Balance of nature: importance of ecosystems (Introduction)

by David Turell , Wednesday, March 24, 2021, 19:07 (1339 days ago) @ David Turell

A new study on deforestation and its bad effects:

https://www.theguardian.com/environment/2021/mar/24/disease-outbreaks-more-likely-in-de...

"Outbreaks of infectious diseases are more likely in areas of deforestation and monoculture plantations, according to a study that suggests epidemics are likely to increase as biodiversity declines.

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"Even tree-planting can increase health risks to local human populations if it focuses too narrowly on a small number of species, as is often the case in commercial forests, the research found.

"The authors said this was because diseases are filtered and blocked by a range of predators and habitats in a healthy, biodiverse forest. When this is replaced by a palm oil plantation, soy fields or blocks of eucalyptus, the specialist species die off, leaving generalists such as rats and mosquitoes to thrive and spread pathogens across human and non-human habitats. The net result is a loss of natural disease regulation.

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"The researchers examined the correlation between trends for forest cover, plantations, population and disease around the globe using statistics from international institutions such as the World Health Organization, the World Bank, the Food and Agricultural Organization and the Gideon epidemic database. Over the period of study from 1990 to 2016, this covered 3,884 outbreaks of 116 zoonotic diseases that crossed the species barrier and 1,996 outbreaks of 69 vector-borne infectious diseases, mostly carried by mosquitoes, ticks or flies.

"The paper shows outbreaks increased over time, while plantations expanded rapidly and overall forest cover declined gradually. By itself, a correlation is not proof of causality because other factors may be involved, such as climate disruption. The authors bolster their argument with multiple references to individual case studies that highlight the links between epidemics and land use change.

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"The new study adds to a growing body of evidence that viruses are more likely to transfer to humans or animals if they live in or near human-disturbed ecosystems, such as recently cleared forests or swamps drained for farmland, mining projects or residential projects.

"This is shaped by trade patterns and consumer behaviour. A quarter of global forest loss is driven by the production of commodities such as beef, soy, palm oil and wood fibre. Mining adds to this problem by contaminating rivers and streams that are vital for a resilient ecosystem, carbon sequestration and soil quality.

"Morand said his study showed that disease risks needs to be added to risk-benefit analysis of new projects. “We should take the costs of public health into account when considering new plantations or mines. The risks are first to local people, but then worldwide because we have seen with Covid how quickly diseases can spread.'”

Comment: Same old point: all original ecosystems are exquisitely balanced. They should not be disturbed.