​​Roy Leggitt, owner of Tree Management Experts and arborist for over 30 years, volunteered his time to addresses consequences that could occur if the leather industry was forced to switch to vegetable tanning.

Q: What natural materials are required for vegetable tanning?

A: [Roy Leggitt] It is my understanding that 30 kg bark, 20kg fruit (acorns) or 90 kg oak wood are required to tan one hide.

Q: In 2011, 1.8 billion sq. meters of leather were produced annually. How many oak trees are needed if the industry switched to vegetable tanning?

A: Over 700 million oak trees. It would require approximately two 10- or 12-year-old oak trees of most larger species, if those trees were grown in an open setting, to produce enough biomass to tan one hide.

Q: Based on the quantity of oak trees required for “vegetable tanning,” is it a good use of natural resources?

A: Absolutely not. Oak woodlands in a native landscape provide valuable and irreplaceable resources for environmental health and habitat. To deforest a native oak woodland anywhere oaks are found would be incredibly damaging and would strip the landscape of an irreplaceable resource.

Q: Are you aware of prior examples of where vegetable tanning caused deforestation?

A: Yes. California was historically a Spanish territory that had extensive cattle ranching. Much of the revenue during that time was derived from cattle hides and many areas were deforested and stripped of their oak trees for tanning leather.

Oak woodlands are under constant threat from introduced diseases, climate change, development pressure and expanding agriculture. This added impact on oak survival would be potentially catastrophic to whole ecosystems.

Q: What impact would this have on the environment?

A: Oaks sequester carbon for up to several hundred years (their potential lifespan) and, during that time, provide many environmental benefits. There are whole ecosystems that depend on oak woodlands and that includes the many animal species and birds that rely on oaks for survival.

For this to be a sustainable practice, trees would need to be grown as an agricultural crop. This would displace resources for growing food and would put strain on natural resources such as water, soil resources and available agricultural land. Oaks tend to be very long-lived trees and harvesting a crop of young trees would eliminate most benefits normally provided by trees that only become significant as they mature.

Q: Could vegetable tanning further climate change and global warming effects?

A: Absolutely. The need to either deforest oak woodlands or convert agricultural land into oak production would place a significant strain on the environment. Cyclical short-term harvesting of oaks interrupts the carbon sequestration and releases the carbon back into our environment. These harvested oaks would no longer be sequestering carbon like they would normally do and that carbon would be a contributor to global warming and climate change.

CONTACT: treemanagementexperts.blogspot.com