The only way is up: Trees help reptiles thrive

James Cook University researchers in Queensland say if graziers leave trees in place on their land all types of reptiles will benefit.

JCU's Heather Neilly was part of a team that looked at the effect of cattle on ground-dwelling lizards and snakes—as opposed to tree-dwelling species.

She says the difference in well-being was marked.

"We looked at four different types of paddock near Townsville, all with different approaches to stock levels. We found that ground-based reptiles in paddocks with high numbers of cattle were heavily impacted by grazing. However, tree-dwelling reptiles were able to thrive in all of the grazing treatments, including the heavily stocked paddocks."

She said the benefits of trees extend beyond just the tree-dwelling reptiles, with more tree cover improving the prospects for ground-dwelling reptiles too.

"They often like woody debris, leaf litter and fallen logs, which further emphasises the importance of trees to ground features and the importance of retaining trees in grazed environments," she said.

Ms Neilly said it was common practice to clear trees from grazing land but the key to the reptiles' survival at the study site was that trees were left in place.

She said any significant change to the environment brought costs and benefits to different species, but there was one universal management practice that came out of the study.

"If you want to increase or keep the current number of native animals on your farm it's best to graze with conservative stocking rates and retain standing trees and woody debris."

Ms Neilly said 25% of the Earth's land surface is grazed by domestic livestock, so it was important to understand how this land use affects native wildlife.

She said native wildlife play an important role in maintaining functioning ecosystems—through pollination, seed dispersal, eating insect pests and maintaining soil health.