Herself’s Houston Garden

Could a “hot” flower attract pollinators by serving as a reward in a plant-pollinator mutualism? Many flowering plants produce nectar and pollen as rewards in exchange for pollination services by insects and other animals. Interestingly, however, a few plants have flowers that also produce heat metabolically — so what is the adaptive function of this flower heating?

Susanne Renner from the University of Munich, Germany and Shi-Xiao Luo from the South China Botanical Garden, along with collaborators from China and Taiwan, were interested in determining whether there was a connection between the heating of flowers and the pollination services of flies in an ancient Chinese family, Schisandraceae. Although this family is quite widespread, including Asia and the Americas, its center of diversity is in China, which is one reason Renner and colleagues chose to examine this question in two Chinese Illicium species. Their novel findings are published in the July issue of the American Journal of Botany.

“A few flowers, usually ones pollinated by beetles or flies, produce heat to help scent emission or to create especially attractive egg laying sites for their pollinators,” Renner commented. “Usually such heating occurs only during flowering, simultaneous with the release of pollen and stigma receptivity. We discovered that in an Asian Illicium species, flowers reach their highest temperatures during early fruit development, and experiments revealed that this is for the exclusive benefit of the pollinator’s larvae, which develop in the spent flowers.” Read more, When flowers turn up the heat

Read the paper:
Flower heating following anthesis and the evolution of gall midge pollination in Schisandraceae

The world is a cooler, wetter place because of flowering plants, according to new climate simulation results published in the journal Proceedings of the Royal Society B. The effect is especially pronounced in the Amazon basin, where replacing flowering plants with non–flowering varieties would result in an 80 percent decrease in the area covered by ever–wet rainforest.

The simulations demonstrate the importance of flowering–plant physiology to climate regulation in ever–wet rainforest, regions where the dry season is short or non–existent, and where biodiversity is greatest.

“The vein density of leaves within the flowering plants is much, much higher than all other plants,” said the study’s lead author, C. Kevin Boyce, Associate Professor in Geophysical Sciences at the University of Chicago. “That actually matters physiologically for both taking in carbon dioxide from the atmosphere for photosynthesis and also the loss of water, which is transpiration. The two necessarily go together. You can’t take in CO2 without losing water.”

This higher vein density in the leaves means that flowering plants are highly efficient at transpiring water from the soil back into the sky, where it can return to Earth as rain.

“That whole recycling process is dependent upon transpiration, and transpiration would have been much, much lower in the absence of flowering plants,” Boyce said. “We can know that because no leaves throughout the fossil record approach the vein densities seen in flowering plant leaves.”

For most of biological history there were no flowering plants—known scientifically as angiosperms. They evolved about 120 million years ago, during the Cretaceous Period, and took another 20 million years to become prevalent. Flowering species were latecomers to the world of vascular plants, a group that includes ferns, club mosses and confers. But angiosperms now enjoy a position of world domination among plants.

“They’re basically everywhere and everything, unless you’re talking about high altitudes and very high latitudes,” Boyce said.

Dinosaurs walked the Earth when flowering plants evolved, and various studies have attempted to link the dinosaurs’ extinction or at least their evolutionary paths to flowering plant evolution. “Those efforts are always very fuzzy, and none have gained much traction,” Boyce said.

Boyce and Lee are, nevertheless, working toward simulating the climatic impact of flowering plant evolution in the prehistoric world. But simulating the Cretaceous Earth would be a complex undertaking because the planet was warmer, the continents sat in different alignments and carbon– dioxide concentrations were different.

“The world now is really very different from the world 120 million years ago,” Boyce said. Read more

Read the paper
An exceptional role for flowering plant physiology in the expansion of tropical rainforests and biodiversity

A new national map of the ecosystems of America could help keep healthy species from ending up endangered.

Through ground and satellite surveys of land cover, the U. S. Geological Survey’s Gap Analysis Program has generated data that conservationists may be able to use to create and sustain habitat for wildlife.

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More importantly the map show areas being lost. While you can’t save the world you can save your little piece of it with smart landscaping.

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GAP Keeping common species common
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