A rugged, whitewater river flowing northward through deep canyons, the New River is among the oldest rivers on the continent. New River Gorge National River in West Virginia encompasses over 70,000 acres of land along the New River, is rich in cultural and natural history, and offers an abundance of scenic and recreational opportunities.
Big Southern Butte is one of two domes rising from a sea of basalt near the center of the eastern Snake River Plain in Idaho. The butte is one of the largest volcanic domes in the world, but at 300,000 years old it is also one of the youngest. Hikers who trek to the 7,550-foot high summit are rewarded with spectacular panoramic views. Photo by Devin Englestead, BLM Upper Snake Wildlife Biologist.
First light at Bosque del Apache National Wildlife Refuge in New Mexico. Established in November 22, 1939, the refuge has provided a critical stopover and wintering spot for thousands of sandhill cranes, geese and other waterfowl for 75 years. Bosque del Apache's sandhill crane population has multiplied from 18 birds in the 1840s to more than 20,000 birds today. Photo by Kim Hang Dessoliers (www.sharetheexperience.org).
Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer.