Positive effects of tree species diversity on litterfall quantity and quality along a secondary successional chronosequence in a subtropical forest
Created at: 2016-11-03
Envisaged journal: Journal of Plant Ecology
Envisaged date: 2016-11-03
Litterfall, as the link between aboveground and belowground processes, plays a key role in forest ecosystems. Here, we test for effects of species richness on litterfall production and litter quality. The study encompasses a factorial gradient of secondary succession that resulted from human exploitation. Given that a large percentage of subtropical forests are in secondary successional stages, understanding the role of biodiversity in forest growth after disturbance appears critical.
We monitored leaf litterfall in 27 Comparative Study Plots (CSPs) that spanned a gradient of species richness (3 – 21 species) and secondary successional ages (~ 20 – 120 years) from January 2009 to December 2014 at the BEF-China platform in Gutianshan, Zhejiang Province, China. Monthly leaf litters were separated into leaf and non-leaf components, and sorted to dominant species. C and N contents of leaf litter were analysed each month for one year at community level. Generalized linear mixed-effects models were applied to test for effects of tree species diversity and successional stage on litter quantity and C/N ratio.
Diversity had a strong positive effect on litterfall production and leaf litter quality along the successional stages investigated.
1) Litterfall production increased with species richness among and within successional stage each year. Successional stage increased litterfall production through higher species richness. However, species richness did not change the temporal stability of litterfall among different months.
2) Increasing canopy species richness increased leaf litter quality (decreased C/N ratio), while successional stage had no effect on leaf C/N ratio.
Our study indicates that high litterfall production and high leaf litter quality could be the main drivers of the positive effects of tree diversity on forest growth.
No datasets are linked to this paperproposal.