Incorporating Biodiversity-Ecosystem Function Relationships into Models and Conservation Planning

Unsustainable use of nature and climate change are leading to unprecedented biodiversity declines. These declines have cascading impacts on ecosystem function and ecosystem services, and ultimately on human well-being. International agreements have been adopted that aim to address both crises. The Paris Agreement, adopted in 2015, set global emission reductions targets. In 2022, most countries agreed to the Kunming-Montreal Global Biodiversity Framework (GBF). The GBF sets 23 ambitious targets for 2030 ranging from reducing threats to biodiversity, meeting people’s needs through sustainable use and benefit sharing, and solutions for implementation. Although adopting global goals and targets is an important first step, additional work is required for on-the-ground implementation. Important knowledge gaps include understanding how biodiversity, ecosystem functions, and ecosystem services are linked, modeling how policy scenarios could lead to different outcomes for biodiversity and ecosystem services, and guidance for where and how to prioritize conservation actions. This dissertation aims to fill some of these gaps. Chapters 1 and 2 explore how biodiversity conservation can affect important ecosystem functions and services. Chapter 3 moves from improving our baseline knowledge to thinking about how we can achieve our conservation goals through prioritizing restoration actions. In chapter 1, I focus on the importance of biodiversity-ecosystem function relationships for urban systems. The proportion of people living in urban areas is growing globally. Thus, understanding how to manage urban biodiversity, ecosystem functions, and ecosystem services is important. Biodiversity can increase ecosystem functioning in natural systems. However, few studies have assessed the relationship between biodiversity and ecosystem functioning in urban areas, which differ in abiotic factors, species compositions, food webs, and turnover rates. I systematically reviewed documented evidence of biodiversity-ecosystem function relationships in urban environments and assessed factors that influenced the direction of the relationships. I show that increasing biodiversity, even in small areas, can increase local ecosystem functioning in urban areas. Therefore, local management that increases biodiversity can have positive benefits for ecosystems and people. I also identify research gaps and opportunities to improve biodiversity-ecosystem function research in the urban realm moving forward and discuss how to improve urban green space management. In chapter 2, I explored how biodiversity-ecosystem functioning relationships can be incorporated into modeling. Models of how changes in drivers, including land use change and climate change, lead to changes in biodiversity and ecosystem services are useful tools for policymakers as they consider how to sustainably manage natural resources. Despite known interactions between biodiversity, ecosystem functioning, and ecosystem services, models projecting changes in these domains typically operate independently and do not account for interactions or feedbacks, which may lead to inaccurate estimates in ecosystem functioning and ecosystem service projections. In this chapter, I focused on how plant species diversity affects biomass production and carbon storage. I used the Biogeographic Infrastructure for Large‐scaled Biodiversity Indicators (BILBI) model, a macroecological community-level model, to estimate plant species persistence under different climate and land use change scenarios in 2050. I linked this with empirical data on biodiversity-biomass production relationships to assess how biodiversity loss will affect carbon storage globally. I found that biodiversity has the potential to cause as much carbon loss as emissions from other sources (i.e., they are within the range of uncertainty from biodiversity-mediated carbon loss), so achieving Sustainable Development Goal 15 (Life on Land) is essential to achieving Goal 13 (Climate Action). Because the Paris Agreement does not account for emissions from biodiversity loss, science on its carbon impacts, and action as a result, could be underestimated. This analysis points to the important role that maintaining and/or enhancing the diversity of plant species within areas of natural vegetation, rather than simply maximizing the extent of these areas, can play in addressing the climate change crisis. Alongside increasing the global extent of protected areas to prevent rapid carbon loss from ecosystem degradation, increasing plant species diversity in degraded ecosystems can increase carbon storage potential. However, existing international initiatives like the Bonn Challenge and the Paris Agreement focus on forest extent rather than forest quality for protection, afforestation, and reforestation, and thus are missing a key opportunity for action. In chapter 3, I looked at how we can achieve proposed biodiversity conservation goals. Reversing trends in biodiversity loss and achieving the Convention on Biological Diversity (CBD) 2050 vision of “Living in harmony with nature” will require not only conserving remaining biodiversity, but also restoring degraded areas. Recent legislative and executive actions in the U.S. have recognized the importance of restoration. Given limited budgets, deciding where to restore habitat will be an important need in the coming decade. In this chapter, I developed a modeling approach to maximize conservation benefit/restoration cost ratios that can be used to map restoration priorities. I illustrated this approach using a case study for highly threatened grassland ecosystems in the Great Plains region of Kansas. I found that for the indicator species that we chose, shortgrass and mixed-grass prairies had the highest conservation benefit to cost ratio. Setting a minimum restoration threshold for each habitat type allowed me to identify high priority tallgrass prairie sites. The modeling approach is flexible and can be updated for different ecosystems, species, and conservation priorities. I outlined potential alterations that can be made in future analyses, depending on desired restoration goals. Biodiversity conservation can increase ecosystem functioning and services. In this dissertation, I show that conserving biodiversity is important for urban ecosystem functioning and global carbon sequestration. Restoring biodiversity will have positive outcomes for ecosystem functions, ecosystem services, and people. My restoration prioritization model can therefore be used to implement conservation actions to achieve global and national biodiversity conservation goals and targets

When the brain takes 'BOLD' steps: Real-time fMRI neurofeedback can further enhance the ability to gradually self-regulate regional brain activation

Brain-computer interfaces (BCIs) based on real-time functional magnetic resonance imaging (rtfMRI) are currently explored in the context of developing alternative (motor-independent) communication and control means for the severely disabled. In such BCI systems, the user encodes a particular intention (e.g., an answer to a question or an intended action) by evoking specific mental activity resulting in a distinct brain state that can be decoded from fMRI activation. One goal in this context is to increase the degrees of freedom in encoding different intentions, i.e., to allow the BCI user to choose from as many options as possible. Recently, the ability to voluntarily modulate spatial and/or temporal blood oxygenation level-dependent (BOLD)-signal features has been explored implementing different mental tasks and/or different encoding time intervals, respectively. Our two-session fMRI feasibility study systematically investigated for the first time the possibility of using magnitudinal BOLD-signal features for intention encoding. Particularly, in our novel paradigm, participants (n=10) were asked to alternately self-regulate their regional brain-activation level to 30%, 60% or 90% of their maximal capacity by applying a selected activation strategy (i.e., performing a mental task, e.g., inner speech) and modulation strategies (e.g., using different speech rates) suggested by the experimenters. In a second step, we tested the hypothesis that the additional availability of feedback information on the current BOLD-signal level within a region of interest improves the gradual-self regulation performance. Therefore, participants were provided with neurofeedback in one of the two fMRI sessions. Our results show that the majority of the participants were able to gradually self-regulate regional brain activation to at least two different target levels even in the absence of neurofeedback. When provided with continuous feedback on their current BOLD-signal level, most participants further enhanced their gradual self-regulation ability. Our findings were observed across a wide variety of mental tasks and across clinical MR field strengths (i.e., at 1.5T and 3T), indicating that these findings are robust and can be generalized across mental tasks and scanner types. The suggested novel parametric activation paradigm enriches the spectrum of current rtfMRI-neurofeedback and BCI methodology and has considerable potential for fundamental and clinical neuroscience applications

Brain tissue properties differentiate between motor and limbic basal ganglia circuits

Despite advances in understanding basic organizational principles of the human basal ganglia, accurate in vivo assessment of their anatomical properties is essential to improve early diagnosis in disorders with corticosubcortical pathology and optimize target planning in deep brain stimulation. Main goal of this study was the detailed topological characterization of limbic, associative, and motor subdivisions of the subthalamic nucleus (STN) in relation to corresponding corticosubcortical circuits. To this aim, we used magnetic resonance imaging and investigated independently anatomical connectivity via white matter tracts next to brain tissue properties. On the basis of probabilistic diffusion tractography we identified STN subregions with predominantly motor, associative, and limbic connectivity. We then computed for each of the nonoverlapping STN subregions the covariance between local brain tissue properties and the rest of the brain using high-resolution maps of magnetization transfer (MT) saturation and longitudinal (R1) and transverse relaxation rate (R2*). The demonstrated spatial distribution pattern of covariance between brain tissue properties linked to myelin (R1 and MT) and iron (R2*) content clearly segregates between motor and limbic basal ganglia circuits. We interpret the demonstrated covariance pattern as evidence for shared tissue properties within a functional circuit, which is closely linked to its function. Our findings open new possibilities for investigation of changes in the established covariance pattern aiming at accurate diagnosis of basal ganglia disorders and prediction of treatment outcom

Extrapyramidal plasticity predicts recovery after spinal cord injury

Spinal cord injury (SCI) leads to wide-spread neurodegeneration across the neuroaxis. We explored trajectories of surface morphology, demyelination and iron concentration within the basal ganglia-thalamic circuit over 2 years post-SCI. This allowed us to explore the predictive value of neuroimaging biomarkers and determine their suitability as surrogate markers for interventional trials. Changes in markers of surface morphology, myelin and iron concentration of the basal ganglia and thalamus were estimated from 182 MRI datasets acquired in 17 SCI patients and 21 healthy controls at baseline (1-month post injury for patients), after 3, 6, 12, and 24 months. Using regression models, we investigated group difference in linear and non-linear trajectories of these markers. Baseline quantitative MRI parameters were used to predict 24-month clinical outcome. Surface area contracted in the motor (i.e. lower extremity) and pulvinar thalamus, and striatum; and expanded in the motor thalamus and striatum in patients compared to controls over 2-years. In parallel, myelin-sensitive markers decreased in the thalamus, striatum, and globus pallidus, while iron-sensitive markers decreased within the left caudate. Baseline surface area expansions within the striatum (i.e. motor caudate) predicted better lower extremity motor score at 2-years. Extensive extrapyramidal neurodegenerative and reorganizational changes across the basal ganglia-thalamic circuitry occur early after SCI and progress over time; their magnitude being predictive of functional recovery. These results demonstrate a potential role of extrapyramidal plasticity during functional recovery after SCI