Creeping bluestem (Schizachyriwn stolon&mm), a major decreaser on Florida range, is adversely affected by grazing during tbe growing season after a winter bum. To compare tbe effect of defoliation of burned and unburned bluestem range, creeping bluestem was burned (or not burned) on 2 similar sites in February 1978 and 1979 and cut at 2,4,6,8, and 10 months after burning. Once forage was initially cut, it was recut every 2 months. Dry matter (DM) yield, tiller density, total nonstructural carbohydrate (TNC), crude protein (CP), and in vitro organic matter digestibility (IVOMD) were determined. When forage was cut in April and recut every 2 months, average yield of creeping bluestem from unburned areas was 3,000 kg/ha while that of burned was 2,390 kg/ha. Creeping bluestem yield from unburned areas declined linearly within both yearsas initial harvest was delayed, but delaying initial barvest date bad no effect on forage yield from burned areas. Final tiller density was usually a cubic response in burned and unburned plants. Tiller density generally increased in plants cut 1 month after treatment, decreased in plants cut 2,4,6 months after treatment, and increased in plants cut 10 and 12 months after treatment. Rhizomes of plants burned in February 1979, cut initially in April, and rebarvested 4 times bad 9.0% TNC in March 1980, while unburned plants contained 10.2% TNC. Tbe response of CP and IVOMD in initial growth was quadratic or cubic with time of initial harvest because percentages were raised initially due to burning, then they dropped steadily to a low in August, after which they began to rise sligbtly. Protein content in unburned forage bad either a negative linear response or bad no significant regression with time of initial harvest. IVOMD in unburned forage exhibited a quadratic (1978) or a polynomial (1979) response with time of initial harvest where IVOMD increased or fluctuated in the growing season, usually decreasing in fall and winter. Analysis of regrowth data indicated that the response of crude protein and IVOMD was similar regardless of bum treatment. Quality of regrowth declined from June to August and steadily increased from August to December. Creeping bluestem would be weakened by grazing on 6O-day intervals after a February bum. When prescribed burning of creeping bluestem range is carried out every 3 to 4 years, deferment of grazing until June after a February burn will allow grazing of relatively high quality forage and still maintain creeping bluestem stand vigor. Proper timing of burning and grazing should assure the longevity and improve forage quality of creeping bluestem (Schizuchyrium stoloniferum) (Yarlett 1963), one of the most important grasses on the flatwoods range. Many ranges have been depleted of creeping bluestem as a result of repeated burning and uncontrolled grazing and now are dominated with wiregrass (Aristida stricta) (Yarlett 1963). Burning is important on wiregrass range because both forage (Lewis and Hart 1972) and calf production (Kirk et al. 1974) are reduced ...

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Allen Press and Society for Range Management are collaborating with JSTOR to digitize, preserve and extend access to Journal of Range Management. AbstractThis paper reports results of regression analyses of the use of a capacitance meter to estimate herbage weight. Estimation of dry weights was found to be as accurate as estimation of green weights. Analysis of covariance for three factors, site, season of year, and year of data collection, showed only season significantly (P<.01) affected the relationship between herbage weight and meter reading. Simple linear regressions were compared to natural logarithmic regressions. Logarithmic regressions were found to be better predictors of herbage weight as determined by Furnival's Index. Winter and spring proved to be the best time to use the capacitance meter, probably due to decreased effect of moisture fluctuations on the meter's performance. JOURNAL OF RANGE MANAGEMENT 34(3), May 1981 241

No abstract

/ The model presented here is a simulation of the watershed of the Little South Fork of the Cache la Poudre River system located in the Front Range of the Rocky Mountains of Colorado. This simulation model, TERRA, provides information of resource interactions, ecosystem processes, and harvest ramifications for this watershed. The information is generated through sets of difference equations to represent process flows. The model has a modular design that separates the ecologic processes~ weather conditions, hydrologic functions, forage and timber production, wildlife and domestic population dynamics, recreation use, and management activities--from the "simulation planning overhead' '------updating, plotting, and printing.The model is designed such that the output is readily usable information for an allocation model and the decision-making process. This is accomplished by allowing different levels of specified management activities as input and producing responses and output on a per unit land area basis.This simulation is a useful research tool for estimating parameter and variable values and levels of management---resource interaction. Lack of a pertinent field data base inhibits the model from actually being used as a management tool in the planning process.

Understory standing crop biomass was studied on three culturally imposed microsites (bed, furrow, and flat) bedded slash pine (Pinus elliottii) plantations in north Florida. Biomass was clipped in the late spring of 1977 on plantations 2,5, and 10 years old and separated into five classes: grass, forb, sedge, shrub, and litter (including standing dead). After an initial abundance following site preparation, sedges and forbs dropped to relatively low levels within the first 5 years of plantations development. Grasses were the dominant live vegetation in two-year-old plantations. Shrubs became dominant by the fifth year and remained so through the 10th year. Litter, as a result of the lack of cultural treatments designed to remove accumulated dead vegetation, was the major biomass class (more than 8,000 kg/ha by the fifth year following pine establishment). Total live understory biomass increased from the second to the fifth year after which it decreased. Grass standing crop biomass was highest on the flats, lowest in furrows. Hence, forage inventories should be stratified by microsite. Prescribed burning on a properly managed cattle operation may prevent high accumulations of litter while effectively improving the availability of palatable forage. Forage may also be increased by decreasing the proportion of land occupied by the less productive microsites, namely the furrows and beds.