Forest Biology Center

Maria will join our team in October, working on the climate change biology of trees reproduction, which will include altitudinal gradients in fecundity, local adaptations, and more. Stay tuned for outcomes!

Our new review explores the phenomenon of mast seeding, where perennial plants produce highly variable and synchronized seed crops. We synthesize current knowledge on the mechanisms plants use to achieve this variability, from hypersensitivity to weather cues to interactions between pollination, fruit maturation, and internal resource dynamics. We highlight that variation in flowering effort, rather than fruit maturation, is often the main driver of masting, and that weather cues synchronize reproduction more strongly than pollen limitation. The review also considers emerging genetic insights, challenges long-held assumptions about the geographic scope of masting, and examines how climate change and management contexts may reshape these patterns.

In the latest publication, co-authored by our colleague Urszula Eichert, you can read about the behaviour of captive-born European hamsters after being released into the wild. The study examined how sex, age, and the origin of the parent (from the wild or from captivity) affect the behaviour of the offspring in the first days after being placed in acclimatisation aviaries. The full paper can be accessed here:
https://doi.org/10.1016/j.gecco.2025.e03784

Our latest paper, Solstice, selection, and synchrony of seed masting, addresses how the summer solstice serves as a fixed, range-wide cue that synchronizes temperature sensing for flowering in European beech. Unlike growth processes, where local adaptation to environmental conditions is beneficial, masting relies on synchrony among individuals to enhance pollination efficiency and predator satiation. We show that this fixed-date cue, unaffected by local conditions, is key to achieving large-scale reproductive synchrony—but may also make masting vulnerable to climate warming. Read the whole story here: https://doi.org/10.1073/pnas.2515264122

We’re thrilled to announce that Dr. Jessie Foest has been awarded a Marie Skłodowska-Curie Actions ERA Fellowship for her project FECUND, which tackles the urgent issue of forest regeneration under changing climate conditions. The project will explore how climate conditions influence early life stages of trees, from seed production to recruitment, combining field data, experimental work, and ecological modelling. Supported by a Europe-wide research network and interdisciplinary collaboration, FECUND aims to generate vital insights into the factors driving forest resilience. Congratulations, Jessie!

I’m honoured to have received a START stipend from the Foundation for Polish Science (FNP). The award is designed to support early-career researchers, offering recognition for work to date and space to grow.

For me, it’s a deeply appreciated vote of confidence as I continue to build my research on forest regeneration and long-term seed production dynamics.

Many thanks to the FNP for supporting me and other early-career scientists across disciplines!

New research led by Dr Jessie Foest has just been published in Ecology, entitled:
“Intraspecific variation in masting across climate gradients is inconsistent with the environmental stress hypothesis.”

This study offers fresh insights into the diversity of reproductive strategies in trees and challenges long-standing assumptions in the field of mast seeding.

Masting – the phenomenon where trees produce large seed crops in some years and little to none in others – is often considered a species-level characteristic. But is that the full story? How much does masting vary between populations within a species?

This question has largely gone unanswered until now.
We analysed 437 long-term time series across 19 tree species and found that intraspecific variation in masting can exceed variation between species.

We also tested a widely held assumption, namely that climatic stress drives this variation. The environmental stress (or productivity gradient) hypothesis suggests that trees in more stressful, marginal climates exhibit more pronounced masting. However, our findings tell a different story:

• Populations growing toward climatic margins did not show greater variability in seed production.
• In fact, they exhibited more stable reproductive patterns – directly contradicting the environmental stress hypothesis.

This suggests that factors other than climatic stress / productivity may play a greater role in shaping masting, and calls for a re-evaluation of some foundational ideas in the field.

Improving our understanding of these mechanisms is crucial for predicting how forest ecosystems will respond to changing environmental conditions and for informing effective conservation and management strategies.

Read the full paper here.

In our new paper, just published in New Phytologist, we used extensive long-term observations of snow tussocks (Chionochloa pallens) and European beech (Fagus sylvatica) to explore how plant resources and weather cues interact to influence mast seeding. Our results highlight a key finding: when plants have abundant internal resources, they respond strongly to even moderate weather cues, triggering substantial reproductive events. Conversely, low resource reserves significantly dampen reproductive responses, even under strong cues. This interaction between resource reserves and weather cues improves our understanding of masting mechanisms, offering valuable insights for forecasting seed production—crucial for managing ecosystems and adapting to climate change. The full paper can be accessed here.

Tropical montane forests are characterized by heterogenous environmental conditions drastically changing across elevational gradient that contribute to high diversification of species. The exceptionally species-rich plant communities in tropical mountains are reflected as well in their high functional diversity, and functional traits can mirror different life strategies of plants depending on the local environment and access to the resources. Previous studies have shown that different traits tend to decrease in communities with increasing elevation, but little is known how functional traits of plants at different plant life stages change in relation to elevations and local resources. We showed that specific leaf area in adult trees, seed mass in seed rain and initial height of seedlings significantly decrease with elevations in tropical montane forest in Southern Ecuador. In contrast, we found that the same trait composition responds differently to local soil and light conditions with pronounced differences between trait-environment associations at different plant life stages. Our study emphasizes the role of both, broad-scale and local-scale environmental conditions for tree communities in tropical mountains and the overlooked aspect of ontogeny in trait-environment associations in diverse tropical communities. https://doi.org/10.1111/oik.10421

In our new paper, just published in Journal of Applied Ecology, we suggest intensifying livestock predation on prematurely dropped-infested acorns by allowing livestock foraging from October 1st onward. Pigs are usually released free range in early November, once weevil larvae have completed their development and escaped predation. The proposed management would increase the availability of healthy acorns, thus increasing the farm capacity and the economic profit by up to 20%, tens of millions of euros of additional profits when translated into the prices of the Iberian pork market. https://doi.org/10.1111/1365-2664.70012