Member of Vengerberg Vaenor Laralis tackles the problems of immortal beings versus the long-lived species on the Material Plane. Per his definition, there are very few actually immortal beings in the world. One of his most controversial theses is that not even deities are truly immortal, since evidence suggests that they can be killed.
I will not go as far in my proposition. For the purposes of this article, I will define longevity as any age span longer than a human's and immortality as indefinite existence outside of a violent death.
On Elven Customs and Traditions
More details on Elven traditions can be found in my main works, so in keeping this article accessible to those who are not familiar with my books, I will keep this short.
Elven people on Andrathis, so called Tel'Quessir, place an enormous value on the protection and regrowth of the Arvandor, the forest homeland that forms their empire. They react harshly to anyone treating it with disrespect and are generally wary of outsiders until they have proven to be considerate and accepting of their customs concerning the forest and its inhabitants. Many of their festivities are centered around the Arvandor or involve it in some degree. Their everyday lives are structured with their ancestral homeland in mind. Most of their customs simply would not work without their connection to the Arvandor and its special assets
On the other hand, the Fhaorn I have encountered in Akzidia and other places seem purposefully disconnected from most of their ancestors traditions. For a long time, I blamed this on rebellious acts, but with my new theory in mind, this deliberate separation from age-old cultures I propose a different reason.
Understanding Origins: Elves and the Age of Arkana
Almost all of the scarce information we have on the Age of Arkana comes from the Elves. There are still records detailing their exile into the Feywild and the changes they underwent there, as well as - even more rare - accounts of life before the destruction. From these accounts, we know that during the Age of Arkana, magic was almost limitless, available everywhere at a strenght almost inconceivable even to its contemporaries.
We also know that many Elves lived to almost a thousand years during this time. Elven legends and stories, most notably The Song of Dusk and Dawn, adress these extremely long-lived individuals in a way that suggests their historical significance. In modern times, magic has become far less available, leaving only few truly magical enclaves in the world. One of those is the Arvandor, with a high density of leylines and quite a few clusters in its territory.
Magic and Age
I want to suggest the possibility of a correlation between the availability and prevalence of magical energies and longevity in a species, especially Elves and Dragons.
Albeit the historical records are few, there are most definitely accounts of seemingly immortal Elves throughout history. This is a fact. I reject the notion that these records are merely fictional - for a good reason.
Fhaorn are somteimes Elven, just like Tel'Quessir. Unlike the Elves we are used to, however, they live merely two hundred to three hundred years where Tel'Quessir can reach up to five hundred. Even stranger is the run-in I had with a young elf from Var Calashiel who insisted on spending at least one month every year in the Arvandor. He told me that the longer he was away from home, the more tired and irritable he felt. According to him, visiting his homeland did not just fill him with joy for memories sake, but actually invigorated him.
Obviously, this is only one story, and unfortunately I do not have time to back up my claims right now. Further investigations will need to be made, especially in regards to the question whether it is actually the Arvandor that gives Elves their longevity or if any leyline cluster could work.
It seems obvious to me that the Arvandor, in some way, contributes to the long-lived Elves we know. Prolonged absence apparently quickens the aging process. Fhaorn might reject the Elven traditions at least in part because of the longevities insignificance in their lives.