The species richness–productivity relationship in the herb layer of European deciduous forests
Article first published online: 19 AUG 2011
© 2011 Blackwell Publishing Ltd
Global Ecology and Biogeography
Volume 21, Issue 6, pages 657–667, June 2012
How to Cite
Axmanová, I., Chytrý, M., Zelený, D., Li, C.-F., Vymazalová, M., Danihelka, J., Horsák, M., Kočí, M., Kubešová, S., Lososová, Z., Otýpková, Z., Tichý, L., Martynenko, V. B., Baisheva, E. Z., Schuster, B. and Diekmann, M. (2012), The species richness–productivity relationship in the herb layer of European deciduous forests. Global Ecology and Biogeography, 21: 657–667. doi: 10.1111/j.1466-8238.2011.00707.x
- Issue published online: 10 MAY 2012
- Article first published online: 19 AUG 2011
- Broad-leaved woodland;
- diversity–productivity relationship;
- herb-layer biomass;
- humped-back model;
- light availability;
- plant community;
- soil pH;
- temperate forest
Aim In contrast to non-forest vegetation, the species richness–productivity (SR-P) relationship in forests still remains insufficiently explored. Several studies have focused on the diversity of the tree layer, but the species richness of temperate deciduous forests is mainly determined by their species-rich herb layer. The factors controlling herb-layer productivity may differ from those affecting tree layers or open herbaceous vegetation, and thus the SR-P relationship and its underlying processes may differ. However, the few relevant studies have reported controversial results. Here we explore the SR-P relationship in the forest herb layer across different areas from oceanic to continental Europe, and put the effect of habitat productivity on species richness into context with other key factors, namely soil pH and light availability.
Location North-western Germany, Czech Republic, Slovakia and southern Urals (Russia).
Methods We measured herb-layer species richness and biomass, soil pH and tree-layer cover in 156 vegetation plots of 100 m2 in deciduous forests. We analysed the SR-P relationship and the relative importance of environmental variables using regression models for particular areas and separate forest types.
Results We found a consistent monotonic increase in the herb-layer species richness with productivity across all study areas and all forest types. Soil pH and light availability also affected species richness, but their relative importance differed among areas.
Main conclusions We suggest that the monotonically increasing SR-P relationship in the forest herb layer results from the fact that herb-layer productivity is limited by canopy shading; competition within the herb layer is therefore not strong enough to exclude many species. This differs fundamentally from open herbaceous vegetation, which is not subject to such productivity limits and consequently exhibits a unimodal SR-P relationship. We present a conceptual model that might explain the differences in the SR-P relationship between the forest herb layer and open herbaceous vegetation.