A test of McGinley and Charnov's multiple resource pool hypothesis

Summary McGinley and Charnov (1988) propose that seasonal seed weight decline results from optimization of independently varying resource components: in particular, carbon and nitrogen. Canada thistle (Cirsium arvense) (L.) Scop, does not express seasonal seed weight reduction when the number of seeds competing for the plant's resources is reduced by low pollination success. Seeds sampled from thistles treated to high and low pollination regimes were analyzed here for relative investment of carbon and nitrogen. The ratio of these two elements remained constant over the season in both treatment groups. The seasonal decline in mean seed weight displayed by this plant under high pollination is therefore not explainable by McGinley and Charnov's multiple resource pool hypothesis.