Using drones to aid the recovery of Native Grasslands
BACKGROUND
The long stretches of grasslands we typically see on our road trips contains an extraordinary number of diverse native species. Hidden in plain sight, Victoria's temperate grasslands of southeastern Australia contain many wildflowers that grow between the tussocks of grasses.
Source: Greening Australia
Native grasslands are defined by the presence of native grasses, where trees are found in few numbers or completely absent.
In Victoria, the volcanic plains that stretch from Melbourn to Hamilton contain a rich ecosystem that is now reemerging to be of incredibly cultural and ecological significance.
Viewed from a European colonialism perspective from the 20th century, the native grasslands posed a vast opportunity for agriculture and grazing oppportunity.
Now, we see the devasting impacts of this sweeping viewpoint. Overgrazing, use of fertilization, and lack of burning off have led to notable degradation of the native grasslands ecosystem. Recently the urban sprawl has rapidly crept into the undulating western native grasslands leading to a staggering figure - less than 1% of native grasslands of their original context in the Victorian volcanic plain exist according to a paper titled “Vegetation of the Victorian Volcanic Plain”
Currently. Victoria’s grasslands face major challenges in maintaining the patches that already exist. Threats including urbanization, weed invasion, and broad-scale use of herbicides and fertilizers continue to threaten the important ecosystem. Now, these grasslands can only be found nestled within agricultural and urban landscapes.
An important tool of defense is the use of regular burning off to allow for the wildflowers to have an opportunity to grow within the density of the native and non-native grasses. However, due to complicated public relations problems, regular burning off is difficult to tackle against the current agricultural landholders.
Stripping the soil. Source: John Delpratt
Result of the stripped soil source: John Delpratt
Luckily, there are those organizations and people who are incredibly dedicated to protecting these overlooked ecosystems to ensure the health of the grasslands and the living creatures within them.
PROJECT
Specifically, XM2 EARTH had the opportunity to meet John Delpratt, who is an honorary fellow with the University of Melbourne and conducts work with Woorndoo Chatsworth Landcare Group. His involvement focuses on the cultivation and seed production system for grassland forms. In recent times, he focuses his attention on the reconstruction and management of diverse native grassland communities both for ecological and horticultural applications.
The XM2 EARTH team was sent to the Woorndoo district. The district supports very high-quality remnants of nationally significant temperate natural grasslands. XM2 EARTH conducted an NDVI and photogrammetry scan.
The objective was
Comparision of photogrammetry scan with Google Maps
Better visualisation for the defined area for needed revegetation work.
Calculate the biomass levels when preparing the strip of the land.
Give the contractor on the stripping machinery precise information to work within.
3D Model of Native grasslands for client: John Delpratt
METHOD
We used the DJI Phantom 4 RTK with an RTK base station. We set a grid mission and conducted the mission. The 3-hour mission. One of the requests from John was to determine if we can observe the wildflower species from the aerial scan. From our scan, the orthomosaic resolution was 0.9 cm/px, which allowed us to zoom in and show detailed differentiation of native grasslands.
An orthomosaic is many aerial images taken by a UAV stitched together that created a highly detailed, distortion-free map. It provides the end-user with incredible visibility that cannot be shown from satellite imagery and precision measuring services that are accurate within a few centimeters.
Our goal is to conduct many scans of the same site to see patterns of the patches of native grasslands which gives the opportunity for more potential funding.
Annotated issues for the site using orthomosaic native grasslands model
Mapping tools for contractor to showcase native grasslands to protect.
Plant health index on the stretch of native grasslands, near Hamilton, Victoria.
Detailed imagery of orthomosaic, able to detect species of native grasslands
XM2 EARTH acknowledges the Gunditjmara land that stretches south to the coast, the Tjapwurong land to the northeast and the Bunganditj territory which spreads west into South Australia.