Summary
-
1.
A study was designed to investigate the effects of intra and inter-specific competition on the productivity of single and multi-species stands of plants normally dominant in first year old-field communities of mid-Michigan. The four species used were Amaranthus retroflexus, Chenopodium album, Panicum capillare and Setaria viridis.
-
2.
Specifically, we tested (1) the relationship between diversity and productivity, (2) the effect of arrangement (pattern) of individuals within an array of old-field dominants on yield and (3) the expression of dominance and resultant allocation of yields within mixture arrays of different plant species. In direct contrast to many earlier studies, our experiments were completed in the field under natural conditions.
-
3.
Mean yield of the highest yielding monoculture, Amaranthus, was greater than any of the yields of the mixture plots.
-
4.
Changing the pattern within mixtures had no significant effect on the yields of the mixture plots. Distribution of biomass among the component species followed a geometric pattern similar to that predicted by the niche pre-emption hypothesis (Whittaker, 1965, 1969). Using yield as a criterion, dominance was clearly expressed in the mixture plots. Amaranthus contributed more than 50% of the yield in all of the mixture plots.
-
5.
A relative competitive ability index (RCA) was developed to demonstrate more clearly the intra and interspecific relationships among the species in mixture plots and to “equalize” the inherent weight differential among species. Relative Competitive Ability, from highest to lowest, was Amaranthus, Chenopodium, Setaria and Panicum.
-
6.
The paired species experiment demonstrated that the performance of species in multi-species arrays cannot be predicted from paired competition experiments.
-
7.
In the diversity-yield experiment and the paired-species competitive ability experiment, dicotyledons were clearly superior to monocotyledons.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bornkamm, R.: Competition for light in arable plants (German text). Flora Jene 151, 126–143 (1961)
Goodall, D.W.: Quantitative effects of intraspecific competition: An experiment with mangolds. Bull. Res. Coun. of Israel Sec. D. Botany 8, 181–194 (1960)
Haizel, K.A.: The productivity of mixtures of two and three species. J. Appl. Ecol. 9, 601–608 (1972)
Harper, J.L.: Approaches to the study of plant competition. Mechanisms in Biological Competition (F.L. Milthorpe ed.), pp. 1–39. London: Oxford Univ. Press (1961)
Harper, J.L.: The individual in the population. J. Ecol. (Suppl.) 52, 149–158 (1964)
Sakai, K.: Competition in plants and its relation to selection. Cold Spring Harbor Symp. Quant. Biol. 20, 137–157 (1955)
Stephenson, S.N.: A comparison of productivity and diversity in early and late season old-field communities. Mich. Acad. 5(3), 325–334 (1973)
Whittaker, R.H.: Dominance and diversity in land plant communities. Science 147, 250–260 (1965)
Whittaker, R.H.: “Evolution of diversity in plant communities.” Diversity and Stability in Ecological Systems, Brookhaven Symposia in Biology 22, 178–260 (1969)
Whittaker, R.H.: (1970): Communities and Ecosystems. pp 162. Macmillan, London
Whittington, W.J., O'Brian, T.A.: A comparison of yields from plots sown with a single species or a mixture of grass species. J. Appl. Ecol. 5, 209–213 (1968)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kroh, G.C., Stephenson, S.N. Effects of diversity and pattern on relative yields of four michigan first year fallow field plant species. Oecologia 45, 366–371 (1980). https://doi.org/10.1007/BF00540207
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00540207