Study Finds Forest Fragmentation Lowers Biodiversity Globally

A newly released study in Nature has supported that forest fragmentation has a direct negative impact on biodiversity globally. The research gives a conclusive answer to a debate spanning five decades as to the most effective approach to maintaining biodiversity following deforestation and habitat destruction.

The study contrasted information gathered from 37 biodiversity surveys that had been carried out on six continents in over 4,000 species with varying forest regimes. Fragmented forests, the study found, harbored a mean 12% less species than larger, intact patches of similar size. Species richness persisted even when the effect of covariates including general forest size and among-patch spatial fragmentation was accounted for.

This means that, when forests are fragmented into patches, they are not as effective in supporting a variety of wildlife. Fragmentation breaks up species populations, limits gene flow, and decreases ecosystem functioning so that forests are more vulnerable to stresses from outside such as climatic change.

Loss of biodiversity was not only seen at the patch level but also at the landscape level as a whole. The research incorporated alpha, beta, and gamma diversity estimates—the terms that have been applied to describe diversity within a patch, between patches, and between landscapes. Contrary to previous statements that patchy habitat can create more diversity between patches, evidence did not demonstrate a significant "biodiversity bonus" once distances among patches were accounted for.

The research indicates that larger, intact forests are more effective at supporting species and the environment. They maintain stable populations, can accommodate species migration, and form microclimates that allow species to adapt to changes in temperature, drought, and other conditions.

The authors say that conservation has to be for the protection and defense of large, unbroken forest blocks. Wherever forests have already been lost or degraded, especially in urban or high-density landscapes, there must be an attempt at restoring them. Returning native tree species, wildlife corridors, and reconnecting isolated fragments can reverse processes of ecology lost.

These same discoveries are made about forests. Maybe the same applies to grasslands, wetlands, coral reefs, and all the rest, too. The same rule never changes: more and larger habitats are required in order to promote biodiversity.

In conservation policy and planning, the study indicates that intact nature must be preserved through working at a landscape scale. It cannot be preserved in protection areas as remnants of broken-up nature, but as part of a system that is integrated. Land use planning must take into consideration not only how much is going to be lost, but how what remains is planned.

As additional pressure is put on it by climate, the bigger woods become a more significant factor. Larger woods consist of diverse microhabitats that serve as refugia for mass casualty incidents and store widespread and threatened species during times of transition.

The research also gives recommendations to resource-constrained organizations. Instead of attempting to save space just to save space, effort must be put into saving patches of habitat that are more valuable ecologically.

With the world still rapidly losing species at an unprecedented rate, this study has a straightforward message: forest fragmentation should be prevented and conservation measures that address the connectivity, size, and integrity of native habitat. To do so is not only crucial for wildlife, but for the long-term integrity of the ecosystems upon which human life relies.

Source and Credits:
Posted on: 7 July 2025. By Nature research. Written by Cyrene Oraya Reyes.