Docentföreläsningar på S-fakulteten 3 november

Hyungwoo Lim, Department of Forest Ecology and Management

Forest carbon allocation is the distribution of assimilated carbon among functional pools, like leaves, stems, roots, etc. It is an important process to link photosynthesis to forest growth and ecosystem functions, and their feedbacks. Carbon is first fixed through photosynthesis, but its allocation determines which biological processes are supported and how trees respond to environmental changes. For example, allocating more carbon to leaves may not result in immediate wood growth, but it increases leaf area and photosynthetic capacity, eventually enhancing future wood production. Likewise, more carbon can be invested in building roots in nutrient poor or dry soils, thereby enhancing water and nutrient acquisition capacity. Because these carbon pools are replaced on a different time scale, from a season for leaves and fine-roots to decades for stems, ecosystem carbon sink strength varies with allocation patterns. Understanding carbon allocation is therefore essential for assessing and projecting forest responses to environmental changes.

Despite its importance, carbon allocation remains one of the less constrained terms in forest modeling. This is because direct measurements are challenging due to its variability with forest structure, soil resource availabilities, and atmospheric conditions. These uncertainties are often propagated in both measurements and ecosystem models, where allocation is generally represented using simplified assumptions. To fill this knowledge gap, my research has been focused on how carbon allocation varies across spatial and temporal scales, and how experimental findings can be scaled to inform model projections. This docent lecture is presentation of my attempts to quantify, characterize, and upscale forest carbon allocation.

I will first present carbon allocation to tree branches, an often-overlooked component, as an example to highlight why allocation matters for both field-based assessment and ecosystem modeling. I will then discuss how trees adjust allocation patterns to improved soil nutrient conditions, such as forest fertilization, and potential consequences of these responses to soil and atmospheric water deficits.

Biology, the study of living organisms, is a large area including many perspectives, including anatomy, physiology, taxonomy, genetics, botany, zoology and ecology. Veterinary medicine might perhaps by many not be seen as biology, but it is an in-depth application of biology. We work with the events where normology (the normal biological state) turns into pathology (disease) and how to turn that back into normology or how to prevent pathology from at all occurring. To do this, we need to know not only what is causing a disease, but also the subsequent effects at an individual level and often also at population level that we need to deal with.

My focus research area is fish health, with emphasis on the Baltic salmon. Proper stock management and interpretations of causes for population drops requires extensive data collection and knowledge about factors that on their own or through interaction with other factors affect population dynamics. Here, diseases, and especially infectious diseases, are often neglected although the effects on a population can be devastating. In my lecture, I will show how my research has approached recent and current health issues of the salmon population in both farms and in the wild to investigate acute or more long-time problems, using different approaches. Some approaches to increase the amount of health data that can be collected, while decreasing the invasiveness of the research are under development, meaning less animals are subjected to sampling. We also foresee that these methods can be used in e.g. future population management and preparedness, meaning that systematically collected disease data as well as an increased amount of conventional biological population data can be collected simultaneously. In wild populations, treatment of a disease is often impossible. However, merging health/disease data and population data can help researchers predict population effects in both a short and long-term perspective based on different scenarios for improved stock management.

To sum up, population events and dynamics cannot only be explained by factors such as feed availability and quality, predation etc., but (infectious) diseases, often with multiple contributing factors, must also be taken into consideration. I aim to continue to bridge different biology research fields, contributing to an improved wild and farmed fish health management as a holistic perspective cannot be reached without laying a multi-piece puzzle.

ABSTRACT: Surviving and reproducing in the wild require that animals are adept at navigating their social and ecological surroundings. My research explores how the social and reproductive systems of animals are adapted to their particular environments, and how human activities are now changing these environments thereby altering animal social and reproductive behaviours. I am a behavioural ecologist who likes to study fish, and I now employ emerging data-driven and computer-assisted tools to study fish behaviour in a changing world.

A central focus of my work has been the extraordinary diversity of social and reproductive strategies found among cichlid fishes in Lake Tanganyika, East Africa. These fishes provide a powerful system for investigating why animals form social groups and how group members resolve their social conflicts. I have also been using these fishes to better understand how social animals respond to emerging chemical pollutants like pharmaceuticals and plastics. In my docent talk, I will present some of my past, present, and future planned research, starting with classic behavioural ecology field studies on cichlid fish social structures and reproduction. I will then talk about more recent work examining behavioural responses to pharmaceutical pollution, which has demonstrated novel effects that have evolutionary implications. These findings have been made possible because I have started using data-driven approaches to quantify animal behaviour at large scales and at high resolution: including computer vision methods for animal tracking, automated behavioural classification, and 3D topographical habitat reconstructions. Lastly, I will present one of my future planned research directions which is to examine how fish reproduction may be altered by macro-plastic pollution.

Together, my research emphasises an understanding of both the natural processes that drive animal behaviour and how anthropogenic pollutants are altering these processes, such that we can ultimately better assess how animals respond to human-driven environmental change.

Globally, restoration is expected to contribute to many different goals, including biodiversity conservation, climate change mitigation, and human well-being. However, in practice, many restoration programs are designed around a single or primary goal, without considering the synergies or trade-offs that may occur with other goals. For example, some programs primarily aim to restore biodiversity, while others primarily aim to support human well-being and/or livelihoods. This can miss opportunities for synergy; biodiversity can support people’s livelihoods through ecosystem services, while successful conservation depends on meeting the needs of local societies. I study which factors influence the degree to which restoration supports both biodiversity and people.

The island of Madagascar provides an important case study for my research, with exceptional biodiversity, extensive forest loss, strong dependence of people on forests and forest products, and ambitious restoration commitments. Most of the reforestation in Madagascar is composed of fast-growing, non-native tree species to support the livelihoods of local forest users. However, some reforestation is conservation-led, planting native tree species and aiming to support biodiversity recovery with little or no use by local people. My research program therefore addresses the need for synergies in two different directions. First, can restoration primarily intended for biodiversity also support people and livelihoods? Second, can reforestation that is primarily intended for people also support biodiversity?

These research questions require an interdisciplinary approach, using both social and natural science methods. For local forest users, we ask which tree species people use, what tree characteristics they prefer, how much they use relative to what is planted, and where trees should be planted to meet those needs. We have so far found that biodiversity-oriented restoration can potentially support livelihoods through provisioning of diverse tree species and traits, but we need to understand how, where, and why people use trees and design restoration accordingly.

To know whether reforestation that is primarily intended for people also supports biodiversity, we first need to decide which species to target, and how best to detect those species. We have so far focused mainly on species that perform important ecosystem functions like seed dispersal. We use sensor-based technologies like camera traps and acoustic recorders to scale up biodiversity monitoring, but different methods are more likely to detect different types of animals, so combining them is important. Using these technologies, we are discovering that several factors may influence whether animals return to forested areas, including tree size structure and the diversity of potential food species.

I and my collaborators will continue this work to determine how biodiversity recovers through time. We will also ask if species presence and behaviour tell us the same story. For example, are animals that we detect in reforestation areas also exhibiting behaviours related to reproduction?

Ultimately, I want to move beyond determining whether restoration designed for one goal can support another toward asking how we can design restoration that supports both biodiversity and people. This will require continuing to design more efficient, scalable biodiversity monitoring methods; understanding recovery across different types of organisms; and broadening which human benefits we consider. This approach applies beyond forests to other types of restored landscapes.

Lucas Dawson, School of Forest Management, Swedish University of Agricultural Sciences (SLU)

Swedish forest management is, by several measures, a success. Over many decades it has been refined into a highly productive and technically sophisticated system that underpins a major export industry. Yet society now asks forests for far more than timber: carbon storage, biodiversity, recreation, clean water and rural livelihoods, simultaneously. Policy ambitions at national and European levels point towards greater diversity in how forests are managed. Management practices, however, have changed remarkably little. Alternatives to even-aged, clearfelling-based forestry remain a small fraction of the managed forest, despite years of research, pilot projects and dialogue. Why? This lecture begins from that puzzle. How does something new emerge inside a system organised, in nearly all its parts, to reproduce something else – and can that change be steered?

My research approaches this as a problem of complex systems. Forest management emerges from interacting economic, institutional, technological, socio-cultural and ecological factors across several levels, with feedbacks, delays and path-dependent dynamics that no single actor controls. Complexity, in this view, is a condition to be understood rather than a problem to be removed. I combine the socio-technical transitions perspective, which explains how established regimes stabilise and how alternatives develop in protected niches, with causal mapping, system archetypes and leverage-point analysis. Together, these make it possible to ask not only which factors matter, but where in the system an intervention is likely to make a difference.

In the lecture, I will introduce these theories and methods using forest management as the main case, and show how they can be applied by researchers to engage with complexity and uncertainty. I will draw on findings from several of my studies of alternative forest management in Sweden, including expert and forest owner perspectives, the institutional landscape, and local collaborative governance initiatives. Taken together, they suggest that persistent constraints lie in institutions, knowledge systems and norms, and that efforts to change forestry tend to concentrate where leverage is easiest to reach rather than where it is greatest. In addition, I will discuss what this might imply for steering a transition in practice, including the roles of collaboration, policy and learning under uncertainty.

Furthermore, I will show how this approach travels beyond Swedish forest management and outline where my research is heading. My hope is that the lecture leaves doctoral students from across the faculty with a sharper sense of why change is so difficult in complex systems, and with a useful way of working within them.