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Wildfires, wildflowers

Out of the ashes

Carol Kaesuk Yoon wrote much of the story below in 1999, from which this is adapted — giving credit, of course. Her story was beautiful. I merged text from my ‘Let There Be Life’ (2002) . Here is Wildfires, wildflowers …

¶ ‘Ninety million years ago, on what [was, in 1999] an empty lot in Sayreville, New Jersey, a tropical forest went up in flames. The canopy of this ancient forest must have been open enough to let light reach the ground because the forest floor beneath the trees was cloaked in wildflowers. The fire raged through the trees, littering the ground with hot ash which buried the low-growing plants on the forest floor.’

publicdomainpictures.net // Public Domain

Wildfires, wildflowers

This had the effect of cooking the ground-hugging plants in the embers, preserving their flowers, leaves and buds as fossils transformed into charcoal. Writing in the New York Times, Carol Kaesuk Yoon described the result as ‘the most bountiful and exquisitely preserved cache of ancient flowers in the world.’ [1] Thus wildfires, wildflowers. The fire likely had the effect of opening the canopy so that a new crop of living flowers grew through the nutrient-rich ashes, as well.

The site reveals more than two hundred species of flowering plants, including ancestral oaks, pitcher plants, magnolias, and species related to carnations, azaleas, tea shrubs and water lilies. Most remarkable, the fire that destroyed the forest had the effect of preserving the exact forms of flowers in the embers, down to the level of single cells. After wildfires, wildflowers grow profusely.

It used to be thought that the burgeoning evolution and divergence of flowering plants took place much later. It came as an enormous, and pleasant, surprise to botanists to discover that angiosperms (flowering plants) diverged so long ago. The very fact that the Sayreville site was home to so many species tells us that the divergence of flowering plants was well under way.

Wildfires, wildflowers, flowers (Clusia lanceolata)

(Clusia lanceolata) Red-Heart Porcelain Flower. Photograph: https://www.logees.com

Insects and flowers

The diverse shapes and relative dimensions of flowers in the Sayreville array suggest that insects, too, had diversified, with specific insect species pollinating specific species of flower. One theory holds that insects and flowering plants went through an explosive evolutionary phase together. If so, their rapid divergence was mutually dependent: specific flowers evolved to take advantage of specific flying insects as pollinators; meanwhile, specific insects adapted their bodily form to serve, and be nourished by, specific host flowers. These two groups, flowering plants and insects, account for the vast majority of living species in our world. Which group drove the great divergence: insects or flowering plants? Surely it was both, changing in tandem with each other, changing for mutual advantage, mutually recognized. We may never know for sure. But, thanks to the Sayreville array, we do know that this process of mutual change and divergence is much, much older than was previously thought.

Wildfires, wildflowers, bees. USGS. Public Domain

~ Melipona, Stingless bee. ~ USGS Bee Inventory/Monitoring Lab, Beltsville, Maryland. Public Domain. Photo info below, [2]

Consider the example of Paleoclusia. (Many of these preserved charred fossil flowers are shown in the American Journal of Botany.) This ancient species, found at the Sayreville site, is the ancestor of modern plants in the Clusia family. Modern relatives produce a sticky resin which tiny tropical, stingless bees (Melipona and Trigona) use to build nests and protect themselves against attack by ants. The ancient fossil flowers contain resin channels similar to modern ones.

Back in time, past expectation

This came as a surprise to researchers who had no record of such bees living ninety million years ago. However, as if to oblige, a fossil melipone bee of appropriate age has now been found preserved in amber.

Which came first, the sticky plant resin or a bee adapted to make use of it? However plant and animal came to serve each other, they reached their mutual arrangement ninety million years ago. The plant and the insect have enjoyed a stable relationship ever since.

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[1]  Carol Kaesuk Yoon, in the New York Times:  https://www.nytimes.com/1999/12/21/science/tiny-fossils-botanists-see-flowery-world-empty-lot-yields-trove-ancient-plants.html?rref=collection%2Fbyline%2Fcarol-kaesuk-yoon

[2] Photo information: Canon Mark II 5D, Zerene Stacker, Stackshot Sled, 65mm Canon MP-E 1-5X macro lens. Source: https://en.wikipedia.org/wiki/Melipona#/media/File:Stingless_bee_3,_f,_side,_peru_2014-07-30-13.17.15_ZS_PMax_(15839098322).jpg