Probably density-independent factors are more important at the edge of the range of a species . 可能,在某物種的分布區(qū)的邊緣,非密度制約因素最為重要。
Density - independent factor 密度無關(guān)因子
In order to understand the nature of the ecologist ' s investigation , we may think of the density - dependent effects on growth parameters as the “ signal ” ecologists are trying to isolate andinterpret , one that tends to make the population increase from relatively low values or decrease from relatively high ones , while the density - independent effects act to produce “ noise ” in the population dynamics 為了能理解生態(tài)學(xué)家們所從事的研究的性質(zhì),我們可以把那些作用于增長(zhǎng)參數(shù)的密度依賴效應(yīng)視作生態(tài)學(xué)家們力圖將其分離并予以解釋的“信號(hào)” ,正是這一信號(hào)傾向于使種群從相對(duì)較低的數(shù)值遞增,或從相對(duì)較高的數(shù)值遞減;而與此同時(shí),那些密度獨(dú)立效應(yīng)起到的作用則構(gòu)成了種群動(dòng)態(tài)變化中的“噪音” 。