Photo of Dr Andrew Hacket Pain

Dr Andrew Hacket Pain BA, PhD

Lecturer in Biogeography and Ecology Geography and Planning

Research

Seed masting ecology

A bumper crop of acorns in Fontainbleau forest, France (October 2018). Mast years are associated with bumper crops of seeds, with are synchronised across individuals and populations
A bumper crop of acorns in Fontainbleau forest, France (October 2018). Mast years are associated with bumper crops of seeds, with are synchronised across individuals and populations

Masting is the synchronous and highly variable production of seeds and fruits, and is a characteristic reproductive strategy in many grass and woody species (Fernández-Martínez, 2019; Hacket-Pain, 2021; Pesendorfer et al., 2021). Most plants do not produce regular annual seed crops, but switch between years of bumper seed crops (known as "mast years") and years with low seed production. Intriguingly, these bumper crops occur simultaneously in plants living alongside each other, but the synchronisation can also extend across hundreds of kilometres (Vacchiano et al., 2017; Ascoli et al. 2020; Bogdziewicz et al. 2021a; Bogdziewicz et al. 2023).

A series of papers has focused on understanding patterns and drivers of masting in two of the most widespread tree species in Europe - European Beech and Norway Spruce. In 2017 we drew together published data from the literature and our own datasets, and developed the largest published masting database (MASTREE, Ascoli et al. 2017a), a dataset we recently expanded to the global scale as part of the MAST-NET project. This expanded dataset – MASTREE+ – contains >80,000 records of plant reproduction from >1000 species, with the earliest datasets extending back to 1677 (Hacket-Pain et al., 2022). Analysis of this dataset has revealed distinct spatial structures in masting patterns, including the occasional occurrence of continent-wide mast years (i.e. simultaneous high seed production across Europe) (Vacchiano et al. 2017; Ascoli et al., 2017b; Bogdziewicz et al. 2023). We are currently using this dataset to understand how masting varies between and within species (Foest et al., Submitted). For example, our work shows that the evolution of masting is linked to life-history strategies promoting long-lifespans (i.e. high wood density) (Journé, Hacket-Pain & Bogdziewicz, 2023). A summary of that work is included in this bog post. Through a collaboration between the MAST-NET project and the MASTIF project we have contributed to work revealing how investment in reproduction varies between dramatically between species and along climate gradients (Journé et al., 2022; Qiu et al., 2022).

A major motivation of our current research is to better understand the response of masting to environmental change (Hacket-Pain and Bogdziewicz, 2021). We have shown that climate warming is associated with a "breakdown" in masting in UK beech trees (Bogdziewicz et al., 2020b; Bogdziewicz et al., 2021b), which has led to a dramatic decline in viable seed production in this species (Bogdziewicz et al.,2023). New research shows that a dampening of interannual variability in seed production in beech is occuring across Europe in association with warming summer temperatures (Foest et al., Submitted). Future research will examine whether these changes are occurring in other species and regions, and what this means for forest regeneration under climate change. A summary of this work was featured on BBC AutumnWatch.

Masting is beneficial for plants because in years of bumper seed crops, seed predators cannot consume all the available seeds, which ensures that some survive to germinate the next spring (Bogdziewicz et al., 2020a). In ecosystems that are influenced by disturbance such as wildfires, windstorms and logging by humans, the timing of the next bumper seed year is also crucial to the ability of plants to regenerate. For example, I'm currently working with collaborators in Europe and North America to understand this interplay of climate, fire disturbance and masting in Canadian boreal forests (Ascoli et al., 2020), and mountain beech forests in the European Alps (Maringer et al., 2019). As part of the COST-Action project “PROFOUND”, I worked with foresters, field ecologists and modellers to investigate how masting can be incorporated into forest models, aiming to improve predictions of the response of forest dynamics to climate change (Vacchiano et al. 2018). As part of a Treescapes Fellowship funded by the UKRI and Defra, I am working with policy-makers and practitioners, and partners in the Austrian FORSEE project to understand how we can use knowledge of masting to help secure the native tree seed supply we need for the expansion of woodland in the UK.

Forest response to climate change

Field camp on Mt. Vermio, Greece. Field campaign at the southern distribution limit of Fagus sylvatica. Tree ring sampling in the
Field camp on Mt. Vermio, Greece. Field campaign at the southern distribution limit of Fagus sylvatica. Tree ring sampling in the "resonant" spruce forests of Paneveggio, Italian Alps

Changes in climate are causing significant changes in the functioning, composition and structure of Europe’s forests. For example, increased temperatures and drought stress, coupled with changes in atmospheric CO2, nutrient availability, disturbance dynamics and management are resulting in changes in the productivity of forests, with implications for carbon storage and the future of terrestrial carbon sink.

This research theme uses tree ring chronologies to create to create long time-series of tree and forest growth. Long-term changes in growth are linked to decadal patterns in climate (Hacket-Pain and Friend 2017; Dorado-Liñán et al., 2022; Martinez del Castillo et al., 2022), inter-annual variations in growth are used to assess the sensitivity of growth to seasonal climate variability (Muffler et al., 2020), and the response of growth to extreme climate events is used to quantify the sensitivity of forests to drought events (Hacket-Pain et al. 2017; Castagneri et al. 2022). Current research is focused on developing a distribution-wide network of tree ring chronologies (Hacket-Pain et al., 2018; Dorado-Liñán et al., 2022). We are using this network of tree ring chronologies to understand how the sensitivity of these species to drought and other climatic driver of growth varies within this species geographic distribution. This includes the effect of between-tree competition, with implications for how we can manage forest ecosystems to mitigate the impacts of future increases in drought frequency and severity (Castagneri et al., 2022).

However, forest responses to global environmental change are dependent not only the response of tree growth, but also on forest demographic processes. We are particularly interested in the links between climate, fire disturbance and tree mortality and recruitment. Recent work has included studying the mortality and recruitment in Alpine beech forests after novel fire disturbance (Maringer et al., 2019; Maringer et al., 2021), and a large-scale study to establish the links between climate teleconnections, drought, fire and seed production in North American boreal forests (Ascoli et al., 2019). You can read more about the links between climate, wildfire and seed production in boreal forest on The Journal of Ecology blog, and the response of growth to extreme climate events is used to quantify the sensitivity of forests to drought events (Hacket-Pain et al. 2017; Castagneri et al. 2022). Current research is focused on developing a distribution-wide network of tree ring chronologies (Hacket-Pain et al., 2018; Dorado-Liñán et al., 2022). We are using this network of tree ring chronologies to understand how the sensitivity of these species to drought and other climatic driver of growth varies within this species geographic distribution. This includes the effect of between-tree competition, with implications for how we can manage forest ecosystems to mitigate the impacts of future increases in drought frequency and severity (Castagneri et al., 2022). However, forest responses to global environmental change are dependent not only the response of tree growth, but also on forest demographic processes. We are particularly interested in the links between climate, fire disturbance and tree mortality and recruitment. Recent work has included studying the mortality and recruitment in Alpine beech forests after novel fire disturbance (Maringer et al., 2019; Maringer et al., 2021), and a large-scale study to establish the links between climate teleconnections, drought, fire and seed production in North American boreal forests (Ascoli et al., 2019). You can read more about the links between climate, wildfire and seed production in boreal forest on The Journal of Ecology blog.

Understanding trade-offs between tree growth and reproduction

Tree ring sampling in the
Tree ring sampling in the "resonant" spruce forests of Paneveggio, Italian Alps

This work draws together my interests in masting and tree-rings. Tree growth is the primary process by which carbon fixed by photosynthesis is sequestered in forest ecosystems, but the supply of carbon from photosynthesis is not the only factor that controls tree growth (and productivity more generally). For example, the allocation of available resources plays a key role. The production of flowers, pollen, fruits and seeds all require significant investment of resources, which can result in a "trade-off" with growth. Consequently, year-to-year variation in allocation to reproduction (masting) is an important control on tree growth, and years with high investment in reproduction are associated with reduced growth (Hacket-Pain et al. 2017; Hadad et al., 2021). Furthermore, as reproduction is influenced by weather conditions in various biologically relevant seasonal windows (Vacchiano et al. 2017), the interplay with reproduction creates important indirect mechanisms by which climate can influence growth (Hacket-Pain et al. 2018). Research has focused on European Beech, but the next step is to investigate these dynamics for other species (Hacket-Pain et al., 2019; Hadad et al, 2021). For example, in a project funded by the Royal Society we are investigating the dynamics of climate, masting and tree growth in Araucaria araucana, a conifer native to northern Patagonia (Hadad et al, 2021; Hacket-Pain et al. In Prep; Hadad et al., In Prep).

Research Group Membership

Research Grants

Seeds for Treescapes

NATURAL ENVIRONMENT RESEARCH COUNCIL

January 2023 - September 2023

Individual variation in masting traits

ADAM MICKIEWICZ UNIVERSITY (POLAND)

April 2022 - September 2023

Assessing and predicting variation in oak acorn production in response to climate change

BRITISH COUNCIL FRANCE (FRANCE)

January 2022 - December 2023

Treeline advances in a changing climate: understanding how climate affects reproduction and early life stages in Black spruce

UK RESEARCH AND INNOVATION

April 2021 - March 2022

MonkeyPuzzle: Reconstructing mast events and climate in Patagonia using Araucaria araucana tree rings

ROYAL SOCIETY

December 2019 - December 2022

MAST-NET: masting responses to climate change and impacts on ecosystems

NATURAL ENVIRONMENT RESEARCH COUNCIL

December 2018 - June 2022

Untangling climate drivers of wildfire in the Northwest Territories

DEPARTMENT FOR BUSINESS, ENERGY AND INDUSTRIAL STRATEGY (BEIS) (UK)

March 2018 - February 2019