Possibly the most widely used term in ecology, stress (a special, extreme form of limitation), is often used in a very misleading way. Note:

• What is stressful to humans is not necessarily stressful for other organisms (the anthropocentric bias).

• What is too stressful to some wild organisms, opens life conditions for others, although these conditions may be far from those permitting maximum growth rates (the optimality bias).

• A relief from what is considered stressful, commonly leads to the extinction of those suspected of having suffered from stress, mostly because of competitive exclusion.

Remember:

• Only those which are not fit are stressed.

• Evolution selects for fitness.

• Old succession communities which have passed the sieve of evolutionary selection hardly ever experience fatal stress conditions.

1 - Moving Ranunculus glacialis from the "harsh" alpine environment to the "mild" lowland life conditions will kill Ranunculus glacialis. No lowland botanical garden therefore exhibits exclusive high alpine taxa, (1) because they cannot survive the lowland "stress" or (2) because they will be overgrown by others.

2 - Ranunculus glacialis in midsummer at 3150 m

29 August 2011
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