Determining the type of relationship between plants and environment factors

[First paragraph...]
Plant growth is probably controlled by a combination of all environmental factors. But in particular situations some factors will exert greater influence than others. so that, for practical purposes, it is unnecessary to consider all factors in attempting to predict plant growth. The interaction between plant and environment could be one ofseveral types:
(a) the major aspect of growth is influenced by a single factor,
(b) growth is influenced by a few factors and each is of similar importance,
(c) a few factors influence growth but the importance of each is different, and
(d) growth is influenced by a multitude of factors and the effect of each is different.
I believe it is possible to determine which of these various alternatives applies by using the results of a step-wise multiple regression analysis involving plant response and measurements of many environmental factors. The method is explained and examples given from earlier work on the relationship between measurements of standing crop and 55 environmental factors on 50 sites in a Wyoming alpine tundra (Scott and Billings 1964).