Post by HazelSnail on Oct 1, 2016 20:18:57 GMT
Hello!
First off, I would like to apologize for not being very active recently, with classes starting and all.
Secondly, I would like to talk about some observations and research I have done, involving land snails.
I'll start by saying that I live in a suburban area, only 30 minutes from a large city. Very near my house is a 139 acre park, that is considered and old growth forest. Overall, the area I live in is very forested, and my yard itself is a small forest. However, I have lived here my entire life and never found a single snail, besides a single species of microsnail. But apparently, it was not always so barren of snail activity. According to my mom, who has also lived here her entire life, used to find (what I can only estimate to be mesodon thyroidus, or some other mesodon sp, based on her descriptions) snails, right in our yard. But as more and more houses were build around our small, one acre property, the snails began to dwindle, until neither of us have seen them again. In fact, it wasn't until around 8 years ago did I see my first snail, and this snail (who is surprisingly still alive) was found at the park I mentioned earlier.
So, for 8 years I have been going back and forth, from my neighborhood, to the park, trying to find snails. I have still never seen any other species of snail in my area, but this park is a snail paradise. I have found Mesodon normalis, M. thyroidus, trochulus striolatus, and many more snail species at this park. But even then, specific species could only be found in small areas of the park. For example, trochulus snails have only been found near a dried creek bed, and mesodon thyroidus have only been found in the heart of the park, where the largest trees can be found. For a long time, I was very confused as to why these snails were at this park mere minutes from my house, but not a single of them could be found in my backyard.
I researched the park's history, and it was then I realized that it had almost no human disturbances, besides the occasional hiker (it's not a well known park, I am usually the only one there). While the area around it had become a sprawling suburb, that relatively tiny area had remained almost completely unchanged. I began to branch out, exploring dozens (if not more) of parks as I traveled. I researched every park I went to, and began to notice a pattern; The parks with little to no human disturbances were the most populated with snails. This is incredibly obvious, of course, but doing the research about the parks, and that research confirming the theory I have had for years was very rewarding. So, snails like old growth forests.
It only makes sense that snails are susceptible to habitat fragmentation; they're not exactly good at migrating, or moving in general. In fact, after doing more research I found a study that actually found out the average distance different snail species move in a day. Needles to say, they hardly made progress, and larger species moved larger distances than microsnails.
Habitat fragmentation seems to be epically prevalent in suburban areas, like the one I live in. I have even found areas where a species may be found on one side of a road, but not the other. But it made me wonder, how many species have been lost already? Especially with microsnails, it seems that even building a singe house could destroy an entire population in that area, if not wipe out an entire species.
Anyway, I wondered if anyone else had come to this same conclusion. It didn't take long to find a thesis paper by Daniel Dourson/Douglas, who is a biologist/naturalist. Here is the link to that paper: encompass.eku.edu/cgi/viewcontent.cgi?article=1031&context=etd (written in 2011)
The paper includes tables listing species and number of individuals found in old growth, VS second growth forest, and the difference is incredible. It also demonstrated how land snails are an excellent indicator of an undisturbed forest.
I think that the saddest thing about this, was this basically the only paper I could find that talked about the relationship between snails and undisturbed forests. Sure, other articles might have mentioned that snails can indicate if a forest is undisturbed, but this seemed to be the only one that really focused on snails. So many people are so oblivious to these amazing animals that have become such a huge part of my life, and are a huge part of the ecosystem. Even when I went to the WI park with helix pomatia, while I stared at the beautiful snails in shock, hardly able to contain my excitement, people in the park just walked right by them, not seeing or simply not caring.
Sorry for such a long, and probably rambling, post. If someone actually read this far, I applaud you, and hopefully you found this interesting.
