Hastings Natural History Reservation

10 May, 12 PM - 30 Jun, 09 AM

Mechanisms for observed community composition patterns have long been sought by ecologists. This is increasingly important because humans are changing the composition of communities at local, regional and global levels. Community structure has been shown to impact other large questions in ecology such as invasions, stability of ecosystems, and ecosystem processes. Competition among species for resources such as nitrogen and water is one prevalent theory invoked to explain community composition. Other theories such as niche complementarily has been proposed in which assemblages of species exist with each individual species able to exploit a different resource. Studies have shown that manipulating resource availability can change plant community structure and while these mechanisms have been studied at length, little attention has been paid to the effect of soil development and dynamics on resource availability. In particular, how do natural geochemical processes involving rock weathering and nutrient availability affect community structure and species richness on the landscape level? I would like to propose an experiment that for summer of 2003 will be mostly observational. I will test whether the availability of different nutrients, namely, nitrogen, phosphorus and sulfur, differ depending upon the slope and aspect of a hill. On 10 different hills, 4 transects will be laid out that connect each of the plant communities from the valley, over the south slope, ridge, and north slope, for a total of 160 locations. A soil sample and biomass of the dominant species will be taken in each of the locations and analyzed for nitrogen, phosphorus and sulfur content. I would also like to construct a factorial fertilization experiment with N, P, S, S+N, S+P, N+P, S+N+P and no fertilization in each of the 4 distinct communities and replicate this design on four hills for a total of 128 plots. The plots will be 2m x 2m. Aboveground and belowground biomass and species composition within the plots will be measured, before the experimental fertilization starts and annually to estimate changes in species composition and productivity. I would not be fertilizing until late fall 2003. The specific sites within the reservation will be determined upon arrival, but no sampling will take place without consent from Hastings? staff so as not to interfere with ongoing research. The transect work should leave no long-term effects. The soil samples are a 1? diameter hole in the ground that will naturally close in a short period of time. Because most plants recover quickly from clipping, there should be no lasting effects from biomass sampling. I will just be targeting dominant plant species so there should not be any damage to rare or endangered species of any kind. The fertilization experiment will be sampled a bit more intensively because in each year I will take above and below ground biomass samples. The aboveground biomass will be sampled by clipping a strip with a 10cm width and 1m length. The belowground biomass samples will be taken within this clip strip and will consist of 2, 2.5? diameter holes. Eventually, these holes will naturally close, but it takes more time than a soil sample. The clip strip will be unnoticeable by the following season. The plots will be marked by rebar in each of the 4 corners of each plot and a tag with a plot number and treatment code. The rebar will be removed at the end of the experiment. I would like to arrive at Hastings around May 10-11 and stay until June 30th. I will require housing for this period of time. I will be driving and so will have a vehicle on site. I may request use of an atv to haul rebar, but that would be very limited use.

Visit #1294 @Hastings Natural History Reservation

Approved

Under Project # 1082 | Research

University of Nebraska-Lincoln - Biology

graduate_student - University of Nebraska

Reservation Members(s)

Amy Kochsiek May 10 - Jun 30, 2003 (52 days)

Reserve Resources(s) | Create Invoice

Bunk House Cottage 1 May 10 - Jun 30, 2003