Ecological succession is the process of how species compositions change in an ecological community over time.
The two main categories of ecological succession are primary succession and secondary succession. Primary succession occurs after the initial colonization of a newly created habitat with no living organisms. Secondary succession occurs after a disturbance such as fire, habitat destruction, or a natural disaster destroys a pre-existing community.
A beech–maple forest or a maple beech forest is a climax mesic closed canopy hardwood forest. It is primarily composed of American beech and sugar maple trees which co-dominate the forest and which are the pinnacle of plant succession in their range. A form of this forest was the most common forest type in the Northeastern United States when it was settled by Europeans and remains widespread but scattered today.
Snowpack is an accumulation of snow that compresses with time and melts seasonally, often at high elevation or high latitude. Snowpacks are an important water resource that feed streams and rivers as they melt, sometimes leading to flooding. Snowpacks provide water to down-slope communities for drinking and agriculture. High-latitude or high-elevation snowpacks contribute mass to glaciers in their accumulation zones, where annual snow deposition exceeds annual melting.
Assessing the formation and stability of snowpacks is important in the study and prediction of avalanches. Scientists study the physical properties of snow under different conditions and their evolution, and more specifically snow metamorphism, snow hydrology (that is, the contribution of snow melt to catchment hydrology), the evolution of snow cover with climate change and its effect on the ice–albedo feedback and hydrology, both on the ground and by using remote sensing. Snow is also studied in a more global context of impact on animal habitats and plant succession. An important effort is put into snow classification, both as a hydrometeor and on the ground.