria and fungi. These, in turn, become food for larger animals within the food web. And wetlands ecosystems are sustained by the functions of these tiny organisms.

 

Wetlands and Water

Wetlands that see water once every few years, or those that are permanently waterlogged, every wetland ecology is unique. Species of plants and animals have evolved to suit these very specific conditions of dampness, salinity and nutritional availability.

Urban and rural encroachment have posed some serious threats to the wetland ecology.

Paved roads and concrete structures mean that a greater volume of water now finds its way into the wetlands. Road run-off often contains oil, heavy metals and various other substances that leach into the wetlands. Fertilizers, pesticides and chemicals from nearby home gardens or agricultural fields too seep into the groundwater, from where they travel to the wetlands.

Environmental degradation has caused drastic changes in the water cycle. Wetlands now face prolonged inundation or drying and a constant change in the physical, chemical and biological composition of water entering the wetlands. This imbalance adversely impacts native species that are unable to survive or cope. Further, loss of native vegetation has the potential to disrupt and collapse the delicate wetlands food web.

 

Wetlands Rehabilitation

Our wetlands are an important and essential resource. They provide us with a natural filtration system, cleaning our waterways of harmful pollutants, absorbing and trapping carbon in the marshy soil, and replenishing our groundwater and underground aquifers. Wetland plants and animals function to strengthen this delicate link between water and wetlands.

They help regulate the climate. They supply food, fibre, fuel and medicinal plants.

Above and beyond the functions they fulfil, wetlands are a source of great beauty. They are gateways to adventure and for “experiencing nature” away from the hustle and bustle of our cities and suburbs. The abundant life they support – from native species to migratory long-distance travellers. The deep interlinkages and connections, and the balance they restore.

Wetlands rehabilitation is, therefore, the single most crucial calling of our time – revegetation, habitat restoration, conservation and protection. An involved community and teamwork. And spreading awareness about their importance.

 

A water level guage mirrored on a still wetland surface.

Water Conservation

Inland freshwater wetlands provide water to over three billion people around the world.

Without our wetlands, the water in our households, industries and farms would have been unusable.

Water conservation is a vital aspect of wetlands rehabilitation work. It involves using and uncovering innovative wetlands management techniques that help control the quality of water within catchments.

Water Sensitive Urban Design Principles, in the context of urban wetlands, protect the wetlands from urban run-off and degradation. Applying these principles ensures that the infrastructure we create does not impact them unfavourably.

Water conservation is also largely dependent on the native plant and animal species, their distribution and propagation. And on our sustained rehabilitation efforts.

 

Come, Get Involved!

At ‘The Wetlands Centre Cockburn’, here in the heart of the breathtaking Beeliar Regional Park, we are working towards building healthier wetlands for everyone.

We are involved in landcare, conservation and rehabilitation work. We run some exciting educational programs. We are community driven, we have fantastic community outreach. And, we are pioneers in wetlands management.

With a dedicated team of volunteers and staff, and our love for wetlands, we are doing just what it takes. Come join the team and get involved with us today. You can make a difference!