Forest Biology Center

Masting, the synchronized seed production among plants, is often seen as a reproductive strategy. But is it inherited? We studied 110 Sorbus aucuparia L. trees for 22 years to find out. We discovered that trees with similar genetics and growing conditions shared similar reproductive patterns. Also, trees of similar sizes had comparable fluctuations in fruiting from year to year, influenced partly by genetics. These findings suggest that masting behavior is inherited and can adapt to nature’s challenges, giving us new insights into how plants reproduce and thrive.

New study in European Journal of Forest Research dissects 22 years of rowan tree fecundity, emphasizing the pivotal role of DBH and the dominance of light availability. Notably, neighborhood crowding unveiled a correlation with pollinator competition. This research advances seed production ecology understanding, offering insights for effective fruit supply management. Read the full study:
https://link.springer.com/article/10.1007/s10342-024-01661-5

New paper in Ecology shows that reproductive performance of Wood Warblers – small, ground-nesting songbirds – is much lower in years following mast seeding than in years preceded by mast failures, as mast seeding indirectly increases predation pressure on Wood Warbler nests. Moreover, matrix population models revealed that regional variation in mast seeding frequency is a possible explanation for divergent population trends of Wood Warblers in different regions of Europe. The paper can be found here: https://doi.org/10.1002/ecy.4227

New paper in Nature Communications takes 517 plant species and links their interannual variation of seed production with functional traits. While interannual variation in seed production is highest in temperate and boreal zones, our analysis controlling for environment and phylogeny indicates that masting is more frequent in species that invest in tissue longevity.

There is a write-up on that paper in the Nature blog, and the paper is here.

Phenology, corresponding to the study of periodic events, plays an important role in fitness and species distribution because it determines when a species grows and reproduces. Here, F. Jean et al. compiled a dataset of leaf phenology observations for European Beech and Silver fir. The data has been recorded at the tree level, from bud development to leaf unfolding date, along the Mont-Ventoux, a mountain in the South of France. 

A new paper in Methods and Ecology Evolution rediscovers CVk, a CV-based metric that has some interesting features making it worth looking at in masting studies. These include the reduced sample size needed to discover trends, especially worthy one given the logistical challenges of long-term seed production monitoring and the scarcity of such data.

In June 2023, the Forest Biology Center organized a conference at Gułtowy Palace (near Poznań).
We had a great time discussing science, exchanging ideas, planning papers, and networking.
Now, we are in the process of writing a perspective paper that will gather the work we accomplished during the meeting. Stay tuned!

Last month our lab member, Kasia Kondrat defended her master’s thesis on Drivers of intraspecific variation in fecundity in rowan. This study investigated the factors influencing fecundity using a 22-year fruit-count dataset from 167 individual trees. Findings highlighted diameter at breast height (DBH) as the best size proxy for standardizing fecundity, and light availability played a major role in rowan’s fecundity. Congratulations Kasia!

Masting not only enhances plant reproductive efficiency and fitness but also influences entire food webs. However, quantifying the year-to-year variability in masting has been a subject of intense debate. The commonly used coefficient of variation falls short in accounting for the serial dependence and the presence of zeros in individual-level datasets, limiting its suitability for phenotypic selection, heritability, and climate change studies. To overcome these limitations, our three case studies introduce volatility and periodicity as novel metrics that capture both high and low-frequency variance, even in the presence of zeros. By examining multiple plant species, including Sorbus aucuparia, Pinus pinea, Quercus robur, Quercus pubescens, and Fagus sylvatica, we demonstrate how these new metrics greatly enhance ecological interpretations and pave the way for significant advancements in the analysis of long-term, individual-plant datasets.

Understanding the timing of masting is crucial for successful management and conservation efforts in ecosystems dominated by masting species. That’s why understanding the mechanisms behind masting and developing forecasting tools for seed production is urgently needed. In our recent New Phytologist paper we evaluated the predictive capabilities of three models—foreMast, ΔT, and a sequential model—in forecasting seed production in trees. By utilizing a comprehensive pan-European dataset of Fagus sylvatica seed production, we tested these model’s abilities to recreate past seed production dynamics, and identified dimensions that work well and gaps. One key finding from our study is the influence of high-quality data on prior seed production on the model’s predictive power. Incorporating good-quality data enhances models’ predictive power. This underscores the importance of implementing effective methods to monitor seed production, as they may serve as the foundation for developing accurate forecasting tools. While our models exhibit moderate success in predicting seed production dynamics, they are better at forecasting crop failures rather than bumper crops. The factors that reduce seed production are better understood compared to those responsible for large reproductive events. We acknowledge these challenges and present a roadmap to drive the discipline forward and encourage further advancements in mast forecasting.