Discover Nature Series with Jim Pierson

Ecological Succession
In life, change is inevitable.This concept also applies to our natural environment which we call ecological succession. It is the process by which the structure of a biological community changes over time. If you observe a field that has been left fallow for several years you will eventually notice that vegetation like perennial grasses, golden rod, and woody shrubs take over. In our area after many years the “old field” will become a mixed deciduous forest.

One of the more prominent features you will notice when hiking on the trails in Moreau Lake State Park are all the rock outcroppings along the ridges. However, on closer examination it is not bare rock, but rather the beginning of a new community. One of the first organisms to colonize the rock (pioneer species) are lichen.

They secrete acids that help break down the rock that starts the formation of soil.
Lichen are a classic example of mutualistic symbiosis where different species interact to the benefit of both. For years, scientists knew the roles of the symbiotic partners. The ascomycete fungi provide shelter, while the photosynthetic partner, which could be algae or cyanobacteria, produces food from the sun. It is now generally accepted that there is a third partner, yeast, that protects the organisms through the production of acid.

One of the more interesting lichens in the park are the “leafy” boulder lichens.

Most lichens grow very slowly take years and years to put on biomass, so when you find them tread softly. Once enough soil has formed, moss is often the next vegetation to colonize the area.

As weathering of the rock occurs, eventually enough soil forms and accumulates in the nooks and crannies to support much larger vegetation

 

So the next time you are out hiking the many trails of Moreau Lake State Park, take the time to examine your surroundings and observe the changes that are going.

 

Jim is the Friend’s Treasurer and a retired science teacher. He is a avid hiker and has a constant thirst for discovery of all the natural features in the park. Living close to the park, he regularly hikes the miles of trails and captures his finds in photos. We enjoy and appreciate his collection and will profile many of his discoveries in the new year. If you have any questions for Jim – he can be reached at treasurer@friendsofmoreaulake.org