Naturally Madrona: Taking a Trip Back in Time

Chocolate Lilly's on the shores of Salt Creek

This weekend’s field trip to the Olympic peninsula had more education in store than I could have expected! We visited two very different landscapes, an old growth forest and the minus tide of Salt Creek, but both had several of the characteristics that can be found in any natural environment.

Image of competition in Salt Creek

The first process that was most apparent at Salt Creek is the process of competition between species. One of the fiercest examples of natural competition I think I’ve ever seen was the competition for surface area on the beaches of Salt Creek. It was a battle royal between the mussels and the three major barnacle species, the acorn barnacle (Balanus crenatus), the goose barnacle (Pollicipes polymerus), and the thatched barnacle (Semibalanus cariosus). The beach floor and large rocks were largely covered with large bay mussels and the mussels were largely covered with barnacles. Surface area and large numbers are vital to the survival of these species because they are such a sought after meal by many. It was so interesting to see the barnacles move onto the mussels to further their space advantage. This seemed like an age-old competition that shows no signs of ending any time soon. At first glance there weren’t many direct examples of disturbance in the forest. In fact, that is part of what made it so remarkable. The habitats seemed like they had never been disturbed by anything. A closer look quickly proved different. The first giveaway of a previous disturbance was the heavy burns that we found on some of the trees left from a 300 year old forest fire. The trees that had lived to tell the tale contained burns that had carved out their center some that were clear through to the other side. These signs showed us that the trees not containing burns had either grown after the fire (which would have resulted in the process of succession for their species growth) or had simply avoided the flames. Either way the evidence of the forest fire disturbance was amazing. The trees that had been burned and lived were able to do so because of the survival of their cells on the outer layer of the trunk. We also learned that the trees were in the process of healing from the outside in and were slowly growing around the burned interior to enclose their exposed middle and continue living and thriving. This process was almost unbelievable but the proof lied right in front of us. In this particular case of disturbance the order of succession wasn’t as important as the individual trees ability to repel fire. So the more established trees with the strongest defense to fires lived on.

A rare sighting of a Rose Enenemy

One of the most interesting examples I learned about predation was on the mussel beds of Salt Creek. I had never seen so many muscles or such big mussels… ever. They seemed to be the dominant species in the area with no threat of predation because of their large numbers. Although, upon closer inspection I found that even though the mussels dominated most of the space at the beach, looking back through my photos I found that wherever I photographed sea stars I would see no muscles. With help from the experts of the area I learned that sea stars feed on mussels but to seeing the drastic special differences really drove this point home. There were several square meters covered in oyster beds but as soon as I would spot a mature sea star the mussel population would disappear. This showed me how the entire landscape of an area can and is changed by predation even if the predator population is only a small fraction of that of its prey.

Notice the lack of mussels in this area

Disturbance in the mussel bed caused by strong waves

I learned about the ripple effects that are had on ecosystems both in the forest and in the tide pools. This process, also known as trophic cascade, contains a keystone predator species that changes the ecosystem through its presence or absence. An example of this at Salt Creek would be a long chain of sea life with the greatest predator being the keystone species. For example, we saw several sea stars that were responsible for regulating the muscle and barnacle population. If a sea star predator were introduced and ridded the area of most of its sea stars there would be an over population of mussels and barnacles that would fill in the areas where sea urchins and algae currently dwell in. Changing the sea star population would result in an over population of one species and essentially not leave room for the others to survive as well. There are several other possible examples but this was one that I could easily identify based on what I was able to see during minus tide. While hiking along the trails of the Olympic forest we learned very quickly that it rained a lot there. During parts of our walk it seemed to be raining on the forest floor, as a result of collected water from the canopy, when the rain had actually stopped. This factor plays a giant role in the ecological structure and the species of vegetation found in one of the world’s wettest places. The first thing you notice is the incredible amount of moss. I don’t believe that I found one tree that didn’t have moss from top to bottom. Even the youngest trees were covered. I was concerned that this could be invasive or dangerous to the trees sort of like ivy is. We learned that not only is moss not harmful to trees. To the contrary new research has shown it to be contributing to the life of a tree in an extraordinary way. A UW professor has recently found the moss on trees to be contributory to the creation of canopy soil. Older and larger trees have also been found to be sprouting roots in their canopies and enhancing their health and growth through this process. This is a direct result of the very wet climate of the area and a prime example of the continued wonder of forest’s ability to self sustain.

Moss on the ground and on trees!

This was definitely a trip to remember. I learned so much more than I am able to fit into one blog entry. The incredible balance and infinite nature of these environments is nothing short of astonishing. Although this could be considered common sense knowledge, to see it in action and to gain an understanding of the processes was the most enjoyable part. I am indebted to the naturalists who have come before me and documented all these species with description and history. Having my field guide and the knowledge of predecessors allows me to simply enjoy and wonder at what is in front of me. It is so true that there is no substitute for simple getting out there experiencing nature with all your senses. The excitement of spotting out wildlife, the peace of simply observing, and the deep sense of connection to the natural world is an experience that should not be missed. I thoroughly enjoyed this trip and my only regret is that I hadn’t experienced it sooner.