By Eric Ralls
A decade-long investigation suggests that the diversity of tree species planted in forests can significantly contribute to their survival, according to the latest findings from the Smithsonian Environmental Research Center (SERC) and The Nature Conservancy.
These organizations embarked on a monumental study, BiodiversiTREE, which was conceived as a century-long exploration of the impacts of various tree planting strategies on sapling survival and the broader ecosystem.
Nature’s own design features forests brimming with diverse species. This biological assortment confers several advantages, including a built-in resistance to pests and diseases, the resilience to adapt to changing climates, and the creation of an expansive habitat for wildlife.
But this truth is often overlooked, as many forest plantations and restoration projects resort to monocultures – planting a single species on a given tract of land.
Such an approach leaves forests, managed or otherwise, susceptible to shifting conditions, placing their ecological and economic stability at risk. Monocultures also harbor a heightened risk of planting failures, leading to early sapling death.
Biodiversity is a well-established catalyst for healthier ecosystems, as evidenced by hundreds of scientific studies. This fact hints at the potential for greater tree survival rates when diversity is included in the planting process.
Until BiodiversiTREE, few tests of this theory involving trees were conducted. Scientists constructed this project to examine the influence of tree diversity on the ecosystem function, setting a new record as the most extensive study of its kind in North America.
A decade ago, a team of scientists and volunteers planted 20,000 saplings on former farmland near Chesapeake Bay to establish BiodiversiTREE. They opted for varying levels of species diversity, ranging from single-species sections to plots with four or twelve different species.
Throughout the years, around 8,000 trees in the project have been monitored, first annually for three years, then every two to three years following that.