Tropicalization of temperate ecosystems in North America: The northward range expansion of tropical organisms in response to warming winter temperatures.

Tropicalization is a term used to describe the transformation of temperate ecosystems by poleward-moving tropical organisms in response to warming temperatures. In North America, decreases in the frequency and intensity of extreme winter cold events are expected to allow the poleward range expansion of many cold-sensitive tropical organisms, sometimes at the expense of temperate organisms. Although ecologists have long noted the critical ecological role of winter cold temperature extremes in tropical-temperate transition zones, the ecological effects of extreme cold events have been understudied, and the influence of warming winter temperatures has too often been left out of climate change vulnerability assessments. Here, we examine the influence of extreme cold events on the northward range limits of a diverse group of tropical organisms, including terrestrial plants, coastal wetland plants, coastal fishes, sea turtles, terrestrial reptiles, amphibians, manatees, and insects. For these organisms, extreme cold events can lead to major physiological damage or landscape-scale mass mortality. Conversely, the absence of extreme cold events can foster population growth, range expansion, and ecological regime shifts. We discuss the effects of warming winters on species and ecosystems in tropical-temperate transition zones. In the 21st century, climate change-induced decreases in the frequency and intensity of extreme cold events are expected to facilitate the poleward range expansion of many tropical species. Our review highlights critical knowledge gaps for advancing understanding of the ecological implications of the tropicalization of temperate ecosystems in North America.

Gastric Outlet Obstruction Caused by Foley Catheter: A Complication when Substituting for Commercial Gastrostomy Tubes.

The technique of using percutaneous endoscopic gastrostomy (PEG) for long-term enteral feeding is well established and commonly used. While the technique is relatively safe and simple, the gastrostomy tube itself may deteriorate or malfunction, requiring a replacement tube. We present a case of a 58-year-old woman who was found to have gastric outlet obstruction from the inflated balloon of a Foley catheter being used as a replacement for her PEG tube. This case illustrates a potential complication of using a Foley catheter in place of commercially available gastrostomy tubes.