Although trees have responded to global warming in the past‐ to temperatures higher than they are now- the rate of change predicted in the 21st century is likely to be unprecedented. Greenhouse gas emissions could cause a 3°-6°C increase in mean land surface temperature at high temperatures and temperatures latitudes. Despite this, few experiments have isolated the effects of temperature for this scenario on trees and forests. This review focuses on tree and forest responses at boreal and temperate latitudes, ranging from the cellular to the ecosystem level. Adaptation to varying temperatures revolves around the trade- off between utilizing the full growing season and minimizing frost damage through proper timing of hardening in autumn and dehardening in spring.
The four bases in DNA are: adenine, thymine, cytosine, guanine. In RNA, thymine gets replaced by uracil. Purine is only a name for the two bases guanine and adenine.