13 research outputs found

    Plant Richness-Biomass Relationships in Restored Northern Great Plains Grasslands (USA)

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    We investigated plant richness-biomass relationships in tall grass (Field 1, 12 years) and mixed grass (Field 2, 5 years) restoration experiments located in the northern Great Plains grasslands (USA). They were organized as randomized factorial experiments with fertilization rates (N or P) and number of species as factors. Results were as follows: (1) above ground biomass (AGB) increased and year-to-year variability declined with plant species and functional form richness. (2) AGB was higher when the species had various combinations: (a) high relative growth rates, root density, root surface area, N or P uptake rates, and N use efficiency; (b) low root-to-shoot ratio and root plasticity. (3) Biomass stability was positively related to high root surface area in Field 1 and N use efficiency and P uptake rates in Field 2. (4) Invasion of nonseeded species declined with plant species and functional form richness

    Plant Richness-Biomass Relationships in Restored Northern Great Plains Grasslands (USA)

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    We investigated plant richness-biomass relationships in tall grass (Field 1, 12 years) and mixed grass (Field 2, 5 years) restoration experiments located in the northern Great Plains grasslands (USA). They were organized as randomized factorial experiments with fertilization rates (N or P) and number of species as factors. Results were as follows: (1) above ground biomass (AGB) increased and year-to-year variability declined with plant species and functional form richness. (2) AGB was higher when the species had various combinations: (a) high relative growth rates, root density, root surface area, N or P uptake rates, and N use efficiency; (b) low root-to-shoot ratio and root plasticity. (3) Biomass stability was positively related to high root surface area in Field 1 and N use efficiency and P uptake rates in Field 2. (4) Invasion of nonseeded species declined with plant species and functional form richness

    Plant Richness-Biomass Relationships in Restored Northern Great Plains Grasslands (USA)

    Get PDF
    We investigated plant richness-biomass relationships in tall grass (Field 1, 12 years) and mixed grass (Field 2, 5 years) restoration experiments located in the northern Great Plains grasslands (USA). They were organized as randomized factorial experiments with fertilization rates (N or P) and number of species as factors. Results were as follows: (1) above ground biomass (AGB) increased and year-to-year variability declined with plant species and functional form richness. (2) AGB was higher when the species had various combinations: (a) high relative growth rates, root density, root surface area, N or P uptake rates, and N use efficiency; (b) low root-to-shoot ratio and root plasticity. (3) Biomass stability was positively related to high root surface area in Field 1 and N use efficiency and P uptake rates in Field 2. (4) Invasion of nonseeded species declined with plant species and functional form richness

    Relationships between Remotely Sensed Data and Biomass Components in a Big Sagebrush (Artemisia tridentata) Dominated Area in Yellowstone National Park

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    Abstract: The predictive power of a hyperspectral imagery for estimating woody and herbaceous biomass were examined for a big sagebrush (Artemisia tridentata) dominated area in Yellowstone National Park, Wyoming, United States of America. The normalized difference vegetation (NDV) and structure insensitive pigment (SIP) indices were used to investigate the relationships between biomass components and reflectance spectra. Ground data were collected in 13 sample plots 1 m 2 in size by clipping all herbaceous vegetation to ground level and stripping green leaves from big sagebrush plants. Strong relationships (R 2 from 0.83 to 0.96) were found between the hyperspectral data and biomass components. The results indicate that fine resolution hyperspectral imagery is capable of estimating various biomass components in big sagebrush dominated areas

    Prairie Reconstruction Unpredictability and Complexity: What is the Rate of Reconstruction Failures?

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    The outcomes of prairie reconstructions are subject to both unpredictability and complexity. Prairie, tallgrass, and mixed grass reconstruction is defined as the planting of a native herbaceous seed mixture composed of multiple prairie species (10 or more) in an area where the land has been heavily cultivated or anthropogenically disturbed. Because of the unpredictability and complexity inherent in reconstructions, some outcomes end up being failures dominated by exotic species. We propose that these failures follow a fat-tailed distribution as found in other complex systems. Fat-tailed distributions follow the Pareto principle, where 80% of the time reconstructions work as expected but 20% of the time they are surprising and far from the typical response. Therefore, we suggest managers be informed that reconstruction failures follow fat-tailed distributions as opposed to assuming reconstructions are simple and predictable with few failures. Once managers realize failures are inherent in reconstructions, resources can be allocated to more effective methods of dealing with failures rather than working to perfect the predictability of reconstructions. We suggest implementing adaptive management, especially where unpredictability is high, as a way to learn from failures. Combining learning from adaptive management with a reconstruction design process, in which goals and constraints are iteratively adjusted, can be a way to deal with failures and develop better outcomes

    Dynamics of Green Ash Woodlands in Theodore Roosevelt National Park

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    Green ash (Fraxinus pennsylvanica Marsh.) communities are valuable as sources of biological diversity and shelter for livestock in the Northern Great Plains. Excessive use of stands by livestock tends to convert these woodland communities to less valuable shrublands. We monitored 12 green ash stands in Theodore Roosevelt National Park (TRNP) from 1985 through 1996 to determine changes in species composition, plant density, and canopy coverage in green ash communities that were protected from livestock but exposed to foraging by native ungulates. Over the 12-year sampling period, density of choke cherry (Prunus virginiana L.) and Saskatoon service-berry (Amelanchier alnifolia Nutt.) in the tree stratum declined, shrub density showed no consistent trends, and canopy cover of grasses and forbs increased. The changes we observed were more likely attributable to succession and weather conditions than to impacts of native ungulates

    Hyperspectral One-Meter-Resolution Remote Sensing in Yellowstone National Park, Wyoming: II. Biomass

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    This study was designed to determine the utility of a 1-m-resolution hyperspectral sensor to estimate total and live biomass along with the individual biomass of litter, grasses, forbs, sedges, sagebrush, and willow from grassland and riparian communities in Yellowstone National Park, Wyoming. A large number of simple ratio-type vegetation indices (SRTVI) and normalized difference- type vegetation indices (NDTVI) were developed from the hyperspectral data and regressed against ground-collected biomass. Results showed the following: 1) Strong relationships were found between SRTVI or NDTVI and total (R2 = 0.87), live (R2 = 0.84), sedge (R2 = 0.77), and willow (R2 = 0.66) biomass. 2) Weak relationships were found between SRTVI or NDTVI and grass (R2 = 0.39), forb (R2 = 0.16), and litter (R2 = 0.51) biomass, possibly caused by the mixture of spectral signatures with grasses, sedges, and willows along with the variable effect of the litter spectral signature. 3) A weak relationship was found between sagebrush biomass and SRTVI or NDTSI (R2 = 0.3) that was related to interference from sagebrush photosynthetic or nonphotosynthetic branch and twig material, and from the indeterminate spectral signature of sagebrush. This study has shown that hyperspectral imagery at 1-m resolution can result in high correlations and low error estimates for a variety of biomass components in rangelands. This methodology can thus become a very useful tool to estimate rangeland biomass over large areas.  The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 2020Legacy DOIs that must be preserved: 10.2458/azu_rangelands_v58i5_norlan

    Hyperspectral One-Meter-Resolution Remote Sensing in Yellowstone National Park, Wyoming: I. Forage Nutritional Values

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    Hyperspectral 1-m-resolution remote sensing has the potential to reduce the time spent sampling and reduce spatial sampling errors found in traditional forage nutritive analysis over large areas. The objective of this study was to investigate if 1-m-resolution hyperspectral techniques are useful tools to provide reliable estimates of forage nitrogen (N), phosphorus (P) and neutral detergent fiber (NDF) in Yellowstone National Park. The vegetative communities investigated varied in the amount of canopy coverage and species diversity, and ranged from xeric, semiarid environments to mesic, wetland/riparian environments. A large number of simple ratio-type vegetation indices (SRTVI) and normalized difference-type vegetation indices (NDTVI) were developed with the hyperspectral dataset. These indices were regressed against N, P, and NDF values from ground collections. We found that 1) there were strong linear relationships between selected SRTVI and N (R2 = 0.7), P (R2 = 0.65), and NDF (R2 = 0.87) nutritive values on an area basis (g m-2); and 2) there were no strong linear relationships (R2 < 0.3) between a variety of SRTVI and NDTVI and N, P, and NDF on a dry matter basis (g g-1 X 100). The lack of relationship is related to 1) the highly variable relationship between the dry matter biochemical signal and total plant biomass and water content and 2) the weakening of the biochemical signal from exposed soil in low-canopy situations, from nonphotosynthetic vegetation (bark, stems, and litter), and from different plant species.  The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 2020Legacy DOIs that must be preserved: 10.2458/azu_rangelands_v58i5_crabtre
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