Climate change wreaks havoc on microbial diversity
Many potential effects of climate change on humans, wildlife and plants are relatively well understood. Higher temperatures and extreme weather events can cause food insecurity, habitat lossand the decline or extinction of species living beings. However, it is also important to discuss how climate change may affect microorganisms or the small living beings found all over the planet that the naked eye cannot see.
Microorganisms are the earliest known life forms on earth. They play a critical role in ecological processes like organic matter decomposition, nutrient recycling, soil aggregation and even pathogen control. Their abundance and diversity help maintain a stable and healthy global ecosystem. However, if microbial diversity were to change, the ability of other organisms to respond to climate change could be affectedtoo.
A study Posted in Natural microbiology this month reported that long-term global warming is reducing microbial biodiversity in grassland soil. The authors conducted a seven-year experiment to observe changes in microbial communities in response to climatic changes such as warming, changing precipitation, and annual biomass removal. They found that the richness of bacteria, fungi and protists decreased.
Microbial diversity is essential in maintaining soil health and quality and achieving function as a living system that sustains biological productivity and sustains the health of plants and animals. Unfortunately, loss of microbial diversity is associated with loss of function. This bodes ill for humans, as it translates to a decreased ability to grow crops, increased environmental damage, and a reduced ability to fight microbes and plant pathogens, says Martin J. Blaser, holder of the Henry Rutgers Chair of the Human Microbiome at Rutgers University, who was not involved in the study.
To sustain food production for a growing human population, farmers need for healthy soils. Climate change, through the reduction of microbial diversity, may not only affect our ability to grow food, but also results in some foods with lower nutritional value, says Blaser. Indeed, microbial diversity is necessary to promote nutrient uptake and allow plants to more easily obtain essential minerals and micronutrients from the soil.
[Related: Bacteria wars are raging in soil, and it’s keeping ecosystems healthy.]
More than two billion people around the world are already suffering from micronutrient deficiencies, leading to various health problems such as cardiovascular diseases, congenital disabilities and mental health problems. For example, many children in China lack iron and zinc, which can derive deficiencies of these elements in soils and foods. In 2007, about 40 percent of the total land area in China lacked iron and zinc.
“Human well-being is directly linked to microbes,” says Jay T. Lennon, a professor in the Department of Biology at Indiana University who was not involved in the study. “Of course, our health is intimately affected by the trillions of microbes that live on and in us. But, in nature, they also have to bring essential services, in terms of breaking down contaminants, purifying water and ensuring the fertility of soils needed to feed a growing planet.
An essential role of germs is to reduce contaminant levels in crops, which is crucial because pathogen contamination of fresh produce poses a pressing threat to human health. For example, eating contaminated vegetables grown in soil amended with uncomposted animal manure can allow pathogens like Salmonella and E.coli enter the human body. Also, some plant defenses don’t work as effectively when temperatures get too high, making them more susceptible to pathogens. Overall, soil microbial diversity helps repress soil pathogenic organisms due to the complex interactions that occur below the ground and potentially inhibit the development or persistence of pathogens.
“Scientists are concerned about how climate change will affect Distribution diseases such as cholera, but also emergence new pathogens,” says Lennon. “Plant and animal hosts form complex relationships with microbial symbionts. It is currently unclear how climate change will alter these relationships and what the consequences will be.
Ultimately, it is crucial to protect biological diversity — the variety of everything life on Earth — for maintain the stability of the global ecosystem. The loss of biodiversity is leads by climate change, but this decline in biodiversity can also accelerate climate change, making it a positive feedback loop. For example, the instability of ecosystems due to the loss of biodiversity weakens the Earth’s ability to regulate greenhouse gas (GHG) emissions and prevent extreme weather events, which, in turn, amended the structure of many ecosystems and makes species more vulnerable.
Since you can’t see the germs, it can be harder to protect them. Some studies show that the degree of understanding of microbial ecosystems and their services must increase at the same level of knowledge with plants and animals before they are taken seriously in conservation initiatives and policies. Yet protecting flora and fauna remains vital, because as some plants and animals die out, microbes associated with them can also disappear.
“In a certain way, [the] conserving plants and animals will also help maintain their associated microbiota,” says Lennon. “For example, a recent article explains how “acoustic restoration” – that is, working to restore natural soundscapes – contributes to conservation efforts, including maintaining ecosystems.
Blaser says the loss of microbial diversity may also be due to the use of fertilizers, pesticidesand monoculture practices. Specific solutions, such as the reduction use of chemical pesticides and crop diversification, will likely reduce the negative impact on microbial diversity. The fight against climate change requires all kinds of attention, and biodiversity the loss must be addressed, including the living beings we depend on and which hardly ever cross our minds.