Biology of Organisms 2 Laboratory / Bio 132
Due April 28th, 2015
Laboratory Report 7
Umass Dartmouth Ecological Succession
Succession is an important ongoing process in ecosystems and nature in general. Communities are always changing, or evolving. Vegetation changes over time, as well as the types of animals in a general area. The hypothesis in this experiment is the Diversity of organisms increases as ecological succession occurs because the pioneer species alter the habitat in a way that can be tolerated by a wide range of organisms. This is found to be true because the species closest to the forest in the unmaintained areas of Umass Dartmouth were found to be more diverse versus the species in the maintained areas.
Ecological succession is the observance of the structure of an ecological community over time after change. Ecological succession can be somewhat predictable, and it shows in this experiment. There are two forms of ecological succession which are primary and secondary. Primary succession refers to the formation of an ecosystem in lifeless areas, such as areas where lava flow is a factor because the soil would be incapable of sustaining a habitat (Offwell Woodland & Wildlife Trust,1998). Secondary succession refers to an ecosystem being destroyed by human existence or natural disasters, such as fire, tsunamis, and so forth. The class prediction was that the unmaintained lawn at Umass Dartmouth would have a lot of trees compared to the maintained areas. There would also be more grass and bugs in the unmaintained area versus the maintained area. The hypothesis was that, “Diversity of organisms increases as ecological succession occurs because the pioneer species alter the habitat in a way that can be tolerated by a wide range of organisms” (Winslow, 2014). Pioneer species therefore are species which first colonize damaged ecosystems. Pioneer species begin a chain which develops over time into a more diverse ecosystem.
Materials and Methods
This experiment called for several grassy areas on the Umass campus near the Cedar Dell Pond along the Tree Swallow Trail system. The hypothesis was tested by walking transect lines and estimating the percent cover of each of the different species found along the Tree Swallow trail system. Measuring tape was used for the transect lines, and white grids were used to estimate percent cover. Other materials required were notebooks, and writing utensils to write down the data that was discovered. Also, proper clothing was a must due to weather, and mostly ticks. The main line ran 50 feet with grids adjacent to the line at 10 feet, 20 feet, 30 feet, 40 feet and 50 feet. The grid my group had was at 30 feet. The amount of different species that occupied each grid was recorded. Specific species names were not needed, just the type and total number of species present. This was performed in three sections, early succession, mid succession and late succession. The species included in the experiment were moss, grass, forbes, shrubs, evergreen, trees, and dirt.
Figure 1: Transect A
Figure 2: Percent Cover of Transect A
Figure 3: Average Species Diversity & Standard Deviation of Transect A