Matrix Quality part 1: The Unsung Hero of Landscape Health (and Why It Matters More Than You Think)
What Exactly Is the Matrix (No, Not the Movie)?
When people talk about habitat fragmentation, the conversation often focuses on the bits of nature that are left behind — the fragments. These are the patches of forest, wetland, or grassland that somehow survive when human activity carves up the landscape. But there’s something just as important that often gets ignored: the matrix — the land between those fragments.
The matrix is everything that fills the space between natural habitats — farms, roads, towns, industrial zones, and even low-intensity grazing land. And matrix quality — how friendly or hostile that land is to biodiversity — can make or break the health of a fragmented landscape (Fahrig, 2003; Haddad et al., 2015).
The Matrix is Everywhere — But It’s Not All Equal
Imagine you’re a dung beetle (stick with me here) living in a fragment of Renosterveld in the Klein Karoo. If the farmland next to you uses regenerative grazing practices, keeps some natural vegetation intact, and limits pesticide use, you might be able to move across that matrix without too much trouble. Maybe you find enough dung along the way to survive the journey. In this case, the matrix is relatively high quality — it doesn’t act like a hard barrier.
Now, imagine instead that the land around your fragment is heavily ploughed monoculture farmland, doused in chemicals, and cleared of any vegetation that isn’t the crop. Suddenly, that matrix becomes hostile territory — a biological desert you can’t easily cross. This low-quality matrix isolates your fragment, cutting off access to new food, mates, and genetic diversity (MacDonald et al., 2017; Ries et al., 2017).
Why Matrix Quality Matters More Than Ever
With global populations growing and pressure on land intensifying, the debate over land sharing vs. land sparing is only becoming more urgent. Do we intensively farm small areas and leave large fragments untouched (land sparing)? Or do we mix biodiversity-friendly farming into larger landscapes, blurring the line between natural and human spaces (land sharing)?
Matrix quality is the hinge point of that debate. A high-quality matrix makes land sharing more viable because species can move and ecosystem processes can function across a patchwork landscape. A low-quality matrix pushes us toward land sparing, because species need larger, unbroken fragments to survive at all (Fischer et al., 2014; Kremen, 2015). A balance is needed, then, of both high quality land sharing and land sparing.
It’s Not Just About Nature Reserves
This isn’t just a conservation issue for remote wilderness areas. Matrix quality matters in cities, farms, and even your backyard. Urban green corridors — strips of parkland, gardens, and roadside trees — can improve matrix quality for pollinators, birds, and small mammals in urban areas. On farms, techniques like cover cropping, agroforestry, and rotational grazing can soften the edges between agricultural and natural land, turning the matrix into a corridor rather than a wall (Keesstra et al., 2018).
Rewilding Needs Good Matrices Too
In my own research at Sanbona Wildlife Reserve, we studied how reintroducing megafauna like elephants, buffalo, and rhinos impacts soil, vegetation, and biodiversity. But what happens when those animals want to move between reserves, or into surrounding farmland? If the matrix is a barren, degraded landscape, they’re stuck — isolated populations in genetic silos. But if the matrix allows for some degree of movement — through corridors, well-managed grazing land, or cooperative private farms — then rewilding can extend beyond reserve boundaries (Svenning et al., 2016; Haddad et al., 2015).
Measuring the Matrix: A GIS Toolkit for Nature’s Health
The good news? Matrix quality isn’t just some abstract concept — it can be measured and mapped. In a GIS-based analysis, you can layer data on land use, species movement, habitat quality, and ecological vulnerability to see where high-quality matrices exist, and where they need improvement (Franklin et al., 2002; Kremen, 2015).
This is practical, applied science. With the right tools, conservation planners, farmers, and even municipal authorities can see their land as part of a bigger ecological puzzle — and figure out how to make their piece of the puzzle more hospitable to life.
Final Thought: It’s All Connected
If there’s one thing I’ve learned from studying rewilding and ecosystem health, it’s this: Nothing works in isolation. You can’t just protect a fragment, fence it off, and hope for the best. The health of that fragment depends on what happens around it — in the matrix. Whether you’re a policymaker, a farmer, or just someone who cares about nature, understanding and improving matrix quality might be one of the most powerful things you can do for biodiversity.
References:
Fahrig, L. (2003). Effects of habitat fragmentation on biodiversity. Annual Review of Ecology, Evolution, and Systematics, 34(1), 487–515.
Fischer, J., et al. (2014). Land Sparing Versus Land Sharing: Moving Forward. Conservation Letters, 7(3), 149–157.
Franklin, A.B., Noon, B.R., & George, T.L. (2002). What is habitat fragmentation? Studies in Avian Biology, 25, 20-29.
Haddad, N.M., et al. (2015). Habitat fragmentation and its lasting impact on Earth’s ecosystems. Science Advances, 1(2), e1500052.
Kremen, C. (2015). Reframing the land-sparing/land-sharing debate for biodiversity conservation. Annals of the New York Academy of Sciences, 1355(1), 52–76.
MacDonald, Z.G., et al. (2017). Decoupling habitat fragmentation from habitat loss. Oecologia, 186(1), 11–27.
Ries, L., et al. (2017). Closing Persistent Gaps in Knowledge About Edge Ecology. Current Landscape Ecology Reports, 2(1), 30–41.
Svenning, J-C., et al. (2016). Science for a wilder Anthropocene: Synthesis and future directions for trophic rewilding research. PNAS, 113(4), 898-906.
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