In addition to hypothesized theories involving global warming and non native viruses as reasons for amphibian decline across the planet, it is now found that the non native(to the USA) European Buckthorn plant now found across the Eastern and Midwestern USA gives off the chemical Emodin which seeps into frog breeding pools and kills them.................Somehow, the chemical interferes with frog and salamander embryos, preventing hatching................Readers of this blog, you are urged to use only plants native to your part of the world in your gardens..................Too many exotics ripping deep fissures in our natural fissures both here and abroad

Midwestern Frogs Decline, Mammal Populations Altered by Invasive Plant, Studies Reveal

sciencedaily.com — Researchers at Lincoln Park Zoo and Northern Illinois University have discovered a new culprit contributing to amphibian decline and altered mammal distribution throughout the Midwest region -- the invasive plant European buckthorn. This non-native shrub, which has invaded two-thirds of the United States, has long been known to negatively impact plant community composition and forest structure, but these two innovative studies slated to publish in upcoming editions of the Journal of Herpetology and Natural Areas Journal 

demonstrate how this shrub negatively impacts native amphibians and affects habitat use by mammals including increased prevalence of coyotes and other carnivores.

Amphibians are facing an extinction crisis worldwide, with 165 species likely having gone

 extinct in recent years according to the Amphibian Ark, a coalition of conservationists

 devoted to seeking solutions to the decline. Lincoln Park Zoo Reintroduction Biologist Allison

 Sacerdote-Velat, Ph.D. and Northern Illinois University Professor of Biological Sciences 

Richard King have identified European buckthorn as a contributor to amphibian decline in the

 Chicagoland area.

 The plant releases the chemical compound emodin, which is produced in

 the leaves, fruit, bark and roots of the plant, into the amphibian breeding pond environment 

at various times of year. Sacerdote-Velat and King's research has found that emodin is toxic

 to amphibian embryos, disrupting their development, preventing hatching.