Mechanisms shaping plant biomass and species richness: plant strategies and litter effect in alkali and loess grasslands
Article first published online: 27 DEC 2012
© 2012 International Association for Vegetation Science
Journal of Vegetation Science
Volume 24, Issue 6, pages 1195–1203, November 2013
How to Cite
Kelemen, A., Török, P., Valkó, O., Miglécz, T., Tóthmérész, B. (2013), Mechanisms shaping plant biomass and species richness: plant strategies and litter effect in alkali and loess grasslands. Journal of Vegetation Science, 24: 1195–1203. doi: 10.1111/jvs.12027
- Issue published online: 7 OCT 2013
- Article first published online: 27 DEC 2012
- Manuscript Accepted: 31 OCT 2012
- Manuscript Received: 22 FEB 2012
- Bolyai János Research Scholarship of the Hungarian Academy of Sciences
- Hungarian Scientific Research Fund . Grant Numbers: OTKA, PD 100192
- Alkali landscape;
- C-S-R strategies;
- Plant trait;
Explaining the biomass–species richness relationship is key to understanding vegetation dynamics. Several possible mechanisms have been suggested, but complex analysis of plant strategies, major biomass and species richness components along a long productivity gradient is still lacking. We provide a detailed analysis of the relationship between major biomass components (total above-ground biomass, green biomass and litter), plant strategies and species richness along a long gradient of alkali and loess grasslands in a steppe landscape in Central Europe.
Hortobágy, Great Hungarian Plain, East Hungary.
Above-ground biomass of characteristic alkali and loess grassland stands was sampled along a gradient of increasing productivity. In each grassland stand, a 25-m2 sample site was randomly selected. Within each site, ten above-ground biomass samples (20 × 20 cm) were collected randomly in June 2009, at the peak of biomass production. We classified all species into mixed C-S-R strategy types. To obtain correlations between various biomass and species richness data, Spearman rank correlation was used. The relationship between plant strategies and species composition were displayed with a DCA ordination.
The frequently detected humped-back relationship was valid for the relation of total biomass and species richness. With increasing amount of total biomass, we detected an increasing proportion of competitors, and a decreasing proportion of stress tolerators in green biomass. A low proportion of ruderals was detected at both low and high biomass levels. Species richness was affected positively by litter at low litter scores, but there was a negative litter effect from much lower scores than detected previously (from 400 g·m−2). There was a positive relationship between green biomass production and species richness.
The study revealed that at the initial part of a productivity gradient, stress is likely responsible for low species richness. Our results show that litter can shape changes in species richness along the whole biomass gradient, thus the litter effect is one of the major mechanisms structuring grassland diversity.