This week we'll be reading:
Smith, Felisa A. and Julio L. Betancourt. 2006. Predicting woodrat (Neotoma) responses to anthropogenic warming from studies of the palaeomidden record. Journal of Biogeography 33: 2061-2076.
You might recognize the name of the first author as our official faculty member, Felisa! This is a paper on using middens to study how packrats have reacted to changing temperatures over time.
This paper focuses on using fecal pellets to study body size change in the woodrats. Traditionally the data sources from packrat middens are plant macrofossils and pollen. These are analyzed in a similar way to pollen from lake cores that we discussed earlier in the semester. We'll talk about using these data in class.
Packrat paleomiddens can also contain other material from the environment, such as archaeological artifacts, bones, and teeth. I'll probably throw in some teeth, since that's what I study for my research.
For our discussion on Thursday, I want you to start thinking about designing studies of your own. How has climate change affected species and ecosystems in the past? Design a study and post it in the comments.
Study: Track the movement, lattitudinal and elevational, of Pinus species such as Pinus. Aristate: (Rocky Mountain Bristlecone) or Pinus. Flexilis (Limber orWhite Pine) in reaction to climate change. In this case, global warming of climate.
ReplyDeleteThese species of the Genus Pinus require specific climates and growing conditions. They evolved during the last global cooling event and following warming. I would study the Rocky Mountain and western U.S. species which are reacting strongly to the global warming and appear to be moving in latitude and elevation. I say this because I have witnessed it in my many meanderings in my local areas of Southern and Northern Rocky mountains of Northern New Mexico and SW Montana.
The evidence for their inability to survive where they are is obvious as they succumb to disease as a result of drought, warmth and infestations. This could serve as back up reasoning for looking at their survival tactics.
Rat middens could be used as an adjunt in this study, if it is possible to access them from recent times. I would also collect specimens from young trees that are growing at top most elevations/lattitudes and compare them with data from previous findings on records for their expected habitat. Naturally this study would require some time in field. I would also try to find work others are doing or have done in this area.
So my hypothesis would be that the pines would prove to be moving in response to climate warming to grow in areas that more resemble those they evolved in and that are cool and moist enough for their survival.
I also think looking at plant patterns would be interesting. Specifically, I'd like to look into the invasion of exotic species into different areas throughout the world and the influence climate had on invasion ability / success. I would use datasets such as lake pollen, paleomiddens, and climate proxies to examine the conditions which facilitated invasions and plant community shifts. Of course, exotic species presumably became distributed with much higher frequency when human travel became common, so I envision the time period to be within the past few thousand years.
ReplyDeleteI think I would want to try to put a study of the correlation of the miller moth invasion with climate. Complete factors are unknown of what may determine the abundance of miller moths each season. Dryness and temperature may be a large factor. I would like to try to find out exactly what causes the different patterns and what it could tell us about climate.
ReplyDeleteIf I had to design a study I think I would look into how climate has affected our species. I think it would be interesting to see how humans have changed either habits or culture. I think this would be difficult to look at in a developed country. Yet it could be possible in groups that are more reliant on their environment for survival. I'm not even sure a study like this would be allowed depending on what you would exactly look into. But nevertheless I believe seeing how we respond to global climate change would say a lot about what we can expect.
ReplyDeleteMike
ReplyDeleteI would be most interested in hunting down a similar type of environment as Death Valley (or as close as possible) which had a similar past i.e. used to be a completely different environment like a lake, and do an intense field campaign searching for middens. Hopefully we would find some interesting and well preserved middens and I would attempt to reconstruct the environmental past with all the tools middens hold. I would be interest to see what the material could reveal when ran through a mass spec. I would focus most of my time to develop a means of accurately estimating the temperature when major environmental shifts occurred.
It would seem that if you could run the collected fecal pellets through a mass spec and get reliable results, then you would be able to assess the main food (at least C3 or C4 plant determination) source.
From the different tools we have learned about this semester it seems like you could actually come to a strong argument in reconstructing the past environment of at least some regional scale areas.
Experiment:
I would obtain a huge amount of funding first of all then: I would pick A certain desert in Bolivia. Most of the is part of Bolivia is in the rain shadow of the Andes, just as Death Valley is of the Sierras. I would hire 5 post docs to lead groups of students consisting of five teams. Team 1: would be my coring team. They would be responsible for obtain and analyzing ice core, sea cores, lake cores and tree cores. Team 2: would be my midden team. They would be responsible for finding, preserving and analyzing the midden data. Team 3: would be my fossil team. They would be responsible for determining the information the fossil record holds for that and surrounding areas during a time span before during and after our identified focus. Team 4: would be my stratigraphy, volcano, extraterrestrial impact team. They would be responsible for assessing ancient past records of the area, and non-biotic stressors that could have influenced such a change in the environment. Team 5: would be my people team. They would be responsible for studying all the information that anything having to do with humans could tell us about the environment and environmental change that happened in the area and surrounding areas.
Since climate change significantly impacts environments and all the species within them, in the past climate change has led to mass extinctions and rapid genetic shifts within populations. I would study middens from a paleorecord here in the southwest and try to determine if climate change led to a drought which led to the evacuation and abandonment of Chaco. I would do a study using packrat middens to study how packrats have reacted to changing temperatures over time, using fecal pellets to study body size change in the woodrats. I would also look at macrofossils. If I could get enough funding, I would also look at pollen from lake cores. Archaeological artifacts (if recovered) would point to a human presence in the area, so I would also definitely look at that. Teeth are important because they can tell us about animal and human habitats and diets. In addition, the isotopic evidence (once again if funding would allow) would be invaluable in determining if there were significant changes in the rainfall patterns during the period in which Chaco was occupied and the period shortly thereafter.
ReplyDelete