Speaker
Description
During times of unprecedented biodiversity loss, understanding biodiversity ecosystem-functioning (BEF) relationships is essential to mitigate the consequences. One well-established observation is that the effect of biodiversity on ecosystem functions strengthens over time. A proposed explanation for this pattern is the increase of trait dissimilarity between co-occuring species, which results in more complementary utilisation of resources and thus, less competition. Another process that can determine species growth and coexistence, and hence ecosystem functioning, is facilitation. Increasing facilitation between species over time is another potential reason for strengthening BEF relationships. To test their relative importance, we zoom in on individual tree pairs in the large-scale tree diversity experiment “BEF-China” and assess how facilitative and competitive inter-specific as well as intra-specific pairwise interactions change over time.
We applied Bayesian statistical modelling on tree growth data spanning seven years and partitioned individual tree growth into intrinsic growth and its pairwise interactions with neighbouring trees.
Our results reveal that, over time, intra-specific interactions (predominant in low diversity plots) become more negative, while facilitative and competitive inter-specific interactions (predominant in high biodiversity plots) become marginally more positive or more negative, respectively. This result hints at a strengthening diversity effect on biomass growth as the difference between inter- and intra-specific interactions increases. However, when simulating biomass growth, we find that the temporal pattern of these interaction strengths is not the driving force behind the steepening of the diversity effect, as perturbing it produces similar results. Instead, the overall more positive inter-specific interactions yield more biomass in plots with species mixtures, which in return produce more biomass in a positive feedback loop.
With this study, we provide insights into the temporal dynamics of tree-tree interactions and elucidate the mechanisms underlying the steepening of diversity effects on productivity over time.
| Status Group | Doctoral Researcher |
|---|---|
| Poster Presentation Option | Yes, I’m willing to present as a poster. |
