Across six continents, a sweeping study of grassland ecology has arrived at a conclusion that humbles human assumptions about nature's resilience: some losses, once made, echo for centuries. Ancient grasslands—shaped by millennia of drought, fire, and grazing—harbor slow-growing plants whose very patience makes them vulnerable when disturbed, unable to reclaim ground seized by faster, opportunistic species. The research, published in the Proceedings of the National Academy of Sciences, reminds us that what we call 'recovery' is often merely a different kind of landscape wearing the same name,
Destroyed grasslands may never fully recover, global study finds
Grassland degradation affects livelihoods of over a billion people globally who depend on grasslands for habitat, fodder, and ecosystem services.
Once destroyed, you don't quickly get back what you lost
Mark
So the study looked at 742 species across six continents. That's a lot of data. What exactly did they find that was surprising?
Mimi
The consistency. The differences between old-growth and secondary grasslands showed up the same way everywhere—in the Americas, Africa, Asia. It wasn't regional variation; it was a global pattern.
Luke
But what does "different" actually mean here? Are we talking about which species are present, or their abundance, or something else?
Mimi
Both. The old-growth grasslands have slow-growing perennials with tough leaves. The secondary ones are dominated by faster-growing competitors. It's a shift in the whole plant community.
Mark
And this matters because?
Mimi
Because it means the grassland doesn't function the same way. Carbon storage, nutrient cycling, water retention—all of that depends on the plant community. A grassland full of fast-growing annuals behaves differently than one with slow perennials.
Luke
The study says differences persist for centuries. But do we know if they eventually resolve? Or is 300 years just the longest observation period they had?
Mimi
That's the question they're flagging. They don't know yet. But the fact that after 300 years the secondary grassland plants were still taller suggests the shift might be very long-term, possibly permanent.
Mark
What would it take to fix this? Can you just replant the old species?
Mimi
That's what Brudvig is saying—you need active restoration. Seed sowing, transplanting. But it's labor-intensive and expensive.
Luke
And we don't actually know if that works at scale, right? The study is about what's happening, not about testing restoration methods.
Mimi
Correct. They're saying passive recovery isn't enough. But the proof that active methods work—that's still ahead.
Mark
So the real message is: don't destroy these grasslands in the first place.
Mimi
Exactly. Nerlekar was clear about that. Once they're gone, you don't quickly get back what you lost.
Le Pouls
- A global analysis of 742 plant species confirms that secondary grasslands—those regrowing after disturbance—remain ecologically distinct from ancient ones, not for decades but for centuries.
- The biological mechanism is unforgiving: old-growth grassland plants are slow-growing perennials built for endurance, not competition, and faster-reproducing species overwhelm them the moment the ground is disturbed.
- In one documented case, secondary grassland plants were still growing taller than old-growth species 300 years after regeneration began, exposing the illusion that abandoning land allows nature to heal itself.
- Researchers are pressing for active restoration—seed sowing, transplanting native species—as the only viable path, while warning that protecting surviving ancient grasslands must come first.
- The urgency is amplified by scale: grasslands cover nearly a quarter of Earth's land surface, store vast amounts of carbon, and sustain the livelihoods of over a billion people whose dependence on these ecosystems is already under strain.
Across six continents, a sweeping study of grassland ecology has arrived at a conclusion that humbles human assumptions about nature's resilience: some losses, once made, echo for centuries. Ancient grasslands—shaped by millennia of drought, fire, and grazing—harbor slow-growing plants whose very patience makes them vulnerable when disturbed, unable to reclaim ground seized by faster, opportunistic species. The research, published in the Proceedings of the National Academy of Sciences, reminds us that what we call 'recovery' is often merely a different kind of landscape wearing the same name, and that for more than a billion people whose lives are woven into these ecosystems, the difference is not academic.
A research team studying grasslands across six continents has reached a disquieting conclusion: once destroyed, these ecosystems may never truly return to what they were. Published in the Proceedings of the National Academy of Sciences, the study analyzed 742 plant species to understand why grasslands that regrow after disturbance remain fundamentally different from the ancient ones they replace—and found that the pattern holds everywhere, from the Americas to Africa to Asia.
The explanation lies in biology. Old-growth grasslands are defined by slow-growing perennials with tough leaves—plants shaped over millennia to endure drought, fire, and grazing. That resilience comes at a cost: when disturbed, these species cannot compete with faster-growing plants that rush in to claim water, nutrients, and sunlight. In the pine savannas of the southeastern United States, for example, drought-tolerant wiregrass is crowded out by faster-reproducing annuals. The structural consequences persist long after the initial disturbance; in one case studied, secondary grassland plants remained taller than old-growth species even 300 years into regeneration.
The researchers are clear that passive restoration—simply abandoning disturbed land—is not enough. Co-author Lars Brudvig of Michigan State University argued that sowing seeds and transplanting native species are essential, not optional. Lead author Ashish Nerlekar of IISER Pune added that the more urgent priority is protecting what remains: ancient grasslands, once lost, are extraordinarily difficult to recover.
The stakes reach well beyond ecology. Grasslands cover nearly a quarter of Earth's land surface, anchor the livelihoods of more than a billion people, reduce erosion, and store significant amounts of terrestrial carbon. Centuries of conversion to cropland and urban development have already claimed vast tracts, while abandoned agricultural land has produced secondary grasslands that resemble the originals in appearance but not in function. The researchers acknowledged that further work is needed to quantify the differences in carbon storage and nutrient cycling—but on the central question, their finding is already plain: prevention is far more effective than any cure.
A team of researchers examining grasslands across six continents has reached a sobering conclusion: once destroyed, these ecosystems may never fully return to what they were. The study, published in August in the Proceedings of the National Academy of Sciences, analyzed 742 plant species to understand why grasslands that regrow after disturbance remain fundamentally different from the ancient, undisturbed grasslands they replace.
The pattern holds everywhere. Whether in North or South America, Africa, Asia, or elsewhere, the ecological gap between old-growth and secondary grasslands is consistent and persistent. Ashish Nerlekar, the lead author now at IISER Pune, and his collaborators found that the slow recovery documented in earlier work—where some plant species remain absent even after centuries—has a clear biological explanation. The plants that characterize ancient grasslands are slow-growing perennials with tough leaves, traits that allow them to endure drought, grazing, and fire but come at the cost of sluggish reproduction. When these grasslands are disturbed, they lose their competitive edge. Faster-growing species move in, better equipped to capture water, nutrients, and sunlight before the native plants can establish themselves. In the pine savannas of the southeastern United States, for instance, wiregrass—a drought-tolerant perennial typical of old-growth systems—gets crowded out by faster-reproducing annuals like white goosefoot.
The consequences linger far longer than intuition might suggest. Secondary grassland plants often grow taller, giving them an advantage in the race for sunlight, and this structural difference can persist for centuries. In one case examined by the researchers, secondary grassland plants remained taller than their old-growth counterparts even 300 years after regeneration began. The implication is stark: simply abandoning disturbed land and letting nature take its course will not restore what was lost.
Lars Brudvig, a professor at Michigan State University and co-author of the study, emphasized that active intervention is necessary. Sowing seeds and transplanting native species are not optional extras but essential tools if secondary grasslands are to function like the ancient ones they replaced. Nerlekar stressed a complementary point: the real priority must be protecting existing old-growth grasslands in the first place. Once destroyed, they are extraordinarily difficult to recover.
The stakes are substantial. Grasslands cover nearly a quarter of the Earth's land surface and anchor the livelihoods of more than a billion people globally, providing habitat, fodder, and critical ecosystem services. Their root systems reduce water runoff and erosion, and their soils store a significant portion of the carbon held in terrestrial ecosystems. Yet over the past two centuries, vast tracts of ancient grassland have been converted to cropland, plantations, and urban development. At the same time, abandoned agricultural land has created new secondary grasslands—ecosystems that look like grasslands but function differently. The researchers acknowledged that further study is needed to measure how these differences affect carbon storage, nutrient cycling, and other ecosystem services. What is already clear is that restoration cannot be passive, and prevention is far more effective than cure.
Citations marquantes
Differences between old-growth and secondary grasslands are remarkably consistent around the globe— Lars Brudvig, Michigan State University
Simply abandoning disturbed land and allowing it to regrow naturally may not be enough to recreate the ecological characteristics of ancient grasslands— Study findings
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