What limits a species life?

[Wolfie]

Just looked at a job and during our chat the guy asked "what causes the tree to died?"

For example, why would a Birch die of old age at 80 but an Oak live on for 900 years?

 

I didn't have an answer.

Can anyone enlighten me?

[se7enthdevil]

genetics i think mate.

 

as you say some trees only live 80-100 years but some can be thousands.

 

i'd guess conditions have a part to play.

[David Humphries]

Man usually limits the life span of a tree

 

 

Have a look at David Lonsdale here talking about trees indefinite growth patterns which in some species could potentially make them immortal.....

 

VETree - Aging processes in trees, a lecture by David Lonsdale in VETree EN on Vimeo

 

 

 

.

[AA Teccie (Paul)]

In that particular instance, Birch is a pioneer species occupying new ground and hence is 'relatively' short-lived, such that it enriches the ground / flora conditions for longer lived species such as Oak etc. Hence., all species have a natural life cycle which contributes to the greater good I guess.

 

Thereafter, others, far more educated than I will hopefully be along to help.

 

Cheers..

Paul

[Wolfie]

In that particular instance, Birch is a pioneer species occupying new ground and hence is 'relatively' short-lived, such that it enriches the ground / flora conditions for longer lived species such as Oak etc. Hence., all species have a natural life cycle which contributes to the greater good I guess.

 

 

 

Thereafter, others, far more educated than I will hopefully be along to help.

 

 

 

Cheers..

 

Paul

 

 

Ah...The Greater Good.

 

[easy-lift guy]

Man and natural selection.

easy-lift guy

[woodyguy]

Sadly there is no such thing as the greater good. Just what has worked on an evolutionary basis for that particular species of tree. So Birch need light and will establish very quickly and grow very fast. Like most such organisms, they die young but produce prolific seed at low cost (cf acorn) so are quickly replaced but in a different place.

An oak takes most of a birch lifecycle to get big enough to fruit. Its seed are expensive and not produced every year. But by being long lived they only need to be successful once every few hundred years for the species to spread.

So different survival strategy between the two species.

[Bren.]

Man and natural selection.

easy-lift guy

I thought that the words Natural and selection weren't to be used together over your side of the pond. Nice to see some of you do.

[Gary Prentice]

What an interesting question.

 

Without researching I'll propose a number of factors.

Species that are prolific in seed production, like birch are generally shorter lived. Defense mechanisms are poorer, with a greater proportion of resources diverted to growth. Slower growing species, like oak, reproduce less prolifically and often have mast years, their wood is more durable to pathogenic attack but growth is slower.

 

The protective/defensive mechanisms that allow longer life are probably absent in quick growers, pollarding birch will lead to decay and demise, do the same to oak and beech and their lives are extended. It's a complex answer, evolution, genetics and sex (reproduction and continuation of the species)

[Bren.]

Hmm, very interesting question.

I think most of the answers so far relate to r/K Selection theory, which does not always correlate to species longevity.

The limiting factor is more likely to be the ability of an organism to repair DNA over its lifespan, some species can do it for longer than others.