When we imagine restoring a tallgrass prairie, we might picture conservationists scattering diverse seed mixes across the land. Yet, many restored prairies still fall short of the resilience and biodiversity found in natural remnants. The missing piece might lie not in which plants are chosen, but in their evolutionary relationships.
Key Insight
Recent research reveals a surprising phenomenon: restored tallgrass prairies are maintaining their phylogenetic diversity—the evolutionary breadth of species—even as the total number of species declines over time. This preservation of deep evolutionary history may be the key to creating resilient, self-sustaining ecosystems that can withstand environmental challenges for generations to come 1 .
What is Phylogenetic Diversity and Why Does It Matter?
Beyond Species Counting
Traditional conservation has often focused on species richness—the simple count of different species in a given area. While important, this approach misses crucial information about how different these species are from one another in evolutionary terms.
The Resilience Connection
Ecological research has consistently shown that phylogenetically diverse communities tend to be more stable and productive. This is because distantly related species have evolved different strategies for surviving drought, resisting diseases, and utilizing resources 3 .
Benefits of Phylogenetic Diversity
Greater Productivity
Enhanced biomass production in plant communities
Enhanced Persistence
Better recovery after disturbances
The Prairie Experiment: Testing Evolutionary Ecology in Action
Setting the Stage
To understand how phylogenetic diversity functions in restored ecosystems, researchers from the Chicago Botanic Garden, The Morton Arboretum, and several universities launched an ambitious long-term study 5 .
Research Approaches
- Pattern analysis of existing restorations and remnant prairies
- Restoration experiments testing effects of phylogenetic diversity
- Long-term monitoring of community development and stability 2
Methodology: A Step-by-Step Approach
Site Selection and Preparation
Identified and prepared restoration sites with different land-use histories, including both natural grassland soil and soil abandoned from agricultural practices decades earlier.
Species Selection
Carefully selected plant species representing different branches of the evolutionary tree to create varying levels of phylogenetic diversity in experimental plots.
Community Establishment
Sowed seed mixtures of perennial dry grassland species in outdoor mesocosms and field plots.
Long-term Monitoring
Tracked plant community development over 13 years, allowing natural invasion by both native and exotic species from outside the sown species pool.
Data Collection & Analysis
Measured multiple response variables including species richness, productivity, invasion resistance, and phylogenetic diversity metrics.
Key Metrics in Prairie Restoration Studies
| Metric Category | Specific Measurements | Significance in Restoration |
|---|---|---|
| Taxonomic Diversity | Species richness, Species evenness | Traditional measures of biodiversity |
| Phylogenetic Diversity | Mean pairwise distance, Mean nearest taxon distance | Evolutionary breadth of community |
| Community Stability | Resistance to invasion, Temporal stability | Ecosystem resilience to disturbances |
| Soil Properties | Microbial biomass, Nutrient availability | Belowground ecosystem health |
The Surprising Results: Preservation of Evolutionary History
Key Finding
While the number of species (species richness) declined in restored prairies as expected, the evolutionary breadth of the remaining community was maintained.
Ecological Significance
This preservation of phylogenetic diversity occurred even as some species disappeared from the ecosystem. The finding suggests that restored plant communities might naturally stabilize in a way that conserves evolutionary history, potentially protecting the functional diversity necessary for long-term ecosystem health.
Comparison with Remnant Prairies
When scientists compared restored prairies to remnant (never-plowed) prairies, they found that restored sites still had significant room for improvement. Restored prairies generally showed:
- 13% lower biodiversity on average compared to reference ecosystems
- 20% higher variability in biodiversity outcomes 6
However, the maintained phylogenetic diversity in successful restorations suggests they're on the right trajectory, potentially developing the foundational structure needed for long-term stability.
Restored vs. Reference Prairie Ecosystems
| Ecosystem Attribute | Restored Prairies | Remnant Prairies | Ecological Significance |
|---|---|---|---|
| Species Richness | Generally lower, declines over time | Consistently higher | Traditional measure of diversity |
| Phylogenetic Diversity | Maintained despite richness losses | Naturally high | Evolutionary history preservation |
| Temporal Stability | Variable, improves with age | Consistently high | Resistance to environmental fluctuations |
| Invasion Resistance | Variable, context-dependent | Generally high | Resilience to non-native species |
Phylogenetic Diversity Over Time in Restored Prairies
Interactive chart showing phylogenetic diversity maintenance despite species richness decline
Chart would visualize data from long-term monitoring studiesThe Microbial Connection: Underground Networks Support Aboveground Diversity
Decoupled Networks
In stable plant communities on natural grassland soil, scientists found decoupled prokaryote and fungal soil networks—meaning these two major components of the soil microbiome operated somewhat independently 4 .
Agricultural Soil Challenge
Plant communities on previously agricultural soils showed coupled prokaryote and fungal networks and promoted destabilizing properties. This coupling was mediated by strong interactions of plants and microbiota with soil resource cycling 4 .
How Decoupling Works
This decoupling appears to be mediated by a large variety of past plant community pathways that shape especially fungal networks. The diversity of plant inputs (root exudates, leaf litter, etc.) creates specialized niches for different microbial groups, allowing them to develop semi-independent networks that collectively support plant health 4 .
Implications for Restoration Practice
"Restored prairies that we have analyzed to date have significantly lower phylogenetic diversity than remnant prairies, which serve as targets for restoration. This could be one factor leading to shortfalls in restored prairies' functional equivalency with restoration sites" 2 .
Moving Beyond Species Checklists
The findings about phylogenetic diversity maintenance have profound implications for how we approach ecological restoration, driving a shift toward evolutionarily informed restoration that considers not just which species to include, but their evolutionary relationships and the functional diversity they represent.
The Scientist's Toolkit
Essential research tools for studying phylogenetic diversity in restoration include phylogenetic trees, DNA sequencing, field experiments, long-term monitoring, and soil microbial analysis.
Research Tools for Phylogenetic Restoration
| Tool or Method | Function in Research | Application in Restoration |
|---|---|---|
| Phylogenetic Trees | Maps evolutionary relationships among species | Guides selection of distantly related species |
| DNA Sequencing | Determines genetic relationships between taxa | Provides data for building accurate phylogenies |
| Field Experiments | Tests ecological principles in real-world settings | Validates theoretical models of diversity effects |
| Long-term Monitoring | Tracks community changes over decades | Reveals patterns invisible in short-term studies |
| Soil Microbial Analysis | Characterizes belowground microbial communities | Assesses complete ecosystem recovery |
The Future of Restoration Ecology
Addressing the Variability Challenge
While restoration generally enhances biodiversity compared to unrestored levels, there remains substantial variability in outcomes among restoration projects. A global meta-analysis found that restoration sites continue to show higher variability (20%) in biodiversity compared to reference sites, and this pattern persists over time 6 .
This suggests that sources of variation—such as prior land use, restoration methods, and historical contingencies—have an enduring influence on restoration outcomes. Understanding how to manage phylogenetic diversity may be key to reducing this variability and creating more predictable restoration outcomes.
New Research Frontiers
Scientists are now expanding this work in several exciting directions:
- Testing the effects of intentionally maximizing phylogenetic diversity in restoration plantings
- Exploring how phylogenetic diversity influences ecosystem functions beyond stability
- Investigating how climate change may alter the relationship between phylogenetic diversity and ecosystem resilience
- Developing practical tools and guidelines for restoration practitioners 5
Future Research Directions in Phylogenetic Restoration
Genetic Tools
Advanced DNA sequencing for better phylogenies
Climate Resilience
Phylogenetic diversity under climate change
Practical Applications
Tools for restoration practitioners
Global Patterns
Comparative studies across ecosystems
Conclusion: An Evolutionary Perspective on Ecosystem Recovery
The discovery that restored tallgrass prairies maintain phylogenetic diversity despite losses in species richness offers both insight and hope for conservation efforts. It suggests that by focusing on the deep evolutionary relationships between species, we can create restored ecosystems that are truly resilient in the face of environmental change.
As we continue to learn how to better restore these complex ecosystems, each patch of replanted prairie becomes not just a collection of species, but a carefully reconstructed piece of evolutionary history—one that maintains the breadth of life's solutions to ecological challenges that have been developed over millions of years.
The preservation of phylogenetic diversity in restored prairies represents a powerful, naturally occurring mechanism that may help ensure these cherished ecosystems endure for generations to come, protecting both biological diversity and the evolutionary processes that generate it.