Search

Great efforts have been made to manage and restore native prairies to protect native species, enrich biodiversity, protect ecological resilience, and maintain ecosystem services. Much of this has been focused on preventing degradation from overgrazing and crop conversion. Understanding the consequences of management polices is important to identify best practices. Previous research has compared restoration outcomes from variable intensity grazing, prescribed fire, and grazing removal. However, few studies have explored the optimal durations of management practices and variation in restoration outcomes among vegetation communities. This study evaluates whether the impact of grazing cessation and reintroduction varies among native vegetation communities and measures the effective time periods of grazing cessation and reintroduction. Restoration outcomes were evaluated using four biophysical indicators (fresh biomass, soil organic matter, green cover, and litter cover) and two vegetation indices (normalized difference vegetation index (NDVI) and normalized difference water index (NDWI)) measured from Landsat images using seasonal Kalman filter and raster time series analysis. The results show that: (i) Grazing cessation increased soil organic matter and green cover while decreasing fresh biomass compared to moderate grazing management, while grazing reintroduction influences those indicators in an opposite direction; (ii) The effective time period for prairie conservation is about 11–14 years and varies among vegetation communities and biophysical indicators; (iii) The effective intensity of grazing cessation is highest in valley grassland, moderate in upland grassland, and mildest in sloped grassland; (iv) Grazing reintroduction returned the three native vegetation communities to the initial condition (i.e., the stage in 1985 before large grazers were removed), with less time than the time consumed for grazing cessation to restore the prairie ecosystem to the maximum changes; (v) Grazing reintroduction effectively influences upland and valley grasslands for 7 to 9 years, varying from different indicators, while it continuously affected sloped grassland with no clear time lag; (vi) The intensity of grazing reintroduction was strongest in sloped grassland, moderate in upland grassland, and mildest in valley grassland. The results of this study suggest expected time periods for prairie management methods to achieve results.

ABSTRACT Wildlife managers use spring prescribed burns to set back succession in managed grasslands throughout the prairie pothole region. Yet, prescribed burns are expensive and weather dependent. Autumn biomass harvest of native prairie plants may also simulate natural disturbances and help prevent the invasion of woody species. As such, biomass harvest can be an attractive management option that can augment, and in some cases, replace spring burning programs. We compared vegetation characteristics (vegetation ht and density, and residual litter depth) and changes to the plant community (e.g., species richness, relative abundance of native and exotic plant species) in restored native grasslands of Minnesota, during 2007-2009, in response to spring prescribed burns and autumn biomass harvest. We used a randomized block design to control for site-to-site variability, and compared treatments using mixed models that accounted for this source of variation as well as within-plot repeated measures. This framework also allowed us to consider additional variables (e.g., Julian date, yr effects) thought to influence response patterns, and also additional fields that were treated with an autumn biomass harvest during the same time period. Vegetation characteristics exhibited substantial site-to-site and temporal variability, but, with the exception of litter depths, vegetation characteristics were largely similar in biomass harvest and burned subplots. We conclude that autumn biomass harvests deserve more consideration as a potential grassland management tool. © 2013 The Wildlife Society. [ABSTRACT FROM AUTHOR]

We assessed attainability of landscape-level conservation planning goals in the United States portion of the Prairie Pothole Region by summarizing and analyzing data on status, trends, and potential future of grasslands and wetlands. All published literature and new data analyses consistently indicate declines in grassland and wetland area. When we incorporated time as a conservation planning metric, the importance of seemingly small wetland (0.05-0.57%) and grassland (0.4-1.3%) annual loss rates became apparent. Moreover, we highlighted large differences in the amount of future grassland (30-67%) and wetland (47-93%) resulting from seemingly small changes in loss percentages. Our analyses clearly demonstrate that time, along with current status and trends of target habitat(s), must be incorporated when setting habitat conservation goals, otherwise goals may be unrealistic. Prairie Pothole Joint Venture (PPJV) partners protected an average of 0.20% of the 3.3 million ha extant wetlands and 0.26% of the 10.7 million ha extant grasslands/year. Consequently, PPJV partners cannot reach stated conservation goals given current habitat loss rates unless 1) increased funding is secured for land conservation, 2) landowner interest and acceptance of conservation programs remains high, and 3) wetland and grassland loss rates are decreased via public policy, particularly through agriculture programs, or other mechanisms. Otherwise, PPJV habitat conservation goals, and ultimately species population goals, will need to be reduced accordingly. Our comprehensive assessment may help the PPJV and other landscape-level planning efforts discriminate between goals they would like to attain versus goals they are likely to achieve. © 2013 The Wildlife Society. [ABSTRACT FROM AUTHOR]

This article draws from the transcript of a talk given to Australian audience in Perth directly following the SERI conference in Western Australia 2009. It discusses Bill Jordan’s role in the genesis of the term ‘restoration ecology’ and the discipline of ‘ecological restoration’ whilst working at the University of Wisconsin-Madison Arboretum. In 1977, Bill, a plant physiologist by training, was engaged by the Arboretum to develop a public outreach program. He felt that the Arboretum had a special story to tell as it was the site of the Depression-era creation of a collection of restored ecological communities, which has since gained recognition as one of the earliest systematic attempts at what Dr Jordan and his colleague George Lubick have called ‘allocentric’– that is, other-centered – ecological restoration. The centrepiece of that project, a 24-ha prairie restoration on former cropping land and pasture now called the John T. Curtis Prairie dates back to an effort undertaken by a small group of scientists, including botanist Norman Fassett, ecologist Theodore Sperry and pioneering conservationist Aldo Leopold, and is now recognised internationally as a kind of locus classicus of this distinctive form of land management. Thinking hard about the meaning of this unique restoration project and its relationship to the University and to environmentalism, Bill and his colleague Keith Wendt coined the term ‘restoration ecology’ to describe the process of using restoration to field test ecological hypotheses. They also started the journal ‘Restoration & Management Notes’ (now ‘Ecological Restoration’) which, under Bill’s editorship, provided an influential early forum for the emerging discipline of ecological restoration. [ABSTRACT FROM AUTHOR]

The Cold Regions Hydrological Modelling platform (CRHM) was used to create a prairie hydrological model for Smith Creek Research Basin (∼400 km2), eastcentral Saskatchewan, Canada. Physically based modules were sequentially linked in CRHM to simulate snow processes, frozen soils, variable contributing area and wetland storage and runoff generation. Five "representative basins" (RBs) were defined and each was divided into seven hydrological response units (HRUs): fallow, stubble, grassland, river channel, open water, woodland, and wetland. Model parameters were estimated using field survey data, LiDAR digital elevation model (DEM), SPOT 5 satellite imageries, stream network and wetland inventory GIS data. Model simulations were conducted for 2007/2008 and 2008/2009. No calibration was performed. The model performance in predicting snowpack, soil moisture and streamflow was evaluated against field observations. Root mean square differences (RMSD) between simulation and observations ranged from 1.7 to 25.2mm and from 4.3 to 22.4mm for the simulated snow accumulation in 2007/2008 and 2008/2009, respectively, with higher RMSD in grassland, river channel, and open water HRUs. Spring volumetric soil moisture was reasonably predicted compared to a point observation in a grassland area, with RMSD of 0.011 and 0.009 for 2008 and 2009 simulations, respectively. The model was able to capture the timing and magnitude of peak spring basin discharge, but it underestimated the cumulative volume of basin discharge by 32% and 56% in spring 2008 and 2009, respectively. The results suggest prediction of Canadian Prairie basin snow hydrology is possible with no calibration if physically based models are used with physically meaningful model parameters that are derived from high resolution geospatial data. [ABSTRACT FROM AUTHOR]

1. Climate change will cause changes in average temperature and precipitation as well as increased fluctuations around the mean, yet few studies have considered the impacts of altered climate variability on plant populations. We tested whether life-history traits (expected life span, generation time and seed size) can predict plant responses to increased environmental variability across similar plant species sharing the same habitat. 2. We combined long-term demographic data on 10 prairie forb species with stochastic demography techniques to estimate the effects of potential changes in matrix element means and variances on the long-term stochastic population growth rate. 3. For all 10 species, recruitment had higher contribution and elasticity values than survival, meaning that climate change is more likely to influence population growth through effects on recruitment than on survival for these relatively short-lived forbs. Species with longer generation times had lower elasticities to increases in matrix element variability. 4. Synthesis. Our analysis of a unique, long-term data set suggests that longer-lived plant species will be less vulnerable to the effects of future increases in climate variability. While this relationship was previously reported for diverse taxa from many locations, our results show that it also applies within a guild of short-lived species from a single community. The generality of the pattern demonstrates the potential for using life-history traits to make predictions about which species may be the most vulnerable to climate change. [ABSTRACT FROM AUTHOR]

The article presents a study which evaluates the potential of Conservation Reserve Program (CRP) and other grassland conservation on biofuel production, plant species and ethanol yield in the U.S. The study the Whittaker plot technique to identify the composition and diversity of plant species. It shows that grassland conservation with many plant species had lesser biomass and ethanol yields and the C4 prairie grass abundance has negative correlation with the number of plant species.

The article describes the state of prairie potholes in the U.S. The prairie pothole region (PPR) is the area covered by Wisconsin Pleistocene glaciation and is dominated by tall and mixed grasslands. The region also includes the areas of north central Iowa and western Minnesota, the North and South Dakota, and northeastern Montana. Formed by ice blocks buried in glacial till that has melted, prairie potholes are considered productive ecosystems which are significant to breeding waterfowl and other species of wetland wildlife.

A 10-year experiment tested for variation in competition intensity over time in a natural grassland at the northern edge of the Great Plains. Growing-season precipitation varied fivefold during the study. All ecosystem-level variables varied significantly among years, and most covaried in expected ways. The covers of all common grasses possessing the C3 photosynthetic pathway varied significantly among years; in contrast, all common species with traits associated with drought tolerance (a C4 grass, a lichen, a spikemoss, and a subshrub) did not vary. Annual transplant experiments measured the competitive effects of neighbors on the growth of individuals of the native grass Bouteloua gracilis. A significant interaction between year and competition showed that competition intensity varied among years. The size of this effect, however, was small (η2 = 0.074) relative to the size of the direct effect of competition (η2 = 0.20) or the year in which the experiment was conducted (η2 = 0.51). Further, competition intensity was not significantly related to any variable describing standing crop or resources, or species richness. Species richness was highest in years with high precipitation, standing crop, and individual growth, due to the recruitment of rare species that were absent from dry years. In summary, variation in competition intensity was statistically significant but had small effects relative to the direct effects of climate. [ABSTRACT FROM AUTHOR]

Global temperature has been increased by 0.6 °C over the past century and is predicted to increase by 1.4-5.8 °C by the end of this century. It is unclear what impacts global warming will have on tallgrass species. In the present study, we examined leaf net photosynthetic rate ( Pn) and leaf respiration rate in darkness ( Rd) of Aster ericoides (L.) Nesom, Ambrosia psilostachya DC., Helianthus mollis Lam., and Sorghastrum nutans (L.) Nash in response to experimental warming in a tallgrass prairie ecosystem of the Great Plains, USA, in the autumn (fall) of 2000 and through 2001. Warming has been implemented with infrared heaters since 21 November 1999. The Pn increased significantly in spring, decreased in early fall, and did not change in summer and late fall in the four species under warming compared with control. The Rd of the four species increased significantly until mid-summer and then did not change under warming. Measured temperature-response curves of Pn showed that warming increased the optimum temperature of Pn ( Topt) by 2.32 and 4.59 °C for H. mollis and S. nutans, respectively, in August, whereas there were no changes in May and September, and A. ericoides and A. psilostachya also showed no changes in any of the 3 months. However, Pn at optimum temperature ( Popt) showed downregulation in September and no regulation in May and August for all four species. The temperature-response curves of Rd illustrate that the temperature sensitivity of Rd, Q10, was lower in the warmed plots compared with the control plots, except for A. ericoides in August, whereas there were no changes in May and September for all four species. The results of the present study indicate that photosynthetic and respiratory acclimation varies with species and among seasons, occurring in the mid-growing season and not in the early and late growing seasons. [ABSTRACT FROM AUTHOR]

The article cites that increasing spatial and temporal heterogeneity of disturbance in grasslands increases variability in vegetation structure that results in greater variability at higher trophic levels. Management that creates a shifting mosaic using spatially and temporally discrete disturbances in grasslands can be a useful tool in conservation. In the case of North American tallgrass prairie, discrete fires that capitalize on preferential grazing behavior of large ungulates promote a shifting mosaic of habitat types that maintain biodiversity and agricultural productivity.

Reviews the exhibition "Acres of Dreams: Selling the Canadian Prairies," on view at the Canadian Museum of Civilization in Gatineau, Quebec from October 28, 2005 to January 29, 2006.

Species-area relationships and island biogeography theory are commonly used to predict how species richness will decline with fragmentation. There are a variety of largely untested assumptions in these approaches, including the assumptions that populations are distributed uniformly before fragmentation, and that local extinctions are due to effects of small population sizes. If populations are not distributed uniformly, then populations can be abundant locally but rare globally. This would cause extinction rates to be smaller than predicted. We tested extinction theory by developing estimates of the number of plant species that should be present in small tallgrass prairie fragments and then testing the uniformity assumption by partitioning species richness into α (within site) and β (among site) components in Iowa prairies. Many more native prairie plant species were present in surveys of prairie fragments (491) than was predicted based on theory (27–207). A large proportion (75%) of the total species richness was β richness. We suggest that the high proportion of β richness was responsible for the shallow species-area slopes and the lower than expected number of species losses and that a better understanding of what determines β diversity will improve predictions of fragmentation effects on richness of plants. We also suggest that plants in prairie remnants may be best conserved by protecting different prairie types rather than by protecting a few large areas containing a single prairie type. [ABSTRACT FROM AUTHOR]

Grain-size distributions and optically stimulated luminescence (OSL) dates were obtained for the sand from Iowa's five sand prairie state preserves, which are Bebren's Ponds and Woodland, Cedar Hills Sand Prairie, Kish-Ke-Kosh Prairie, Marietta Sand Prairie and Rock Island. OSL dates ranged from the late Pleistocene (15,560 years B.P.) to the very late Holocene (as recent as 590 years B.P.), indicating that the late Pleistocene and Holocene Epochs in Iowa have seen multiple episodes of aridity, which is consistent with results from the Nebraska Sand Hills and eolian sand stringers in southeastern Minnesota. The grain-size distributions were anomalous in that, compared with typical eolian deposits, the transition grain sizes between the traction / saltation populations and saltation / suspension populations were shifted toward coarser grains, and the percentage of sand in the suspension population was high. The anomalous grain-size distributions could not be explained by post-depositional weathering or poor sorting in the source region, but were consistent with the eolian transport of sand through grass prior to deposition. It is suggested chat the anomalous grain-size distribution could be one of a set of criteria for distinguishing paleo-sand prairies from other buried bodies of eolian sand or sandstone. [ABSTRACT FROM AUTHOR]

Reliable ecological indicators of wetland integrity are necessary for assessing recovery of restored wetlands; yet, little consensus currently exists on which indicators are most appropriate. We employed indicators derived from simple, standard measures of ecosystem function selected on the basis of ecological succession theory developed by [Science 164 (1969) 262; Bioscience 35 (1985) 419], which suggests that respiration:biomass ratios should increase in disturbed systems due to the diversion of energy from growth to maintenance. This hypothesis holds potential for the development of a simple ecological indicator and therefore was tested among prairie wetlands restored after drainage disturbance. No difference was observed in respiration:biomass ratios in restored wetlands and reference wetlands designated as controls. Plankton respiration or biomass may be poor indicators of disturbance because plankton responds quickly to re-establishment of a wetland hydrology regime and/or because different plankton species may have redundant function. We suggest employing more revealing assessment techniques that employ simultaneous examination of ecosystem structure and function to better characterize subtle or lingering effects of wetland disturbance after restoration. [Copyright &y& Elsevier]

Journal of Applied Ecology (2004) 41, 389 –397 [ABSTRACT FROM AUTHOR]

The Prairie Adaptation Research Collaborative (PARC) has implemented an Internet Map Server (IMS) at the PARC web site (www.parc.ca) to 1) disseminate the geo-referenced results of PARC sponsored research on climate change impacts and adaptation, and 2) address data, information and knowledge management within the PARC network of researchers and partners. PARC facilitates interdisciplinary research on adaptation to the impacts of climate change in the Canadian Prairie Provinces. The web site is intended as a platform for sharing information and encouraging discussion of climate change impacts and adaptation. The IMS enables scientists and stakeholders to apply simple climate change scenarios to geo-referenced biophysical and social data, and dynamically create maps that display the geographic distribution of potential impacts of climate change. With a limited capacity for spatial analysis, most geo-processing and the climate impact modeling is done offline within a GIS environment. The IMS will serve the output from climate impact models, such that the model results can be customized by the web site user and be most readily applied to the planning and analysis of adaptation strategies. [ABSTRACT FROM AUTHOR]

Presents an analysis of long-term changes, from 1976 to 1996, in burned and unburned prairie remnants in Northwestern Illinois. Information on study site location and burn treatment, sample size and habitat characteristics; Discussion on compositional changes that might accompany changes in species richness; Identification of species sensitive to burning or lack of burning.

Presents a study that characterized soil surface carbon (C) and nitrogen (N) contents with depth in two tallgrass prairie topochronosequences in southern Wisconsin to evaluate the role of soil parent material, topography and time in controlling C and N sequestration. Site locations and descriptions; Role of texture, slope and ecosystem age in controlling C and N sequestration; Implications for level and types of prairie restoration management.

Great efforts have been made to manage and restore native prairies to protect native species, enrich biodiversity, protect ecological resilience, and maintain ecosystem services. Much of this has been focused on preventing degradation from overgrazing and crop conversion. Understanding the consequences of management polices is important to identify best practices. Previous research has compared restoration outcomes from variable intensity grazing, prescribed fire, and grazing removal. However, few studies have explored the optimal durations of management practices and variation in restoration outcomes among vegetation communities. This study evaluates whether the impact of grazing cessation and reintroduction varies among native vegetation communities and measures the effective time periods of grazing cessation and reintroduction. Restoration outcomes were evaluated using four biophysical indicators (fresh biomass, soil organic matter, green cover, and litter cover) and two vegetation indices (normalized difference vegetation index (NDVI) and normalized difference water index (NDWI)) measured from Landsat images using seasonal Kalman filter and raster time series analysis. The results show that: (i) Grazing cessation increased soil organic matter and green cover while decreasing fresh biomass compared to moderate grazing management, while grazing reintroduction influences those indicators in an opposite direction; (ii) The effective time period for prairie conservation is about 11–14 years and varies among vegetation communities and biophysical indicators; (iii) The effective intensity of grazing cessation is highest in valley grassland, moderate in upland grassland, and mildest in sloped grassland; (iv) Grazing reintroduction returned the three native vegetation communities to the initial condition (i.e., the stage in 1985 before large grazers were removed), with less time than the time consumed for grazing cessation to restore the prairie ecosystem to the maximum changes; (v) Grazing reintroduction effectively influences upland and valley grasslands for 7 to 9 years, varying from different indicators, while it continuously affected sloped grassland with no clear time lag; (vi) The intensity of grazing reintroduction was strongest in sloped grassland, moderate in upland grassland, and mildest in valley grassland. The results of this study suggest expected time periods for prairie management methods to achieve results. [ABSTRACT FROM AUTHOR]

Argues for the conservation of the biological diversity of native prairie in North America. Importance of prairie conservation; Description of the Great Plains; Decline in herbivores' populations; Reasons of population declines; Relation between economics and ecology; Recommendations on prairie conservation.

The prairie-deciduous, forest ecotone changes from a distinct boundary, in northern Minnesota to a fragmented mosaic type in Wisconsin, Iowa, and Illinois. The differences largely can be attributed to topography and tire. but edaphic factors, the survival of disjunct relicts, and the differential migration rates of some taxa are contributor).. Fossil pollen spectra from the Driftless Area attest to the persistence of the mosaic character throughout the Holocene. Modern surface spectra illustrate the difficulties of recognizing vegetation changes along and across the ecotone. [ABSTRACT FROM AUTHOR]

A mathematical model was constructed to simulate various above-ground and below-ground compartments of the producer subsystem for a shortgrass prairie. Simulated above-ground compartments are live shoots, recent and old dead shoots, litter, and crowns. Major below-ground compartments are live and dead juvenile roots, non-suberized, and suberized roots. The rooting depth is divided into six layers and all of the below-ground compartments are simulated for each layer. Driving variables in the model are: daily rainfall, daily maximum and minimum air temperatures, long-term monthly average cloud cover, relative humidity, and wind speed. The major processes linking the state variables are: net photosynthesis; translocation to crowns and roots; death of shoots, crowns, and roots; production of litter; aging of roots; respiration of crowns and roots; and decomposition of litter, crowns, and roots. Results obtained from the model were compared with observed biomass from 1974 and 1975. In general, the model output compared favorably with observed data; however, the model tended to overestimate crown and shoot production. A sensitivity analysis of the model shows that above- and below-ground production are most sensitive to the translocation parameter, the photosynthesis rate, and root respiration. CO2 evolution from soils is relatively insensitive to direct changes in primary production but sensitive to decomposition and root respiration rates. [ABSTRACT FROM AUTHOR]

Presents the study conducted by Peter Heus which describes an example of a wet prairie remnant in Virginia. Physical description of the prairie; Species thriving in the area; Need to protect and restore native plant habitats by periodic burning and short duration grazing.

Discusses how the United States Conservation Reserve Program (CRP), which began in 1985 to rejuvenate eroding cropland, may be threatening the native prairie habitat. Practices not prohibited by the program, such as planting invasive grasses and sodbusting, which undermine the native prairie habitat; Need for a program aimed at preserving the prairie ecosystem.