Despite ongoing global warming, the rate of change within ecosystems is not accelerating; in fact, it is slowing down. Research indicates that this decline may signal a gradual weakening of nature’s natural recovery mechanisms, a process linked to the loss of biodiversity.

Expectations and New Observations

It was previously assumed that as global temperatures rose and climate zones shifted, ecosystems would adapt more rapidly. The expectation was that higher temperatures would lead to faster species migration, local extinctions, and the swift colonization of new areas, thereby increasing the rate at which species turnover occurs within communities.

However, an analysis of extensive biodiversity data from marine, freshwater, and terrestrial ecosystems over the past century has revealed the opposite trend. The speed at which species replace one another in local communities (the so-called “turnover”) has significantly decreased.

The Impact of Global Warming on Species Turnover

The study focused on the period since the 1970s, when the pace of global warming accelerated. Researchers compared species turnover rates before and after this period. If climate change were the main driver, turnover should have increased. Yet, the data showed that over short time spans (1–5 years), the rate of species turnover generally declined. This trend was observed across various ecosystems—from terrestrial bird communities to marine benthic organisms.

Internal Ecosystem Dynamics

To explain these results, scientists considered not only external climatic factors but also the internal organization of ecosystems. It was found that ecosystems function not just under the influence of temperature, but also through internal biological interactions. In the “multiple attractor” phase, species continually replace each other even under stable external conditions, maintaining ecosystem dynamics. The new study provided evidence for the existence of this phase and its crucial role in shaping ecosystems.

Biodiversity Loss and Environmental Degradation

The slowdown in species turnover is linked to environmental degradation and the shrinking of regional species pools. In a healthy ecosystem, a broad regional pool ensures a steady influx of new species, sustaining the cycle of replacement. Habitat destruction and declining biodiversity reduce the number of potential colonizers, which in turn slows down species turnover.

The findings suggest that ecosystems appearing stable are not necessarily healthy. A slowdown in local species turnover may indicate a broader depletion of biodiversity and a weakening of the natural processes that support ecosystem dynamism and resilience.