Life processes in the biosphere

Adaptations to the environment

Organisms must be adapted to abiotic and biotic conditions in their habitat to survive, achieved through evolution by random mutations and natural selection.

Ecological succession

The process where a habitat changes over time due to the colonization and replacement of species, leading to the development of a climax community.

Seres

Sequential stages in ecological succession named after the initial conditions, such as Hydrosere (water), Lithosere (bare rock), and Psammosere (sand).

Climax community

The final stable community of species in an area, controlled by climate, like natural rainforests or grasslands.

Plagioclimax communities

Communities altered by human activities, requiring conservation methods like burning, grazing, and mowing to maintain.

Secondary succession

The process where a disturbed habitat regenerates and progresses towards a climax community faster than primary succession.

Population

All the individuals of a species living in a particular area.

Population dynamics

Processes causing changes in population size and structure, influenced by birth rates, death rates, and environmental factors.

Species

A groupd of organisms that resemble each other more than other organisms + interbreed to produce fertile offspring

r-selected species

Species with high reproductive rates and rapid responses to environmental changes, like mice and locusts.

K-selected species

Species with slower recovery rates, reaching sexual maturity later, producing fewer young, and living longer, such as whales and elephants.

Maximum Sustainable Yield (MSY)

The maximum number of individuals in a species that can be harvested sustainably, considering births, deaths, immigration, and emigration.

Carrying capacity

The greatest population that an area can support indefinitely without damaging or over-exploiting the environment. The mortality rate changes if the population size is above or below this capacity, leading the population size back to it.

Predator-prey population relationship

The relationship where more prey leads to more predators due to increased food availability. High predator population causes prey decline, while low prey results in predator population decrease, allowing prey to rise again.

Artificial population control

The practice of controlling populations through culling to help species or habitats survive when natural control mechanisms are insufficient. This is necessary in cases like low breeding rates of endangered species, introduction of non-indigenous species impacting indigenous populations, or removal of indigenous predators leading to prey overpopulation.

Biome

(Large geographical) region with particular climatic features + a unique community/vegetation.

Community

The populations of all the species living in a particular area.

Ecological niche

The role an organism plays in its habitat, includes the way it uses environmental resources + its relationship to other species

Ecosystem

Is a combination of biotic + abiotic features of an area. They are usually relatively self-contained with few movements of organisms in or out of the ecosystem