The Ancient Resilience of Trees

In aged woods you lie,
bodies bent
with wind
and rot
and time.
Withered roots
entwine the soil,
labyrinths of memories
that bind you to your past
and future selves.
Cracked and suppurated skin
bear the scars of your survival,
as gnarled, arthritic limbs
weave hardy histories
to share.
Supple secrets
whispered willingly,
until their boughs
can sing no more.

This poem is inspired by recent research, which has found that ancient trees are essential for forest survival.

Old and ancient trees are those trees that are many times older than the average individual age of a forest. The importance of such trees in forested ecosystems has been previously shown to be extremely diverse, ranging from providing long-term habitats for endangered species to sequestering large amounts of carbon from the atmosphere. However, despite the essential role that these trees provide, there remains in general a poor understanding of tree age structure in forested ecosystems. In part this is because the longevity of such trees means that they outlive even the most long-term scientific study, while there are also several difficulties in the actual methods that are used to perform the dating processes themselves. For example, among tropical tree species in seasonal climates, growth rings are not as tightly linked to annual cycles as they are in other regions, making such readings difficult to interpret. As such, the most reliable methods require complex, time-consuming studies, that are rarely performed over an entire forest or population of trees.

In this new study, researchers used a model based on observed mortality rates to obtain the age distribution for a large number of old and ancient trees in different forested ecosystems. These modelled results were then found to closely match other results that had been obtained from reliable observational studies. As well as helping to better determine the proportion of trees that reach large ages (for example, one quarter of tress were found to reach ages that are three to four times greater than the median age), this research also helped to clarify how old and ancient trees help to sustain the entire population of a forest’s ability to adapt to a rapidly changing environment. These trees have survived a large number of environmental changes over hundreds or thousands of years, and in turn, this genetic resilience is passed on to the forest, thereby helping to make it more resilient. Given that old and ancient trees cannot be replaced through restoration or regeneration for many centuries, it is essential that they are protected to preserve their invaluable diversity and benefits to the forests that they inhabit.