Pella Tomlinson model

In the Schaefer production model, the production curve is symmetrical about BMsY. In the Pella-Tomlinson (generalized) production model, the production curve may be symmetrical or skewed in either direction (Figure 5). Fletcher's form of that model replaces eqn [36] with dBt Bt

where m is MSY, n determines the shape of the production curve, and 7 is a function of n:

At n = 1, where eqn [41] has a removable singularity, the Pella-Tomlinson model is known as the Fox model. At n = 2, it is the Schaefer model.

In the Pella-Tomlinson model, yield (the analog to eqn [39]) must be solved by numerical approximation, as no analytical solution to the corresponding catch equation is known. The parametrization of eqn [40] does not include r, because when n < 1, r is infinite, implying an extremely resilient population. The consequences of that theoretical property in modeling actual populations is unknown.

Oplan Termites

Oplan Termites

You Might Start Missing Your Termites After Kickin'em Out. After All, They Have Been Your Roommates For Quite A While. Enraged With How The Termites Have Eaten Up Your Antique Furniture? Can't Wait To Have Them Exterminated Completely From The Face Of The Earth? Fret Not. We Will Tell You How To Get Rid Of Them From Your House At Least. If Not From The Face The Earth.

Get My Free Ebook


Post a comment