Grassland genomics and niche dynamics

Minor allele frequency (MAF) thresholds on population landscape genomics across the North Great Plains Tallgrass prairie grassland species

Santosh Kumar Rana, Kyra LoPiccolo, Jill Hamilton*

Manuscript in Preparation

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The assessment of three remnant grassland species—Helianthus maximiliani, Helianthus pauciflorus, and Rudhbeckia hirta—has brought focus on the influence of landscape connectivity and minimum allele frequency (MAF) on genetic health.

Minor Allele Frequency (MAF) and population landscape genomics

MAF is a fundamental concept in population genetics studies, representing the proportion of the least common allele in a given population. It plays an essential role in understanding genetic variation and identifying rare alleles that could have significant biological implications. Population landscape genomics examines the interaction between environmental variables and genetic diversity in a spatial context. It is vital for understanding the genetic diversity in grassland species and helps in identifying the genetic factors influencing the adaptation to specific landscapes.

Importance of selecting appropriate MAF thresholds

The selection of appropriate MAF thresholds is crucial in population landscape genomics analysis. MAF thresholds help differentiate between rare and common alleles, thereby enabling a more precise understanding of genetic diversity. In grassland species, appropriate selection can lead to accurate predictions about population dynamics and survival. The integration of statistical analysis in measuring health and population connectivity provides insights into the biological aspects of species. It helps in identifying the factors affecting population structure, gene flow, and genetic health. This analytical approach is essential to establish the complex relationship between genetics and the environment.

Research Objective

The core objective of the study was to evaluate the impact of different MAF thresholds on population landscape genomics, focusing on the three specific grassland species. Understanding the effect of landscape connectivity and MAF on these species will contribute valuable insights into their genetic health and overall survival.

Conclusion

The study emphasizes the importance of MAF in population genetics and landscape connectivity in the context of grassland species. Proper selection of MAF thresholds and integrating statistical analyses enable a comprehensive understanding of genetic diversity and connectivity. The case study of H. maximiliani, H. pauciflorus, and Rudhbeckia hirta provides a practical perspective on the significance of these factors and opens pathways for future research to conserve and manage these critical grassland species.

Enhancing resilient connectivity of grassland hotspots for restoration and conservation in a changing climate

Santosh Kumar Rana, Jessica Lindstrom, Marissa Ahlering, Jill Hamilton#

Manuscript in submission

Summary:

Restoration theory emphasizes using genetically and species-diverse seed mixes to safeguard the long-term resilience of biodiverse grassland communities. However, due to climate change, identifying appropriate species and their habitat for seed sourcing is increasingly challenging. Therefore, robust decision-making tools must incorporate our knowledge of species-rich connected landscapes, providing comprehensive insights for climate-informed grassland restoration. 

The research utilized ensemble species distribution modeling (eSDM) to investigate the drivers of grassland species’ range shifts identifying species-rich hotspots of suitable habitat using Biomod2 for current and future (2050) climate scenarios. We further modeled to analyze the connectedness of landscapes to locate species-rich hotspot regions for restoration.

We identified a similar extent of distribution and suitability by analyzing the distribution of 26 grassland species and their functional groups in relation to bioclimatic and environmental variables. However, the interplay of the temperature and precipitation of the warmest period contributed to the suitability of most species. We delineated species-rich hotspots of suitable grassland habitats in Minnesota, North Dakota, and South Dakota, emphasizing their connectivity and resilience in climate change for restoration and conservation efforts. To ensure the long-term survival of grassland hotspots, the study revealed limited overlap between hotspots and protected areas, emphasizing the need for proactive conservation measures. Apart from revealing a small and expanding region of hotspots within designated protected areas, we explore the alignment of hotspots with The Nature Conservancy's Resilient and Connected Networks (RCN), designed for climate change resilience. Our analysis demonstrates significant alignment, particularly in concentrated and diffuse flow regions, providing vital corridors for genetic exchange and sustaining grassland ecosystems.

In conclusion, our study underscores the importance of decision-making tools for resilient connectivity in grassland restoration and conservation efforts. By identifying and protecting hotspots of suitable grassland habitats and promoting connectivity through strategic planning, we can enhance the adaptive capacity of these ecosystems in the face of climate change. These findings provide critical insights for policymakers and land managers seeking to prioritize conservation actions and safeguard the integrity of grassland ecosystems in an ever-changing world.