Pioneer Species - the first organisms that live in a previously uninhabited area
Climax Community-the culmination of succession, in which there is a sufficiently stable ecosystem
Tolerance - an approach to succession with the idea that all species involved in succession are equally capable of being pioneer species; however, those that can reproduce quickly are the most dominant pioneers
Inhibition - an approach to succession with the idea that all species involved can be pioneers, but some species, such as those that release toxins into the soil, can make the site less suitable for other species
Facilitation - an approach to succession with the idea that pioneer species (species with the best ability to settle a new area) help make the area more suitable for other species (thus facilitating their movement into the area); as more species move in, there is more competition (Succession)
What is primary and secondary succession?
Primary Succession: establishment and development of an ecosystem in an area that was previously uninhabited
Secondary Succession: reestablishment of a damaged ecosystem in an area where the soil was left intact (Nowicki)
Primary Succession in the Amazon Rainforest
Landslides help begin primary succession by causing companies to abandon strip mines (uninhabited areas); the landslides also help place soil in the mines for plants to grow
Pioneer Species: Salix humboldtiana (the Humboldt’s Willow), Cecropia latiloba, and Senna reticulata (the maria mole)
These plants have very fast growth rates, allowing them to colonize new, fertile areas very quickly
Climax Community: strangler figs, jaguars, velvet worms, and kapok trees
strangler figs move in after the first plants take hold; they help regulate the amount of plant growth so that the soil’s nutrients are not completely depleted
Jaguars (carnivores) help regulate animal populations in the area, keeping any certain species from growing out of control; they move in after herbivores & omnivores take hold
Velvet worms help restore nutrients to the soil, benefiting plant populations
Kapok trees offer wide canopies, thus restoring the rainforest to its usual condition; they move in after soil has reached a high quality (Parolin)
Secondary Succession in the Amazon Rainforest
Wildfires and flooding begin the process of secondary succession
Wildfires clear out large portions of the rainforest, but the heat from the fire helps certain seeds germinate and helps certain nutrients be returned to the soil
Flooding wipes out certain areas, but the flood waters also bring nutrients to the areas, and plants can grow again as soon as the waters recede
Inhibition: a species that might make the new site less suitable for other species would be the strangler fig
Facilitation: the velvet worm would make the site better for other species by helping nutrients return to the soil; the velvet worm would also be a good pioneer species because it can break down some of the organic material left behind by a natural disaster (Succession)
Tolerance: the pioneer plant species mentioned above are examples of tolerance because they are dominant due to their quick reproduction; however, many species could be equally able to be pioneer species because they could take advantage of nutrients left behind by something like a wildfire