https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1537&context=usgsstaffpub

Monitoring gradual ecosystem change using Landsat time series analyses: Case studies in selected forest and rangeland ecosystems

https://d2k78bk4kdhbpr.cloudfront.net/media/content/files/King_et_al_2015_VcrHRIB.pdf

Estimation of potential evapotranspiration from extraterrestrial radiation, air temperature and humidity to assess future climate change effects on the vegetation of the Northern Great Plains, USA

The United States Northern Great Plains (NGP) has a high potential for landscape-scale conservation, but this grassland landscape is threatened by encroachment of woody species. We surveyed NGP land managers to identify patterns in, and illustrate a broad range of, individual managers' perceptions on (1) the threat of woody encroachment to grasslands they manage, and (2) what management practices they use that may influence woody encroachment in this region. In the 34 surveys returned, which came from predominantly public lands in the study area, 79% of responses reported moderate or substantial woody encroachment. Eastern redcedar (Juniperus virginiana) and Rocky Mountain juniper (Juniperus scopulorum) were the most problematic encroachers. Thirty-one survey respondents said that prescribed fire was used on the lands they manage, and 64% of these responses reported that controlling woody encroachment was a fire management objective. However, only 18% of survey respondents using prescribed fire ...

/pdf/woody-encroachment-in-northern-great-plains-grasslands-3fnxw4hqp7.pdf

Woody encroachment in Northern Great Plains grasslands: perceptions, actions, and needs.

Woody encroachment of grasslands is a common phenomenon worldwide, but the consequences of this encroachment for ecosystem carbon storage, particularly belowground are not clear. We quantified total ecosystem carbon in the 3 major natural upland vegetation communities (grassland, shrubland, and forest) at the northern edge of the North American Great Plains. Total ecosystem carbon storage was significantly greater in forest (125.3 mg C·ha-1) than in shrubland (92.4 mg C·ha-1) or grassland (80.7 mg C·ha-1), and this difference was due mainly to greater aboveground biomass, coarse root biomass, and the presence of a humus layer in the forest. Fine and total root biomass were also greater in forest than shrubland or grassland. In contrast, soil carbon was significantly greater in shrubland (80.6 mg C·ha-1) and grassland (75.4 mg C·ha-1) than in forest (48.6 mg C·ha-1). We also investigated whether aboveground variables could be used to predict belowground carbon pools. Soil carbon increased signifi...

Ecosystem carbon changes with woody encroachment of grassland in the northern Great Plains

Tree and forest encroachment into fescue grasslands on the Cypress Hills plateau, southeast Alberta, Canada.

We evaluated the status of remnant prairie patches in the Loess Hills of southeastern South Dakota using three parallel approaches. Aerial photograph analysis, vegetation surveys and stable carbon isotope analysis of soil organic matter all yielded evidence of woody plant encroachment. Time series analysis of aerial photos indicated that forest cover expanded by 37.5% between 1941 and 2000. Vegetation surveys revealed several distinct community types ranging from forested ravines supporting basswood, American elm and black walnut trees to upland prairie remnants and oak savannas that now include encroaching eastern red cedar trees, and/or a dense understory of prickly ash, ironwood and other woodland species moving up from the ravines. Finally, carbon isotope values (δ13C) in soil cores decreased as much as 5–7‰ towards the soil surface consistent with increased prevalence of C3 forest species over C4 prairie species in recent years. One consequence of forest encroachment appears to be an increas...

Mark Steck

Papers

Forest Expansion and Soil Carbon Changes in the Loess Hills of Eastern South Dakota