Rangeland Ecology & Management

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PATTERNS OF HETEROGENEITY IN TALLGRASS PRAIRIE: COMPARING RANGELANDS MANAGED FOR HOMOGENEITY VS HETEROGENEITY
Author
Griffith, Callie D.
Twidwell, Dirac
Schacht, Walter H.
Publisher
Society for Range Management
Publication Year
2015
Body

Lands enrolled in the Conservation Reserve Program (CRP) have served as the basis for grassland conservation on private lands. To date, disturbances such as fire and grazing have been minimized on CRP grasslands and many public-owned conservation lands, resulting in homogeneous grasslands characterized by high herbaceous biomass. This approach contrasts with the modern purview that heterogeneity in vegetation structure is needed to support the diverse habitat requirements of grassland species. In this study, we (1) quantify the degree of structural heterogeneity in non-grazed grasslands, and (2) compare measures of heterogeneity in non-grazed grasslands to lands managed with patch burn grazing. To assess these objectives, we measured vegetation structure in three different burn and grazing treatments in the Grand River Grassland region of Southern Iowa. The three treatments were 1) patch burn graze-early intensive stocking 2) patch burn graze-conventional stocking and 3) burn non-grazed. Each treatment was replicated twice. We measured visual obstruction and canopy cover of vegetation every three meters on 300m transects which crossed two or more topographic types (top, slope or bottom). One transect was set up in each patch of the patch burn grazed sites, and in each of the non-grazed sites. In this paper we will discuss how topoedaphic characteristics, an invasive cool season grass, and grazing deferral after fire, interact and influence patterns of heterogeneity on non-grazed lands compared to patch burn grazed lands. We will consider how the patterns and processes of heterogeneity can affect the ability to manage for heterogeneity in grasslands and the implications for land management. 

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Sacramento, CA