(Photo by Matthias Oben via Pexels)
By Stephen Beech
Avocado may be permanently off the menu if native vegetation doesn't survive alongside crops, warns a new study.
Avocado trees are native to Mexico and Central America, but are now grown in many other parts of the world, including Australia.
Now, scientists Down Under have found that the future of avocado crops might depend on patches of native vegetation preserved alongside farmland.
The study, published in the journal Environmental and Sustainability Indicators, revealed the hidden role of the habitats in supporting the insects that keep crops - and brunch menus - thriving.
The Curtin University research team found that insect communities in avocado orchards next to native remnant vegetation foraged on more than twice as many plant species at times when crop flowering was limited, compared to those in orchards bordered by pasture.
They explained that insects with more diverse food sources are more likely to survive and pollinate crops, so their findings offer a potential clue to safeguarding global food security.
(Photo by Manoel Jaus via Pexels)
It is estimated that up to 10 billion people around the world will require access to safe and nutritious food by 2050, meaning agricultural productivity will need to increase by as much as 75%.
Lead author Dr. Joshua Kestel, who completed the research as part of his PhD at Curtin, says the study was "particularly compelling" because it had been traditionally difficult to quantify the diversity of pollen collected by entire insect communities, especially across vast agricultural landscapes.
He said: “Using a novel method pioneered at Curtin University, we applied a cutting-edge biodiversity assessment technique - environmental DNA (eDNA) metabarcoding - to pan traps to identify the diversity of pollen transported by entire insect communities collected during sampling.
“This approach allowed us to demonstrate that natural vegetation adjacent to orchards may enhance the resilience of insect communities, potentially contributing to greater food security.”
Joshua Kestel (centre) with field work volunteers William Thomas (right) and Lily Whelehan (left). (Curtin University via SWNS)
Co-author Professor Paul Nevill, from Curtin’s School of Molecular and Life Sciences, said the research was significant because insects pollinate 75% of all agricultural crops, yet many face extinction.
He said: “In order to meet the food needs of the planet, diverse and healthy insect communities play a critical role in supporting essential ecosystem services such as pollination and the biological control of pests.
“In Australia alone, an estimated 320,000 insect species exist, yet only 35% have been formally identified - and the plant resources many of them rely on remain largely unknown."
Avocado orchards were sampled in the Pemberton-Manjimup region of WA adjacent to either pasture or natural vegetation. (Curtin University via SWNS)
He added: “By using sophisticated eDNA metabarcoding capable of detecting the trace of a single grain of pollen or even the footprint of a bee, we’re helping to close these knowledge gaps and better understand how these insects might contribute to safeguarding global food security.”
The researchers collected more than 2,000 insect specimens and identified more than 250 plant taxa from eDNA, including crops, weeds and native Australian flora.
The team recommended incorporating standardised biodiversity surveys into regular farm monitoring, protecting ecosystems by recognising the value of natural vegetation and revegetating uncultivated land within orchards.
