Carrying capacity of elk and bison in Grand Teton National Park

Authors(s): F. Singer and T. Hobbs

Publication:

Publisher:

Publication Date: 0000-00-00

Type: progress report

Location:

Abstract: Objectives Among the goals are determining the carrying capacity of elk and bison in Jackson Hole, determining if present grazing levels are sustainable, and studying the relationships between domestic ungulates and wild ungulates. Summer 2001 fieldwork included herbaceous clipping, willow measurements and wildlife surveys and a new nitrogen sustainability set of experiments (Incubation tubes, soil bulk density, resin bags, decomposition bags, litter trays, shrub biomass and herbaceous clipping). Nitrogen work took place at one exclosure in Grand Teton NP, Davis Hill. Five iterations of herbaceous production clipping were carried out in 2001. These were Spring, Summer, Cattle July, Cattle August and Fall Grazing clipping. The normal procedure for clipping was to clip a quarter square meter plot inside and outside 3 grazing cages at each site. Willow measurements were done at 18 sites in Jackson Hole. Three new sites were also added this year. Each willow site has three subplots denoted by A, B and C. At each subplot all the shrubs within a radius of 1.72 m were measured. Data was collected for all sites in the spring and again in the summer. Wildlife Observation Surveys were conducted on a weekly basis to monitor the effects of domestic ungulate distribution and foraging on wild ungulate behavior and distribution. The survey area included the Elk Ranch, Moosehead Ranch and Triangle X areas. Nitrogen Work Work was carried out to determine Nitrogen levels in the soil and the sustainability in regards to Nitrogen at current grazing levels. These experiments were carried out with the assistance of Bob Stottlemyer of the USFS in Fort Collins, CO. Only one exclosure in our study is in Grand Teton National Park - Davis Hill. Incubation tubes were placed at each point at the exclosures (2 total). Tubes were replaced about once a month.Samples were labeled and put in the freezer to await shipment to the USFS Biogeochemistry lab in Fort Collins under the supervision of Bob Stottlemyer and Banning Star. Another subsample of about five grams of soil from the sample was also removed, weighed, dried and weighed again. An additional five to ten grams was separated out and sent to the USFS biogeochemistry lab for further analysis. A set of tubes were left in over the winter to be collected in the spring. Soil bulk density measurements were carried out at different times throughout the summer to determine the bulk density of the soil inside and outside the five exclosures. Samples were collected by digging a hole approximately 10cm by 20cm by 10cm deep. Resin bags were placed at the exclosures to measure Nitrogen flows in the soil. Bags were buried about 10cm in the soil, 2m apart in a linear transect. Five bags were placed at each point. The bags were placed around July 2 and collected and replaced on September 11. The bags will be left in over the winter. Decomposition bags were place in September. Six bags were tied to a fishing line and strung out from each point. The bags were left out to sit over the winter. Litter trays were put out inside and outside the exclosures - eight inside and eight outside each exclosure. Trays were collected on October 1. To determine the shrub production difference inside and outside the exclosures shrub plots were measured using the normal willow procedures. Findings and Status We have submitted all samples from the nitrogen sustainability research to Rober Stottlemyer at the US Forest Service Biogeochemistry Lab in Fort Collins CO for analysis. All other data has been entered and is being analyzed. A final report will be issued in September 2002.

Keywords: Grand Teton National Park, management, animal, mammal, ungulate, elk, Cervidae, wapiti, Cervus elaphus, bison, Bison bison, population, food, forage, livestock, wildlife, disease, brucellosis, Jackson Hole, Teton County, Bridger-Teton National Forest, National Elk Refuge