By: Sigrid Heise-Pavlov, PhD
Restoration on a Cinder Cone: A Syntropic Story
Written in part by: SFS Professor in Rainforest Ecology, Dr. Sigrid Heise-Pavlov, and Spring 2024 Alumni: Sheila Hulseman, Madelyn Radtke, Eleanor Buchanan, EJ Holm, and Andrew Kim
Over the years, Trees for the Evelyn and Atherton Tablelands (TREAT) has been a source of knowledge on restoration methods and experiences in restoration practices for students and faculty of the Center for Rainforest Studies (CRS) in Australia. By partnering with TREAT, students have had the opportunity to learn about the history of local restoration efforts, as well as standard planting procedures.
In 2022, the Center was approached by local landowners requesting assistance in the restoration of an endangered type of rainforest, the Mabi rainforest, on a cinder cone volcano on their property. Mabi rainforest had been completely removed from this volcano in the 1980’s to use the area for cattle grazing. Today, only about 4.5% of the original extent of this rainforest type is left on the Atherton Tablelands where CRS is located.
Since the landowners are allowing us to restore this rainforest type on approximately 7.5ha, this restoration project will take several years to be completed. Additionally, the project provides the Center with numerous opportunities to do intensive research on Mabi restoration on cinder cone volcanoes since this type of rainforest has never been restored on steep volcanoes.
GETTING STARTED
The restoration project began during the dry season of 2023 with generous financial support from SFS alumni and donors. Contributions allowed the Center to fence off an 1800m2 area from the existing cattle paddock via an electric fence, perform extensive weed control, conduct soil analysis, and collect baseline data for monitoring the development of restoration.
Students from the spring 2024 semester took inspiration from previous student cohorts and TREAT to commence restoring Mabi rainforest on the first plot of the cinder cone during this year’s wet season. This first planting required overcoming some major challenges.
The first challenge arose due to the landowner’s request to not use herbicides as means of weed removal. This required countless weeks of cutting grass manually on this first 60x32m planting plot as grass had grown immensely after the plot was first isolated from the surrounding cattle. Additional donations allowed for the purchase of hedge cutters and other materials to make the work possible. Although a more laborious process, not using herbicides provides added soil benefits and allows students to compare seedling growth on this site with that of seedlings on a similar Mabi site that was treated with RoundUp (glyphosate).
The second challenge was the steep slopes of the cinder cone, which measured to be around 45 degrees in incline in some areas. The steep angle results in a plot of land prone to water runoff and soil erosion. To combat this issue, a decision was made to add a syntropic element to the typical TREAT method of planting. Syntropic farming is a type of regenerative agroforestry developed by farmer and ecologist Ernst Gosch (Götsch, 2018). It involves mimicking natural forests in structure and function, outcompeting grassy weeds while maximizing ground cover and water retention with taller, shade-giving companion plants.
After speaking to a local syntropic farmer, SFS students learned that banana plants are a perfect companion to support seedling growth. They grow fast to provide shade for shade-loving species and hold water in their leaves and trunks—which can be later pruned to create ground cover and natural fertilizer. To test the effect of incorporating syntropic principles into restoration, eight subplots (measuring 11x11m) were created within the first planting plot, with banana plants between the native seedlings in four of the eight subplots and four control subplots without interspersed banana plants. The subplots were arranged in random order to reduce bias from placement on the cinder cone (see Figures 1 & 2).
In each of the eight subplots, holes for native seedlings were placed 1.57m apart, creating a 6×6 grid.
Dead grass and roots had to be removed from the drill spots using hoes to allow for digging holes with an auger (see Figure 3).
In early April 2023, SFS students and faculty picked up banana plants from ‘Petals in the Park,’ a syntropic permaculture farm on the Atherton Tablelands. Digging out banana saplings was an interesting task for the students—large banana trees have many saplings around them which needed to be dug up and tops cut off. Students learned interesting tips for planting, including banana saplings are best planted upside down! When placed upside down, they grow like a hook before appearing above the ground. This method improves root stability, which is especially important when planting at a windy site (and the cinder cone is indeed windy!).
The next stop was Lake Eacham Nursery to pick up 288 native seedlings, complements of TREAT and Queensland’s Park and Wildlife Service (QPWS). Nursery staff and volunteers from the community had prepared the seedlings and gave us advice on how to prepare them overnight for their “birthday” the next day.
On planting day, students and faculty transported the 288 native seedlings, 100 banana saplings, buckets with water crystals, and 25kg of fertilizer to the cinder cone and distributed everything to the previously created planting holes. Later that morning, additional SFS students arrived to help plant the seedlings into the holes that had been prepared (see Figures 4, 5 & 6). No lesson or bit of advice was cast aside, as banana saplings were planted upside down between the native seedlings for optimal growth.
Students planting seedlings on the first planting plot of the cinder cone on April 10, 2024
Future SFS Australia students will monitor the growth of seedlings to compare their growth between subplots with and without banana plants. For this purpose, students and faculty measured every seedling that was planted. Each subplot has the same Mabi seedling species composition (nine species in total) with four stems of each species making that comparison possible. Surveys were also completed of ants and dung beetles, as well as soil samples, to provide baseline data to monitor changes of these attributes while native Mabi rainforest slowly establishes.
PROTECTING THE “GREEN BABIES” FROM EXTREME WEATHER CONDITIONS
As the tropical winter emerged (June to August), night time temperatures can drop considerably due to the higher elevation of the Atherton Tablelands, raising concerns of frost affecting the seedlings. This was a worry since the seedlings were fully exposed to the elements. But, although the Atherton Tablelands experienced two nights of frost in August 2024, we were lucky as no seedling showed signs of frost impact; some only showed some black spots at the lower leaves which were attributed to lasting wet conditions during the winter (Figure 7). The fact that our seedlings were not affected by these frost events was mainly due to the slight elevation of our planted plot on the cinder cone, as frost is mainly located in lower areas. To protect the seedlings from further frost impacts, mulch was added by utilizing the cut grass that accumulated from weed control, which was packed around each seedling.
Dry seasons in the Wet Tropics can be just as severe and dramatically reduce the survival rate of the seedlings. With the upcoming dry season approaching (which is usually from September to December), the next priority became the transportation of water to the planted area at the cinder cone. QPWS provided two 300-liter water tanks and a pump to the Center, while a volunteer from TREAT donated a 1,000-liter trough to the project. The next cohort of SFS students transported the trough to the fenced-off area to be filled with water as a temporary watering source.
During the first summer semester, students collected water from the trough by buckets to be carried uphill and distributed equal amounts of water to each seedling using measuring cups. Providing equal amounts of water to each seedling is particularly important to the experiment as we want to monitor the growth of seedlings under different conditions (with and without bananas), not due to different amounts of water the seedlings received.
In the meantime, a proper irrigation system was being developed with input from QPWS to utilize two 1,000-liter water pods that were secured by the landowners.
For this to happen, the two water pods had to be transported and placed in the top center of the planted area and connected with a pump on the owner’s property that retrieved water from their well (approximately 1,000 meters away). Water could then be pumped to the water pods and gravity could be used to drain water from them to the seedlings via small hoses.
In July, students from the second summer semester worked amongst the cattle to prepare the area for the pods before moving them in place, which was no small task—each weighed 60kg! (Figures 8 – 13)
Figures 8 – 13: Site preparation for the water pods; water pod transportation and installation in top center of planted plot.
At the end of July, the Center was awarded an environmental grant from the Tablelands Regional Council to purchase material for the remaining irrigation system. This included two 500m long rolls of thick pipes. Their size and material thickness were chosen to protect them from being damaged by cattle, while also allowing water under considerable pressure to be pumped up the hill to the water pods. (Figures 14 & 15)
Connecting water pods with the pressure pump near the landowners via strong pipes.
In early October, the seedlings required additional watering to combat the effects of Australia’s harsh dry season (Figure 16). Each seedling received three liters of water using the installed irrigation system for the first time.
PROJECT PLANS
This project is not only benefiting the local environment, but it is serving as an ongoing research opportunity for SFS. The project will continue over the several years. SFS plans to restore this Mabi-type rainforest on 75,000m2 of this cinder cone. During each wet season, students will plant another area by including research questions. Each year, we will pick another research question so that, over the years, we understand how to better restore Mabi rainforest on a steep cinder cone volcano. During our summer sessions and the dry semesters students will carefully monitor the progress of seedling growth to answer the research questions.
SFS is seeking additional support to ensure the survival and growth of the seedlings, and fence off a new, much steeper area to continue restoration in the coming year (see Figures 17 & 18 with elevation profile). Your donation can make a significant impact by providing essential resources for students to further develop and track the progress of the restoration.
REFERENCE
Götsch, E. (2018). Differences between organic and syntropic farming – Agenda Gotsch. Agendagotsch.com. Available at: https://agendagotsch.com/en/diferencas-entre-a-agricultura-sintropica-e-organica-2/
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