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A new study from Rice University has revealed a mechanism by which rising temperatures affect the decline of populations of organisms through increased intraspecific competition, which is critical for understanding the effects of global warming.
Discovering the hidden mechanism of extinction
Rising global temperatures pose a greater threat to ecosystems than previously thought. A study published in the journal Ecology has experimentally confirmed for the first time the link between warming and changes in population dynamics. Scientists led by Volker Rudolf conducted a series of controlled experiments in the laboratory. They focused on the study of Daphnia pulex, a small freshwater zooplankton.
“Our study provides an important missing detail in understanding the broader impact of warming on natural populations”, said Rudolph, a professor of biological sciences. The experiments showed that even when individual organisms appear healthy, the entire population can be at risk. The reason is that competition for limited resources increases at higher temperatures.
Every 7 degrees Celsius increase in temperature doubles the effect of intraspecific competitionThis discovery forces us to reconsider previous ideas about the thermal limits of population survival. When temperatures approach the physiological limit for a species, competition becomes a critical factor.
Unexpected results of experiments
The researchers manipulated temperature and population density under controlled conditions, recording changes in the dynamics of reproduction and survival of individuals. The results were ambiguous and complex.
Moderate warming (12-19°C) initially promoted population growth. This was due to increased metabolism and reproductive processes. However, with further temperature increases, the situation changed dramatically. Increased competition led to a population reduction of 50% at the highest temperatures studied.
“We know that warming increases metabolism and reproduction in ectothermic conditions, but we found that higher temperatures also create competition that limits survival and reproduction.”, – explained Lilly Stockset, the first author of the study. Previously, scientists assumed that warming was always beneficial for ectothermic organisms. The new study refutes this assumption.
Implications for biodiversity conservation
The mechanism identified has serious implications for species conservation strategies. Populations can disappear at temperatures well below their physiological tolerance limits, making it difficult to predict the impact of climate change on biodiversity.
“Our results suggest that many species may face rapid population declines long before they reach the limits of their thermal tolerance.”, – noted Zoe Neal, co-author of the study. The mechanism of intraspecific competition can affect even species that were considered resistant to temperature changesThis changes our understanding of ecosystem vulnerability.
Increased competition can also destabilize populations, increasing the risk of local extinctions, especially in environments with frequent temperature fluctuations. Such findings have important implications for modeling future changes in biodiversity.
Such studies provide critical information for developing effective conservation strategies. Understanding the underlying mechanisms helps predict which species need special attention. This allows preventive measures to be taken before it is too late.
The results of the study highlight the need for a comprehensive approach to studying the impacts of climate change. It is necessary to consider not only the direct physiological effects of temperature increases, but also complex ecological interactions. Only in this way can we effectively confront the challenges of global warming.
