Scientists say it is a striking example of the way seemingly small climatic changes are disturbing the balance of nature. They see these changes as a warning of the costly impact that is likely to come with continued high emissions of greenhouse gases.
The disturbances are also raising profound questions about how to respond. Old battles about whether to leave nature alone or to manage it are being rejoined as landscapes come under stress.
The New Jersey situation resembles, on a smaller scale, the outbreak of mountain pine beetles that has ravaged tens of millions of acres of forest across the Western United States and Canada. That devastation, too, has been attributed to global warming — specifically, the disappearance of the bitterly cold winter nights that once kept the beetles in check.
In contrast to the West, where dying evergreens are splayed across steep mountainsides for all to see, the invasion in New Jersey has received barely any notice. The state’s pine forests occupy relatively flat land, and the scope of the damage is obvious only from the air.
“It’s a tremendously serious issue, but it hasn’t gotten anybody’s attention,” said State Senator Bob Smith, a Democrat from Piscataway and the chairman of the Environment and Energy Committee.