Succession is essentially the replenishing and spring cleaning of an ecosystem in many ways, from nutrients and species, to other chemical processes. Many different species get to cycle through existence and dominance in succession, and can be characterized by how fast they replenish themselves after a system-changing event, such as a fire.
Primary succession is when a successional cycle starts in an area that has not been affected by a successional cycle-starting event, such as a fire. Secondary succession cycles begin in an area that has hosted a successional cycle before.
During succession, the physical conditions of the forest change over time (generally speaking, the physical environment becomes less extreme). Other changes also occur. Name three.
– Nutrient cycling is more efficient and closed-loop, decreasing the need for nutrients outside the system
– Species improve the intricate relationships they have with other species
– Structures of ecosystems become more intricate as well
A keystone species is a species directly linked to the health and well being of an ecosystem. Like a keystone in a stone arch, it holds together the ecosystem and is responsible for the entirety of its existence. Its disappearance does unprecedented damage to the environment. Some play very beneficial roles in the soil structure and initiate processes in the ecosystem.
An indicator species is one that is a symbol of the condition of a habitat. Like a traffic light at a bridge crossing, for instance, an indicator species’ population has a direct relationship with the health of the ecosystem: the healthier it is, the more populous a species will be.
The spotted owl serves as an indicator species due to its reliance on mice for food. If the wood rats and mice cannot get sustenance, than the owl could suffer as a direct consequence.
3 benefits of snags to forest health.
– Food and shelter for birds and mammals
– Increase ecosystem complexity
– Provides food storage and refuge for animals
4 benefits of downed trees to forest health.
– Rotting trees return nutrients back to the soil
– Adds biomass to the soil
– Provides a surface for lichen and moss to grow upon
– Reduce prevalence of fire
3 ways litterfall contributes valuable nutrients to the forest floor.
– Provides food for epiphytes
– Rain dissolves nutrients from the canopy down the trunk
– Creatures that crawl around the forest floor, which are eaten by predators.
An “Old Growth” forest is characterized by many old trees amongst young and mature ones. To be considered an old growth forest, trees can be thirty-two inches in diameter and over two hundred years old, populated with many of them (usually eight or more per acre). There are many dead and fallen trees present in old growth forests, which provide nutrients, shelter, and ground cover for many species of animals and plants. Notably, many lichens and mosses grow on top of them, providing habitat for insects at the microclimate level. Old growth forests also have many layers in their canopies: vegetation at the bottom layer, followed by deciduous trees and young coniferous trees, and then the largest trees at the top.