Trees are often celebrated as a universal solution to environmental challenges. They absorb carbon, prevent soil erosion, provide shade, and support wildlife. But a new study by Hiroshima University suggests that the relationship between trees and biodiversity is more complex than it appears.
Researchers examining shelterbelts, rows of trees planted along farmland to protect crops from strong winds, found that while these tree lines can benefit some bird species, they may simultaneously harm others. In particular, birds that depend on open grasslands and wetland habitats were found to be less abundant and less diverse in areas close to shelterbelts.
The findings challenge a widely held belief that increasing tree cover automatically leads to greater biodiversity. According to environmentalist Jasmit S. Arora, also known as the ‘Gutliman of India’, the study highlights an important ecological reality. “This new research fundamentally challenges the common assumption that planting more trees always improves overall biodiversity,” he says. “While shelterbelts benefit forest-edge and shrub species, they create ecological walls that severely harm grassland and wetland birds.”
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to.
The research found that the abundance of grassland birds dropped significantly near tree lines. Arora explains that this is likely because trees fragment open habitats and increase exposure to predators that use branches as perches.
“This clearly demonstrates that conservation is not a one-size-fits-all approach,” he notes. “Simply adding trees creates winners and losers, proving that well-intentioned landscape changes can have drastic, unintended consequences for open-habitat species.”
Finding the right balance
As climate change intensifies, many governments are promoting tree-planting initiatives to strengthen agricultural resilience. However, Arora argues that policymakers need a more nuanced strategy.
“To balance climate-resilient agriculture with the protection of open-habitat species, policymakers must shift from a blanket ‘more trees’ approach to context-specific land management,” he says.
One solution is strategic spatial planning. Sensitive grassland and wetland habitats can be identified and designated as tree-free conservation zones, while shelterbelts can be established in areas where they do not fragment critical ecosystems.
Trees are often celebrated as a universal solution to environmental challenges (File photo)
Arora also recommends rethinking shelterbelt design. “Instead of dense, tall rows of trees that act as ecological walls, guidelines can promote lower-density planting, shorter vegetation, or native shrubs,” he explains. Such approaches can still protect crops while reducing risks to open-habitat birds.
He further suggests incentivising alternative climate-smart agricultural practices, including no-till farming, cover cropping, and retaining crop stubble, which can improve soil health and reduce wind erosion without introducing structures that disrupt bird habitats.
Lessons for global tree-planting campaigns
The study carries important implications for large-scale afforestation and restoration efforts around the world.
“Conservationists must respect the ‘right biome, right place’ principle,” says Arora. “Trees do not belong everywhere. Many threatened ecosystems, such as grasslands, savannas, and wetlands, are naturally open. Blanket afforestation in these areas is not restoration; it is habitat destruction.”
He also believes that conservation success should no longer be measured simply by the number of trees planted.
“High tree counts can cause net biodiversity loss if they displace specialised open-habitat species,” he says. “Success metrics must shift towards holistic ecological health, measuring the survival of all native species, not just trees.”
Beyond tree counts
Rather than focusing solely on increasing tree cover, Arora advocates for creating habitat mosaics that accommodate multiple species.
“Restoration should aim for diverse landscapes that include open fields, wetlands, native shrubs, and carefully planned tree cover,” he says. “No single intervention benefits every species.”
Ultimately, the study serves as a reminder that effective conservation requires understanding the unique needs of local ecosystems.
“Ecological context is everything,” Arora concludes. “We need to move beyond the simplistic idea that ‘trees are always good’ and embrace a science-based approach that recognises both the benefits and trade-offs of every conservation action.”
DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to.
Trees are often celebrated as a universal solution to environmental challenges (Photo: AI) 
Trees are often celebrated as a universal solution to environmental challenges (File photo)
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