Collapsing ecosystems

The Proceedings of the National Academy of Sciences recently issued a report on the status of arthropods in rainforests. The report’s shocking analysis discovered a collapsing food web in tropical rainforests. Can ecological news get any worse than this?

Biologists Brad Lister and Andres Garcia of the Universidad Nacional Autónoma de México returned to Puerto Rico’s Luquillo Rainforest after 40 years, and what they found blew them away. The abundance of insects, and arthropods in general, declined by as much as 60-fold and average temps had risen by 2 degrees Centigrade over the past four decades. According to the scientists, global warming is impacting the rainforest with distinctive gusto.

It doesn’t get much worse than “crashing” of ecosystem support systems, i.e., insects and arthropods in general, which are in the phylum Euarthropoda, inclusive of insects, arachnids, myriapods, and crustaceans. This equates to a loss of basic structures of biosphere life forces.

The research team believes they are already seeing today what the recent IPCC report predicted for climate change in 2040. In their words: “It’s a harbinger of a global unraveling of natural systems.”

“The central question addressed by our research is why simultaneous, long-term declines in arthropods, lizards, frogs, and birds have occurred over the past four decades in the relatively undisturbed rainforests of northeastern Puerto Rico. Our analyses provide strong support for the hypothesis that climate warming has been a major factor driving reductions in arthropod abundance, and that these declines have in turn precipitated decreases in forest insectivores in a classic bottom-up cascade.”

Lister and Garcia also compared insect abundance studies conducted in the Chamela-Cuixmala Biosphere Reserve in western Mexico in 1980 to the year 2014, finding temps increased 2.4 degrees Centigrade and biomass of insects, and arthropods in general, declined 8-fold.

Their report prompts all kinds of questions about the health and stability of the world’s ecosystems. For one, tropical rainforests are the final frontier of pristine wilderness in the world. People do not live there and other than scientists, few people visit.

Therefore, if arthropods or invertebrate animals like insects and spiders are crashing in abundance, then something is horribly amiss. After all, the Luquillo is a protected rainforest, but alas, that doesn’t prevent the impact of global warming, which is on the rise in the tropics.

Already, it was reported back in March of 2018 that insect losses of 40% up to 80% were happening around the world outside of and beyond tropical rainforests.

Now, it appears that insect loss is truly global, not missing a corner of the planet. It’s everywhere. That’s worse than bad news; it’s dreadful. It’s indicative of a living planet in its early stages of dying throes but still hanging in there. Nobody knows for how much longer.

The big question is: What are the consequences of loss of large portions of insect life? Answer: All living things in the food chain above insects also decrease in abundance or in plain English, they die, e.g. frogs, lizards, and birds and ultimately Homo sapiens, assuming ecosystems eventually crumble.

This article has been excerpted from: ‘Collapsing Rainforest Ecosystems’.

Courtesy: Counterpunch.org