The Comparative Biology of Closely Related Species: VI. ANALYSIS OF THE GROWTH OFTRIFOLIUM REPENSANDT. FRAGIFERUMIN PURE AND MIXED POPULATIONS

Abstract

An analysis was made of the first season's growth of pure and mixed stands of Trifolium repens and T. fragiferum. T. repens, although having smaller seeds and cotyledon area, achieved a faster early rate of leaf production than T. fragiferum and quickly developed a larger area of leaf both in pure stands and in mixtures. By the 18th and 21st weeks from sowing, T. fragiferum had more elongated petioles than T. repens, leaves were borne higher in the canopy and contributed an increasing part to the Leaf Area Index of mixtures. The increase in leaf area of swards with time was largely associated with increased area of individual leaves. The differences between species were largely due to differences in number of leaves. These results are discussed in relation to the conditions under which stable associations of species may be formed.