1. Ecological succession describes the pattern of changes in communities over time. The graph below shows changes in plant diversity following the abandonment of an agricultural field in a temperate biome.
A.) Discuss the differences in plant diversity shown in the graph and explain how the changes affect the animal species composition between years 0 and120.
In the graph, the species diversity is much more significant in the ground flora shrubs and in the shrubs than in the understory trees and in the canopy trees. The ground flora had the quickest change from years 0-20, and then kept a pretty steady and small, if any, increase in species diversity. The next highest amount of species diversity was in the shrubs. They were able to also reach a high level of species diversity, but it took them closer to 100 years to reach that amount. On the other hand, the taller understory and ...view middle of the document...
If the temperature and climate doesn’t stay fairly static or a natural disaster occurs, then the vegetation and animals would be in danger because they wouldn’t be adapted to the new types of weather. Another influential abiotic factor would be extreme weather conditions. If dramatic changes such as (extreme examples) a hurricane or a forest fire were to occur, then it would affect the succession greatly.
A biotic factor that could greatly impact the pattern of ecological succession would be seed dispersal. The organisms within the community would help with pollination and the dispersing of seeds. Without them, it would be a harder and longer process to try and get seeds far out enough for them to be a healthy distance apart to successfully grow with the resources that they need. Another biotic factor would be competition between organisms. If organisms were constantly competing for a certain niche, then that would mean that there is only so many resources available to only one population in the community for that specific niche.
C.) Design a controlled experiment to determine how the diversity of a plant species in a newly abandoned field would be affected by large herbivores.
First a hypothesis would have to be made. The hypothesis that I would make would be that when large herbivores are present, the diversity of a plant species would not increase; it would decrease. The independent variable in the experiment would be whether or not the large herbivores would be present. The dependent variable would be determining the change in plant diversity. For this experiment, a field with certain plants would be grown for a couple of years. Controls would be the certain plant species, a constant in temperature, in the soil used, and the amount of water given to these fields. One of the fields would include large herbivores, and the other field would NOT include the herbivores. To gather data, the different plant species would have to be determined in each field, and then the two would have to be compared, leading to a conclusion of whether or not the diversity of a plant species would be affected by large herbivores.