A boreal ecosystem is an ecosystem with a subarctic climate located in the Northern Hemisphere, approximately between 50° to 70°N latitude. These ecosystems are commonly known as taiga and are located in parts of North America, Europe, and Asia. The ecosystems that lie immediately to the south of boreal zones are often called hemiboreal. There are a variety of processes and species that occur in these areas as well. The Köppen symbols of boreal ecosystems are Dfc, Dwc, Dfd, and Dwd. Boreal Species The species within boreal ecosystems varies as it consists of both terrestrial and aquatic habitats. The species composition include many generalized and less specialized feeders. From the equator to the poles, species richness decreases, and there is a negative relationship with species richness changes as climate changes. However, despite not being as biodiverse as tropical systems, this area has a variety of species. Boreal ecosystems are filled with a multitude of flora species from black and white spruce, to willows, wildflowers, and alders. Caribou, although not there year round, come down and into these regions during the winter to forage for lichen. A few fish species include salmonids, smelts, sticklebacks, lamprey and sculpins. For salmon these systems are vital: relying on the riparian systems within boreal ecosystems for multiple life stages in both the beginning and the end of their life cycle, sockeye rely on the provided freshwater environments as eggs, fry and adult stages. Succession Success and succession happen in tandem in boreal forests. Primary succession, while part of the original landscape formation, is not vital like secondary succession. Secondary succession consists of varied events: wildfires, flooding, mudslides and even excessive insect foraging act in this progression and cycle of boreal forests. Boreal Ecosystem-Atmosphere Study (BOREAS) The Boreal Ecosystem-Atmosphere Study (BOREAS) was a major international research field study in the Canadian boreal forest. The main research was completed between the years of 1994-1996, and the program was sponsored by NASA. The primary objectives were to determine how the boreal forest interacts with the atmosphere, how climate change will affect the forest, and how changes in the forest affect weather and climate. Climate change effects Boreal ecosystems display high sensitivity towards both natural and anthropogenic climate change. Due to greenhouse gas emissions, atmospheric warming ultimately leads to a chain reaction of climatic and ecological effects. The initial effects of climate change on the boreal ecosystem can include,