本篇論文主要探討當物種在不同環境對其生物總量所造成的影響。當一個環境中資源分布差異懸殊時，相對於資源均勻分佈的環境下所能維持的生物總量將會比較大。我們考慮不同種類的異質性環境，估計在何種情況下其生物總量所能達到的最大效益。

In this thesis, a single species logistic model is used to study the heterogeneity eects
to migration. If dispersal is allowed, the population in an environment in which resources
vary spatially will reach a higher total equilibrium biomass than that in an environment in
which the same total resources are distributed homogeneously. We consider several examples
for heterogeneous distribution of resources and give some estimates for the total equilibrium
biomass.

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