ECOLOGICAL SUCCESSION
NS GWHS

An ecological succession is when one community is replaced by another. An example of this is when a sand dune is replaced by woodland. Sand dunes are located near the sea; the wind coming from the sea’s water carries sand which eventually piles up to create a sand dune (see dune building in diagram) [“Costal Sand Dunes”]. This process of a sand dune transforming into woodland spans over many years and has many steps to it.

To start any ecological succession, a pioneer species, or the first organisms to start the succession, must be present (see pioneer stage on diagram). In this situation, the pioneer species is one that can withstand lots of water and salt intake (for example, lyme grass). The introduction of this lyme grass to the environment creates a windbreak, which causes more sand carried from the wind to pile up in that same location. When more sand is added to the sand dune, the sand that was there from the beginning gets pushed back, further away from the sea. In this part of the sand dune, other kinds of species that do not need to withstand a lot of water intake are able to survive. With the introduction of many green plants, animals such as rabbits and prairie dogs inhabit the location in search of food to eat. From here the succession picks up speed quickly and more and more species are being introduced to the sand dune. Eventually, the sand dune is transformed into woodland and the environment reaches it’s climax community, which is a stable community of a diverse number of species (see conifer plantation stage) [“Costal Sand Dune”]. The climax community occurs when the environment is most diverse. Abiotic factors that might affect both the pioneer species and the climax community are temperature, sunlight and precipitation.
In this succession, primary succession begins at stage one (see dune building in diagram). In order for primary succession to occur, there must be a lot of sand on the beach. Also, the winds must be strong enough to carry that sand [“Environmental Science”]. Secondary succession however, which consists of an ecosystem that is ready to be reestablished, begins at the gray dune stage. Secondary succession begins here because secondary succession occurs after the land is already developed and ready to accept seeds carried by the winds (which is what occurs in pioneer stage and yellow dune stage). In order for secondary succession to occur, there must be wind to blow seeds onto the land. There also must be enough food already on the land for all species and not too much water (which would flood the plants, therefore kill them) [“Environmental Science”]. This succession is a xerosere because, although it occurs near water, it